Discrimination of human CD4 T cell clones based on their reactivity with antigen‐presenting T cells

Abstract

In this report, we describe the discrimination of human T cell clones based on their reactivity with activated T cells as antigen-presenting cells (APC). CD4+ T cell clones specific for peptide P30 of tetanus toxin (amino acids 947-967) and restricted to the DP4 molecule were established and tested for proliferation to peptide presented either by peripheral blood mononuclear cells (PBMC), Epstein-Barr virus (EBV)-transformed B cells or major histocompatibility complex (MHC) class II-expressing T cells. We found two sets of T cell clones: one set proliferated to peptide presentation by PBMC, EBV-transformed B cell lines (EBV-B cells) and MHC class II+ T cells (termed T-responder clones), while the other set of clones was only stimulated to proliferate, if the peptide was presented by PBMC or EBV-B cells, but not by T cells (T-nonresponder clones). Nevertheless, these T-nonresponder clones recognized P30 also on T cells, as revealed by Ca2+ influx. The discrimination of the clones was not due to different avidities of the T cell receptors (TcR) of individual clones for the MHC-peptide complex as T-responder and T-nonresponder clones had similar dose-response curves to P30 presented by fixed EBV-B cell lines. Addition of cytokines [interleukin (IL)-1, IL-2, IL-4 and interferon gamma] did not change the proliferative response of the clones, which was consistent throughout an observation period of greater than 4 months. T-nonresponder clones, exposed to P30 on MHC class II-expressing T cells, became not anergic, as they could be restimulated by P30 presented on EBV-B cells. The measurement of a panel of T cell activation markers and adhesion molecules on T-responder and T-nonresponder clones revealed a higher expression of the CD28 molecule on the T-nonresponder clones. The data suggest that freshly cloned T cells can be differentiated by peptide presentation on classical (PBMC, EBV-B cells) or non-classical APC (class II+ T cells), and that this discrimination is further underlined by different levels of adhesion molecules.

Human CD4+ T Cells Displaying Viral Epitopes Elicit a Functional Virus-Specific Memory CD8+ T Cell Response

“…By contrast, unidirectional presentation has been shown to lead to a significant proliferative response (31). Moreover, depending on the state of activation of the reactive T cell line, stimulation with T-APCs may induce anergy or proliferation (37). In this study, we demonstrate that in contrast to activated T cell lines and clones, freshly activated CD4 ϩ T cells can stimulate the expansion of autologous memory CD8 ϩ T cells.…”

HLA-DP4, the Most Frequent HLA II Molecule, Defines a New Supertype of Peptide-Binding Specificity

“…Nevertheless, we also assessed that other peptides known to bind HLA-DP4 molecules were equally good binders in our assays. The HLA-DP4 eluted peptide IL3R 127-146 (33) and the T cell epitopes MAGE3 245-268 (28), HSV 283-302 (29), NSP2 (24), and tetanus toxoid (TT) peptide 947-963 (26) inhibited the binding at different levels of efficiency. In sharp contrast, the HA 306 -318 peptide, which is known to bind efficiently to multiple HLA-DR molecules (5,37), and the peptides HCI 46 -63 and DQB [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] , which bind efficiently to HLA-DQ molecules (38), were totally inactive.…”

“…We first aligned the sequences of the good DP4 binders that we described in Fig. 1: IL3R 127-146 (33), MAGE3 (28), HSV 283-302 (29), NSP2 (24), and TT 947-963 (26) (Table VI). Only the NSP2 peptide did not exhibit the HLA-DP4 motif although it bound efficiently to HLA-DP4 molecules.…”

“…Therefore, we could expect that peptides that efficiently bind to DP401 and DP402 will have a large impact as epitope-based vaccines. However, although multiple clones or T cell lines of various peptide specificities are restricted to HLA-DP4 (23)(24)(25)(26)(27)(28)(29)(30), the binding specificity of HLA-DP4 molecules remains unknown. To our knowledge, only the peptide specificities of HLA-DP2 and HLA-DP9 molecules have been investigated (31,32), and only preliminary data of naturally processed peptides eluted from a DP4 molecule have been reported (33).…”

Costimulatory signalling potential of murine MHC class II‐positive T‐clone cells

“…Although evidence suggests, that T cells can function as APC for established T-cell clones and in primary mixed lymphocyte reactions, 2,3 other reports indicate a failure of T-cell clones to present soluble peptide. 4,5 Similar to human T cells, rat T cells activated in vivo during the course of experimental allergic encephalomyelitis synthesized MHC class II proteins. 6 Likewise, rat-helper T-cell lines and clones were capable of MHC class II synthesis [6][7][8] and antigen presentation.…”