摘要:

AbstractEarlier studies from this laboratory had shown that rat basophilic leukemia cells carry two major receptors for IgE, named R and H, and a third minor receptor, designated 71K. It is now apparent that 71K is induced by the action ofMycoplama hyorhinis, a common contaminant of tissue cultures. This induction is reversible. Decontamination either inin vitroorin vivoleads to a disappearance of 71K and re‐infection causes its reappearance. The 71K receptor appears to be induced by the action of the mycoplasma on a surface molecule, most likely R, present on the cells at the time of infection. When receptors are occupied by IgE, 71K induction is inhibited. Other effects of mycoplasma infection include the significant reduction in the expression of transferrin receptors and increased histamine content of infected cell

ISSN:0014-2980    

DOI:10.1002/eji.1830161102

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractCells from sea star(Asterias rubens)axial organs stimulated with trinitrophenyl (TNP) or fluoresceinyl‐haptened polyacrylamide beads and subsequently stimulatedin vitrowith the same antigen produced and released a specific antibody‐like protein which induced lysis of haptened sheep erythrocytes in the presence of serum complement. The anti‐TNP antibody‐like protein isolated by ammonium sulfate precipitation, gel filtration and affinity chromatography exhibited a single precipiting peak after crossed immunoelectrophoresis against rabbit antiserum to partially purified culture supernatant. The anti‐TNP antibody‐like protein gave a specific affinity precipitate in crossed affino‐electrophoresis using a p‐nitrobenzoyl‐substituted gel. The analysis by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis under both reducing and nonreducing conditions evidenced a unique 30‐kDa polypeptide chain. According to gel filtration experiments, the molecular weight of the major component isolated by affinity chromatography was about four times higher. Therefore, the antibody‐like molecule could be a tetrameric protein devoi

ISSN:0014-2980    

DOI:10.1002/eji.1830161103

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractA monoclonal antibody (INN‐CH‐16) was prepared which reacts with a cell surface antigen termed chicken activated T lymphocyte antigen. This antigen is expressed on antigen‐ or mitogen‐activated T lymphocytes and is not present on nonstimulated lymphocytes. It has an apparent molecular mass of 48‐50 kDa under reducing conditions. The value of this antibody for the immunohistochemical characterization of infiltrating cells in the thyroid glands from Obese strain chickens with spontaneous thyroiditis is dem

ISSN:0014-2980    

DOI:10.1002/eji.1830161104

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThe heavy metale cations Pb2+, Ni2+and Zn2+have previously been shown to induce T cell proliferation which required the presence of both T cells and Ia+cells at the initiation of culture. This work has examined the ability of these metals to induce cell cycle entry as determined by acridine orange cell cycle analysis. Cell surface phenotype analysis, performed on splenocytes stimulated with optimum metal concentrations (100 μM), indicated thatin vitroT cell recovery (growth and/or longevity) was enhanced by Pb2+, Ni2+and Zn2+. Furthermore, simultaneous examination of cell surface phenotype and cell cycle progression (propidium iodide) indicated that the predominant cell type proliferating in response to these metals was Thy‐1.2+. The metals differentially induced L3T4+and Lyt‐2+cells to enter the cell cycle. The ability of various monoclonal antibodies to modulate metal‐induced proliferation was examined. Anti‐L3T4a, anti‐I‐A and anti‐I‐E blocked metal‐induced proliferation. Anti‐Lyt‐2 only partially inhibited whereas anti‐Lyt‐1 was stimulatory. These results suggest that recognition of major histocompatibility complex‐encoded class II molecules is required for the induction of proliferation by these metals (similar to the autologou

ISSN:0014-2980    

DOI:10.1002/eji.1830161105

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThe family of human T cell activation‐associated proteins, named VLA complex, is formed by the molecular association of cell surface glycoproteins of 210, 165, 130 and 80 kDa. In this report, we describe eight different monoclonal antibodies (HP mAb) specific for the 80‐kDa polypeptide which preferentially associates with the 165‐kDa member. Comparative immunoprecipitation and cell‐binding studies demonstrated that the HP mAb recognize an epitope(s) on the 165/80 kDa subset different from those recognized by other anti‐VLA mAb previously described. Furthermore, cellular and tissue distribution studies by flow cytometry and peroxidase staining showed that the HP reactivity pattern is different from other VLA specificities. The 165/80‐kDa complex defined by HP mAb is present on human thymocytes, peripheral blood lymphocytes as well as on T, B and myelomonocytic cell lines. However, only the 80‐kDa subunit was precipitated by HP mAb from activated T lymphocytes. These results suggest that the association between the 165‐ and 80‐kDa subunits diminishes during the activation process, and that the epitopes recognized by the HP mAb are located on the 80‐kDa protein. The novel polypeptide association of 165/80 kDa ha

ISSN:0014-2980    

DOI:10.1002/eji.1830161106

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractWe isolated cDNA clones coding for the functionally important tryptic N‐terminal 38‐kDa fragment of human complement control protein factor H using polyclonal and monoclonal antibodies to screen a human liver cDNA library cloned in a bacterial expression vector, PEX‐1. By testing the reactivity of antibodies specific for the recombinant proteins produced by individual clones with proteolytic fragments of serum H the exact position of these cDNA clones within H was mapped. One clone, H‐19, coding for the 38‐kDa fragment of H was sequenced and found to code for 289 amino acids derived from the 38‐kDa N‐terminal fragment as well as for the first 108 amino acids belonging to the complementary 142‐kDa tryptic fragment. The derived protein sequence could be arranged in 6 highly homologous repeats of about 60 amino acids each, the homology between the repeats being determined by the characteristic position of cysteine, proline, glycine, tyrosine and tryptophane residues. The region coding for the epitope recognized by one of our monoclonal antibodies was localized by subcloning restriction fragments of H‐19 into the expression plasmid and testing for the expressio

ISSN:0014-2980    

DOI:10.1002/eji.1830161107

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractGp140 is the Epstein‐Barr virus receptor and the C3d receptor (EBVR/C3dR) of human B lymphocytes. Recently, we have shown that cross‐linking of EBVR/C3dR on cell surface by polyclonal anti‐gp140 induced B cell activation, in presence of T cell factors.Immunoregulatory abnormalities of EBV‐induced B cell activation have been demonstrated in rheumatoid arthritis (RA) patients. These data prompted us to analyze the putative presence of anti‐EBVR/C3dR autoantibodies in human sera. The IgG fractions from eleven RA and 10 normal sera were tested for their ability to: (a) bind to Raji cell surface; (b) inhibit the binding to cell surface of 3 anti‐EBVR/C3dR monoclonal antibodies (mAb), which recognized different epitopes on gp140; (c) inhibit the binding of particle‐bound C3d and (d) react with 1% Nonidet‐P40‐solubilized gp140 from Raji cell membranes, in immunoblotting assays. Three RA sera carry anti‐ EBVR/C3dR autoantibodies which react with gp140 expressed on Raji cell surface or its solubilized form. The purification of monomeric IgG fraction of selected RA sera ruled out involvement of immune complexes carrying C3 molecules, which could interfere in these assays. One of these 3 RA sera was able to inhibit the binding to cell surface of anti‐EBVR/C3dR mAb and particle‐bound C3d. However, the 2 other RA sera, found positive by immunoblotting, did not inhibit particle‐bound C3d and presented differences in their inhibitory effect on anti‐EBVR/C3dR mAb binding to Raji cell surface. These data allow us to demonstrate differences which exist in the properties of anti‐EBVR/C3dR autoantibodies. These autoantibodies were not detected in all the normal and other RA sera. Anti‐EBVR/C3dR autoantibodies could play a role“in vivo”in B l

ISSN:0014-2980    

DOI:10.1002/eji.1830161108

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThe functional role of the T8 antigen of human T cells was studied by inhibition with anti‐T8 monoclonal antibodies (mAb) of the cytotoxic action of T8+cytotoxic T lymphocyte clones (CTL). All clones were allospecific and directed against HLA‐B7. The ability of seven different anti‐T8 mAb to inhibit the cytotoxicity of these alloreactive CTL clones corresponded with their avidity for a particular target cell. The lysis of cross‐reactive antigen‐bearing target cells was more readily blocked by anti‐T8 mAb than lysis of the specific B7 target cell against which a clone was raised. The seven anti‐T8 mAb showed a spectrum of CTL blocking ability ranging from strong blocking with all five CTL clones tested to weak inhibition of only two out of five clones. mAb inhibition of CTL reactivity and cold target inhibition studies with one of the five CTL clones indicate a post‐binding role of the T8 molecule. Functional epitope mapping based on CTL blocking with the anti‐T8 mAb resulted in the definition of one nonfunctional epitope on the T8 molecule which is only expressed on mature T lymphocytes and a cluster of closely related functional epitopes expressed on both thymocytes and mature T lymphocytes.Not only allospecific cytotoxicity, but also nonspecific cytotoxicity induced by anti‐T3 mAb in these allospecific clones was inhibited by anti‐T8 mAb in the absence of HLA class I expression on the target cell (Daudi cell line). The hierarchy of blocking with anti‐T8 mAb and the classification of functional epitopes on T8 in anti‐T3‐induced nonspecific cytotoxicity were similar to those obtained in blocking of allospecific reactivity of the CTL clones. This analogy points to an identical function of the T8 antigen in both allospecific and anti‐T3‐induced nonspecific cytotoxicity. If HLA class I molecules are the counter structures of the T8 antigen, then these results argue against an adhesion‐like function of the T8 structure. The combined results show that the T8 molecule has a regulatory role in CTL activation. It is postulated that the T8 antigen might serve as a receptor that transduces a negative feedback signal for T cell activation which prevents T cell trig

ISSN:0014-2980    

DOI:10.1002/eji.1830161109

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractWe have established idiotope (Id)‐specific T cell lines and clones derived from at least 4 different BALB/c mice immunized with the light chain (λ2315) of the BALB/c myeloma protein M315 (α,λ2). Independently derived clones were indistinguishable in that they reacted to Vλ2315, one or more of the amino acids corresponding to somatically mutated codons 94, 95 and 96 of the third hypervariable region being essential for expression of the Id. While the Id was efficiently expressed on Vλ2315, Fv315and λ2315fragments, about a 100–1000‐fold higher molar concentration of Fab315and M315 was needed to induce equivalent responses. Thus, Ig quaternary structure heavily influenced the availability of the Id for T cells. The Vλ2315‐specific T cells were Thy‐1.2+, L3T4+, Ly‐2.2−and I‐Edrestricted. Some of the T cell clones produced interleukin 2 (IL2), IL3 and B cell growth and differentiation factors upon activation. In addition, T cells were cytotoxic in long‐term assays for E βdE αk, but not E βkE αk‐transfected L cells in the presence of Id. The cytotoxic effect was the basis for an L cell growth inhibition assay for T cell activation that was at least 10‐fold more sens

ISSN:0014-2980    

DOI:10.1002/eji.1830161110

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractTwelve L3T4+Ly‐2.2−subclones, derived from 4 independent BALB/c T cell lines, responded to a combination of the I‐Edmolecule and a synthetic peptide corresponding to residues 91–108 of the λ light chain from BALB/c myeloma protein M315 (α, λ2). Peptide analogues in which the mutated residues Arg95or Asn96were exchanged with the corresponding germ‐line‐encoded Ser95or Thr96had an abolished or greatly reduced capacity to stimulate T cell clones. However, responses of subclones to an analogue where the mutated Phe94was substituted with the germ‐line‐encoded Tyr94revealed three specificity patterns: 5 clones reacted only with the λ2315peptide, 6 clones responded equally well to both peptides and a single clone reacted better with the Tyr94analogue. Analysis of the T cell receptor β‐chain gene rearrangements disclosed 7 distinct rearrangements, identical rearrangements only being found for subclones originating from the same line. At least 3 different Vβgenes were used. Subclones with identical or nearly identical peptide specificity, major histocompatibility complex‐restriction and alloreactivity could differ in their Vβor

ISSN:0014-2980    

DOI:10.1002/eji.1830161111

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY