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Background/Objectives:In obesity, B cells accumulate in white adipose tissue (WAT) and produce IgG, which may contribute to the development of glucose intolerance. IgG signals by binding to Fcγ receptors (FcγR) and by activating the complement system. The aim of our study was to investigate whether activation of FcγR and/or complement C3 mediates the development of high-fat diet-induced glucose intolerance.Methods:We studied mice lacking all four FcγRs (FcγRI/II/III/IV−/−), only the inhibitory FcγRIIb (FcγRIIb−/−), only the central component of the complement system C3 (C3−/−), and mice lacking both FcγRs and C3 (FcγRI/II/III/IV/C3−/−). All mouse models and wild-type controls were fed a high-fat diet (HFD) for 15 weeks to induce obesity. Glucose metabolism was assessed and adipose tissue was characterized for inflammation and adipocyte functionality.Results:In obese WAT of wild-type mice, B cells (+142%, P<0.01) and IgG (+128% P<0.01) were increased compared to lean WAT. Macrophages of FcγRI/II/III/IV−/−mice released lower levels of cytokines compared to wild-type mice upon IgG stimulation. Only C3−/−mice showed reduced HFD-induced weight gain as compared to controls (−18%, P<0.01). Surprisingly, FcγRI/II/III/IV−/−mice had deteriorated glucose tolerance (AUC +125%, P<0.001) despite reduced leukocyte number (−30%, P<0.05) in gonadal WAT (gWAT), whereas glucose tolerance and leukocytes within gWAT in the other models were unaffected compared to controls. Although IgG in gWAT was increased (+44 to +174%, P<0.05) in all mouse models lacking FcγRIIb, only FcγRI/II/III/IV/C3−/−mice exhibited appreciable alterations in immune cells in gWAT, for example, increased macrophages (+36%, P<0.001).Conclusions:Lack of FcγRs reduces the activity of macrophages upon IgG stimulation, but neither FcγR nor C3 deficiency protects against HFD-induced glucose intolerance or reduces adipose tissue inflammation. This indicates that if obesity-induced IgG contributes to the development of glucose intolerance, this is not mediated by FcγR or complement activation.

Celiac disease is caused by inflammatory T-cell responses against the insoluble dietary protein gliadin. We have shown that, in humanized mice, oral tolerance to deamidated chymotrypsin-digested gliadin (CT-TG2-gliadin) is driven by tolerogenic interferon (IFN)-γ- and interleukin (IL)-10-secreting type 1 regulatory T-like cells (Tr1-like cells) generated in the spleen but not in the mesenteric lymph nodes. We aimed to uncover the mechanisms underlying gliadin-specific Tr1-like-cell differentiation and hypothesized that proteolytic gliadin degradation by splenic macrophages is a decisive step in this process. In vivodepletion of macrophages caused reduced differentiation of splenic IFN-γ- and IL-10-producing Tr1-like cells after CT-TG2-gliadin but not gliadin peptide feed. Splenic macrophages, rather than dendritic cells, constitutively expressed increased mRNA levels of the endopeptidase Cathepsin D; macrophage depletion significantly reduced splenic Cathepsin Dexpression in vivoand Cathepsin D efficiently degraded recombinant γ-gliadin in vitro. In response to CT-TG2-gliadin uptake, macrophages enhanced the expression of Il27p28, a cytokine that favored differentiation of gliadin-specific Tr1-like cells in vitro, and was previously reported to increase Cathepsin D activity. Conversely, IL-27 neutralization in vivoinhibited splenic IFN-γ- and IL-10-secreting Tr1-like-cell differentiation after CT-TG2-gliadin feed. Our data infer that endopeptidase mediated gliadin degradation by macrophages and concomitant IL-27 production drive differentiation of splenic gliadin–specific Tr1-like cells.

Celiac disease is an autoimmune-like disorder that is triggered by dietary gluten and has a strong genetic association with the human leukocyte antigen locus, specifically, HLA-DQ2.5/DQ8. Here, Dahai-Koirala et al.apply ex vivosingle-cell sequencing of TCRs from celiac disease patients, and show that biased T-cell receptor usage underpins the response to two gluten epitopes, which has implications for disease pathogenesis, diagnosis, and treatment.

Natural killer (NK) cells are cytotoxic lymphocytes of the innate immune system with the ability to detect HLA class I disparities via killer‐cell immunoglobulin‐like receptors (KIR). To test whether such KIR‐ligand mismatches contribute to the rejection of human solid allografts, we did a retrospective cohort study of 397 HLA‐DR‐compatible kidney transplantations and determined the KIR and HLA genotypes of recipients and the HLA genotypes of donors. In transplantations compatible for HLA‐A, HLA‐B and HLA‐DR (n = 137), in which a role for T cells and HLA antibodies in rejection was minimized, KIR‐ligand mismatches were associated with an approximately 25% reduction in 10‐year death‐censored graft survival (p = 0.043). This effect was comparable to the effect of classical HLA‐A and HLA‐B incompatibility, and in HLA‐A,‐B‐incompatible transplantations (n = 260) no significant additional effect of KIR‐ligand mismatches was observed. Multivariate Cox regression analysis confirmed the effect of KIR‐ligand mismatching as an independent risk factor in HLA‐A,‐B,‐DR‐compatible transplantations (hazard ratio 2.29, range 1.03–5.10, p = 0.043). This finding constitutes the first indication that alloreactive NK cells may thwart the success of HLA‐compatible kidney transplantations, and suggests that suppression of NK‐cell activity can improve the survival of such kidney grafts.

The association of celiac disease (CD) with HLA-DQ2 and HLA-DQ8 is indicative of preferential mucosal T cell recognition of gluten fragments bound to either DQ allele. We have recently identified two gluten-derived, HLA-DQ8-restricted T cell stimulatory peptides, one each from gliadin and glutenin, recognized by specific T cell clones derived from the small intestine of CD patients. We have now performed molecular modeling and examined the fine specificity of these peptides in complex with HLA-DQ8. There is only one binding register for both peptides, with glutamine residues at the p1 and p9 anchor positions. Both T cell clones recognize substituted peptides at p1 and p9, but poorly so at p2-p8, especially the gliadin-specific clone. Contrasting patterns of recognition of p9Gln → Glu peptide variants (both predicted as better DQ8 binders by modeling) were observed: enhancement of recognition for the gliadin peptide, yet complete absence thereof for the glutenin peptide. The double-substituted gliadin peptide variant p1/9Gln → Glu, which can also arise by pepsin/acid/transglutaminase treatment, shows a considerable increase in sensitivity of recognition, consistent with better binding of this peptide to DQ8, as predicted by energy minimization. Surprisingly, the two native peptides are also recognized by their respective T cell clones in the context of the related molecule HLA-DQ9 (β57Asp⁺). The p1/9Gln → Glu gliadin peptide variant is likewise recognized, albeit with a 10-fold lower sensitivity, the first reported p9Glu binding in a β57Asp⁺ MHC II allele. Our results have important implications for the pathogenesis of autoimmune disease and the possible manipulation of aberrant responses thereof.

The association of celiac disease (CD) with HLA-DQ2 and HLA-DQ8 is indicative of preferential mucosal T cell recognition of gluten fragments bound to either DQ allele. We have recently identified two gluten-derived, HLA-DQ8-restricted T cell stimulatory peptides, one each from gliadin and glutenin, recognized by specific T cell clones derived from the small intestine of CD patients. We have now performed molecular modeling and examined the fine specificity of these peptides in complex with HLA-DQ8. There is only one binding register for both peptides, with glutamine residues at the p1 and p9 anchor positions. Both T cell clones recognize substituted peptides at p1 and p9, but poorly so at p2-p8, especially the gliadin-specific clone. Contrasting patterns of recognition of p9Gln --> Glu peptide variants (both predicted as better DQ8 binders by modeling) were observed: enhancement of recognition for the gliadin peptide, yet complete absence thereof for the glutenin peptide. The double-substituted gliadin peptide variant p1/9Gln --> Glu, which can also arise by pepsin/acid/transglutaminase treatment, shows a considerable increase in sensitivity of recognition, consistent with better binding of this peptide to DQ8, as predicted by energy minimization. Surprisingly, the two native peptides are also recognized by their respective T cell clones in the context of the related molecule HLA-DQ9 (beta57Asp(+)). The p1/9Gln --> Glu gliadin peptide variant is likewise recognized, albeit with a 10-fold lower sensitivity, the first reported p9Glu binding in a beta57Asp(+) MHC II allele. Our results have important implications for the pathogenesis of autoimmune disease and the possible manipulation of aberrant responses thereof.

Alloreactive T cells form an important barrier for organ transplantation. To reduce the risk of rejection patients are given immunosuppressive drugs, which increase the chance of infection and the incidence of malignancies. It has been shown that a large proportion of alloreactive T cells specifically recognize peptides present in the groove of the allogeneic MHC molecule. This implies that it might be possible to modulate the alloresponse by peptides with antagonistic properties, thus preventing rejection without the side effects of general immunosuppression. Peptide antagonists can be designed on the basis of the original agonist, yet for alloreactive T cells these agonists are usually unknown. In this study we have used a dedicated synthetic peptide library to identify agonists for HLA-DR3-specific alloreactive T cell clones. Based on these agonists, altered peptide ligands (APL) were designed. Three APL could antagonize an alloreactive T cell clone in its response against the library-derived agonist as well as in its response against the original allodeterminant, HLA-DR3. This demonstrates that peptide libraries can be used to design antagonists for alloreactive T cells without knowledge about the nature of the actual allostimulatory peptide. Since the most potent agonists are selected, this strategy permits detection of potent antagonists. The results, however, also suggest that the degree of peptide dependency of alloreactive T cell clones may dictate whether a peptide antagonist can be found for such clones. Whether peptide antagonists will be valuable in the development of donor-patient-specific immunosuppression may therefore depend on the specificity of the in vivo-generated alloreactive T cells.

Human monocyte-derived dendritic cells (DC) use mannose receptor (MR)-mediated endocytosis for efficient antigen capture and targeting to the endosomal/lysosomal compartment. Active biosynthesis of the MR takes place in such cells. We now report that a substantial percentage (up to 20%) of these newly synthesized MR are secreted into the culture medium. The secretion of the soluble MR (sMR) was found to be proportional to the rate of synthesis. The addition of the inflammatory mediator lipopolysaccharide (LPS) to DC, known to induce maturation, strongly reduced MR synthesis, expression and shedding of the MR. The sMR is ~10 kDa smaller than the membrane-bound form, but contains an intact N-terminus, indicating the lack of the cytoplasmic and transmembrane region. The sMR appeared to be directly generated from the cell-bound form, indicative of proteolytic cleavage. Importantly, the sMR has maintained its mannose-binding properties since it was capable of binding a mannosylated ligand. The high amount of sMR released by DC and its ability to bind mannosylated ligand might indicate that this molecule plays a role in the transport of mannosylated proteins from the site of inflammation to other parts of the body. Whether that contributes to the generation of immune responses remains to be determined.

Alloreactive T cells form an important barrier for organ transplantation. To reduce the risk of rejection patients are given immunosuppressive drugs, which increase the chance of infection and the incidence of malignancies. It has been shown that a large proportion of alloreactive T cells specifically recognize peptides present in the groove of the allogeneic MHC molecule. This implies that it might be possible to modulate the alloresponse by peptides with antagonistic properties, thus preventing rejection without the side effects of general immunosuppression. Peptide antagonists can be designed on the basis of the original agonist, yet for alloreactive T cells these agonists are usually unknown. In this study we have used a dedicated synthetic peptide library to identify agonists for HLA-DR3-specific alloreactive T cell clones. Based on these agonists, altered peptide ligands (APL) were designed. Three APL could antagonize an alloreactive T cell clone in its response against the library-derived agonist as well as in its response against the original allodeterminant, HLA-DR3. This demonstrates that peptide libraries can be used to design antagonists for alloreactive T cells without knowledge about the nature of the actual allostimulatory peptide. Since the most potent agonists are selected, this strategy permits detection of potent antagonists. The results, however, also suggest that the degree of peptide dependency of alloreactive T cell clones may dictate whether a peptide antagonist can be found for such clones. Whether peptide antagonists will be valuable in the development of donor-patient-specific immunosuppression may therefore depend on the specificity of the in vivo-generated alloreactive T cells.

We have produced a T cell hybridoma line by fusion of an IL-2-dependent, long-term T cell receptor (TCR) gamma/delta+ Thy-1+, bone marrow-derived, dendritic epidermal cell line to the BW5147 tumor line. The resultant hybridoma was rapidly growing, lymphokine independent, and expressed T3 in association with the TCR gamma/delta heterodimer. Several subclones of the hybridoma line produced easily detectable levels of IL-2 after stimulation by anti-T3 or Con A. The availability of these cloned cell lines should greatly facilitate further functional, biochemical, and molecular studies of the TCR delta chain.

Before and after bone marrow transplantation (BMT) for hematologic malignancies, peripheral blood mononuclear cells from 10 patients were obtained. The relative and absolute numbers of CD3+ T-cell receptor gamma delta+ (TCR gamma delta+) cells, as defined by the reaction of monoclonal antibodies (MoAbs) directed against CD3 and the TCR gamma delta (anti-TCR gamma delta-1), were determined. Before transplantation, eight of nine patients tested had less than 10% CD3+TCR gamma delta+ cells. Consistent increased numbers of gamma delta cells up to eightfold the pretransplant level can be seen in four of nine patients tested within the first 4 months after BMT. The large majority of early posttransplant gamma delta and alpha beta T cells express the CD45RO antigen, which is usually expressed on “memory” cells only. The V-region usage of the TCR gamma delta+ T cells was analyzed using fresh mononuclear cells and MoAbs against known V gamma and V delta regions. For more detailed analysis, CD3+TCR gamma delta+ cells were sorted and cultured in bulk and cloned. Using fresh cells and bulk cultures, mainly V gamma 9+V delta 1-V delta 2+ cells were found during engraftment. Only after 6 weeks post-BMT, V gamma 9-V delta 1+V delta 2- cells appear. Analysis of the V gamma and V delta usage at the clonal level confirmed the observation that early after BMT only V gamma 9+V delta 2+ cells are present, whereas gamma delta T- cell clones expressing other gamma delta TCR phenotypes can only be detected 4 to 6 weeks post-BMT. The predominance of V gamma 9+ cells during early engraftment could be explained by several mechanisms: (A) sequential rearrangements during T-cell development, leading to an early wave of V gamma 9+ cells, or (B) selective outgrowth of preexisting V gamma 9+V delta 2+CD45RO+ TCR gamma delta cells in the bone marrow graft, possibly as a result of antigen driven expansion due to exposure to environmental antigens.

The force-velocity curve (FVC) of arm flexion was established in 123 untrained males and 110 untrained females aged from 15 to 36 years, and 48 arm-trained athletes competing in different sport disciplines. The FVC was described by Hill's equation and defined by the parameters: maximal static moment (M0), maximal angular velocity (O0), maximal power (P0) and the concavity of the FVC (H). Within the given age range the level of the curve parameters of both untrained men and women was independent of age.

Altered peptide ligands (APL) have the potential to modulate pathogenic T cell reactivity. High concentrations of APL, however, are required to achieve efficient blocking of the T cell response. We have therefore investigated whether improved delivery of APL to professional antigen-presenting cells (APC) can lead to more efficient application of such peptides. For this purpose APL were bis-mannosylated in order to facilitate their uptake by mannose receptor-positive dendritic cells (DC) in vitro. We present evidence that a 100- to 1000-fold lower concentration of bis-mannosylated APL were similarly effective in the inhibition of the T cell response against whole protein antigens. In contrast, unrelated, bis-mannosylated class II binding peptides were ineffective, indicating that the increased efficiency of the mannosylated APL was not due to competition for binding to class II molecules. Furthermore, a strong increase in the efficiency of presentation of APL was also observed when macrophages and peripheral blood mononuclear cells were used as APC. Thus, bis-mannosylation of APL greatly increases their potency to inhibit proliferative T cell responses. Moreover, it is likely that the use of bis-mannosylated APL will result in preferential presentation by mannose receptor-positive, professional APC. These results may be of relevance for more effective use of APL for immunoregulation in vivo.
Keywords:altered peptide ligand, mannosylation

MHC class II molecules can exist in two conformations which can be distinguished on the basis of their stability in SDS. The formation of SDS-stable dimers has been shown to correlate with persistent expression of antigen MHC class II-peptide complexes by murine antigen-presenting cells. HLA DR molecules contain either a Val or a Gly at position 86 of the beta chain, which is located in a conserved and prominent hydrophobic pocket in the peptide binding site. Here we show that Val86-containing DR molecules more frequently select peptides which induce the formation of SDS-stable dimers than Gly86 variants. Using analogues of the influence virus haemagglutinin epitope 307-319 we found that the replacement of the aromatic hydrophobic anchor residue (Tyr)at position 309 by amino acids with an aliphatic hydrophobic side chain resulted in the specific formation of high numbers of SDS-stable Val86-DR but not Gly86-DR dimers. These results indicate that the fit between the first anchor residue and the hydrophobic pocket around Dr beta 86 plays a critical role in the formation of SDS-stable DR dimers. Synthetic analogues of naturally processed DR-associated peptides displayed promiscuity in their capacity to bind to several DR specificities and in their ability to induce the SDS-stable conformation. However, no correlation was observed between binding capacity and the ability to induce the SDS-stable conformation. Since it has been shown that SDS stability can relate to the kinetics of peptide-MHC class II interactions, the definition of the requirements for the formation of SDS-stable HLA class II molecules may be important for the design of effective peptide-based immunomodulation protocols.

The epidermis of clinically normal-appearing human skin harbors a phenotypically heterogeneous population of T lymphocytes (TCs), the majority of which are CD2+/CD3+/CD5+ "memory" cells, but in an unactivated state, and express the TCR-alpha/beta. In contrast to murine skin, only a very minor subpopulation of CD3+ cells in the human epidermis bears the TCR-gamma/delta. Epidermal TCs primarily are distributed along the rete ridges in the basal keratinocyte layer and are often in close apposition to Langerhans cells (LCs). These TCs were propagated from epidermal cell suspensions after stimulation with TC activating agents (Con A, rIL-1, rIL-2), then evaluated for phenotypic features and TCR diversity. Similar to the in situ situation, most were CD4-/CD8+/TCR-alpha/beta+. In addition, two cultures contained TCR-gamma/delta+ cells; one of these determined to be an adherent CD4-/CD8+ population. Epidermal TCs were significantly (p less than 0.0001) more abundant in the sole than in the other body regions examined (i.e., 40 vs. 7 CD3+ cells/linear centimeter of epidermis) and seemed to have a particular affinity for the acrosyringial epithelium of eccrine sweat ducts. Moreover, the sole usually contained a greater number of CD8+ relative to CD4+ TCs, whereas the epidermal CD4/CD8 ratio in the trunk and extremities was quite variable, although the trend also was towards a slightly larger percentage of CD8+ cells. Collectively, our data suggest that the volar epidermis has a unique microenvironment which is responsible for both the higher density of TCs, preferentially CD8+, and lower number of LCs. This study has not only provided evidence for significant regional variability in the human epidermal TC population of normal skin, but also strengthens the concept for skin-associated lymphoid tissues (SALT), whereby memory TCs recirculate back to the epidermis and interact with resident antigen-presenting cells (i.e., LC).

The TCR-gamma and -delta chains of six murine hybridomas were compared by one-dimensional SDS-PAGE and two-dimensional NEPHGE/SDS-PAGE analysis. This allowed the identification of three distinct gamma chains (gamma a, gamma b, and gamma c) and three distinct delta chains (delta a, delta b, and delta c). Four gamma/delta chain combinations (gamma a delta a, gamma b delta b, gamma b delta c, and gamma c delta a) were observed. These results indicate that multiple forms of the delta chain are expressed and suggest that the delta chains are encoded for by an Ig-like rearranging gene. This delta chain polymorphism significantly enhances the potential diversity of TCR-gamma/delta, which may be of importance for a better understanding of the putative ligand(s) recognized by this receptor.

Altered peptide ligands (APL) have the potential to modulate pathogenic T cell reactivity. High concentrations of APL, however, are required to achieve efficient blocking of the T cell response. We have therefore investigated whether improved delivery of APL to professional antigen-presenting cells (APC) can lead to more efficient application of such peptides. For this purpose APL were bis-mannosylated in order to facilitate their uptake by mannose receptor-positive dendritic cells (DC) in vitro. We present evidence that a 100- to 1000-fold lower concentration of bis-mannosylated APL was sufficient for complete blocking of the proliferative T cell response against the agonist peptide compared to the non-mannosylated APL. Moreover, bis-mannosylated APL were similarly effective in the inhibition of the T cell response against whole protein antigens. In contrast, unrelated, bis-mannosylated class II binding peptides were ineffective, indicating that the increased efficiency of the mannosylated APL was not due to competition for binding to class II molecules. Furthermore, a strong increase in the efficiency of presentation of APL was also observed when macrophages and peripheral blood mononuclear cells were used as APC. Thus, bis-mannosylation of APL greatly increases their potency to inhibit proliferative T cell responses. Moreover, it is likely that the use of bis-mannosylated APL will result in preferential presentation by mannose receptor-positive, professional APC. These results may be of relevance for more effective use of APL for immunoregulation in vivo.

1. An experiment was conducted to study the effect of method (low-lysine or quantity of food) and phase (starter or grower) of restriction during rearing on growth and laying performance in Leghorn hybrids.2. A reduction in body weight gain was achieved by feeding pullets a low-lysine diet in either the starter phase (0-6 weeks of age: 4.0 g/kg digestible lysine) or the grower phase (7-18 weeks of age: 3.0 g/kg digestible lysine).3. In each phase, the lysine restriction was compared with a daily food restriction, in which pullets received a quantity of food sufficient to pair-gain with their lysine-restricted counterparts.4. The delay in onset of production was greatest in the lysine-restricted birds, for both phases of restriction.5. Hens restricted during the grower phase laid heavier eggs than those restricted during the starter phase, despite having similar body weights at end of rearing. This effect was not influenced by the restriction method.6. Production traits varied between pullets reared on different feeding strategies up to similar body weights at 18 weeks and onwards. It is concluded that body weight is not the only factor determining laying performance.

Cell-cell and cell-extracellular (ECM) protein interactions are mediated through heterodimers termed integrins. We have demonstrated that dendritic epidermal T cell (DETC) lines adhere to the ECM proteins, fibronectin, fibrinogen, and vitronectin but not to collagen, laminin, or control proteins. This adhesion was blocked by the tetrapeptide RGDS, but not the control peptide, RGES. We have derived a hamster mAb H9.2B8, and a rat mAb, 8.18E12, from immunizations with DETC lines. The mAbs in combination, but not individually, specifically inhibited the adhesion of DETC lines to fibronectin, fibrinogen, and vitronectin. Immunoprecipitation analysis revealed that both mAbs reacted with a heterodimer composed of noncovalently linked 140- and 95-kD subunits. The 140-kD subunit can be reduced to 120- and 23-kD fragments. Although the two mAbs did not cross-compete for binding to DETC, sequential immunoprecipitation studies indicated that they react with the same 120-kD fragment. While all DETC cell lines and several T cell clones were reactive with the mAbs, the mAbs were not reactive with normal spleen, lymph node, thymus, or skin. Stimulation of splenic T cells with Con A or allogeneic cells induced mAb reactivity after 1 wk in vitro. These data demonstrate that a single lymphocyte receptor, with biochemical features characteristic of integrins, mediates RGD-dependent binding to the ECM proteins, fibronectin, fibrinogen, and vitronectin. Furthermore, since this integrin is expressed by long-term activated T cells, this receptor may play a physiological role in T cell function.

Heat shock protein gp96 primes class I restricted cytotoxic T cells against antigens present in the cells from which it was isolated. Moreover, gp96 derived from certain tumors functions as an effective vaccine, causing complete tumor regressions in in vivo tumor challenge protocols. Because tumor-derived gp96 did not differ from gp96 isolated from normal tissues, a role for gp96 as a peptide carrier has been proposed. To test this hypothesis, we analyzed whether such an association of antigenic peptides with gp96 occurs in a well-defined viral model system. Here we present the full characterization of an antigenic peptide that endogenously associates with the stress protein gp96 in cells infected with vesicular stomatitis virus (VSV). This peptide is identical to the immunodominant peptide of VSV, which is also naturally presented by H-2Kb major histocompatibility complex class I molecules. This peptide associates with gp96 in VSV-infected cells regardless of the major histocompatibility com- plex haplotype of the cell. Our observations provide a biochemical basis for the vaccine function of gp96.

The murine epidermis is a heterogeneous epithelium composed of keratinocytes, melanocytes, Langerhans cells, and a recently described subpopulation (2-3%) of bone-marrow-derived leukocytes with a dendritic morphology and the cell surface phenotype Thy-1+, L3T4-, Lyt-2-. Previous studies have demonstrated that cell lines derived from freshly explanted Thy-1+ dendritic epidermal cells (DEC) have abundant mRNA for rearranged T-cell receptor (TCR) gamma-chain genes. Analysis of Thy-1+ DEC in situ, freshly isolated cell suspensions of Thy-1+ DEC, and long-term Thy-1+ DEC lines demonstrated that 100% of the Thy-1+ DEC reacted with a monoclonal antibody to the epsilon chain of the murine T3 complex and that 40-60% of resident Thy-1+ DEC were also reactive with an antiserum to the TCR gamma chain. Two Thy-1+ DEC lines expressed a disulfide-linked 70-kDa molecule that could be precipitated with an anti-gamma-chain antiserum and could be coprecipitated with an antiserum to the T3 delta chain; the molecule appeared as a single 34-kDa band under reducing conditions. The phenotype of Thy-1+ DEC (T3+, L3T4-, Lyt-2-, TCR gamma chain+) thus resembles that of the recently described subpopulation of murine and human lymphocytes that have been identified in the thymus, peripheral blood, and fetal blood.

Human TCR γδ positive T cells can proliferate in response to stimulation with staphylococcal enterotoxins (SEs) or mediate lysis of SE pulsed target cells. In the small number of studies reported, the proliferative response of γδ T cells was limited to Vγ9 negative cells and, in vitro, such responses do not require the presence of MHC class II molecules for antigen presentation. Proliferative responses have been found after stimulation with SEA, SEB and TSST. The cytolytic activity of γδ T cells can be mediated by two different mechanisms: either γδ T cells specifically interact with SEA pulsed target cells—this is most likely TCR mediated recognition—or γδ T cells mediate antibody dependent cellular cytotoxicity (ADCC). This latter reactivity depends on Fc-receptor expression by the γδ T cell clones and the presence of SE specific antibodies during the assay. So far cytotoxic γδ T cell reactivity has only been found against the highly homologous enterotoxins SEA and SEE. Finally, HLA-class II positive γδ T cell clones can present SE to other SE reactive T cells but appear to be relatively resistant to T cell mediated lysis. Taken together, TCR γδpositive T cells are able to respond to a number of bacterial superantigens and may therefore be involved in local immune responses to such antigens. This may be especially relevant for those γδ T cell subpopulations that are preferentially found in the (intestinal) epithelia where exposure to bacterial superantigens is likely to occur. Copyright 1993, 1999 Academic Press

We have demonstrated that the PEER cell line, which expresses a CD3-associated TCR gamma chain on the cell surface, synthesizes TCR beta chain intracellularly. A percentage of this TCR beta chain associates with the CD3 complex intracellularly. These results indicate that TCR beta and gamma chains can be synthesized by one cell line, and that these chains can independently associate with the CD3 complex. However, the results argue against the formation of TCR beta gamma chain complexes in this cell line.

The widths of subcutaneous fat, muscular tissues, and compact bone were measured from radiographs of the hand and arm in various groups of Surinam children aged 6–12 years.The Hindustani groups had more adipose tissue and less muscular tissue than the Creole groups. Both groups had less adipose and muscular tissue than American children.There was no difference in width of compact bone compared with American children, although only 9% of the calorie value of the Surinam children’s diet is supplied by proteins, and this diet supplies only 0.4 g calcium/day.There was also no difference in width of cortical substance between Javanese boarding-school children in Surinam, with a daily milk intake of 400 ml, and Javanese schoolchildren whose daily milk intake is only a fraction of this value.

For a period of 15 months, the growth and development were studied of 6- to 12-year-old Surinam children from four boarding schools. The nutritional value of the diets in these schools varied considerably. The protein content in the diets varied per boarding school from 45 to 70 g/day (of which 12-26 g were animal); the calcium content varied from 350 to 900 mg and the amount of riboflavin from 12 to 20 µg/g of protein. The daily intake of milk varied from about 100 to 400 ml.There was no difference in increase of height, weight, circumference measures and skeletal age. In the school children having the greatest intake of milk, the amount of body fat showed a greater increase.In three of the four boarding schools a group of children were given 400 mg of calcium/day extra during the 15-month period. As to the criteria of growth mentioned above, these groups showed no difference with the groups that had no supplementary calcium.The mean calcium content per gram of creatinine in the urine was found a good measure for the calcium content in the diet. The amount of nitrogen per gram of creatinine was also a good standard for the protein content of the diet. That also applies to the urea index, i.e., urea nitrogen in percentages of the total amount of nitrogen. With an average diet protein content of 45 g for 6- to 12-year-old children, the urea index of the urine was 83, the nitrogen content per gram of creatinine was 6.6 g, while the calcium content per gram of creatinine was 39 mg with a calcium intake of 350 mg/day.

Thallium(I) zeigt starke Fluorescenz in einer Lösung, die 3,3 M an HCl und 0,8 M an KCl ist. Diese Erscheinung wurde zur Endpunktsanzeige der Redoxtitration Tl(III)-Tl(I) verwendet (Excitationswellenlänge 253 nm, Fluorescenzwellenlänge 438 nm). Wegen der starken Lichtabsorption von Thallium(III) bei 253 nm kann nur ein reduktometrisch durchgeführtes Titrationsverfahren benutzt werden. Genauigkeit und Selektivität sind beim titrimetrischen Verfahren besser als beim Eichlinienverfahren. Spuren Thallium (bis einige Mikrogramm) können mit guter Genauigkeit bestimmt werden. Die Anwendung der Methode für die Bestimmung von Thallium in Urin im ppm-Bereich wird beschrieben. Thallium(I) shows strong fluorescence in a solution which is 3.3 M in HCl and 0.8 M in KCl. The excitation wavelength is 253 nm and the wavelength selected for the fluorescence 438 nm. Due to the strong absorption at 253 nm by thallium(III) a reductometric rather than an oxidimetric titration will lead to a correct fluorimetric end-point indication. The precision and the selectivity of the titrimetric method are better than those of the corresponding methods based on the use of calibration curves. Traces of thallium down to 1 μg can be determined with good precision. The method can be used for the determination of thallium in urine at the ppm level.

Thallium(I) zeigt starke Fluorescenz in einer Lösung, die 3,3 M an HCl und 0,8 M an KCl ist. Diese Erscheinung wurde zur Endpunktsanzeige der Redoxtitration Tl(III)-Tl(I) verwendet (Excitationswellenlänge 253 nm, Fluorescenzwellenlänge 438 nm). Wegen der starken Lichtabsorption von Thallium(III) bei 253 nm kann nur ein reduktometrisch durchgeführtes Titrationsverfahren benutzt werden. Genauigkeit und Selektivität sind beim titrimetrischen Verfahren besser als beim Eichlinienverfahren. Spuren Thallium (bis einige Mikrogramm) können mit guter Genauigkeit bestimmt werden. Die Anwendung der Methode für die Bestimmung von Thallium in Urin im ppm-Bereich wird beschrieben.

The results of nutritional studies are reported which were carried out in Papuan subjects living in the Central Highlands of New Guinea where 90 to 95 per cent of the staple food consists of sweet potatoes. The daily protein intake is 15 to 35 gm. The protein is poor in the amino acids methionine, cystine and to a lesser degree in lysine.Nitrogen balance studies were carried out in Papuan school children used to sweet potato diets. The nitrogen content of sweet potato leaves is remarkably high, 766 ± 164 mg. per 100 gm., and contributes considerably to the protein value of the diet. On diets consisting of sweet potatoes and sweet potato leaves only, the children retained about 1 gm. of nitrogen when the daily nitrogen intake was 5 gm. or more. Larger quantities of nitrogen are retained from sweet potato diets supplemented with peanut and pigeon pea proteins. Nitrogen retention is seldom improved by supplementation with methionine or lysine, the first and second limiting amino acids.The excretion of nitrogen in the urine is always low, even on diets rich in proteins from peanuts and pigeon peas. The urinary excretion of some constituents related to protein metabolism was studied in these children. The mean excretion of creatinine was 30 per cent lower than in American children. There was no relation between protein or the sulfur-containing amino acid content of the diet and the level of α-amino acid nitrogen or sulfur, per gram creatinine, or the ratio of urea nitrogen to total nitrogen. The possible relationship between sulfur excretion and vitamin A content of the diet is mentioned. The hippuric acid excretion was ten to twenty times higher in the Papuan children than in European children. Increasing the dietary nitrogen with the addition of peanuts increased the hippuric acid excretion.Papuan schoolboys were given 10 gm. supplements of protein during three months as follows: (1) group 1, 30 gm. skimmed milk powder, (2) group 2, 50 gm. beans (Phaseolus vulgaris); and (3) group 3, 50 mg. beans with 400 mg. methionine. All groups increased considerably in weight, i.e., 1.2 to 2.1 kg. The α-amino nitrogen level in blood serum increased, the γ-globulin level was significantly lower than in a control group of older age which was not given supplements. There was no difference in serum proteins, albumin, cholinesterase activity nor in the urinary excretion of urea, α-amino nitrogen, calcium or sulfur between groups.The ossification of the wrist (skeletal age) was comparable with that of American children in the groups eight and ten years of age, but retarded in those twelve and fourteen years of age. The area of the brachial bone was less than that in American children. The breadth of the bones of the lower part of the leg was comparable to measurements in American children.Some constituents of the blood serum from Papuan subjects living on this staple food were compared with Papuan people from the same area earning money and buying additional protein-rich food such as rice and canned fish and with Papuan subjects after a few weeks on a hospital diet. Papuan people using the native diet had lowest values for serum protein, albumin, cholesterol and cholinesterase activity and highest values for γ-globulin. The levels of these constituents increased during hospitalization; the low cholesterol content, initially 108 mg. per 100 ml. in men, even increased 40 to 70 per cent.

A group of 53 healthy elderly Surinams (aged 67-94) was examined for osteoporosis. Cupping of the vertebrae, and spontaneous fractures were found in 11 and 6% of the examined persons, respectively. This is considerably less frequent than has been reported for a group of elderly people in the United States. The lumbar spine score according to Barnett and Nordin (9) was 80 or less in 22% of the persons.