ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00470.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYMHC class II molecules and self antigens, such as Mls, influence T‐cell selection by clonal deletion of potentially self‐reactive T cells. In order to examine the role of various class II molecules in the T‐cell receptor‐self antigen interaction, class II transgenic and recombinant mice were analysed for TCR expression. Our studies indicate that the Aα and Eα chains can present Mls gene products for the clonal deletion of Vβ6‐bearing T cells, and that theAαqchain is defective in this process. We have also shown that Eα Aβ heterodimer in transgenic and recombinant mice is expressed and functions to delete I‐E reactive Vβ11 T cells, demonstrating again the role

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00471.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYInvestigation of the antigenic phenotype of activated lymphocytes using the broadly cross‐reactive mAb 6.3.4 revealed two phenotypic alterations as compared with the resting lymphocytes. The Qa specificity Qa‐m208 disappears after lectin activation of Qa‐m208‐positive T lymphocytes. Analysis ofQ7andQ9transfectants expressing the Qa‐2 polypeptides shows that Qa‐m208 is an epitope of the Qa‐2 antigen. Because the Qa‐2 antigens are still expressed on T lymphoblasts which have lost Qa‐m208, changes of the Qa‐2 molecules occur and result in the loss of certain epitopes.The second phenotypic change that we observed is the appearance of a novel specificity, Qa‐12. Its expression is induced by lymphocyte activation and it is expressed on lymphoblasts of both T and B cell origin. The presence of this novel non‐ubiquitous antigenic specificity is det

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00472.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYThe role of the MHC class II antigens in the activation of resting human B lymphocytes (B‐Go) was examined with respect to both early and late events in the activation process.The (Ca2+)i induced by anti‐IgM was enhanced in the presence of, or following pre‐incubation with, an anti‐MHC class II DR antibody (D1.12). Pre‐incubation with a sepharose conjugated antibody (Seph.‐D1.12) augmented the proliferation of B‐Go in response to a sub‐optimal concentration of anti‐IgM.The 2D PAGE profile of B‐Go differed from that ofin vivoactivated B lymphocytes. The 2D PAGE profile of B‐Go activated by Seph.‐D1.12 was not identical to the profile of B‐Go activated by either anti‐IgM or PMA.These data suggest that the activation of B‐Go via the class II antigens shares part of the pathway of anti‐IgM induced activation but does

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00473.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYWe established the organization of the AKR Qa region and determined the sequence of the 44 and Q5 genes. Restriction mapping and genomic Southern blot analysis revealed that the AKR strain codes for only three H‐2K homologous genes in this region. The AKR Q5 gene is not homologous to the Q5 gene of the C57BL strain, but is presumably allelic to the Q5 gene isolated from Balb/c. The organization and structure of the AKR Qa family is virtually identical to the Qa genes of the C3H mouse. The AKR Q5 gene, in contrast to other H‐2K homologous Qa region genes, codes for a typical transmembrane region, and upon transfection into BHK cells, a 1.6 kb Q5 transcript is detec

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00474.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYThe metastatic B16 mouse melanoma shows a low cell surface expression of H‐2Kband H‐2Dbclass I antigens on cells of both the high‐metastatic line B16‐F10 and the low‐metastatic line B16‐F1. Similarly, newly generated clones of these lines, having different metastatic properties, all express low levels of major histo‐compatibility antigens. One of these clones, the high‐metastatic F10.9, was transfected with H‐2Kbgenes to generate H‐2Kb‐expressing transfectants. The resulting clones showed reduced tumourigenicity and a low metastatic phenotype. Unlike the parental cells, H‐2Kb‐positive transfectants are potent inducers and sensitive targets of H‐2Kb‐restricted syngeneic cytotoxic T cells. Immunization of mice with H‐2Kb‐positive transfectants conferred protection against a subsequent challenge with Kb‐positive transfectants but had only a small effect on growth and

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00475.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYWe have used the 3‐Methylcholanthrene induced T‐10 fibrosarcoma tumour cell system (H‐2bxH‐2k)F1to elucidate the possible correlation between metastatic potential, expression of individual H‐2 antigens and susceptibility to NK cells.Transfection of the non‐metastatic and NK sensitive IC9 cells (Db+, Dk‐, Kb‐, Kk‐) with theH‐2Dkgene, altered the metastatic phenotype of the parental cells, yet had no effect on the susceptibility of these tumour cells to lysis by NK and did not elicit a specific CTL response in syngeneic hosts. Variants of the metastatic and NK resistant IE7 clone (Db+, Dk+, Kb‐, Kk‐), lackingH‐2Dk, were selected by treatment with monoclonal antiH‐2Dkantibodies and complement. These variants were sensitive to NK and poorly or non metastatic. Retransfection of ‘Dk′loss’ variants with theH‐2Dkgene, resulted in the isolation of several clones expressing a wide range of metastatic phenotypes but maintained sensitivity to NK. These results indicate that theH‐2Dregion of the MHC and or closely linked genes may be involved in the complex interrelationship between targe

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00476.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYTransformation of murine NIH3T3 fibroblasts with retroviral vectors carrying the mos, myc and the Ha‐ras oncogene, respectively, was associated with a strong reduction ofH2antigen expression in the cell membrane. Analysis ofH‐2Kand β2‐microglobulin promoter‐driven CAT activity in these oncogenic transformants and normal NIH3T3 fibroblasts revealed unchanged promoter activity, suggesting post‐transcriptional control of MHC class I expression by these oncogenes. Treatment with IFN‐gamma and TNF‐alpha caused 2‐ to 3‐fold enhancement ofH‐2Kand β2‐microglobulin promoter activity, as well as a normalization (TNF‐alpha treatment) or enhancement (IFN‐gamma treatment) ofH2membrane expression. These data suggest that IFN‐gamma as well as TNF‐alpha can counteract downregulation ofH‐2genes by interference with an oncogene‐induced, post‐transcriptional block as well as by a direc

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00477.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SUMMARYIn vivoimmunization and secondary culture techniques were used to generate cytotoxic T lymphocytes against a tumour cell clone obtained from a methylcholantrene‐induced fibrosarcoma. Our CTLs differed from classical CTLs (Ly2 + and MHC restricted) in that our lymphocytes exhibited a non‐MHC restricted cytotoxic activity directed to the original tumour and to other MCA‐induced tumours, but have failed to demonstrate any killing activity against a wide range of tumour cell lines of diverse origin (including NK sensitive targets). Depletion and phenotypic studies demonstrated that these cells bear the Thy1.2 antigen but are negative for both Ly2 and L3T4 antigens. These CTLs may belong to a double negative subset (CD4−, CD8−) involved in the anti‐tumo

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00478.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:1744-3121    

DOI:10.1111/j.1744-313X.1989.tb00479.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY