RANTES and macrophage inflammatory protein 1 alpha selectively enhance immunoglobulin (IgE) and IgG4 production by human B cells

We studied the effects of various chemokines including neutrophil- activating peptide 2 (NAP-2), beta-thromboglobulin (beta-TG), platelet factor 4 (PF-4), melanoma growth stimulating activity (GRO), gamma interferon-induced protein (IP-10), regulated on activation, normal T expressed and secreted (RANTES), macrophage inflammatory protein 1 alpha (MIP-1 alpha), MIP-1 beta, and monocyte chemotactic protein 1 (MCP-1) on Immunoglobulin (IgE) and IgG4 production by human B cells. None of these chemokines with or without interleukin (IL-4), anti-CD40 or -CD58 monoclonal antibody (mAb), induced IgE and IgG4 production by B cells from nonatopic donors. However, RANTES and MIP-1 alpha selectively enhanced IgE and IgG4 production induced by IL-4 plus anti- CD40 or -CD58 mAb without affecting production of IgM, IgG1, IgG2, IgG3, IgA1, or IgA2, whereas other chemokines failed to do so. Enhancement of IgE and IgG4 production by RANTES and MIP-1 alpha was specifically blocked by anti-RANTES mAb and anti-MIP-1 alpha antibody (Ab), respectively, whereas anti-IL-5 mAb, anti-IL-6 mAb, anti-IL-10 Ab, anti-IL-13 Ab, and anti-tumor necrosis factor-alpha mAb failed to do so. Purified surface IgE positive (slgE4) and slgG4+ B cells generated either in vitro or in vivo spontaneously produced IgE and IgG4, respectively, whereas sIgE- and sIgG4- B cells failed to do so. RANTES and MIP-1 alpha enhanced spontaneous IgE and IgG4 production in slgE+ and slgG4- B cells, respectively, whereas neither RANTES nor MIP- 1 alpha did so in sIgE- or sIgG4- B cells. Purified sIgE4+ and sIgG4+, but not sIgE- or sIgG4- B cells, generated in vitro and in vivo expressed receptors for RANTES and MIP-1 alpha, whereas they failed to express receptors for other chemokines. These findings indicate that RANTES and MIP-1 alpha enhance IgE and IgG4 production by directly stimulating sIgE+ and sIgG4+ B cells.     

Interleukin 8 (IL-8) selectively inhibits immunoglobulin E production induced by IL-4 in human B cells

The effect of interleukin 8 (IL-8) on IL-4-induced immunoglobulin E (IgE) production was studied. IL-4 induced IgE and IgG4 production by tonsillar mononuclear cells (MNC) without affecting IgM, IgG1, IgA, IgG2, or IgG3 production. IL-8 inhibited IL-4-induced IgE and IgG4 production, whereas it had no effect on IgM, IgG1, IgA, IgG2, and IgG3 production. The inhibitory effect by IL-8 was specific, since it was blocked by anti-IL-8 mAb, but not by control IgG1. Although interferon gamma (IFN-gamma) also inhibited IgE and IgG4 production by MNC stimulated with IL-4, the inhibitory effect of IL-8 was not mediated by IFN-gamma, since the IL-8-induced inhibition could not be blocked by anti-IFN-gamma. Furthermore, anti-IL-8 mAb had no effect on IFN-gamma-induced inhibition. Moreover, addition of IL-5 or IL-6 did not reverse IL-8-induced inhibition of IgE production. In contrast to these observations with MNC, IL-4 failed to induce IgE and IgG4 production by purified B cells. However, combined treatment of purified B cells cells with IL-4 and anti-CD40 antibody resulted in IgE but not IgG4 production. IL-8 inhibited this IgE production without affecting IgM, IgG1, IgG2, IgG3, IgG4, or IgA production, whereas IFN-gamma, IFN-alpha, or prostaglandin E2 (PGE2) failed to do so. These results indicate that IL-8 antagonizes IL-4-induced IgE production by directly affecting B cells through a specific mechanism that is different from IFN-gamma, IFN-alpha, or PGE2.     

Generation of human monoclonal allergen-specific IgE and IgG antibodies from synthetic antibody libraries

BACKGROUND: Allergen-specific IgE and IgG antibodies play pivotal roles in the induction and progression of allergic hypersensitivity reactions. Consequently, monoclonal human IgE and IgG4 antibodies with defined specificity for allergens should be useful in allergy research and diagnostic tests. We used combinatorial antibody libraries and subsequent recombinant production to make and assess IgE, IgG1, and IgG4 allergen-specific antibodies. METHODS: We used phage display to select a synthetic single-chain antibody fragment (scFv) library against 3 different allergens, from bee venom, bovine milk, and apple. The scFv obtained were converted into IgG1, IgG4, and IgE antibody formats and assessed for their biochemical properties by ELISA, immunoblotting, and fluorescence-activated cell sorting. RESULTS: Two different antibody formats for each IgG1, IgG4, and IgE antibody were produced in mammalian cells as disulfide-linked and glycosylated Ig, which were usable in allergen-specific ELISA assays and immunoblots. In addition, the recombinant IgE antibodies mediated the binding of allergens to HEK-293 cells transfected with the high-affinity IgE receptor, and this binding was blocked by corresponding IgG antibodies. CONCLUSIONS: The use of synthetic libraries for the generation of allergen-specific recombinant IgE and IgG antibodies should have broad applications in allergological research and diagnosis.     

CD40 and IgE: synergism between anti-CD40 monoclonal antibody and interleukin 4 in the induction of IgE synthesis by highly purified human B cells

A novel pathway of IgE-B cell differentiation has been identified. Engagement of the B cell antigen CD40 by F(ab')2 fragments of monoclonal antibody (mAb) 626.1 in the presence of recombinant interleukin 4 (rIL-4) induced intense IgE synthesis, but modest IgG synthesis, by highly purified human B cells. Surface IgE- B cells isolated by cell sorting were induced to produce IgE by mAb 626.1 and IL-4. Thus, IgE synthesis is unlikely to result from expansion of a B cell population precommitted to IgE in vivo. A neutralizing anti-IL-6 antibody strongly, but not completely, inhibited the IgE response. This indicates that autocrine production of IL-6 plays an important amplification role in IgE synthesis triggered by anti-CD40 mAb and IL-4. Although the exact role played by CD40 in IgE responses in vivo remains to be established, this T cell-independent system represents a useful model to characterize the biochemical and molecular events leading to IgE synthesis in human B cells.     

Multiple organ-reactive IgG antibody induced by an antiidiotypic antibody to a human monoclonal IgM autoantibody

MOR-h1 is a human multiple organ-reactive (MOR) monoclonal autoantibody (Ab1) that reacts with human growth hormone (hGH) and a 35 kD protein found in the anterior pituitary, thyroid, stomach, and pancreas. 4E6 is a mouse monoclonal anti-idiotypic antibody (Ab2) that reacts with the paratope of MOR-h1 and is ligand inhibitable. In the present study, we immunized a rabbit with 4E6 and purified an IgG fraction (anti-4E6) from the sera. Competitive inhibition experiments showed that anti-4E6 (Ab3) binds to the same epitope on 4E6 and to the same antigens (i.e., hGH and 35 kD protein) as does MOR-h1. By immunofluorescence, anti-4E6, an IgG antibody, shows the same multiple organ reactivity with tissues as does MOR-h1, an IgM antibody. From these and other studies, we conclude that the 4E6 paratope (Ab2) has a conformational resemblance to an epitope on hGH and the 35 kD protein. This raises the possibility that antibodies made in response to certain anti-idiotypic antibodies may be one of the mechanisms for triggering an autoimmune response.     

抗CD3单克隆抗体对人CD4^＋CD25^＋T淋巴细胞凋亡和自噬的影响

目的观察抗CD3单克隆抗体对分离培养的人外周血CD4^＋CD25^＋T淋巴细胞自噬、凋亡及其分泌的代表性因子转化生长因子β（TGF-β）的影响。方法采用密度梯度离心法及尼龙棉柱法分离32例健康者外周血T淋巴细胞,磁性细胞分离器（MACS）分离得到CD4^＋CD25^＋T淋巴细胞,分别利用电镜及流式细胞仪观察、检测各组（抗CD3单克隆抗体1mg/L组、IgG1同型抗体对照组）干预72h后细胞的凋亡率、自噬率,用ELISA法检测细胞培养上清液中细胞因子TGF-β的水平。结果抗CD3单克隆抗体组CD4^＋CD25^＋T淋巴细胞自噬率、凋亡率及TGF-β水平均增加（均P〈0.01）,凋亡率和自噬率之间无相关性（P〉0.05）。结论抗CD3单克隆抗体可促进CD4^＋CD25^＋T淋巴细胞凋亡和自噬及TGF-β分泌,且自噬与凋亡间相互独立。     

IgE and IgG antibody against human (recombinant DNA) insulin in patients with systemic insulin allergy

We demonstrated IgE and IgG antibodies to human (rDNA) insulin as well as to bovine and porcine insulin in the serum of two patients with systemic insulin allergy by an enzyme-linked immunosorbent assay. We also demonstrated IgE and total antibody binding to bovine insulin with the use of radioimmunoassays. Both patients had cutaneous reactivity to all three insulins. When the serum of one patient was preincubated with human, porcine, or bovine insulin, there was inhibition of binding of the patient's IgE and IgG antibodies to human insulin. The other patient had very low levels of IgE antibodies to insulin and thus only IgG inhibition was possible. Preincubation with human insulin inhibited binding of each patient's antibodies to bovine or porcine insulin. We conclude that, for these two patients, human insulin has all the antigenic determinants that bovine and porcine insulin have. Therefore, human insulin for these two patients will not eliminate insulin allergy in all patients with systemic allergy to animal insulin, because there are patients whose antibodies recognize determinants common to commercial human, bovine, and porcine insulin.     

An interleukin 4 (IL-4) mutant protein inhibits both IL-4 or IL-13- induced human immunoglobulin G4 (IgG4) and IgE synthesis and B cell proliferation: support for a common component shared by IL-4 and IL-13 receptors

Interleukin 4 (IL-4) and IL-13 share many biological functions. Both cytokines promote growth of activated human B cells and induce naive human surface immunoglobulin D+ (sIgD+) B cells to produce IgG4 and IgE. Here we show that a mutant form of human IL-4, in which the tyrosine residue at position 124 is replaced by aspartic acid (hIL- 4.Y124D), specifically blocks IL-4 and IL-13-induced proliferation of B cells costimulated by anti-CD40 mAbs in a dose-dependent fashion. A mouse mutant IL-4 protein (mIL-4.Y119D), which antagonizes the biological activity of mouse IL-4, was ineffective. In addition, hIL- 4.Y124D, at concentrations of up to 40 nM, did not affect IL-2-induced B cell proliferation. hIL-4.Y124D did not have detectable agonistic activity in these B cell proliferation assays. Interestingly, hIL- 4.Y124D also strongly inhibited both IL-4 or IL-13-induced IgG4 and IgE synthesis in cultures of peripheral blood mononuclear cells, or highly purified sIgD+ B cells cultured in the presence of anti-CD40 mAbs. IL-4 and IL-13-induced IgE responses were inhibited > 95% at a approximately 50- or approximately 20-fold excess of hIL-4.Y124D, respectively, despite the fact that the IL-4 mutant protein had a weak agonistic activity. This agonistic activity was 1.6 +/- 1.9% (n = 4) of the maximal IgE responses induced by saturating concentrations of IL-4. Taken together, these data indicate that there are commonalities between the IL-4 and IL-13 receptor. In addition, since hIL-4.Y124D inhibited both IL-4 and IL-13-induced IgE synthesis, it is likely that antagonistic mutant IL-4 proteins may have potential clinical use in the treatment of IgE-mediated allergic diseases.     

The cysteine protease activity of the major dust mite allergen Der p 1 selectively enhances the immunoglobulin E antibody response

The house dust mite Dermatophagoides pteronyssinus allergen Der p 1 is the most immunodominant allergen involved in the expression of dust mite-specific immunoglobulin (Ig)E-mediated hypersensitivity. The reason for this potent IgE-eliciting property of Der p 1 remains unknown, but there is mounting in vitro evidence linking the allergenicity of Der p 1 to its cysteine protease activity. Here we demonstrate for the first time that immunization of mice with proteolytically active Der p 1 results in a significant enhancement in total IgE and Der p 1-specific IgE synthesis compared with animals immunized with Der p 1 that was irreversibly blocked with the cysteine protease inhibitor E-64. We conclude that the proteolytic activity of Der p 1 is a major contributor to its allergenicity.     

阿霉素增强抗人DR5单克隆抗体mDRA-6诱导HL-60细胞凋亡的作用

目的观察抗死亡受体5（DR5）单克隆抗体（单抗）mDRA-6与阿霉素（Adr）对HL-60细胞的协同杀伤作用。方法用DR5蛋白免疫BALB／c小鼠，融合筛选抗DR5杂交瘤细胞，制备抗人DR5单抗mDRA-6；流式细胞术测定Adr对HL-60细胞表面DR5表达的影响；荧光显微镜下观察mDRA-6与Adr协同作用下HL-60细胞的形态变化；MTT法测定1μg／ml Adr与不同浓度的mDRA-6对HL-60细胞存活的影响；琼脂糖凝胶电泳检测mDRA-6与Adr联合对HL-60细胞DNA片断化的影响。结果Adr诱导HL-60细胞表面DR5表达，mDRA-6作用后HL-60细胞出现染色质浓缩、断裂，细胞出芽，凋亡小体形成，mDRA-6与Adr联用细胞形态变化更明显；mDRA-6与Adr对HL-60细胞具有明显的协同杀伤作用，20ng／ml的mDRA-6作用HL-60细胞10h，细胞死亡率为9．32％，1μg／mlAdr作用HL-60细胞10h，细胞死亡率为17.47％，20ng／ml mDRA-6联合1μg／mlAdr，可使HL-60细胞死亡率增至65．06％；20μg／ml mDRA-6与1μg／mlAdr联合作用于HL-60细胞3h，DNA琼脂糖凝胶电泳显示明显“梯形”条带。结论抗DR5单抗mDRA-6与Adr对HL-60细胞具有强大的协同杀伤作用。     

Heterogeneity among human collagenases demonstrated by monoclonal antibody that selectively recognizes and inhibits human neutrophil collagenase

The heterogeneity of human collagenases has been examined using a monoclonal antibody to neutrophil collagenase. This antibody inhibited collagenase activity and, when covalently coupled to Sepharose, bound both latent and active enzyme. Although human neutrophil collagenase was inhibited by the antibody, the activity of human skin and rheumatoid synovial collagenase was not significantly diminished in the presence of the antibody. Competitive inhibition studies also differentiated between these collagenases. Only human neutrophil collagenase effectively blocked the antibody in a competitive enzyme-linked immunosorbent assay while skin and rheumatoid synovial collagenase again failed to interact with the antibody. The unequivocal recognition of neutrophil collagenase as an immunologically distinct entity from other collagenases supports the hypothesis that neutrophil collagenase is a separate gene product from fibroblast or synovial collagenase.     

Synergistic in vitro antiretroviral activity of a humanized monoclonal anti-CD4 antibody (TNX-355) and enfuvirtide (T-20)

Recently, antiretroviral agents directed at several steps involved in viral entry have been shown to reduce viral replication in vitro and in vivo. We have demonstrated a high level of in vitro synergistic antiretroviral activity for two entry inhibitors that are directed at sequential steps in the entry process.     

Familial human short-term sensitizing (IgG S-TS) antibody

Skin tests on a middle-aged English housewife (the initial case) with a history of seasonal grass pollen rhinitis and asthma showed strong immediate and late reactions to grass pollens. Early in the grass pollen season, 1976, RAST showed normal levels of IgE antibodies in the serum. Passive transfer in Rhesus monkey skin was also negative for heat-labile IgE but gave a very vigorous reaction for short-term sensitizing heat-stable IgG antibody (IgG S-TS Ab). Skin tests and studies on sera from other members of the family showed that another five also formed IgG S-TS Ab, and indicated that the ability to form this antibody was familial. One member of the family had only an immediate reaction on skin testing, and much IgE to grass pollen. Towards the end of the grass pollen season the IgE titre in the initial case had been tripled and the IgG S-TS Ab had disappeared. By September the specific IgE titre had risen even further.     

Immunochemical and functional characterization of anti-idiotypic antibodies to a mouse anti-CD4 monoclonal antibody

Summary Immunization of BALB/c mice with the mouse anti-CD4 monoclonal antibody (mAb) HP2/6 resulted in the production of anti-idiotypic antibodies. Analysis of the kinetics of the development of anti-idiotypic antibodies showed a homogeneous response among the immunized animals. Cross-blocking assays performed with anti-CD4 mAbs OKT4, OKT4c and OKT4d showed that syngeneic anti-idiotypic antiserum elicited with mAb HP2/6 recognizes idiotope(s) expressed only on the immunizing mAb. The idiotope(s) is (are) located within or closely related to the antigen-combining site of mAb HP2/6. Hybridization with the myeloma cell line NSO of splenocytes from a BALB/c mouse hyperimmunized with mAb HP2/6 generated the anti-idiotypic mAbs F11-2113, F11-2302 and F11-2444 which recognize idiotope(s) outside the antigen-combining site of mAb HP2/6. Although the anti-idiotypic mAbs cross-inhibit each other in their binding to mAb HP2/6, they differ in the ability to elicit anti-anti-idiotypic antisera. Furthermore, mAb F11-2113 enhances CD4 down-regulation in the presence of mAb HP2/6 to a larger extent than mAbs F11-2302 and F11-2444. The latter results suggest an additional mechanism by which anti-idiotypic antibodies may induce functional abnormalities of CD4⁺ T cells in human immunodeficiency virus-infected T cells.     

Allergen-induced inflammation and the role of immunoglobulin E (IgE).

The prevalence of common allergic disorders such as asthma, allergic rhinitis, and atopic dermatitis has increased significantly in the past 30 years. The impact of these atopic diseases on the patient and the health care system is considerable: Allergic disorders are associated with a high degree of morbidity, which can profoundly impact patient quality of life and health care resource use. Existing strategies to treat allergic disorders beyond simple allergen avoidance focus on diminishing or eliminating the recurrent and/or persistent signs and symptoms that characterize the allergic response. A new strategy has been developed that uses antibodies directed against immunoglobulin E (IgE) to prevent it from binding to cells bearing its receptors and thus neutralizing the allergic response before it begins. These new agents reduce allergic responses in atopic individuals and improve their symptoms while reducing rescue medication and corticosteroid use in patients with allergic asthma or seasonal allergic rhinitis. Thus, anti-IgE antibodies represent proof that IgE plays a central role in allergic reactions and that anti-IgE therapy is a potentially effective treatment for allergic disease.     

Stimulation with a monoclonal antibody (mAb4E4) of scavenger receptor-mediated uptake of chemically modified low density lipoproteins by THP-1-derived macrophages enhances foam cell generation.

mAb4E4, a murine monoclonal antibody that is specific for acetylated LDL and malondialdehyde-treated LDL, binds specifically to modified LDL present in human atherosclerotic lesions. It is directed against an epitope that is poorly exposed in delipidated and solubilized apolipoprotein B-100 from modified LDL. mAb4E4, as well as its F(ab')2 and Fab fragments, enhanced the uptake of both acetylated LDL and malondialdehyde-treated LDL by THP-1-derived macrophages resulting in a sixfold increase of cytoplasmic cholesteryl ester levels. The increased uptake of modified LDL/mAb4E4 complexes did not occur via the Fc receptor and did not depend on aggregation of modified LDL particles. However, their uptake was inhibited by blocking the scavenger receptors with fucoidin or by downregulation of receptor expression with endotoxins or interferon-gamma, indicating that their uptake is mediated via these receptors. Thus, generation of autoimmune antibodies against modified LDL and subsequent endocytosis of soluble modified LDL/antibody complexes via scavenger receptors may enhance foam cell generation. This mechanism may contribute to the progression of atherosclerotic lesions.     

Independent regulation of DNA recombination and immunoglobulin (Ig) secretion during isotype switching to IgG1 and IgE

Induction of switch recombination to the gamma 1 and epsilon immunoglobulin (Ig) heavy chain loci was examined in B cells preactivated with anti-Ig (B lymphoblasts). In B lymphoblasts cultured with interleukin 4 (IL-4), IL-5 induced the accumulation of S micro-S gamma 1 rearrangements, but not epsilon recombination. Thus, IL-5 facilitates switch recombination directed to the gamma 1 heavy chain locus by IL-4, but additional signals are required to drive rearrangements to epsilon. Lipopolysaccharide (LPS), in the presence of IL-4, induced the accumulation of both S micro-S gamma 1 and S micro-S epsilon rearrangements, and cells treated with LPS exhibited 40-50-fold more S micro-S gamma 1 rearrangements than cells cultured with IL-5. Induction of switch recombination was not always associated with secretion of the respective Ig isotype, since concentrations of IL-4 that were sufficient to direct switch recombination to gamma 1 and epsilon in blasts treated with LPS failed to elicit secretion of IgG1 and IgE. These results demonstrate differential requirements for switch recombination to the gamma 1 and epsilon loci, as well as independent regulation of Ig gene rearrangement and secretion of each isotype.     

Passive immunization with the anti-HIV-1 human monoclonal antibody (hMAb) 4E10 and the hMAb combination 4E10/2F5/2G12

OBJECTIVES: To study the safety, immunogenicity and pharmacokinetics of the human monoclonal antibody (hMAb) 4E10 alone and in combination with the hMAbs 2F5 and 2G12 in HIV-1-infected persons. MATERIALS AND METHODS: Eight healthy volunteers with > or =350 CD4 cells/mm3 and < or =100 000 HIV-1 RNA copies/mL were enrolled, seven finished the study. A single 4E10 infusion was administered on day 0, followed by three doses of the hMAb combination 4E10/2F5/2G12 on days 7, 14 and 21 (total amount 8.5 g). Safety was assessed by physical examination, blood chemistry, complete blood cell count and recording of adverse events. 4E10, 2F5 and 2G12 plasma levels were determined before and at the end of each infusion and during the 7 week follow-up. RESULTS: No drug-related adverse events were observed throughout the study. The median plasma concentrations immediately after the first infusion were 371, 253 and 139 microg/mL for 4E10, 2F5 and 2G12. Multiple infusions resulted in maximum plasma concentrations of 407, 294 and 210 microg/mL for 4E10, 2F5, and 2G12, respectively. The median elimination half-lives (t1/2beta) were 6.6, 3.2 and 14.1 days for 4E10, 2F5 and 2G12. A low level antibody response against 2G12 was found in two patients. CONCLUSION: This Phase I trial showed that the hMAb 4E10 can be safely administered, both alone and in combination with 2F5 and 2G12 to HIV-1-infected patients.