CD4-class II major histocompatibility complex interaction does not enhance killing by a class I-restricted CD4+CD8+ cytotoxic T cell clone

1992 ◽  
Vol 22 (9) ◽  
pp. 2461-2464 ◽  
Author(s):  
Alexander J. McAdam ◽  
Timothy M. Blieden ◽  
John G. Frelinger ◽  
Edith M. Lord
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Clone ◽  
Class Ii ◽  
Complex Interaction ◽  
Class I ◽  
Cytotoxic T Cell ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
T Cell Clone

scholarly journals A rare cryptic translation product is presented by Kb major histocompatibility complex class I molecule to alloreactive T cells.

1995 ◽  
Vol 182 (6) ◽  
pp. 1739-1750 ◽  
Author(s):  
S Malarkannan ◽  
M Afkarian ◽  
N Shastri
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Clone ◽  
Receptor Occupancy ◽  
Class I ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Alloreactive T Cells ◽  
T Cell Clone

The identity of allogeneic peptide/major histocompatibility complex (MHC) complexes that elicit vigorous T cell responses has remained an interesting problem for both practical and theoretical reasons. Although a few abundant MHC class I-bound peptides have been purified and sequenced, identifying the unique T cell-stimulating peptides from among the thousands of existing peptides is still a very difficult undertaking. In this report, we identified the antigenic peptide that is recognized by an alloreactive bm1 anti-B6 T cell clone using a novel genetic strategy that is based upon measurement of T cell receptor occupancy in single T cells. Using lacZ-inducible T cells as a probe, we screened a splenic cDNA library in transiently transfected antigen-presenting cells (APCs) and isolated a cDNA clone that allowed expression of the appropriate peptide/Kb MHC complex in APC. The antigenic octapeptide (SVVEFSSL) exactly matched the consensus Kb MHC motif, but was surprisingly encoded by a non-ATG defined translation reading frame. Furthermore, the abundance of the naturally processed analog in untransfected cells was estimated to be <10 copies per cell. These results illustrate a novel strategy for identifying T cell-stimulating antigens in general and directly show that alloreactive T cells can respond to rather rare peptide/MHC complexes. These results also suggest that the total pool of processed peptides expressed on the APC surface may include those generated by cryptic translation of normally expressed transcripts.

Recognition of the HLA class II-peptide complex by T-cell receptor: reversal of major histocompatibility complex restriction of a T-cell clone by a point mutation in the peptide determinant

1989 ◽  
Vol 323 (1217) ◽  
pp. 553-564 ◽  
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Clone ◽  
Class Ii ◽  
Hla Class Ii ◽  
Helical Conformation ◽  
Major Histocompatibility ◽  
Peptide Complex ◽  
Histocompatibility Complex ◽  
T Cell Clone

Recognition of the HLA DR-peptide complex by an influenza haemagglutinin-specific T-cell clone was examined by assaying a variety of peptide analogues for their ability to be recognized. Consistent with earlier experiments arguing that the peptide blinds the restriction element in a helical conformation, acetylation of the amino terminus and amidation of the carboxy terminus of the natural determinant (residues 307-319) resulted in a peptide that exhibited both greater propensity to form a helix, as judged by circular dichroism, and the ability to stimulate the clone at concentrations approximately two orders of magnitude lower than the native sequence. The peptide was modelled into the potential antigen-combining site of HLA class II based on the ability of analogues containing point mutations to stimulate the T-cell clone. The working model was initially tested by examining the ability of Epstein-Barr-transformed B-cell lines expressing in different DR4 subtypes to present the native haemagglutinin sequence and analogues to the clone. The different alleles could be categorized as high, intermediate, or low responders based on the resulting proliferation. DR4 dw 15 was a high-responding allele, dw 4, 13, and 14 were intermediate-responding alleles, whereas dw 10 was a low responder. Mutation of Gin to Arg at 312 in the haemagglutim n sequence converted the high and intermediate responders to non-responders, while turning the low-responding allele into an intermediate responder. Potential explanations for these effects are discussed in the context of the model of the complex between peptide and the major histocompatibility complex.

scholarly journals Antigen recognition by a T cell clone outside the context of the major histocompatibility complex. A role for Mls in antigen presentation.

1984 ◽  
Vol 159 (1) ◽  
pp. 305-312 ◽  
Author(s):  
S J Waters ◽  
S D Waksal ◽  
G P Norton ◽  
C A Bona
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Clone ◽  
Antigen Recognition ◽  
Major Histocompatibility ◽  
Spleen Cells ◽  
Differentiation Markers ◽  
Histocompatibility Complex ◽  
T Cell Clone

A T cell clone isolated from antigen-primed CB6/F1 mice was shown to proliferate to keyhole limpet hemocyanin (KLH) in the presence of irradiated syngeneic F1 spleen cells, as well as spleen cells from either parental strain (BALB/c and C57BL/6). The genetic restriction involved in this antigen-specific proliferation was mapped using BXD (C57BL/6 X DBA/2) recombinant inbred strains of mice to the Mls gene on chromosome one. To exclude the role of Ia antigens as the restricting determinants, monoclonal anti-Ia antibodies were used to block the in vitro proliferative response of this clone. Although anti-Iab and anti-Iad blocked the proliferation of this clone to KLH in the presence of irradiated spleen cells from either parent, this effect was shown to be dependent on Ia molecules passively absorbed by the T cell clone from the irradiated filler cells. Since the T clone expressed Thy-1.2 and Lyt-1+ differentiation markers, its helper activity was compared with other KLH carrier-specific clones in an in vitro antibody synthesis assay. The Mls-KLH-restricted T cell clone, in contrast to other carrier-specific, major histocompatibility complex (MHC)-restricted T cell clones, was unable to cooperate with trinitrophenyl (TNP)-primed B cells in the presence of TNP-KLH to generate an anti-TNP response. These experiments suggest that non-MHC determinants, such as autologous Mls gene products, may play a role in genetically restricted antigen recognition by T lymphocytes.

scholarly journals Greatly reduced lymphoproliferation in lpr mice lacking major histocompatibility complex class I.

1995 ◽  
Vol 181 (2) ◽  
pp. 641-648 ◽  
Author(s):  
M A Maldonado ◽  
R A Eisenberg ◽  
E Roper ◽  
P L Cohen ◽  
B L Kotzin
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Class Ii ◽  
T Cell Subsets ◽  
Cell Surface Receptor ◽  
Class I ◽  
Major Histocompatibility ◽  
Gamma Delta ◽  
Histocompatibility Complex

Mice homozygous for the lpr gene have a defect in fas (CD95), a cell surface receptor that belongs to the tumor necrosis factor receptor family and that mediates apoptosis. This genetic abnormality results in lymphoproliferation characterized by the accumulation of CD4-CD8- (double negative [DN]) T cells, autoantibody production, and background strain-dependent, end-organ disease. Our previous results suggested that major histocompatibility complex (MHC) class I may be involved in the development of DN cells. To test this hypothesis, we derived C57BL/6-lpr/lpr (B6/lpr) mice that were deficient for the beta 2-microglobulin gene (beta 2m lpr) and had no detectable class I expression. At 6 mo of age, compared with B6/lpr littermates with normal class I genes, these mice showed greatly reduced lymphadenopathy, mostly due to a dramatic decrease in the number of DN cells. Significant changes in the percentage of other T cell subsets were noted, but only gamma/delta+ T cells showed a marked increase in both percentage and absolute numbers. Analysis of T cell receptor V beta expression of the remaining DN T cells in beta 2m -lpr mice showed a shift to a CD4-like repertoire from a CD8-like repertoire in control B6/lpr mice, indicating that a small MHC class II selected DN population was unmasked in lpr mice lacking class I. We also found that the production of immunoglobulin G (IgG) autoantibodies (antichromatin and anti-single stranded DNA), total IgG and IgG2a, but not total IgM or IgM rheumatoid factor, was significantly reduced in the beta 2m -lpr mice. This work suggests that >90% of DN T cells in lpr mice are derived from the CD8 lineage and are selected on class I. However, a T cell subset selected on class II and T cells expressing gamma/delta are also affected by the lpr defect and become minor components of the aberrant DN population.

scholarly journals Immunogenicity and tolerogenicity of self-major histocompatibility complex peptides.

1990 ◽  
Vol 172 (5) ◽  
pp. 1341-1346 ◽  
Author(s):  
G Benichou ◽  
P A Takizawa ◽  
P T Ho ◽  
C C Killion ◽  
C A Olson ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Class Ii ◽  
Class I ◽  
Major Histocompatibility ◽  
Autoreactive T Cells ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
Self Tolerance

Mechanisms involved in self-antigen processing and presentation are crucial in understanding the induction of self-tolerance in the thymus. We examined the immunogenicity of determinants from major histocompatibility complex (MHC) molecules that are expressed in the thymus and have tested peptides derived from the polymorphic regions of class I and class II molecules. We found that two peptides corresponding to NH2 termini of the class II alpha and beta chains (Ak alpha 1-18 and Ak beta 1-16) could bind to self-Ak molecules with high affinity and, surprisingly, were immunogenic in that they could elicit strong proliferative T cell responses in B10.A mice (Ak, Ek). Neonatal injection of peptide Ak beta 1-16 resulted in complete unresponsiveness to this peptide at 8 wk of age showing that these T cells were susceptible to tolerance induction. We have also tested certain class I MHC peptides and showed that some can interact efficiently with class II MHC peptides to induce an autoreactive T cell proliferative response. Among these class I peptides is one (Dd 61-85) that has the capacity to bind to self-Ia without being immunogenic, and therefore represents an MHC determinant that had induced thymic self-tolerance. We conclude that some self-MHC molecules can be processed into peptides that can be presented in the context of intact class II molecules at the surface of antigen-presenting cells. Autoreactive T cells recognizing optimally processed self-peptide/MHC complexes are eliminated during development, whereas other potentially autoreactive T cells escape clonal inactivation or deletion. Incomplete tolerance to self-antigens enriches the T cell repertoire despite the fact that such T cells may eventually become involved in autoimmune disease.

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