摘要:

The authors examined the mechanism by which the non‐specific lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) inhibits human lymphocyte proliferative responses and compared its effects with those of cyclosporine (CsA). It was found that CsA‐resistant proliferative responses induced by direct PK‐C activators such as mitogenic concentrations of the phorbol ester TPA or the putative anti‐tumour agent bryostatin 1 (bryo 1) were inhibited in a concentration‐dependent manner by NDGA (IC50 = 2 μM). In contrast, CsA‐sensitive IL‐2‐dependent proliferative responses induced by PHA, anti‐CD3 or the purified protein derivative (PPD) ofM. tuberculosiswere not significantly inhibited by NDGA concentrations as high as 8 μM. The expression of the IL‐2R by lymphocytes was also resistant to NDGA concentrations that effectively blocked the mitogenic effects of TPA or bryostatin, but could be inhibited by higher concentrations of NDGA (IC50 = 8 μM). In addition, NDGA, but not CsA, blocked the production of IL‐6 by human mononuclear cells. Furthermore, PPD‐induced proliferation was significantly enhanced by NDGA. These data would suggest that NDGA at concentrations below 8 μMselectively inhibits IL‐2‐independent proliferation. NDGA’s ability to inhibit IL‐6 while enhancing the proliferative response to PPD may indicate an anti‐inflammatory therapeutic p

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-20.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Murine anti‐CD3 monoclonal antibodies (MoAbs) are used in clinical practice for immunosuppression. However, there are two major drawbacks to this treatment: the associated cytokine release syndrome and human anti‐mouse antibody response. To overcome these side‐effects, the authors generated a chimeric anti‐human CD3 single chain antibody, scUCHT1. It is an IgM variant of UCHT1, a mouse IgG1 MoAb directed against human CD3. scUCHT1 consists of the light and heavy variable chain binding domains of UCHT1 and a human IgM Fc region (CH2to CH4). scUCHT1 was produced by COS‐7 and SP2/0 transfectants, and mainly assembled in a dimeric form. It retained the binding specificity and affinity of the parental MoAb UCHT1. In contrast to UCHT1, scUCHT1 did not induce T‐cell proliferation and cytokine release (TNF‐α and IFN‐γ) inin vitroassays. These results suggest that the engineered chimeric anti‐CD3 single chain antibody (scUCHT1) may be useful in clinical immunosu

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-22.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The clonotypic T‐cell antigen receptor (TCR)‐β chain contains two extracellular intrachain disulfide bonds. It belongs to the immunoglobulin gene superfamily and is subdivided into variable (V), joining (J), diversity (D) and constant (C) region. Monoclonal antibody (MoAb) KJ25 is believed to recognize an epitope in the V‐domain of TCR‐β (Vβ3) chain, but its epitope requirements are unknown. In this study of TCR‐αβ chain interactions using chimeric recombinant TCR‐β chains, the authors found that partial substitution of the Cβ‐domain with that of interleukin‐2 receptor α chain (Tac) sequences led to the loss of TCR‐Vβ3epitope recognition by KJ25. These results suggest that epitope recognition of the TCR‐Vβ3by KJ25 MoAb is dependent not only on the V‐domain, but also on the close contact with the extracellular C‐domain which influences the conformation and epitope recognition of the Vβ3‐region. This may not be unique to Vβ3and may be a gen

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-21.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

This paper shows that the seven HA306–320 specific T‐cell clones isolated from one individual recognize the peptide complexed to both autologous HLA–DRB1*1101 and allogeneic HLA‐DRB1*1601 (or DRB5*0201) molecules. For each T‐cell clone, a single T‐cell receptor (TCR) is involved in the recognition of these two different peptide‐DR complexes as evidenced by cold target competition experiments. Yet, the seven T‐cell clones express several different TCRs as judged by Vβ‐Jβ usage and fine specificities. Furthermore, one representative clone has the same fine specificity for HA306–320 analogues mutated at epitopic residues irrespective of the use of DR1101 or DR1601 APC. These results suggest that structural differences between DRB1*1101 and DRB1*1601 (or DRB5*0201) do not dramatically influence the orientation of HA306–320 in the grooves such that most residues interacting with TCRs are conserved. In another individual, the same pattern of restriction, i.e. DR1101 + DR1601, was found for several HA306–320 specific clones. Two additional patterns, DR1101 + DR0801 and DR1101 + DR0801 + DR1601, were identified. By comparing DR sequences the authors found that DRB1*1101 and DRB1*1601 share four important motifs, i.e. β85–86, β67–71, β57 and β28–31 supposed to line three distinct HLA‐DR pockets. Three of these motifs are also shared with DRB1*0801. All the results further support that the motif similarities allow the peptide to adopt very si

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-23.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

CD69 is an early marker of lymphoid cell activation. The authors report on an up‐regulation of CD69 in splenic B and T cells of C57Bl/6 mice after administration of lipopolysaccharide (LPS) or microbial immunosuppressive/mitogenic (ISM) proteins produced byC. albicans(p43) and African Swine Fever Virus (p36). This up‐regulation of CD69 was observed 6 and 24 h after mitogenic treatments. The same pattern of increased CD69 expression was observed in the lymph nodes of mice treated with p43 or LPS, whereas p36 treatment failed to induce increased CD69 expression in this organ. Intracellular calcium mobilization was induced in splenic B and T lymphocytes after incubation of total spleen cells with LPS, p43 or p36. This increase was higher in B than in T cells. Increased calcium mobilization was also seen in lymph node B cells after incubation with p43 or p36 and in lymph node T cells after p43 stimulation. Up‐regulation of CD69 expression on B and T cells was also observed afterin vitrostimulation of spleen cells with the three mitogens used. Similar results were obtained with culture supernatants of macrophage/monocyte (Mφ) cells activated with LPS (LPS/MφCS). Stimulation of Mφ cells with LPS or with the ISM proteins is demonstrated by the increased production of nitrites by these cells. The increasedin vitroexpression of CD69 was, however, not abolished by monoclonal antibodies to Mφ cytokines such as IL‐6, IL‐10 or TNFα. No increased expression of CD69 was foundin vitroon purified B or T cells, even when mixed upon stimulation with p43, p36, LPS or with LPS/MφCS. However, an increase in the expression of CD69 was observed on B cells co‐cultured with Mφ cells after treatment with LPS or p36. All three mitogens failed to induce increased CD69 expression on cultured T cells

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-25.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The immune stimulating complex (iscom) is a particulate adjuvant formulation combining multimeric presentation of antigen with a built‐in adjuvant, Quillaja saponin. Iscoms induce strong serum antibody responses that are readily boosted. To further characterize this property of iscoms, the development and maturation of primary and secondary antibody responses to iscoms containing influenza virus antigen were investigated, in serum by ELISA and on single B‐cell level by ELISPOT. After a single subcutaneous injection, B cells secreting antigen‐specific IgG (IgG‐SC) were primarily observed in the draining lymph nodes (LN), showing peak numbers at day 7 which then declined rapidly. Serum IgG levels, as well as IgG‐SC in the spleen, persisted for several weeks and, with time, IgG‐SC cells also appeared in the bone marrow (BM). These results suggest that the IgG response to iscoms initially is located to the LN but that IgG‐SC are redistributed with time and may persist for a long time in other organs, including the spleen and BM. Moreover, a booster dramatically enhanced the frequency of IgG‐SC in LN, spleen and BM suggesting that iscoms induce a potent B‐cell memory. Comparisons of antibody responses to iscoms with those to influenza virus antigen in Freund’s complete adjuvant, TiterMaxTMor aluminium hydroxide suggest that the choice of adjuvant influences both the magnitude, kinetics, localization and isotype profile of

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-29.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Amyloid susceptible C57BL/6 and partially amyloid resistant A/J mice, infected intraperitoneally with 250 alveolar hydatid cyst (AHC), the larval stage of a cestode parasiteEchinococcus multilocularis, develop multiple organ amyloid deposits at approximately 1 and 4 weeks post infection (p.i.), respectively. Pooled spleens and livers from each mouse strain, at 8 and 10 weeks p.i., were used for the purification of protein AA utilizing a HiLoad Superdex 200 column equilibrated with 5 M guanidine‐HCl. Protein AA from each mouse strain was separated on 16% Tris‐tricine SDS‐PAGE gels and immunoblotted with monospecific rabbit anti‐mouse AA IgG; five and six immunoreactive AA subspecies were detected in the C57BL/6 and A/J materials, respectively. N‐Terminal amino acid sequence analysis was performed on the bulk column‐purified protein AA as well as on the electroblotted AA subspecies from each mouse strain. The results show a mixture of serum amyloid A1(SAA1) and (SAA2)‐derived AA protein from each mouse strain; SAA1‐derived AA, although alluded to, has never been demonstrated as tissue deposits in mice. These findings suggest that the intense and persistent inflammatory processes in AHC‐infected mice may have induced conversion of weakly amyloidogenic SAA1to AA. This conversion could be detected by amino acid sequencing of electrophoretically sepa

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-26.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Humoral and cellular immune responses were analysed in mice inoculated intranasally withBordetella bronchiseptica. After infection, the number of bacteria that colonized the respiratory tract of the mice increased during the first day and decreased thereafter. Total IgG levels increased as early as 14 days after infection and decreased with time after infection, whereas total IgA and IgM levels were lower but remained stable. Specific antibodies to the bacteria were mainly IgG2a and IgA and persisted up to 10 months after infection. Some of these specific antibodies were directed against adenylate cyclase–haemolysin, the bacterial factor that had been shown to be necessary for initiation of infection. The proliferation ofBordetella bronchiseptica‐reactive spleen cells occurred during the acute phase of infection. T cells from infected mice produced increasing amounts of IFNγ and IL‐2 after infection. Although very low levels of IL‐10 were produced, no IL‐4 was detected after bacterial stimulationin vitro. These results suggest thatBordetella bronchisepticainfection induces primarily a Th1‐type T‐cell response. Importantly, the authors demonstrated that antibody and T‐cell responses directed against bacterial determinants of the virulent strain and to purified adenylate cyclase–haemolysin were long‐lasting. This observation could be due to the fact thatBordetella bronchisepticamay persist intracellularly in the host as it was

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-30.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The immunoglobulin kappa chain gene of human lymphoma cell line HF‐1.3.4 was partially sequenced from the 3′ end of the leader exon 2.0 kb downstream. The sequenced stretch of DNA included 1.5 kb of the non‐coding JK region 3′ to the JK2 element of the mature gene. Among the known VK germline genes the closest relative was KV328, which was 91% homologous to HF‐1.3.4. In the 1.5 kb JK region homology with JK allele of Whitehurstet al.(allele 2) was 89%, with the allele of Hieteret al.(allele 1) 87%. The vast majority of the differences located in the leader intron, the VJ exon or 0.6 kb 3′ to the exon, a localization characteristic of somatic hypermutations of immunoglobulin genes. Another indication that most of the differences observed were due to somatic hypermutations is that the 153 bp stretch of the kappa constant gene (CK) sequenced from the mRNA was 100% homologous with the published CK sequence. The most differences between the JK region sequence and that of Whitehurstet al.probably represent somatic mutations: 43% were transversions, 55% transitions and 2% deletions. In the non‐coding JK region transversions of C.G to G.C rather than to A.T were heavily over‐represented. This is possibly a feature of B‐cell hyperm

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-27.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The recombinant bacillus Calmette–Guérin (rBCG) secretion system utilizing an extracellular α antigen ofMycobacterium kansasii(α‐K) was characterized biochemically and immunologically. The human immunodeficiency virus type1 (HIV‐1) p17gagB cell epitope fused to α‐K was secreted in extremely large amounts. At least three mice out of seven inoculated with rBCG generated high titres of antibody to the epitope. The long‐lasting antibody production persisted more t

ISSN:0300-9475    

DOI:10.1046/j.1365-3083.1996.d01-28.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY