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A catalytic antibody has multiple functions compared with a monoclonal antibody because it possesses unique features to digest antigens enzymatically. Therefore, many catalytic antibodies, including their subunits, have been produced since 1989. The catalytic activities often depend on the preparation methods and conditions. In order to elicit the high catalytic activity of the antibodies, the most preferable methods and conditions, which can be generally applicable, must be explored. Based on this view, systematic experiments using two catalytic antibody light chains, #7TR and H34, were performed by varying the purification methods, pH, and chemical reagents. The experimental results obtained by peptidase activity tests and kinetic analysis, revealed that the light chain’s high catalytic activity was observed when it was prepared under a basic condition. These data imply that a small structural modulation of the catalytic antibody occurs during the purification process to increase the catalytic activity while the antigen recognition ability is kept constant. The presence of NaCl enhanced the catalytic activity. When the catalytic light chain was prepared with these preferable conditions, #7TR and H34 hugely enhanced the degradation ability of Amyloid-beta and PD-1 peptide, respectively.

Organic thin-film transistors (OTFTs) are promising building blocks for low cost, low-environmental load, and lightweight electronic devices. Carbon-based conductors can be potentially used as TFT electrodes. However, a concern is that the carbon electrode is unsuitable for carrier injection into organic semiconductors due to the difficulty in precise work function control. Herein, we have demonstrated that molecular dopants in carbon networks can improve carrier injection with a reasonably low contact resistance of 510 Ω·cm, which constitutes a key step in the realization of noble-metal-free electronic devices.

Programmed cell death 1 (PD-1) is an immune checkpoint molecule regulating T-cell function. Preventing PD-1 binding to its ligand PD-L1 has emerged as an important tool in immunotherapy. Here, we describe a unique human catalytic antibody light chain, H34, which mediates enzymatic degradation of human PD-1 peptides and recombinant human PD-1 protein and thus functions to prevent the binding of PD-1 with PD-L1. H34 degraded one half of the PD-1 molecules within about 6 h under the experimental conditions. Investigating the acquisition of the catalytic function by H34, which belongs to subgroup I and lacks a Pro95 residue in CDR-3, revealed the importance of this sequence, as a Pro95-reconstituted mutant (H34-Pro95(+)) exhibited very little catalytic activity to cleave PD-1. Interestingly, EDTA inhibited the catalytic activity of H34, which could work as a metallo-protease. Zn2+ or Co2+ ions may work as a cofactor. It is meaningfull that H34 was obtained from the human antibody gene taken from a healthy volunteer, suggesting that we potentially have such unique molecules in our body., Programmed cell death 1 (PD-1) is an immune checkpoint regulating T-cell function. A catalytic antibody light chain, H34, could enzymatically degrade the PD-1 molecule. In addition, it inhibited the binding of PD-1 with PD-L1.

Since the discovery of a natural catalytic antibody in 1989, many catalytic antibodies targeting peptides, nucleotides, virus and bacterial proteins, and many molecules have been prepared. Although catalytic antibodies should have features superior to non‐catalytic monoclonal antibodies, the reports on catalytic antibodies are far fewer than those on normal (non‐catalytic) antibodies. Nowadays, we can obtain any monoclonal antibody we want, which is not the case for catalytic antibodies. To overcome this drawback of catalytic antibodies, much basic research must be done. As one way to attain this purpose, we have been making a protein bank of human antibody light chains, in which the light chains were expressed, purified, and stored for use in screening against many kinds of antigen, to then get clues to introducing a catalytic function in normal antibodies. As the number of stored light chains in the above protein bank has reached the hundreds, in this study, we screened them against amyloid‐beta (Aβ), which is well‐known as one of the molecules causing Alzheimer's disease. We found two interesting light chains, #7TR and #7GY. The former could degrade both a fluorescence resonance energy transfer‐Aβ substrate and Aβ1‐40 full peptide. In contrast, #7GY, whose sequence is identical to that of #7TR except for the amino acids at the 29th and 30th positions, did not degrade the FRET‐Aβ substrate at all. By using a synthetic substrate, Arg‐pNA, the difference between the chemical features of the two light chains was investigated in detail. In addition, we found that the presence of Zn(II) ion hugely influenced the catalytic activity of the #7TR light chain but not #7GY. Through these facts and the discussion, we propose one of the clues to how to put a catalytic function in a normal (non‐catalytic) antibody.

Mast cells play a pivotal role in allergic reactions and inflammations. Aggregation of the high affinity IgE receptor (FceRI) eventually leads to the release of granule components such as histamine, as well as the de novo synthesis of inflammatory cytokines and lipid mediators. These substances are involved in the development of allergy and inflammation. Therefore, efficient inhibitors of mast cell activation would be therapeutically beneficial. We previously demonstrated that the synthetic peptide derived from the NH2-terminal region (2-17: GNIFANLFKGLFGKKE) of a small GTPase ARF1 (ADP-ribosylation factor1) inhibited FceRI-induced mast cell degranulation. However, detailed structure-activity relationship study of NH2-terminal portion of ARF1 peptide has not been done. In addition, it is still unclear whether the NH2-terminal peptide of ARF1 suppresses FceRI-induced production of cytokines and lipid mediators such as leukotriene C4 (LTC4) from mast cells. Here we show that amino acid residues K10-K16 are necessary for ARF1 peptide to efficiently inhibit FceRI-induced activation of bone marrow-derived mast cells (BMMCs), indicated by decreased mast cell degranulation, cytokine secretion and leukotriene release. Furthermore, we show that ARF1 peptide inhibits IgE-mediated passive cutaneous anaphylaxis reaction. Our results suggest that the peptide derived from ARF1 could be developed into a novel anti-allergic agent for therapeutic intervention in allergy and mast cell-related pathologies.

We report a system for converting a monoclonal antibody to the corresponding catalytic antibody by deletion of Pro95., Over thousands of monoclonal antibodies (mAbs) have been produced so far, and it would be valuable if these mAbs could be directly converted into catalytic antibodies. We have designed a system to realize the above concept by deleting Pro95, a highly conserved residue in CDR-3 of the antibody light chain. The deletion of Pro95 is a key contributor to catalytic function of the light chain. The S35 and S38 light chains have identical amino acid sequences except for Pro95. The former, with Pro95 did not show any catalytic activity, whereas the latter, without Pro95, exhibited peptidase activity. To verify the generality of this finding, we tested another light chain, T99wt, which had Pro95 and showed little catalytic activity. In contrast, a Pro95-deleted mutant enzymatically degraded the peptide substrate and amyloid-beta molecule. These two cases demonstrate the potential for a new method of creating catalytic antibodies from the corresponding mAbs.

We report a case of rheumatoid arthritis (RA) developing after parvovirus B19 infection. A 30-year-old Japanese woman, who had no significant medical history admitted for tender erythema in the bil...

Understanding the mechanism responsible for the progression of amyloid deposition is important for developing methods to suppress this process in the treatment of Alzheimer's disease. The effects of physical damage during the transition phase of amyloid β fibril formation are unclear. In this study, we used high-speed atomic force microscopy to investigate the effects of damage to the intermediates of amyloid β in real time. Physical damage to intermediates did not suppress, but instead promoted fibrillization. This progression was accompanied by morphological changes from globular oligomers to protofibrils. These results suggest that the properties of the intermediates, such as structural fragility and stability, are highly related to the rate of fibrillization.

We report developing an activity-based probe containing an amyloid β peptide (Aβ) 17-27 and an electrophilic phosphonate diester at the C-terminus. A probe containing an electrophilic moiety is able to react with the nucleophiles on an antibody or an antibody with proteinase activity. The probe reacted with an Aβ specific monoclonal antibody and formed a covalent complex. The covalent binding also occurred specifically when the probe reacted with serum containing anti-Aβ antibodies. These results suggest that the probe would serve as a powerful tool to isolate Aβ specific antibodies that are capable of Aβ hydrolysis activity.

We introduce rare sugars including their derivatives and supramolecular rare sugars, that have been actively researched at Kagawa University, Japan. Although the rare sugars are special sugars which hardly exist in nature, we has succeeded in mass synthesis of the rare sugars by utilizing biological enzyme isomerization reaction. In addition, the rare sugars have various functions such as blood sugar level suppressing function, cancer cell growth suppressing function, and antibacterial action. In addition, since rare sugars have a large number of hydroxyl groups, they have a possibility for using as devices for expressing various functions by employing them as ligands of transition metal complexes. In recent years, it is successful that we have synthesized the suplamolecular rare sugars (SRSs) from the different types of rare sugars, that is not as simple mixtures but as single crystals having supralattice structure, that can be freely controlled optical rotation. It has been found that the crystal structures of these SRSs mostly follow the Wallach rule, but do not satisfy the Wallach rule especially in the case of D, L-psicose. Therefore, we have investigated the single crystal X-ray structural analyses of SRSs, obtaining the detailed crystal structure data, and analyzed the intermolecular interaction between their sugar molecules in the crystal by means of the DV-Xα molecular orbital calculation. According to our detailed analysis of the research, calculating the intermolecular interaction revealed that the stability of the intermolecular interaction in the crystal can not be explained only by following the simple Wallach rule. Specifically, for example in the case of D, L-psicose, the total energy in a crystal can be stabilized by aligning the polarization vectors of the molecules, and as a result, we have clarified that the SRSs crystal structure can be stabilized, even if it does not follow the simple Wallach rule.

Since a natural catalytic antibody found at 1989, many mouse- and human-type of catalytic antibodies cleaving the targeting antigens such as peptides, nucleotides, viruses and bacterial proteins, m...

A 66-year-old woman who had rheumatoid arthritis and underwent a long-term treatment with methotrexate and etanercept developed Pneumocystis jirovecii pneumonia (PCP) 3 months after iguratimod add-on. Although most rheumatologists might have the impression that iguratimod has less toxicity and immunosuppressive effect compared with methotrexate and biologic disease-modifying antirheumatic drugs, this case suggests that iguratimod may increase the risk of PCP, especially in combination with other drugs.

The racemic title compound, C6H12O6, consisting of C-4 epimers of psicose, was crystallized from an aqueous solution of an equimolar mixture of D- and L-sorboses. It was confirmed that D-sorbose (or L-sorbose) formed α-pyranose with a 4 C 1 (or 1 C 4) conformation where the anomer position was designated as carbon-1. The asymmetric unit comprises two crystallographically independent molecules. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming a three-dimensional framework. The unit-cell volume of the title racemic α-D,L-sorbose is 1450.86 (6) Å3 (Z = 8), which is about 41 Å3 smaller than that of twice the amount of chiral α-L-sorbose [V = 745.942 Å3 (Z = 4)].

We report a patient with leptospirosis caused by infection with Leptospira interrogans serovar Rachmati. A 30-year-old Japanese man took part in a survival camp on Iriomote Island, Okinawa, from July 9 to July 15, 2014. During the camp, he swam in the river and kayaked. He developed a high fever and fatigue 7 days after completing his trip and was admitted to our hospital on July 22. On admission, he complained of a posterior cervical pain and a loss of appetite. Laboratory findings revealed granulocytosis, mildly elevated AST and ALT levels, elevated BUN and Cr levels, and a significantly elevated CRP level. No pathogenic bacteria were isolated from blood, urine, or cerebrospinal fluid cultures. We included leptospirosis in the differential diagnosis because of the patient's history of participating in a survival camp on Iriomote Island. Minocycline 200 mg, p.o. showed an excellent efficacy. The Leptospira flagellar gene FlaB was detected using a cerebrospinal fluid PCR. A microscopic agglutination test (MAT) during the convalescent stage demonstrated significant increases in antibodies against L. interrogans serovar Rachmati, confirming the diagnosis of leptospirosis. A medical history including occupation and recent travel history, and an adequate specimen sampling are crucial for the accurate and early diagnosis of leptospirosis.

We report a case of acute generalized pustular bacterid (AGPB) concomitant with erythema nodosum (EN), polyarthritis, and Achilles tendinitis. The patient was admitted with a complaint of fever, widespread plural pustules, erythema, and polyarthralgia. Histopathological examination of the skin lesions demonstrated features of AGBP and EN. Although arthralgia and AGPB can be recognized together, EN and Achilles tendinitis are rare manifestations seen in patients with AGPB. In this case report, we suggest arthralgia, EN, and Achilles tendinitis could coexist with AGPB.

Issues regarding the structural diversity (heterogeneity) of an antibody molecule have been the subject of discussion along with the development of antibody drugs. Research on heterogeneity has been extensive in recent years, but no clear solution has been reached. Heterogeneity is also observed in catalytic antibody κ light chains (CLs). In this study, we investigated how the constant region domain of CLs concerns structural diversity because it is a simple and good example for elucidating heterogeneity. By means of cation-exchange chromatography, SDS-PAGE, and 2-dimensional electrophoresis for the CL, multimolecular forms consisting of different electrical charges and molecular sizes coexisted in the solution, resulting in the similar heterogeneity of the full length of CLs. The addition of copper ion could cause the multimolecular forms to change to monomolecular forms. Copper ion contributed greatly to the enrichment of the dimer form of CL and the homogenization of the differently charged CLs. Two molecules of the CL protein bound one copper ion. The binding affinity of the ion was 48.0 μM-1 Several divalent metal ions were examined, but only zinc showed a similar effect.-Hifumi, E., Taguchi, H., Kato, R., Uda, T. Role of the constant region domain in the structural diversity of human antibody light chains.

We previously reported that anti-amyloid-beta (Aβ) single-chain antibody (scFv59) brain delivery via recombinant adeno-associated virus (rAAV) was effective in reducing cerebral Aβ load in an Alzheimer's disease (AD) mouse model without inducing inflammation. Here, we investigated the prophylactic effects and mechanism of a muscle-directed gene therapy modality in an AD mouse model. We injected rAAV serotype 1 encoding scFv59 into the right thigh muscles of 3-month-old mice. Nine months later, high levels of scFv59 expression were confirmed in the thigh muscles by both immunoblotting and immunohistochemistry. As controls, model mice were similarly injected with rAAV1 encoding antihuman immunodeficiency virus Gag antibody (scFvGag). AAV1-mediated scFv59 gene delivery was effective in decreasing Aβ deposits in the brain. Compared with the scFvGag group, levels of Aβ in cerebrospinal fluid (CSF) decreased significantly while Aβ in serum tended to increase in the scFv59 group. AAV1-mediated scFv59 gene delivery may alter the equilibrium of Aβ between the blood and brain, resulting in an increased efflux of Aβ from the brain owing to antibody-mediated sequestration/clearance of peripheral Aβ. Our results suggest that muscle-directed scFv59 delivery via rAAV1 may be a prophylactic option for AD and that levels of CSF Aβ may be used to evaluate the efficacy of anti-Aβ immunotherapy.

The discovery of Toll-like receptors (TLRs) facilitated our understanding of the innate and adaptive immune systems, and has raised the potential to develop novel methods of vaccine and immunotherapy. For effective vaccination, antigens and adjuvants must be administered simultaneously via the same route. Many studies have demonstrated that TLR ligands covalently coupled to the antigens have several benefits over nonconjugated antigens. This review introduces the applications of TLR ligands as vaccine adjuvants, focusing on the development of vaccines composed of antigen and TLR ligand in single molecules (TLR ligand–antigen conjugates) using Pam3/2Cys, lipid A analogues, recombinant flagellin, imidazoquinoline analogues and unmethylated CpG motifs to activate immune systems through TLR2, TLR4, TLR5, TLR7/8 and TLR9, respectively.

Epidemic studies have shown that rheumatoid arthritis (RA) patients have shorter life expectancy than healthy persons, primarily due to cardiovascular events. The aim of our study was to explore inhibitory effects on atherosclerosis of RA patients by TNF-inhibitor etanercept (ETN). We studied six RA patients with moderate or high disease activity as defined by the European League Against Rheumatism (EULAR) disease activity score (DAS28-ESR) in spite of treatment with methotrexate (MTX) 8 mg/week. We measured their pulse wave velocity (PWV) before and after treatment with ETN 25 mg/week for one year. There were no additional medications other than ETN that might influence on atherosclerosis. Their PWV decreased in five of six patients and the average decreased from 1474.8 cm/sec to 1432.5 cm/sec. The average of DAS28-ESR score was significantly decreased from 5.56 to 2.87 and they achieved good response by the EULAR criteria. There were no significant changes in the blood pressure, serum lipid (total cholesterol and triglyceride) and HbA1c ; all values were within normal limits before and after ETN treatment. It is suggested that the improvement of PWV is due to anti-inflammatory effects, leading inhibition of atherosclerosis, of ETN in RA patients.

We describe murine monoclonal antibodies (mAbs) raised by immunization with an electrophilic gp120 analog (E-gp120) expressing the rare ability to neutralize genetically heterologous human immunodeficiency virus (HIV) strains. Unlike gp120, E-gp120 formed covalent oligomers. The reactivity of gp120 and E-gp120 with mAbs to reference neutralizing epitopes was markedly different, indicating their divergent structures. Epitope mapping with synthetic peptides and electrophilic peptide analogs indicated binary recognition of two distinct gp120 regions by anti-E-gp120 mAbs, the 421–433 and 288–306 peptide regions. Univalent Fab and single chain Fv fragments expressed the ability to recognize both peptides. X-ray crystallography of an anti-E-gp120 Fab fragment revealed two neighboring cavities, the typical antigen-binding cavity formed by the complementarity determining regions (CDRs) and another cavity dominated by antibody heavy chain variable (VH) domain framework (FR) residues. Substitution of the FR cavity VH Lys-19 residue by an Ala residue resulted in attenuated binding of the 421–433 region peptide probe. The CDRs and VH FR replacement/silent mutation ratios exceeded the ratio for a random mutation process, suggesting adaptive development of both putative binding sites. All mAbs studied were derived from VH1 family genes, suggesting biased recruitment of the V gene germ line repertoire by E-gp120. The conserved 421–433 region of gp120 is essential for HIV binding to host CD4 receptors. This region is recognized weakly by the FR of antibodies produced without exposure to HIV, but it usually fails to induce adaptive synthesis of neutralizing antibodies. We present models accounting for improved CD4-binding site recognition and broad HIV neutralizing activity of the mAbs, long sought goals in HIV vaccine development.

本稿は､元癌患者にたいする面接聴き取り調査から得られたナラティブ(語り) のデータを解釈学的に分析したものである｡本論文の第一のねらいは､一人の患者の徴候の自覚から手術を経過して5年後の寛解に至る過程を､病いの経験としてとらえ､トピック毎にその社会学的含意を明らかにすることである｡第二のねらいは､患者がこの過程において､どのような適応戦略を展開したかを､これらのトピックの分析を総合しながら明らかにすることである｡分析の結果､当の病いの経験の意味理解が､先行する病いの経験と分かちがたく結びついていること､先行する病いの経験に規定されていることが明らかにされた｡また､自らの人生を､一旦は失ったかもしれない生の残りとしての余生と位置づけ､患者が持てる文化資本を駆使しながら､生への執着のゆえではなく､つねに自らの生死の座標軸を確認しておきたいという欲求､自らが置かれている存在状況への強い好奇心の充足を基軸に､医師との交渉を状況に応じて柔軟に､かつねばりづよくすすめる適応戦略を展開した｡このことが結果的に効を奏し､癌から生還し､生き続けていることが明らかにされた｡

Immunoglobulins (Igs) in uninfected humans recognize residues 421–433 located in the B cell superantigenic site (SAg) of the HIV envelope protein gp120 and catalyze its hydrolysis by a serine protease-like mechanism. The catalytic activity is encoded by germline Ig variable (V) region genes, and is expressed at robust levels by IgMs and IgAs but poorly by IgGs. Mucosal IgAs are highly catalytic and neutralize HIV, suggesting that they constitute a first line of defense against HIV. Lupus patients produce the Igs at enhanced levels. Homology of the 421–433 region with an endogenous retroviral sequence and a bacterial protein may provide clues about the antigen driving anti-SAg synthesis in lupus patients and uninfected subjects. The potency and breadth of HIV neutralization revives hopes of clinical application of catalytic anti-421–433 Igs as immunotherapeutic and topical microbicide reagents. Adaptive improvement of anti-SAg catalytic Igs in HIV infected subjects is not customary. Further study of the properties of the naturally occurring anti-SAg catalytic Igs should provide valuable guidance in designing a prophylactic vaccine that amplifies protective catalytic immunity to HIV.

The antigen-binding sites of antibodies (Abs) can express enzyme-like nucleophiles that react covalently with electrophilic compounds. We examined the irreversible and specific inactivation of antibodies (Abs) to Factor VIII (FVIII) responsible for failure of FVIII replacement therapy in hemophilia A (HA) patients. Electrophilic analogs of FVIII (E-FVIII) and its C2 domain (E-C2) were prepared by placing the strongly electrophilic phosphonate groups at surface-exposed Lys side chains of diverse antigenic epitopes. IgG Abs to FVIII from HA patients formed stable immune complexes with E-FVIII and E-C2 that were refractory to dissociation by SDS treatment and boiling, procedures that dissociate noncovalent Ab-antigen complexes. The rate-limiting step in the reaction was formation of the initial noncovalent complexes. Conversion of the initial complexes to the irreversible state occurred rapidly. The antigenic epitopes of E-FVIII were largely intact, and most of the Abs were consumed covalently. E-FVIII expressed poor FVIII cofactor activity in clotting factor assays. Nonspecific interference by E-FVIII in clotting factor function was not evident. Treatment with E-FVIII, and to a lesser extent E-C2, irreversibly relieved the FVIII inhibitory effect of HA IgG in clotting factor assays. Small FVIII peptides did not display useful reactivity, highlighting the diverse epitope specificities of the Abs and the conformational character of FVIII epitopes. E-FVIII is a prototype reagent able to attain irreversible and specific inactivation of pathogenic Abs.

Immunoglobulins (Igs) that bind amyloid beta peptide (Abeta) are under clinical trials for immunotherapy of Alzheimer disease (AD). We have identified IgMs and recombinant Ig fragments that hydrolyze Abeta. Hydrolysis of peripheral Abeta by the IgMs may induce increased Abeta release from the brain. The catalytic IgMs are increased in AD patients, presumably reflecting a protective autoimmune response. Reduced Abeta aggregation and neurotoxicity attributable to the catalytic function were evident. These findings provide a foundation for development of catalytic Igs for AD immunotherapy.

Any strong earthquake as a stressor brings not only a lot of harmful effects to our lifeline in a moment, but also gives strong damages to different systems of individual, family and local community. It leads to even functional disorder or dysfunction of each system. The social system, however, restores the balance and is regenerated in consequence of a kind of homeostasis. This essay aims to examine the social process of restoration from the point of view of resilience which shows the power of system coping with crisis. Our findings are as follws. First, individual personality system with resilience could cope with serious crisis, reconstructing the meaning of life. Secondly, family system with resilience could enhance the level of cohesion, coping to the situations of difficulty. Thirdly, local community with resilience could cooperate with outside many associations and social network, recover eventually, and furthemore establish symbolic revival. But these findings are not nonclusive.

We describe IgM class human autoantibodies that hydrolyze amyloid beta peptide 1-40 (Abeta40). A monoclonal IgM from a patient with Waldenström's macroglobulinemia hydrolyzed Abeta40 at the Lys-28-Gly-29 bond and Lys-16-Ala-17 bonds. The catalytic activity was inhibited stoichiometrically by an electrophilic serine protease inhibitor. Treatment with the catalytic IgM blocked the aggregation and toxicity of Abeta40 in neuronal cell cultures. IgMs purified from the sera of patients with Alzheimer disease (AD) hydrolyzed Abeta40 at rates superior to IgMs from age-matched humans without dementia. IgMs from non-elderly humans expressed the least catalytic activity. The reaction rate was sufficient to afford appreciable degradation at physiological Abeta and IgM concentrations found in peripheral circulation. Increased Abeta concentrations in the AD brain are thought to induce neurodegenerative effects. Peripheral administration of Abeta binding antibodies has been suggested as a potential treatment of AD. Our results suggest that catalytic IgM autoantibodies can help clear Abeta, and they open the possibility of using catalytic Abs for AD immunotherapy.

Antibody hydrolysis of the superantigenic gp120 site and HIV-1 neutralization was studied as a potential anti-HIV mechanism in uninfected humans. gp120 hydrolysis by purified serum and salivary antibodies was determined by electrophoresis and peptide sequencing, the proteolytic mechanism was analyzed using electrophilic peptide analogs, and viral neutralization was studied using peripheral blood mononuclear cells as hosts. Polyclonal and monoclonal IgA but not IgG preparations selectively catalyzed the cleavage of HIV gp120 at rates sufficient to predict biologically relevant protection against the virus. The IgA hydrolytic reaction proceeded by noncovalent recognition of gp120 residues 421-433, a component of the superantigenic site of gp120, coordinated with peptide bond cleavage via a serine protease-like mechanism. The Lys-432-Ala-433 bond was one of the cleavage sites. Infection of peripheral blood mononuclear cells by a primary isolate of HIV was neutralized by the IgA but not IgG fractions. The neutralizing activity was specifically inhibited by an electrophilic inhibitor of the catalytic activity. The existence of catalytic IgAs to gp120 in uninfected humans suggests their role in resistance to HIV.

Rare monoclonal antibodies (Abs) can form irreversible complexes with antigens by enzyme-like covalent nucleophile-electrophile pairing. To determine the feasibility of applying irreversible antigen inactivation by Abs as the basis of vaccination against microbes, we studied the polyclonal nucleophilic Ab response induced by the electrophilic analog of a synthetic peptide corresponding to the principal neutralizing determinant (PND) of human immunodeficiency virus type-1 (HIV) gp120 located in the V3 domain. Abs from mice immunized with the PND analog containing electrophilic phosphonates (E-PND) neutralized a homologous HIV strain (MN) ∼50-fold more potently than control Abs from mice immunized with PND. The IgG fractions displayed binding to intact HIV particles. HIV complexes formed by anti-E-PND IgG dissociated noticeably more slowly than the complexes formed by anti-PND IgG. The slower dissociation kinetics are predicted to maintain long-lasting blockade of host cell receptor recognition by gp120. Pretreatment of the anti-PND IgG with a haptenic electrophilic phosphonate compound resulted in more rapid dissociation of the HIV-IgG complexes, consistent with the hypothesis that enhanced Ab nucleophilic reactivity induced by electrophilic immunization imparts irreversible character to the complexes. These results suggest that electrophilic immunization induces a sufficiently robust nucleophilic Ab response to enhance the anti-microbial efficacy of candidate polypeptide vaccines.

IgG class antibodies express catalytic activities rarely and at very low levels. Here, we studied polyclonal IgA and IgG preparations from healthy human sera and saliva for the ability to hydrolyze model peptidyl-aminomethylcoumarin (peptide-AMC) substrates. These substrates permit objective evaluation of the catalytic potential of the antibody classes with minimal effects of noncovalent interactions occurring at sites remote from the reaction center. The IgA preparations hydrolyzed Glu-Ala-Arg-AMC at rates 3-orders of magnitude greater than IgG preparations from the same individuals. The cleavage occurred preferentially on the C terminal side of a basic residue. The activity was confirmed using monoclonal IgAs isolated from patients with multiple myeloma. Active site-directed inhibitors of serine proteases inhibited the catalytic activity and were bound irreversibly by the IgA, suggesting the involvement of a serine protease-like mechanism similar to that utilized by previously described IgM antibodies. These observations suggest that mechanisms underlying B cell clonal selection favor the retention and improvement of catalytic activity in the IgA, but not the IgG compartment of the immune response.

Antibodies (Abs) to the superantigenic determinant of HIV gp120 (gp120(SAg)) are potential protective agents against HIV infection. We report that the light chain subunits of Abs cloned from lupus patients using phage library methods bind and hydrolyze gp120(SAg) independent of the heavy chain. Unlike frequent gp120(SAg) recognition by intact Abs attributable to V(H) domain structural elements, the isolated light chains expressed this activity rarely. Four light chains capable of gp120(SAg) recognition were identified by fractionating phage displayed light chains using peptide probes containing gp120 residues 421-433, a gp120(SAg) component. Three light chains expressed non-covalent gp120(SAg) binding and one expressed gp120(SAg) hydrolyzing activity. The hydrolytic light chain was isolated by covalent phage fractionation using an electrophilic analog of residues 421-433. This light chain hydrolyzed a reporter gp120(SAg) substrate and full-length gp120. Other peptide substrates and proteins were hydrolyzed at lower rates or not at all. Consistent with the expected nucleophilic mechanism of hydrolysis, the light chain reacted selectively and covalently with the electrophilic gp120(SAg) peptide analog. The hydrolytic reaction entailed a fast initial step followed by a slower rate limiting step, suggesting rapid substrate acylation and slow deacylation. All four gp120(SAg)-recognizing light chains contained sequence diversifications relative to their germline gene counterparts. These observations indicate that in rare instances, the light chain subunit can bind and hydrolyze gp120(SAg) without the participation of the heavy chain. The pairing of such light chains with heavy chains capable of gp120(SAg) recognition represents a potential mechanism for generating protective Abs with enhanced HIV binding strength and anti-viral proteolytic activity.

第一に、癌に罹患した高齢者が地域社会や家族、そして最終的には医師との相互作用を通して患者になっていく社会過程、第二に、当の患者とその家族による情報収集と意思決定の過程を、語りの分析を通して明らかにすることを目的にしている。

The title compound, C6H12O5, was crystallized from an aqueous solution of 6-deoxy-L-psicose (6-deoxy-L-allulose, (3S,4S,5S)-1,3,4,5-tetrahydroxyhexan-2-one), and the molecule was confirmed as α-furanose with a3T4(orE4) conformation, which is a predominant tautomer in solution. This five-membered furanose ring structure is the second example in the field of the 6-deoxy-ketohexose family. The cell volume of the title compound [742.67 (7) Å3,Z= 4 at room temperature] is only 1.4% smaller than that of β-D-psicopyranose, C6H12O6(753.056 Å3,Z= 4 at room temperature).

Generally, small peptides by themselves are weak to induce antibody responses. Toll-like receptor (TLR) ligands are attractive candidates of vaccine adjuvants to improve their antigenicity. The covalent conjugation of TLR ligands with antigens to produce self-adjuvanting peptide vaccine is a promising approach. Based on the structure of TLR7/8 ligands, a series of synthetic amino acids 6-imidazoquinolyl-norleucines were synthesized, wherein an imidazoquinoline structure as the TLR7/8 agonistic pharmacophores was constructed on the e-NH2 group of Lys. Of them, 6-(4-amino-2-butyl-imidazoquinolyl)-norleucine showed the most potent TLR7 and TLR8 agonistic activities with EC50 values of 8.55 and 106 μM, respectively. Subsequently, mice were immunized with the influenza A virus M2e antigen mixed with or covalently conjugated to the TLR7/8 agonist amino acid, which led to induction of M2e specific antibody productions in the absence of other adjuvant. We successfully developed a novel efficient tool for self-adjuvanting peptide vaccines targeting TLR7/8.