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There are a number of respiratory diseases characterized by the presence of excess neutrophil elastase (NE) activity in tissues, including cystic fibrosis and chronic obstructive pulmonary disease (COPD). NE is considered a primary contributor to disease development, but the precise mechanism has yet to be fully determined. We hypothesized that NE alters the function of macrophages (Mɸ) which play a critical role in many physiological processes in healthy lungs. We demonstrate that monocyte-derived Mɸ exposed to NE releases active matrix metalloproteinases (MMPs), increase expression of pro-inflammatory cytokines TNFα, IL-1β, and IL-8, and reduce capacity to phagocytose bacteria. Changes in Mɸ function following NE treatment were accompanied by increased adhesion and cytoskeleton re-arrangement, indicating the possibility of integrin involvement. To support this observation, we demonstrate that NE induces phosphorylation of kinases from the Src kinase family, a hallmark of integrin signaling activation. Moreover, pretreatment of Mɸ with a specific Src kinase inhibitor, PP2 completely prevents NE-induced pro-inflammatory cytokine production. Taken together these findings indicate that NE participates in lung destruction not only through direct proteolytic degradation of matrix proteins, but also through activation of Mɸ inflammatory and proteolytic functions.

Pulmonary hypertension complicates the care of many patients with chronic lung diseases (defined as Group 3 pulmonary hypertension), yet the mechanisms that mediate the development of pulmonary vascular disease are not clearly defined. Despite being the most prevalent form of pulmonary hypertension, to date there is no approved treatment for patients with disease. Myeloid-derived suppressor cells (MDSCs) and endothelial cells in the lung express the chemokine receptor CXCR2, implicated in the evolution of both neoplastic and pulmonary vascular remodeling. However, precise cellular contribution to lung disease is unknown. Therefore, we used mice with tissue-specific deletion of CXCR2 to investigate the role of this receptor in Group 3 pulmonary hypertension. Deletion of CXCR2 in myeloid cells attenuated the recruitment of polymorphonuclear MDSCs to the lungs, inhibited vascular remodeling, and protected against pulmonary hypertension. Conversely, loss of CXCR2 in endothelial cells resulted in worsened vascular remodeling, associated with increased MDSC migratory capacity attributable to increased ligand availability, consistent with analyzed patient sample data. Taken together, these data suggest that CXCR2 regulates MDSC activation, informing potential therapeutic application of MDSC-targeted treatments.

α(1)-Antitrypsin deficiency (AATD) is an inherited disease characterized by emphysema and liver disease. AATD is most often caused by a single amino acid substitution at position 342 in the mature protein, resulting in the Z mutation of the AAT gene (ZAAT). This substitution is associated with misfolding and accumulation of ZAAT in the endoplasmic reticulum (ER) of hepatocytes, causing a toxic gain of function. ERdj3 is an ER luminal DnaJ homologue, which, along with calreticulin, directly interacts with misfolded ZAAT. We hypothesize that depletion of each of these chaperones will change the fate of ZAAT polymers. Our study demonstrates that calreticulin modulation reveals a novel ZAAT degradation mechanism mediated by exosomes. Using human PiZZ hepatocytes and K42, a mouse calreticulin-deficient fibroblast cell line, our results show ERdj3 and calreticulin directly interact with ZAAT in PiZZ hepatocytes. Silencing calreticulin induces calcium independent ZAAT–ERdj3 secretion through the exosome pathway. This co-secretion decreases ZAAT aggregates within the ER of hepatocytes. We demonstrate that calreticulin has an inhibitory effect on exosome-mediated ZAAT–ERdj3 secretion. This is a novel ZAAT degradation process that involves a DnaJ homologue chaperone bound to ZAAT. In this context, calreticulin modulation may eliminate the toxic gain of function associated with aggregation of ZAAT in lung and liver, thus providing a potential new therapeutic approach to the treatment of AATD-related liver disease.

There are a number of diseases characterized by the presence of neutrophil elastase (NE) activity in tissues including cystic fibrosis and alpha-1-antitrypsin deficiency induced lung destruction. It is generally accepted that NE actively contributes to this pathological process, but the precise mechanisms has yet to be determined. We hypothesized that NE activates the macrophages (M□) pro-inflammatory program. We demonstrate that following NE exposure, monocyte-derived M□ release proteolytic activity composed of several matrix metalloproteinases (MMPs) which could contribute to extracellular matrix (ECM) degradation. NE upregulates expression of M□ derived pro-inflammatory cytokines including TNFα, IL-1β, and IL-8. Thus, NE-activated M□ can contribute to tissue destruction through the proteolytic activity of metalloproteinases and by supporting chronic inflammation through expression of pro-inflammatory cytokines. We also demonstrate that NE increases M□ adhesion that is attenuated by antibodies specific to integrin subunits. We show that the effects of NE on M□ can be mediated through an activation of integrin pathways. In support of integrin involvement, we demonstrate that NE activates the Src kinase family, a hallmark of integrin signaling activation. Moreover, pretreatment of macrophages with a specific Src kinase inhibitor, PP2, completely prevents NE-induced inflammatory cytokine production. Taken together these findings indicate that NE has effect on lung destruction that extends beyond direct proteolytic degradation of matrix proteins.

Caloric restriction has consistently been shown to extend life span and ameliorate aging-related diseases. These effects may be due to diet-induced reactive oxygen species acting to up-regulate sirtuins and related protective pathways, which research suggests may be partially inhibited by dietary anti-oxidant supplementation. Because caloric restriction is not sustainable long term for most humans, we investigated an alternative dietary approach, intermittent fasting (IF), which is proposed to act on similar biological pathways. We hypothesized that a modified IF diet, where participants maintain overall energy balance by alternating between days of fasting (25% of normal caloric intake) and feasting (175% of normal), would increase expression of genes associated with aging and reduce oxidative stress and that these effects would be suppressed by anti-oxidant supplementation. To assess the tolerability of the diet and to explore effects on biological mechanisms related to aging and metabolism, we recruited a cohort of 24 healthy individuals in a double-crossover, double-blinded, randomized clinical trial. Study participants underwent two 3-week treatment periods—IF and IF with anti-oxidant (vitamins C and E) supplementation. We found strict adherence to study-provided diets and that participants found the diet tolerable, with no adverse clinical findings or weight change. We detected a marginal increase (2.7%) in SIRT3 expression due to the IF diet, but no change in expression of other genes or oxidative stress markers analyzed. We also found that IF decreased plasma insulin levels (1.01 μU/mL). Although our study suggests that the IF dieting paradigm is acceptable in healthy individuals, additional research is needed to further assess the potential benefits and risks.

Alpha-1 antitrypsin (AAT) deficiency-associated emphysema is largely attributed to insufficient inhibition of neutrophil elastase released from neutrophils. Correcting AAT levels using augmentation therapy only slows disease progression, and that suggests a more complex process of lung destruction. Because alveolar macrophages (Mɸ) express AAT, we propose that the expression and intracellular accumulation of mutated Z-AAT (the most common mutation) compromises Mɸ function and contributes to emphysema development. Extracellular matrix (ECM) degradation is a hallmark of emphysema pathology. In this study, Mɸ from individuals with Z-AAT (Z-Mɸ) have greater proteolytic activity on ECM than do normal Mɸ. This abnormal Z-Mɸ activity is not abrogated by supplementation with exogenous AAT and is likely the result of cellular dysfunction induced by intracellular accumulation of Z-AAT. Using pharmacologic inhibitors, we show that several classes of proteases are involved in matrix degradation by Z-Mɸ. Importantly, compared with normal Mɸ, the membrane-bound serine protease, matriptase, is present in Z-Mɸ at higher levels and contributes to their proteolytic activity on ECM. In addition, we identified matrix metalloproteinase (MMP)-14, a membrane-anchored metalloproteinase, as a novel substrate for matriptase, and showed that matriptase regulates the levels of MMP-14 on the cell surface. Thus, high levels of matriptase may contribute to increased ECM degradation by Z-Mɸ, both directly and through MMP-14 activation. In summary, the expression of Z-AAT in Mɸ confers increased proteolytic activity on ECM. This proteolytic activity is not rescued by exogenous AAT supplementation and could thus contribute to augmentation resistance in AAT deficiency-associated emphysema.

Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by early-onset emphysema and liver disease. The most common disease-causing mutation is a single amino acid substitution (Glu/Lys) at amino acid 342 of the mature protein, resulting in disruption of the 290-342 salt bridge (an electrophoretic abnormality defining the mutation [Z allele, or ZAAT]), protein misfolding, polymerization, and accumulation in the endoplasmic reticulum of hepatocytes and monocytes. The Z allele causes a toxic gain of function, and the E3 ubiquitin ligase gp78 promotes degradation and increased solubility of endogenous ZAAT. We hypothesized that the accumulation of ZAAT is influenced by modulation of gp78 E3 ligase and SVIP (small VCP-interacting protein) interaction with p97/VCP in ZAAT-expressing hepatocytes. We showed that the SVIP inhibitory effect on ERAD due to overexpression causes the accumulation of ZAAT in a human Z hepatocyte-like cell line (AT01). Overexpression of gp78, as well as SVIP suppression, induces gp78-VCP/p97 interaction in AT01 cells. This interaction leads to retro-translocation of ZAAT and reduction of the SVIP inhibitory role in ERAD. In this context, overexpression of gp78 or SVIP suppression may eliminate the toxic gain of function associated with polymerization of ZAAT, thus providing a potential new therapeutic approach to the treatment of AATD.

Triggering receptor expressed on myeloid cells 1 (TREM-1) is a superimmunoglobulin receptor expressed on myeloid cells that plays an important role in the amplification of inflammation. Recent studies suggest a role for TREM-1 in tumor-associated macrophages with relationship to tumor growth and progression. Whether the effects of TREM-1 on inflammation and tumor growth are mediated by an alteration in cell survival signaling is not known. In these studies, we show that TREM-1 knock-out macrophages exhibit an increase in apoptosis of cells in response to lipopolysaccharide (LPS) suggesting a role for TREM-1 in macrophage survival. Specific ligation of TREM-1 with monoclonal TREM-1 (mTREM-1) or overexpression of TREM-1 with adeno-TREM-1 induced B-cell lymphoma-2 (Bcl-2) with depletion of the key executioner caspase-3 prevents the cleavage of poly(ADP-ribose) polymerase. TREM-1 knock-out cells showed lack of induction of Bcl2 with an increase in caspase-3 activation in response to lipopolysaccharide. In addition overexpression of TREM-1 with adeno-TREM-1 led to an increase in mitofusins (MFN1 and MFN2) and knockdown of TREM-1 decreased the expression of mitofusins suggesting that TREM-1 contributes to the maintenance of mitochondrial integrity favoring cell survival. Investigations into potential mechanisms by which TREM-1 alters cell survival showed that TREM-1-induced Bcl-2 in an Egr2-dependent manner. Furthermore, our data shows that expression of Egr2 in response to specific ligation of TREM-1 is ERK mediated. These data for the first time provide novel mechanistic insights into the role of TREM-1 as an anti-apoptotic protein that prolongs macrophage survival.

Induced pluripotent stem (iPS) cells have great potential for personalized regenerative medicine. Although several different methods for generating iPS cells have been reported, improvement of safety and efficiency is imperative. In this study, we tested the feasibility of using a triple tyrosine mutant AAV2 (Y444+500+730F) vector, designated AAV2.3m, to generate iPS cells. We developed a polycistronic rAAV2.3m vector expressing three reprogramming factors, Klf4, Oct4, and Sox2, and then used this vector to infect mouse adipose-derived mesenchymal stem cells (AT-MSCs) to induce the generation of iPS cells. We demonstrated that (1) the triple tyrosine mutant AAV2 vector is able to reprogram mouse adult adipose tissue-derived stem cells into the pluripotent state. Those rAAV2.3m-derived iPS (rAAV2.3m-iPS) cells express endogenous pluripotency-associated genes including Oct4, Sox2, and SSEA-1, and form teratomas containing multiple tissues in vivo; (2) c-myc, an oncogene, is dispensable in rAAV2.3m-mediated cellular reprogramming; and (3) transgene expression is undetectable after reprogramming, whereas vector DNA is detectable, indicating that transgenes are silenced. These results indicated the rAAV vector may have some advantages in generating iPS cells.

Invariant natural killer T (iNKT) cells are innate-like T cells that recognize glycolipid antigens and play critical roles in regulation of immune responses. Based on expression of the transcription factors (TFs) Tbet, Plzf, and Rorγt, iNKT cells have been classified in effector subsets that emerge in the thymus, namely, iNKT1, iNKT2, and iNKT17. Deficiency in the TF Bcl11b in double-positive (DP) thymocytes has been shown to cause absence of iNKT cells in the thymus and periphery due to defective self glycolipid processing and presentation by DP thymocytes and undefined intrinsic alterations in iNKT precursors. We used a model of cre-mediated postselection deletion of Bcl11b in iNKT cells to determine its intrinsic role in these cells. We found that Bcl11b is expressed equivalently in all three effector iNKT subsets, and its removal caused a reduction in the numbers of iNKT1 and iNKT2 cells, but not in the numbers of iNKT17 cells. Additionally, we show that Bcl11b sustains subset-specific cytokine production by iNKT1 and iNKT2 cells and restricts expression of iNKT17 genes in iNKT1 and iNKT2 subsets, overall restraining the iNKT17 program in iNKT cells. The total numbers of iNKT cells were reduced in the absence of Bcl11b both in the thymus and periphery, associated with the decrease in iNKT1 and iNKT2 cell numbers and decrease in survival, related to changes in survival/apoptosis genes. Thus, these results extend our understanding of the role of Bcl11b in iNKT cells beyond their selection and demonstrate that Bcl11b is a key regulator of iNKT effector subsets, their function, identity, and survival.

Alpha-1 antitrypsin (AAT) deficiency and tobacco smoking are confirmed risk factors for Chronic Obstructive Pulmonary Disease. We hypothesized that variable DNA methylation would be associated with smoking and inflammation, as reflected by the level of C-Reactive Protein (CRP) in AAT-deficient subjects. Methylation levels of 1,411 autosomal CpG sites from the Illumina GoldenGate Methylation Cancer Panel I were analyzed in 316 subjects. Associations of five smoking behaviors and CRP levels with individual CpG sites and average methylation levels were assessed using non-parametric testing, linear regression and linear mixed effect models, with and without adjustment for age and gender. Univariate linear regression analysis revealed that methylation levels of 16 CpG sites significantly associated with ever-smoking status. A CpG site in the TGFBI gene was the only site associated with ever-smoking after adjustment for age and gender. No highly significant associations existed between age at smoking initiation, pack-years smoked, duration of smoking, and time since quitting smoking as predictors of individual CpG site methylation levels. However, ever-smoking and younger age at smoking initiation associated with lower methylation level averaged across all sites. DNA methylation at CpG sites in the RUNX3, JAK3 and KRT1 genes associated with CRP levels. The most significantly associated CpG sites with gender and age mapped to the CASP6 and FZD9 genes, respectively. In summary, this study identified multiple potential candidate CpG sites associated with ever-smoking and CRP level in AAT-deficient subjects. Phenotypic variability in Mendelian diseases may be due to epigenetic factors.

Summary Previous studies have shown that human alpha-1 antitrypsin (hAAT) gene delivery prevents type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. Furthermore, hAAT protein administration prolongs acceptance of islet allografts. Therefore, we evaluated the use of purified hAAT protein therapy to prevent T1D in NOD mice. Female NOD, non-obese resistant (NOR), Balb/c and C57BL/6 mice were injected intraperitoneally with vehicle alone or vehicle containing hAAT, human albumin or mouse albumin (or mg/injection/mouse; 2×/week). Preparations of clinical-grade hAAT included API®, Aralast®, Prolastin® and Zemaira®. Surprisingly, hAAT administration was associated with a high rate of fatal anaphylaxis. In studies seeking T1D prevention at 4 weeks of age, 100% mice died after six injections of hAAT. When administrated at 8–10 weeks of age, most (80–100%) NOD mice died following the fourth injection of hAAT, while 0% of Balb/c and C57BL/6 mice and 10% of NOR mice died. Interestingly, repeated injections of human albumin, but not mouse albumin, also induced sudden death in NOD mice. Antibodies to hAAT were induced 2–3 weeks after hAAT administration and death was prevented by treatment with anti-platelet-activating factor along with anti-histamine. In studies of disease reversal in NOD mice, using the four pharmaceutical grade formulations of hAAT, anaphylactic deaths were observed with all hAAT preparations. The propensity for fatal anaphylaxis following antigenic administration appears to be NOD- but not hAAT-specific. The susceptibility of NOD mice to hypersensitivity provides a significant limitation for testing of hAAT. Development of strategies to avoid this unwanted response is required to use this promising therapeutic agent for T1D.

Adeno-associated virus (rAAV) mediated gene therapy has shown promise for the treatment of alpha1 antitrypsin deficiency (AATD). Sustained alpha 1 antitrypsin (AAT) expression has been achieved in clinical trails, but the serum AAT concentrations do not reach therapeutic levels. Enhancing transduction efficiency is critical to developing a successful treatment. Since rAAV transduction may be limited by the proteasome, which degrade AAV capsids, we tested the effect of proteasome inhibitors on rAAV mediated AAT production. We treated HeLa and 293 cells with proteasome inhibitors including bortezomib and infected HeLa cells with rAAV2-GFP, rAAV2-AAT or AAV1-AAT and we Infected 293 cells with rAAV2-AAT. We measured AAT in the medium and the lysates of cells. Consistent with previous reports, bortezomib significantly enhanced AAV2 mediated GFP transduction in Hela cells. In rAAV-AAT infected cells, bortezomib treatment resulted in 9.7-13.1 fold increase in of intracellular AAT, while only modest (1.16-1.6 fold) increases of secreted AAT compared to that in cells without bortezomib. Similarly, intramuscular injection of rAAV1-AAT to C57BL6 mice treated with bortezomib also resulted in a small (~1 fold) increases in serum AAT compared with no treatment. These results indicate that bortezomib inhibited AAT protein secretion. To test the role unfolded protein response (UPR) in AAT accumulation, we measured UPR-related genes and showed that bortezomib treatment increased the mRNA levels of the protein chaperone and UPR sensor GRP78 (BiP) indicating an activation of ER stress pathways. Together, our results indicate that bortezomib can enhance rAAV transduction, but it can also inhibit the secretion of transgene product, which will limit the application of this drug for enhancing the efficiency of certain gene therapy, such as alpha 1 antitrypsin gene therapy.

The lungs of individuals with α 1 -antitrypsin (α 1 -AT) deficiency have a reduced antiprotease protective shield. Typically, numbers of neutrophils are elevated in the lungs of affected individuals, carrying large amounts of neutrophil elastase (NE) and α-defensins that are released upon activation. We hypothesized that in individuals with advanced lung disease associated with α 1 -AT deficiency cytotoxic concentrations of α-defensins might be present and unopposed, thus further aggravating lung disease. To evaluate this hypothesis, bronchoalveolar lavage was performed in 20 α 1 -AT deficient individuals with moderate to severe lung function impairment and 13 healthy volunteers. Cell counts as well as concentrations of NE and α-defensins were determined. While concentrations of NE were low (23±14 nM) and α-defensins were undetectable in volunteers, they were significantly elevated in individuals with α 1 -AT deficiency (1313 ± 723 nM and 6605 ± 2856 nM, both p 1 -AT deficient individuals with mild lung disease. Neutrophil numbers and NE concentration correlated with α-defensins concentration ( r = 0.612 and r = 0.758, p = 0.005 and p = 0.0001, respectively). Individuals with α 1 -AT deficiency and moderate to severe lung function impairment have lung α-defensins concentrations in a range known to induce cytotoxicity in vitro in the absence of normal amounts α 1 -AT and thus may contribute to the development of lung disease in this population.

Background α 1 -antitrypsin (A1AT) is an abundant protein that is synthesized in the liver and is secreted into the plasma. From the plasma, A1AT diffuses into various body compartments, including the lung where it provides much of the antiprotease protection. The current understanding of the pathogenesis of emphysema in A1AT-deficient individuals focuses on the polymerization of mutant protein within the liver, which results in a deficiency of circulating A1AT and a protease-antiprotease imbalance in the lungs. Methods and results In this study, we evaluated BAL fluid samples from five healthy volunteers, five individuals with ZA1AT deficiency, and an individual with the PiZZ phenotype who had received a liver transplant. We show that the lung itself is a source of A1AT. In addition, the Z protein formed in the lung polymerizes, and these polymers are detectable in lung epithelial lining fluid by enzyme-linked immunosorbent assay and Western blot analysis. Finally, we show that polymeric ZA1AT is a potent neutrophil chemoattractant that is similar to polymerized MA1AT. Conclusions Our findings suggest that the polymerization of locally produced ZA1AT is a contributory factor to the lung inflammation experienced by those with A1AT deficiency and that standard antiprotease therapies may not address this problem.

Ketogenic diets (KDs) are used for treatment of refractory epilepsy and metabolic disorders. The classic saturated fatty acid-enriched (SAT) KD has a fat:carbohydrate plus protein ratio of 4:1, in which the predominant fats are saturated. We hypothesized that a polyunsaturated fat-enriched (POLY) KD would induce a similar degree of ketosis with less detrimental effects on carbohydrate and lipid metabolism. Twenty healthy adults were randomized to two different weight-maintaining KDs for 5 d. Diets were 70% fat, 15% carbohydrate, and 15% protein. The fat contents were 60 or 15% saturated, 15 or 60% polyunsaturated, and 25% monounsaturated for SAT and POLY, respectively. Changes in serum beta-hydroxybutyrate, insulin sensitivity (S(I)), and lipid profiles were measured. Mean circulating beta-hydroxybutyrate levels increased 8.4 mg/dl in the POLY group (P = 0.0004), compared with 3.1 mg/dl in the SAT group (P = 0.07). S(I) increased significantly in the POLY group (P = 0.02), whereas total and low-density lipoprotein cholesterol increased significantly in the SAT group (both P = 0.002). These data demonstrate that a short-term POLY KD induces a greater level of ketosis and improves S(I), without adversely affecting total and low-density lipoprotein cholesterol, compared with a traditional SAT KD. Thus, a POLY KD may be superior to a classical SAT KD for chronic administration.

Objective Adipose tissue derived stem cells (ADSCs) transplantation has recently gained widespread enthusiasm, particularly in the perspective to use them as potential alternative cell sources for hepatocytes in cell based therapy, mainly because of their capability of hepatogenic differentiation in vitro and in vivo. But some challenges remain to be addressed, including whether ADSCs can be provided effectively to the target organ and whether subsequent proliferation of transplanted cells can be achieved. To date, intrasplenic injection is the conventional method to deliver ADSCs into the liver; however, a number of donor cells retained in the spleen has been reported. In this study, our objective is to evaluate a novel route to transplant ADSCs specifically to the liver. We aimed to test the feasibility of in situ transplantation of ADSCs by injecting bioencapsulated ADSCs into the liver in mouse model. Methods The ADSCs isolated from human alpha 1 antitrypsin (M-hAAT) transgenic mice were used to allow delivered ADSCs be readily identified in the liver of recipient mice, and alginate was selected as a cell carrier. We first evaluated whether alginate microspheres are implantable into the liver tissue by injection and whether ADSCs could migrate from alginate microspheres (study one). Once proven, we then examined the in vivo fate of ADSCs loaded microspheres in the liver. Specifically, we evaluated whether transplanted, undifferentiated ASDCs could be induced by the local microenvironment toward hepatogenic differentiation and the distribution of surviving ADSCs in major tissue organs (study two). Results Our results indicated ADSCs loaded alginate microspheres were implantable into the liver. Both degraded and residual alginate microspheres were observed in the liver up to three weeks. The viable ADSCs were detectable surrounding degraded and residual alginate microspheres in the liver and other major organs such as bone marrow and the lungs. Importantly, transplanted ADSCs underwent hepatogenic differentiation to become cells expressing albumin in the liver. These findings improve our understanding of the interplay between ADSCs (donor cells), alginate (biomaterial), and local microenvironment in a hepatectomized mouse model, and might improve the strategy of in situ transplantation of ADSCs in treating liver diseases.

The conducting airways are the primary target for gene transfer in cystic fibrosis (CF), yet the inflammation associated with CF lung disease could potentially pose a significant barrier to gene transfer vectors, such as recombinant adeno-associated virus (rAAV). In order to investigate this possibility, aliquots of bronchoalveolar lavage (BAL) fluid from eight individuals with CF were tested for their in vitro inhibitory effects on rAAV transduction, along with BAL from non-CF individuals. While the non-CF BAL fluid was not inhibitory, seven of eight CF BAL samples had significant inhibitory activity, resulting in a five- to 20-fold reduction in transduction events. Inhibition of rAAV transduction by CF BAL could be reversed by alpha-1-antitrypsin (AAT), but not by DNase. When neutrophil elastase and neutrophil alpha defensins (human neutrophil peptides, HNP) were measured in these samples, they were elevated by 500- and 10,000-fold, respectively. The levels of HNP correlated inversely with the amount of rAAV transduction. Furthermore, rAAV transduction could be blocked by purified HNP in an AAT-reversible manner at HNP concentrations within the range measured in these fluids. We conclude that products of inflammation in CF BAL fluid are inhibitory to rAAV transduction, and that these effects may be reversible by AAT.

A role for endothelial nitric oxide synthase (NOS3) in the susceptibility of individuals with a 1-antitrypsin ( a 1AT) deficiency to destructive lung disease was evaluated. Six polymorphic sites were identified within the NOS3 gene (i.e., 2 924A/G, 2 788C/T, 2 691C/T, 774C/T, 894G/T, and 1998C/G). The genotype distribution was determined in 339 patients and 94 control individuals. Frequency of the 774T allele in severely affected individuals was 0.417 versus 0.269 in control subjects ( P 5 0.018), whereas the 894T allele frequency was 0.427 versus 0.280 in control subjects ( P 5 0.024). Patients with less severe lung disease had the 774T and 894T allele frequencies of 0.289 and 0.344, respectively, similar to frequencies in a control group ( P . 0.3). No direct correlation between pulmonary function and five other NOS3 polymorphisms was observed. Thus, functional allelic variants that are in linkage disequilibrium with the 774C/T and 894G/T may be present in the specified genomic area. These data are consistent with a modulatory role for NOS3 in destructive lung disease associated with a 1AT deficiency. Novoradovsky, A., M. L. Brantly, M. A. Waclawiw, P. P. Chaudhary, H. Ihara, L. Qi, N. T. Eissa, P. M. Barnes, K. M. Gabriele, M. E. Ehrmantraut, P. Rogliani, and J. Moss. 1999. Endothelial nitric oxide synthase as a potential susceptibility gene in the pathogenesis of emphysema in a 1-antitrypsin deficiency. Am. J. Respir. Cell Mol. Biol. 20:441‐447.

alpha 1-Antitrypsin (alpha 1AT) provides the major protection in the lung against neutrophil elastase-mediated proteolysis. Inheritance of alpha 1AT deficiency alleles is associated with an increased risk of emphysema and liver disease. alpha 1AT null alleles cause the total absence of serum alpha 1AT and represent the ultimate in a continuum of alleles associated with alpha 1AT deficiency. The molecular mechanisms responsible for absence of serum alpha 1AT include splicing abnormalities, deletion of alpha 1AT coding exons, and premature stop codons. We identified an Italian individual with asthma, emphysema, and a very low level of serum alpha 1AT. DNA sequencing demonstrated the Mprocida deficiency allele and a novel null allele, QOtrastevere (c654 G-->A, W194Z), a nonsense mutation near the intron 2 (IVS2) splice acceptor site. To determine the molecular basis of QOtrastevere and specifically to evaluate whether this nonsense mutation interfered with mRNA processing by altered splicing, we used a Chinese hamster ovary cell line permanently transfected with QOtrastevere or normal M alpha 1AT with and without IVS2. Northern blot analysis demonstrated that the normal M construct, with or without IVS2, expressed alpha 1AT mRNA of a similar size. The nonsense mutation was associated with moderately reduced alpha 1AT mRNA regardless of the presence or absence of IVS2. Reduction in alpha 1AT mRNA regardless of the opportunity for splicing supports a translational-translocation model as the cause of reduced alpha 1AT mRNA rather than the nuclear scanning model. Pulse-chase studies followed by immunoprecipitation demonstrated an endoplasmic reticulum-retained 31 kDa QOtrastevere alpha 1AT, which was rapidly degraded. Although mRNA content was moderately reduced, retention and rapid intracellular degradation of the truncated form are the major mechanisms for the absence of secreted alpha 1AT.

Intravenous alpha-1 antitrypsin protein (AAT) augmentation is a prescribed therapy for severe, genetically determined, alpha-1 antitrypsin deficiency (AATD), a genetic basis for pulmonary emphysema. AAT, a predominant systemic inhibitor of neutrophil elastase thus far has not been shown to decrease elastin degradation in a significant number of patients on this therapy. The objective of this study was to compare levels of biomarkers of elastin degradation in plasma, bronchoalveolar lavage (BALF) fluid and urine before and after beginning AAT augmentation therapy in patients with AATD.Desmosine and isodesmosine (DI), which occur only in elastin, are amino acid cross-links in mature elastin. Levels of DI in body fluids measure degradation of elastin and can be measured more specifically by mass spectrometry. This method was used to measure DI levels in plasma, bronchoalveolar lavage fluid and urine in cohorts of severe AATD patients on augmentation, not on augmentation and before and after the initiation of augmentation therapy.Statistically significant reductions in plasma DI and in BALF DI were demonstrated in AATD patients receiving intravenous (IV) augmentation therapy as compared with those not receiving it. Administration by aerosol also produced statistically significant reductions in levels of DI in BALF.Results indicate that the currently prescribed doses of AAT augmentation inhibit neutrophil elastase adequately to reduce elastin degradation, both systemically and in the lung per se. The currently prescribed doses did not reduce elastin degradation to control levels, which may be possible with higher doses.

Recombinant adeno-associated virus (rAAV) vectors have shown promise for the treatment of several diseases; however, immune-mediated elimination of transduced cells has been suggested to limit and account for a loss of efficacy. To determine whether rAAV vector expression can persist long term, we administered rAAV vectors expressing normal, M-type α-1 antitrypsin (M-AAT) to AAT-deficient subjects at various doses by multiple i.m. injections. M-specific AAT expression was observed in all subjects in a dose-dependent manner and was sustained for more than 1 year in the absence of immune suppression. Muscle biopsies at 1 year had sustained AAT expression and a reduction of inflammatory cells compared with 3 month biopsies. Deep sequencing of the TCR Vβ region from muscle biopsies demonstrated a limited number of T cell clones that emerged at 3 months after vector administration and persisted for 1 year. In situ immunophenotyping revealed a substantial Treg population in muscle biopsy samples containing AAT-expressing myofibers. Approximately 10% of all T cells in muscle were natural Tregs, which were activated in response to AAV capsid. These results suggest that i.m. delivery of rAAV type 1–AAT (rAAV1-AAT) induces a T regulatory response that allows ongoing transgene expression and indicates that immunomodulatory treatments may not be necessary for rAAV-mediated gene therapy.

Rotaviruses appear to exist as heterogeneous populations of reassortants and related variants. This phenomenon is consistent with the quasispecies concept of RNA viruses, and suggests that gene reassortment is a crucial evolutionary mechanism for this segmented virus. It also explains puzzling epidemiological findings and controversial results of vaccine-efficacy studies.

Carbohydrate-deficient glycoprotein syndrome (CDGS) is a rare metabolic disorder presenting in infancy with severe neurologic involvement and variable multisystemic abnormalities. Diagnosis relies upon the detection of abnormal serum glycoprotein isoforms on isoelectric focusing (IEF) gels. Carbohydrate structural analyses were performed on the N-linked oligosaccharides of serum alpha 1-antitrypsin (alpha-1AT) from two Danish children with classical type I CDGS. Following preparative gel electrophoresis of alpha-1AT isoforms, oligosaccharide charge and monosaccharide composition analyses revealed increased glycosylation heterogeneity in CDGS compared with normal alpha-1AT. CDGS alpha-1AT isoforms bore N-glycans co-migrating with monosialylated standards, while normal alpha-1AT oligosaccharides co-migrated with both mono- and disialylated standards. While the monosaccharide contents of normal alpha-1AT isoforms were relatively uniform, those of CDGS alpha-1AT isoforms varied widely, and many were relatively mannose enriched. The mannose-rich oligosaccharides of CDGS alpha-1AT were not typical oligomannose structures since they were not released by endo-beta-N-acetylglucosaminidase H (endo H) digestion. Metabolic labelling of CDGS fibroblasts with [3H]mannose showed lower than normal intracellular total mannose, free mannose and phosphorylated mannose species, as well as diminished [3H]mannose incorporation into dolichol-linked and protein-linked oligosaccharides. In addition, the glycans liberated from CDGS dolichol-linked oligosaccharides were significantly truncated compared with those from normal fibroblasts. These data suggest that our type I CDGS patients produce abnormal N-linked oligosaccharides due to impaired biosynthesis of dolichol-oligosaccharide precursors.

Evaluation of human antibody responses to alpha-1 antitrypsin (AAT) in clinical trials and clinical practice has been limited by the lack of a validated assay. Here we describe the development and validation of an ELISA method for quantification of human and nonhuman primate antibody responses to human AAT. A reference anti-human AAT serum standard was generated using sera from a cynomolgus macaque injected with a recombinant adeno-associated virus vector expressing human AAT. The ELISA was validated for use with human serum dilutions as low as 1:10 and was able to distinguish between specific responses in cynomolgus serum and non-specific increases in apparent antibody titer in serum from subjects in a clinical trial of an AAT gene therapy vector.

Background The development of COPD in subjects with alpha-1 antitrypsin (AAT) deficiency is likely to be influenced by modifier genes. Genome-wide association studies and integrative genomics approaches in COPD have demonstrated significant associations with SNPs in the chromosome 15q region that includes CHRNA3 (cholinergic nicotine receptor alpha3) and IREB2 (iron regulatory binding protein 2). We investigated whether SNPs in the chromosome 15q region would be modifiers for lung function and COPD in AAT deficiency. Methods The current analysis included 378 PIZZ subjects in the AAT Genetic Modifiers Study and a replication cohort of 458 subjects from the UK AAT Deficiency National Registry. Nine SNPs in LOC123688, CHRNA3 and IREB2 were selected for genotyping. FEV1 percent of predicted and FEV1/FVC ratio were analyzed as quantitative phenotypes. Family-based association analysis was performed in the AAT Genetic Modifiers Study. In the replication set, general linear models were used for quantitative phenotypes and logistic regression models were used for the presence/absence of emphysema or COPD. Results Three SNPs (rs2568494 in IREB2, rs8034191 in LOC123688, and rs1051730 in CHRNA3) were associated with pre-bronchodilator FEV1 percent of predicted in the AAT Genetic Modifiers Study. Two SNPs (rs2568494 and rs1051730) were associated with the post-bronchodilator FEV1 percent of predicted and pre-bronchodilator FEV1/FVC ratio; SNP-by-gender interactions were observed. In the UK National Registry dataset, rs2568494 was significantly associated with emphysema in the male subgroup; significant SNP-by-smoking interactions were observed. Conclusions IREB2 and CHRNA3 are potential genetic modifiers of COPD phenotypes in individuals with severe AAT deficiency and may be sex-specific in their impact.

Liver disease is a significant cause of death among adults with α(1)-antitrypsin (A-AT) deficiency. Age and male sex are reported risk factors for liver disease. In the absence of adequate risk stratification, current recommendations are to intermittently test A-AT-deficient adults for liver function. We evaluated this recommendation in a large group of adults with A-AT deficiency to determine the prevalence of increased levels of alanine aminotransferase (ALT) and identify risk factors for liver disease.We used the Alpha-1 Foundation DNA and Tissue Bank to identify a cross section of A-AT-deficient adults (n = 647) with and without liver disease; individuals without A-AT deficiency were used as controls (n = 152). Results from ALT tests were compared between groups.The prevalence of liver disease among individuals with A-AT deficiency was 7.9%; an increased level of ALT was observed in 7.8% of A-AT-deficient individuals, which did not differ significantly from controls. Mean levels of ALT fell within normal range for all groups. An increased level of ALT identified patients with liver disease with 11.9% sensitivity. The level of only γ-glutamyl transpeptidase was significantly higher in the A-AT-deficient group than in controls (43 vs 30 IU/mL; P.003). A childhood history of liver disease and male sex were risk factors for adult liver disease in the multivariate analysis.An increased level of ALT does not identify adults with A-AT deficiency who have liver disease. Male sex and liver disease during childhood might help identify those at risk.

Recombinant adeno-associated virus (rAAV) vectors offer promise for the gene therapy of α(1)-antitrypsin (AAT) deficiency. In our prior trial, an rAAV vector expressing human AAT (rAAV1-CB-hAAT) provided sustained, vector-derived AAT expression for1 year. In the current phase 2 clinical trial, this same vector, produced by a herpes simplex virus complementation method, was administered to nine AAT-deficient individuals by intramuscular injection at doses of 6.0×10(11), 1.9×10(12), and 6.0×10(12) vector genomes/kg (n=3 subjects/dose). Vector-derived expression of normal (M-type) AAT in serum was dose dependent, peaked on day 30, and persisted for at least 90 days. Vector administration was well tolerated, with only mild injection site reactions and no serious adverse events. Serum creatine kinase was transiently elevated on day 30 in five of six subjects in the two higher dose groups and normalized by day 45. As expected, all subjects developed anti-AAV antibodies and interferon-γ enzyme-linked immunospot responses to AAV peptides, and no subjects developed antibodies to AAT. One subject in the mid-dose group developed T cell responses to a single AAT peptide unassociated with any clinical effects. Muscle biopsies obtained on day 90 showed strong immunostaining for AAT and moderate to marked inflammatory cell infiltrates composed primarily of CD3-reactive T lymphocytes that were primarily of the CD8(+) subtype. These results support the feasibility and safety of AAV gene therapy for AAT deficiency, and indicate that serum levels of vector-derived normal human AAT20 μg/ml can be achieved. However, further improvements in the design or delivery of rAAV-AAT vectors will be required to achieve therapeutic target serum AAT concentrations.

Alpha-1 antitrypsin (AAT) deficiency is well-suited as a target for human gene transfer. We performed a phase 1, open-label, dose-escalation clinical trial of a recombinant adeno-associated virus (rAAV) vector expressing normal (M) AAT packaged into serotype 1 AAV capsids delivered by i.m. injection. Nine AAT-deficient subjects were enrolled sequentially in cohorts of 3 each at doses of 6.9 × 10 12 , 2.2 × 10 13 , and 6.0 × 10 13 vector genome particles per patient. Four subjects receiving AAT protein augmentation discontinued therapy 28 or 56 days before vector administration. Vector administration was well tolerated, with only mild local reactions and 1 unrelated serious adverse event (bacterial epididymitis). There were no changes in hematology or clinical chemistry parameters. M-specific AAT was expressed above background in all subjects in cohorts 2 and 3 and was sustained at levels 0.1% of normal for at least 1 year in the highest dosage level cohort, despite development of neutralizing antibody and IFN-γ enzyme-linked immunospot responses to AAV1 capsid at day 14 in all subjects. These findings suggest that immune responses to AAV capsid that develop after i.m. injection of a serotype 1 rAAV vector expressing AAT do not completely eliminate transduced cells in this context.

Inappropriate accumulation of the misfolded Z variant of alpha1-antitrypsin in the hepatocyte endoplasmic reticulum (ER) is a risk factor for the development of end-stage liver disease. However, the genetic and environmental factors that contribute to its etiology are poorly understood. ER mannosidase I (ERManI) is a quality control factor that plays a critical role in the sorting and targeting of misfolded glycoproteins for proteasome-mediated degradation. In this study, we tested whether genetic variations in the human ERManI gene influence the age at onset of end-stage liver disease in patients homozygous for the Z allele (ZZ). We sequenced all 13 exons in a group of unrelated Caucasian ZZ transplant recipients with different age at onset of the end-stage liver disease. Homozygosity for the minor A allele at 2484G/A (refSNP ID number rs4567) in the 3′-untranslated region was prevalent in the infant ZZ patients. Functional studies indicated that rs4567(A), but not rs4567(G), suppresses ERManI translation under ER stress conditions. Conclusion: These findings suggest that the identified single-nucleotide polymorphism can accelerate the onset of the end-stage liver disease associated with alpha1-antitrypsin deficiency and underscore the contribution of biosynthetic quality control as a modifier of genetic disease. (HEPATOLOGY 2009.)

Neutrophil elastase (NE) activity is increased in lung diseases such as alpha(1)-antitrypsin (A1AT) deficiency and pneumonia. It has recently been shown to induce expression of cathepsin B and matrix metalloprotease 2 (MMP-2) in vitro and in a mouse model. It is postulated that increased cathepsin B and MMP-2 in acute and chronic lung diseases result from high levels of extracellular NE and that expression of these proteases could be inhibited by A1AT augmentation therapy.Cathepsin and MMP activities were assessed in bronchoalveolar lavage (BAL) fluid from patients with A1AT deficiency, pneumonia and control subjects. Macrophages were exposed to BAL fluid rich in free NE from patients with pneumonia following pretreatment with A1AT. MMP-2, cathepsin B, secretory leucoprotease inhibitor (SLPI) and lactoferrin levels were determined in BAL fluid from A1AT-deficient patients before and after aerosolisation of A1AT.BAL fluid from both patients with pneumonia and those with A1AT deficiency containing free NE had increased cathepsin B and MMP-2 activities compared with BAL fluid from healthy volunteers. The addition of A1AT to BAL fluid from patients with pneumonia greatly reduced NE-induced cathepsin B and MMP-2 expression in macrophages in vitro. A1AT augmentation therapy to A1AT-deficient individuals also reduced cathepsin B and MMP-2 activity in BAL fluid in vivo. Furthermore, A1AT-deficient patients had higher levels of SLPI and lactoferrin after A1AT augmentation therapy.These findings suggest a novel role for A1AT inhibition of NE-induced upregulation of MMP and cathepsin expression both in vitro and in vivo.

The rare P-family of alpha 1-antitrypsin (alpha 1AT) variants is defined by the position of migration of the alpha 1AT protein on isoelectric focusing of serum (IEF) between the common M and S variants. To begin to examine the molecular heterogeneity among the P-type alleles, two unrelated subjects and their families identified by IEF to be carrying a P allele were analyzed. The first, Plowell, is a deficiency allele associated with reduced serum alpha 1AT levels, and the second, Psaint albans, is associated with normal serum levels. DNA sequence analysis of Plowell, the more anodal of the two variants on IEF analysis, showed that if differed from the normal M1(Val213) allele by a single base and amino acid substitution Asp256 GAT----Val GTT. In contrast, Psaint albans, a slightly more cathodally positioned variant on IEF analysis, differed from the coding exons of the normal M1(Val213) allele by two mutations, Asp341 GAC----Asn AAC, and a silent substitution in the same codon as the Plowell variant, Asp256 GAT----Asp GAC. Evaluation of Plowell mRNA transcripts by Northern and cytoblot analyses demonstrated they were of normal size and amount, and Plowell mRNA transcripts could be translated normally in vitro. Retroviral insertion of the Plowell cDNA into the genome of 3T3 fibroblasts demonstrated that it directed the synthesis of alpha 1AT, but at levels 24% that of the Psaint albans cDNA or the normal M1 (Val213) cDNA, with a pattern of biosynthesis consistent with the concept that the Plowell alpha 1AT deficiency state results from intracellular degradation of the newly synthesized Plowell protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe alpha-1 antitrypsin (AAT) deficiency is a proven genetic risk factor for COPD, but there is marked variation in the development of COPD among AAT deficient subjects. To investigate familial aggregation of lung function in subjects with AAT deficiency, we estimated heritability for forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) in 378 AAT deficient subjects from 167 families in the AAT Genetic Modifiers Study; all subjects were verified homozygous for the Z AAT deficiency allele. Heritability was evaluated for models that included and excluded an ascertainment correction, as well as for models that excluded, included and were stratified by a cigarette smoking covariate. In models without an ascertainment correction, and in all models without a covariate for smoking, no evidence for familial aggregation of lung function was observed. In models conditioned on the index proband with covariates for smoking, post-bronchodilator FEV1/FVC demonstrated significant heritability (0.26 ± 0.14, p = 0.03). When we limited the analysis to subjects with a smoking history, post-bronchodilator FEV1demonstrated significant heritability (0.47 ± 0.21, p = 0.02). Severity rate phenotypes were also assessed as potential phenotypes for genetic modifier studies. Significant heritability was found with all age-of-onset threshold models that included smoking and ascertainment adjustments. Using the t-distribution, the heritability estimates ranged from 0.43 to 0.64, depending on the age-of-onset of FEV1 decline used for the severity rate calculation. Correction for ascertainment and consideration of gene-by-smoking interactions will be crucial for the identification of genes that may modify susceptibility for COPD in families with AAT deficiency.

INTRODUCTION: Recombinant adeno-associated virus (rAAV) vectors are capable of sustained expression of therapeutic proteins when administered to skeletal muscle. A single injection of a rAAV2 vector in mice resulted in sustained secretion of human alpha-1 antitrypsin (hAAT) at levels that would be therapeutic for prevention of lung disease in humans (11,000 nM). There is currently no definitive therapy for these patients, since protein replacement products are in short supply and require weekly intravenous infusions. Recently, we completed the ongoing preclinical testing (mouse, rabbit, and primate) of the rAAV2-hAAT vector in muscle, completed clinical grade production of rAAV2-hAAT, and initiated a phase I trial of rAAV-hAAT gene therapy in patients with AAT deficiency. MEHODS: The trial is an open-labeled, single administration study being performed in a total of 15 adult AAT-deficient patients. Five cohorts of three subjects each are being used with a dose escalation between cohorts. The dosages for the four cohorts range from 2 |[times]| 1012 vector genomes (vg) per patient to 2 |[times]| 1014 vg/patient. Subjects are screened and allowed a 28-day period for washout of protein replacement. An ultrasound-guided injection technique is used to avoid intravascular injection. The study endpoints address safety with examinations of the injection site, hematology, chemistry, coagulation studies, and pulmonary function tests. Biological activity of the vector is assessed by detection of normal M-variant hAAT protein by ELISA. Serum is also assayed for antibodies and lymphocyte proliferation responses to rAAV2 capsid and to AAT. Blood and semen DNA are also being assayed for vector DNA sequences. RESULTS: At the time of submission of this abstract, twelve subjects have been treated, and there have been no vector-related adverse events to date. All patients have demonstrated increases in anti-AAV2 capsid protein titers by ELISA, but none have shown increases in anti-hAAT antibody titers or in lymphocyte proliferation responses. Patients in the cohorts 2|[ndash]|4 show PCR evidence of vector DNA in the blood within the first 14 days, but without obvious ill effects. At least one subject in cohorts 3 shows evidence of M-AAT expression in the range of 50|[ndash]|100 nm. CONCLUSIONS: Preliminary evidence of the safety and bioactivity of rAAV2-hAAT are being generated. These support the feasibility of future clinical studies, including one recently begun with rAAV1, a serotype that shows a 500|[ndash]|1000-fold greater bioactivity than the current rAAV2 vector in mice.

Statins possess anti-inflammatory and immunomodulatory properties beyond their cholesterol-lowering effects. To determine whether short-term atorvastatin treatment affects the acute phase and humoral immune responses to tetanus toxoid (TT) in normal healthy volunteers, we conducted a randomized, double blind, placebo-controlled trial. Twenty healthy volunteers were assigned a 10-day treatment with atorvastatin (40 mg) or placebo. All volunteers received a TT booster on the fifth day. Subjects in the atorvastatin group had a significant reduction in total and low-density lipoprotein cholesterol (both p0.001). Unexpectedly, the production of anti-TT antibodies (predominately IgG1) was three-fold higher in the atorvastatin group 15 days post-vaccination (2306 +/- 468 versus 713+/-21 units, p = 0.008). Atorvastatin also suppressed the post-vaccination rise in platelet and lymphocyte counts (both p0.05). Acute phase parameters did not change significantly in either group. This study illustrates a novel immunomodulatory effect of atorvastatin raising the possibility of using HMG-CoA reductase inhibitors to enhance humoral responses to vaccination.

Recombinant adeno-associated virus (AAV) vectors have been used to transduce murine skeletal muscle as a platform for secretion of therapeutic proteins. The utility of this approach for treating alpha-1-antitrypsin (AAT) deficiency was tested in murine myocytes in vitro and in vivo . AAV vectors expressing the human AAT gene from either the cytomegalovirus (CMV) promoter (AAV-C-AT) or the human elongation factor 1-α promoter (AAV-E-AT) were examined. In vitro in C2C12 murine myoblasts, the expression levels in transient transfections were similar between the two vectors. One month after transduction, however, the human elongation factor 1 promoter mediated 10-fold higher stable human AAT expression than the CMV promoter. In vivo transduction was performed by injecting doses of up to 1.4 × 10 13 particles into skeletal muscles of several mouse strains (C57BL/6, BALB/c, and SCID). In vivo , the CMV vector mediated higher levels of expression, with sustained serum levels over 800 μg/ml in SCID and over 400 μg/ml in C57BL/6 mice. These serum concentrations are 100,000-fold higher than those previously observed with AAV vectors in muscle and are at levels which would be therapeutic if achieved in humans. High level expression was delayed for several weeks but was sustained for over 15 wk. Immune responses were dependent upon the mouse strain and the vector dosage. These data suggest that recombinant AAV vector transduction of skeletal muscle could provide a means for replacing AAT or other essential serum proteins but that immune responses may be elicited under certain conditions.

The mutant Z form of alpha1-antitrypsin (alpha1AT) is responsible for > 95% of all individuals with alpha1AT deficiency, an important inherited cause of emphysema and liver disease. Since secreted Z alpha1AT is a functional antiprotease, we hypothesized that interrupting catabolism of retained Z alpha1AT might increase its transport out of cells, causing an increase in extracellular protease protection. Both the protein translation inhibitor cycloheximide and the specific inhibitor of proteasome function, lactacystin, prevented intracellular degradation of Z alpha1AT. Moreover, this inhibition of degradation was associated with partial restoration of Z alpha1AT vesicular transport. This effect was observed in a model system of transfected CHO cells as well as in human alveolar macrophages synthesizing Z alpha1AT. This study supports the hypothesis that altering the intracellular fate of a mutant protein may be an option in the treatment of diseases associated with misfolded but potentially functional proteins.

Abnormal human genes are rarely absolute predictors of the development of disease. With a few notable exceptions, abnormal genes predict risk of disease, and this risk is modified by environmental factors. When these environmental risk factors are known and minimized, early identification may translate into substantial health benefits. One of the best examples of the potential of this paradigm is α1-antitrypsin deficiency. α1-Antitrypsin (AAT) deficiency is most often caused by inheritance of the so-called PI*Z allele (1)(2). “PI” is the former nomenclature for the SERPINA1 [serpin peptidase inhibitor, clade A (α1 antiproteinase, antitrypsin), member 1] gene locus and stands for protease inhibitor. While the number of AAT variants is >100, ∼95% of all AAT-deficient individuals are homozygous for the Z allele. The PI*Z allele is the result of a guanine-to-adenine base substitution, which in turn changes glutamic acid to lysine at position 342 of the mature AAT protein. This amino acid change alters the net charge of the protein and is the basis of its identification in isoelectric focusing gels. Inheritance of this allele increases the risk of developing chronic obstructive lung disease (COPD) and liver disease (1)(2). The diagnosis of AAT deficiency is based exclusively on laboratory assays (3). Risk ratios for COPD range from 1.5–12-fold, depending on whether the Z allele is present in heterozygous or homozygous combinations (4)(5)(6)(7)(8). Among normal …

Null alpha1-antitrypsin (alpha1AT) alleles represent the end of a continuum of variants associated with profound alpha1AT deficiency and an increased risk of emphysema. This study characterizes the molecular basis of QOclayton, a new example of an alpha1AT null allele arising from a mutational hot spot in the alpha1AT gene. The QOclayton allele is identical to the normal M1(V213) alpha1AT allele except for an insertion of a cytosine. This insertion occurs in the alpha1AT sequence which normally has seven cytosines corresponding to amino acid residues 360 to 362. The QOclayton mutation is located in the same reiterated DNA sequence as the alpha1AT QObolton deletion mutation and the insertion mutation allele QOsaarbruecken. The QOclayton cytosine insertion causes a 3' frameshift and results in the formation of a termination codon at residue 376, the same consequence as the alpha1AT QOmattawa mutation (L353 T-insertion with a 3' frameshift). To determine the molecular mechanisms responsible for the absence of alpha1AT associated with the QOclayton gene, an in vitro model of QOclayton was established using Chinese hamster ovary cells (CHO) transfected with the QOclayton gene. These cells were evaluated for alpha1AT mRNA expression, protein synthesis and secretion. Although the QOclayton gene expresses a similar amount of alpha1AT mRNA as compared with the normal alpha1AT gene, no QOclayton protein is secreted. Protein trafficking and double-label immunofluorescence demonstrate that the QOclayton protein is retained in the rough endoplasmic reticulum or pre-Golgi compartment and is degraded (t1/2 = 6.5 h). Since QOmattawa, QObolton, and QOsaarbruecken have similar termination sites in the alpha1AT mRNA, they may share a similar intracellular fate.

Current strategies for hepatic gene therapy are either quantitatively inefficient or suffer from lack of permanent gene expression. We have utilized an animal model of hereditary tyrosinaemia type I (HT1), a recessive liver disease caused by deficiency of fumarylacetoacetate hydrolase (FAH), to determine whether in vivo selection of corrected hepatocytes could improve the efficiency of liver gene transfer. As few as 1,000 transplanted wild-type hepatocytes were able to repopulate mutant liver, demonstrating their strong competitive growth advantage. Mutant hepatocytes corrected in situ by retroviral gene transfer were also positively selected. In mutant animals treated by multiple retrovirus injections >90% of hepatocytes became FAH positive and liver function was restored to normal. Our results demonstrate that in vivo selection is a useful strategy for hepatic gene therapy and may lead to effective treatment of human HT1 by retroviral gene transfer.

Hereditary tyrosinemia type 1, an autosomal recessive disorder caused by deficiency of fumarylace-toacetate hydrolase (FAH), manifests in either an acute or a chronic form. We used reverse transcription and the polymerase chain reaction to amplify the FAH cDNA of a 12-year-old American boy with chronic tyrosinemia type 1. The patient is a compound heterozygote for mutations in the FAH gene. One allele contains a missense mutation in codon 234 changing a tryptophan to a glycine; this allele was of maternal origin. Mutagenesis and transfection into COS cells demonstrated that the W234G mutation abolishes FAH activity. The patient's paternally derived allele is a splicing mutation in the + 5 position of intron 12, causing either insertion of a 105 bp fragment due to a cryptic splice site, or skipping of exon 12, or skipping of both exons 12 find 13. The chronic phenotype of tyrosinemia type 1 in this patient may be due to some residual, correct splicing by the allele with the splicing mutation. © 1995 Wiley-Liss, Inc.1

Rationale: Activation state-dependent secretion of alpha-1 proteinase inhibitor (A1PI) by monocytes and macrophages was first reported in 1985. Since then, monocytes and tissue macrophages have emerged as key sentinels of infection and tissue damage via activation of self-assembling pattern recognition receptors (inflammasomes), which trigger inflammation and cell death in a caspase-1 dependent process. These studies examine the relationship between A1PI expression in primary monocytes and monocytic cell lines, and inflammatory cytokine expression in response to inflammasome directed stimuli. Methods: IL-1 b expression was examined in lung macrophages expressing wild type A1PI (A1PI-M) or disease-associated Z isoform A1PI (A1PI-Z). Inflammatory cytokine release was evaluated in THP-1 monocytic cells or THP-1 cells lacking the inflammasome adaptor ASC, transfected with expression vectors encoding A1PI-M or A1PI-Z. A1PI-M was localized within monocytes by immunoprecipitation in hypotonic cell fractions. Cell-free titration of A1PI-M was performed against recombinant active caspase-1 in vitro. Results: IL-1 b expression was elevated in lung macrophages expressing A1PI-Z. Overexpression of A1PI-M in THP-1 monocytes reduced secretion of IL-1b and TNF-a. In contrast, overexpression of A1PI-Z enhanced IL-1b and TNF- a secretion in an ASC dependent manner. A1PI-Z-enhanced cytokine release was inhibited by a small molecule caspase-1 inhibitor but not by high levels of exogenous wtA1PI. Cytosolic localization of A1PI-M in monocytes was not diminished with microtubule-inhibiting agents. A1PI-M co-localized with caspase-1 in gel-filtered cytoplasmic THP-1 preparations, and was co-immunoprecipitated with caspase 1 from nigericin-stimulated THP-1 cell lysate. Plasma-derived A1PI inhibited recombinant caspase-1 mediated conversion of a peptide substrate in a dose dependent manner. Conclusions: Our results suggest that monocyte/macrophage-expressed A1PI-M antagonizes IL-1b secretion possibly via caspase-1 inhibition, a function which disease-associated A1PI-Z may lack. Therapeutic approaches which limit inflammasome responses in patients with A1PI deficiency, in combination with A1PI augmentation, may provide additional respiratory tissue-sparing benefits. Citation: Wang Y, He Y, Abraham B, Rouhani FN, Brantly ML, et al. (2012) Cytosolic, Autocrine Alpha-1 Proteinase Inhibitor (A1PI) Inhibits Caspase-1 and Blocks IL

Indian childhood cirrhosis (ICC) is a fatal liver disease characterized by the accumulation of copper-sulfur aggregates. We demonstrated that cultured fibroblasts from a patient with ICC contain vesicular aggregates, fibrillar whorls, and crystalloids along with dilated rough endoplasmic reticulum filled with flocculent material. Although the copper content of the fibroblasts was normal, both basal and metal-induced metallothionein (MT) synthesis was reduced in the ICC cells. The lower MT synthesis in ICC cells was seen at copper concentrations of 100, 200, and 400 microM, zinc concentrations of 50 and 100 microM, and a cadmium concentration of 2 microM. The lower MT synthesis in ICC cells was not due to failure of the cells to take up copper because 67Cu uptake kinetics were normal in the mutant cells. MT degradation was also normal in the ICC cells. The size of human MT IIA mRNA was normal in the ICC cells, but its amount was reduced under both basal and metal-induced conditions. The MT IIA gene, which is the predominant MT gene in human beings, showed no sequence alterations in any of its exons, introns, or promoter region in the ICC cells compared with normal cells. These studies demonstrate that this case of ICC represents a genetic disease with some level of expression in cultured fibroblasts; the basic defect may involve insufficient MT mRNA and protein synthesis for the copper load present. However, it remains to be determined whether reduced MT synthesis is a primary or secondary phenomenon.

α1-Antitrypsin (α1AT) is one of the most polymorphic gene loci in the human genome. α l AT variants are typically identified by their migration position in an isoelectric focusing gel at pH 4–5. Heterogeneity of the isoelectric point of α1AT variants, hence variant migration, most often results from amino acid substitutions which alter the net charge of the molecule. We identified an individual heterozygous for an α1AT variant migrating in the “P” variant region which differs from other known “P” variants. Using isoelectric focusing on an immobilized pH gradient at pH 4.50–4.85 the novel P allele, Pduarte migrates between Pst. albans and Plowell. Densitometric analysis of normal “M” type α1AT and the deficiency variant P lowell major bands separated by isoelectric focusing demonstrates that Pduarte contributes approximately 41% as much α1AT to the total serum α1AT concentration as the normal “M” α1AT, similar to Plowell. Direct DNA sequencing of the proband's genomic DNA demonstrates that the Pduarte allele differs from the normal M1(V213) allele by two amino acid substitutions, R101 (CGT H(CAT) and D256 (GAT)V (GTT). Individually, these amino acid substitutions characterize the normal M4 allele (R101H) and the deficient Plowell allele (D256V). Thus the Pduarte allele differs from the Plowell allele only by the normal allelic background in which the V256 mutation occurs. Comparison of amino acid sequences among several α1AT variants demonstrates that Pduarte is an example of a more general observation regarding diversity within the PI (protease inhibitor) systems. It is apparent that the heterogeneity observed among α1AT variants is due in part to combinations of a limited repertoire of amino acid substitutions. These combinations may be the product of mutational hot spots and/or recombination on normal allelic backgrounds. © 1993 Wiley-Liss, Inc.

Diagnosis of the hereditary disorder alpha 1-antitrypsin (alpha 1AT) deficiency is critically dependent on quantification of serum levels of alpha 1AT, a 52-kDa antiprotease that serves to protect the lung from destruction by neutrophil elastase. Although the measurement of serum alpha 1AT levels is not difficult, there is no international standard for alpha 1AT, and investigators in the field recognize that widely used commercially available standards vary by as much as 50 percent. To establish accurate ranges for the common normal and deficient alpha 1AT phenotypes, the present study uses a purified alpha 1AT standard to quantify the alpha 1AT serum levels of 443 individuals with common normal and deficient alpha 1AT phenotypes, including MM, ZZ, SS, MZ, MS, and SZ. Based on the observed values, a statistical model was developed to generate predicted frequency distributions of alpha 1AT serum levels for each of these phenotypes. Based on these studies, the ranges (5th to 95th percentile) for alpha 1AT serum levels of the common phenotypes are: MM, 20 to 53 mumol/L; SS, 20 to 48 mumol/L; ZZ, 3.4 to 7.0 mumol/L; MZ, 15 to 42 mumol/L; MS, 18 to 52 mumol/L; and SZ, 10 to 23 mumol/L. This alpha 1AT standard and these ranges are being used for the National alpha 1-Antitrypsin Deficiency Registry organized under the auspices of the National Heart, Lung, and Blood Institute.

Molecular analysis of alpha 1-antitrypsin (alpha 1AT) Wbethesda revealed that it differs from the normal M1 (Ala213) allele by a single base mutation causing an amino acid substitution Ala336 GCT----Thr ACT. Evaluation of alpha 1AT biosynthesis directed by the Wbethesda allele showed that although Wbethesda alpha 1AT mRNA was translated normally in vitro, transfection of the Wbethesda cDNA into COS-I cells was associated with human alpha 1AT secretion of 50% that of cells transfected with a normal alpha 1AT cDNA. The pattern of alpha 1AT biosynthesis was not intracellular accumulation as observed with the common Z alpha 1AT deficiency allele, but reduced intracellular alpha 1AT, suggesting intracellular degradation of the newly synthesized Wbethesda molecule. Together these observations suggest that in heterozygous combination with a Z or Null alpha 1AT allele, the Wbethesda variant causes "alpha 1AT deficiency", thus classifying it as an alpha 1AT "at risk" allele for emphysema.