T cells specific for different antigens express different HLA‐D region products

Abstract

T cell lines and clones were analyzed for surface expression of Ia antigens using monoclonal antibodies (mAb) that detect monomorphic and polymorphic epitopes on Ia molecules encoded by the HLA-DR and HLA-DQ gene clusters. All mAb bound to B lymphocytes or lymphoblastoid cell lines of the same individuals from whom the T cells were derived. Three mAb detecting monomorphic epitopes, primarily associated with HLA-DR, bound to all T cells showing that each clone or line expressed some type of Ia. Three other mAb defining polymorphic epitopes associated with HLA-DR products showed differential binding patterns. Two reagents, R3 and E15/4 recognizing the supertypic specificity DRw52 (formerly MT2), bound to every alloreactive clone, whereas the 16.23 mAb, detecting a private DR3-associated epitope, failed to bind to any clone. In contrast, the 16.23 epitope was detected on high percentages of T cells specific for purified protein derivative of tuberculin (PPD) or tetanus toxoid (TT). Biochemical studies showed that the 16.23 and DRw52-like epitopes can be present on distinct DR molecules on B cell lines and this may also be the case for T cells. Three other mAb, detecting epitopes associated with HLA-DQ, also revealed differential binding patterns when tested on various T cells. Two failed to bind to any alloreactive clone and to only low numbers of PPD- or TT-specific T cell lines, whereas the third bound distinctly to a CD4+/CD8+ alloreactive clone. Biochemical analyses have shown that these DQ epitopes can be present on different molecules. Combined, these observations indicate that differential expression of Ia molecules encoded by both HLA-DR and DQ occurs between B and activated T cells as well as among T cell populations of the same individual. Whether these differences reflect quantitative variations in expression of given DR or DQ molecules or, alternatively, are due to differential class II gene expression in activated T cells remains to be determined.

Changes in cell surface antigen expression on human articular chondrocytes induced by gamma‐interferon

“…The differential binding patterns of these antibodies might occur because the epitopes recognized can be present in a different Ia antigen setting, precedents of which have been reported for activated T cells (35) and for the epitope detected by reagent 109d6 in patients with RA (36). A similar differential expression of Ia antigens with similar kinetics and dose-response curves has also been found with dermal fibroblasts (14) or synovial fibroblast cell lines after incubation with y-IFN (ref.…”

The control of class II expression on T cells is independent of the regulation of Tac and the induction of proliferation

“…1978;Ko et at.. 1979;Engleman ct al., 1980;Zier. 1982;Schendel & Johnson, 1985;Triebel ct at., 1986). Previously, we have reported that 20-50'!^, of T cells expressed class II on the cell .surface as early as 0-5-2 h after stimulation with PHA and PdB.…”

Differential expression of HLA‐DR allospecificities on antigen specific T cell clones

“…HLA-DR and D typing, 2-dimensional (2-D) gel electrophoretic analysis, peptide mapping and partial aminoacid sequence have detected no difference in the phenotype and in the structural profile of HLA Class I1 antigens synthesized by activated T cells and by autologous B cells (for review, see Solheim et al 1986). Like other types of cells (Natali et al 1986), activated T cells express a higher level of HLA-DR than of HLA-DQ antigens (Schendel & Johnson 1985, Santoli et al 1986, Triebel et al 1986). Furthermore, T cell clones may differ from autologous B lymphoid cells in their reactivity pattern with monoclonal antibodies to polymorphic determinants of HLA-DR antigens (Schendel et al 1984, Santoli et al 1986, Triebel et al 1986).…”