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 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 A MOUSE B-CELL ALLOANTIGEN DETERMINED BY GENE(S) LINKED TO THE MAJOR HISTOCOMPATIBILITY COMPLEX

1973 ◽  
Vol 138 (6) ◽  
pp. 1289-1304 ◽  
Author(s):  
David H. Sachs ◽  
James L. Cone
Keyword(s):  
Major Histocompatibility Complex ◽  
Lymph Node ◽  
T Cell ◽  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Surface Antigen ◽  
Major Histocompatibility ◽  
Spleen Cells ◽  
Histocompatibility Complex

Antibodies cytotoxic for only a subpopulation of C57Bl/10 lymph node and spleen cells were detected when rat antiserum against B10.D2 was exhaustively absorbed with B10.A lymphocytes. Antibodies of similar specificity were also detected in B10.A anti-B10.D2 and in B10.A anti-C57Bl/10 alloantisera. Reactions with recombinant strains of mice indicate that the cell-surface antigen(s) responsible for this specificity is determined by gene(s) in or to the left of the Ir-1 region of the major histocompatibility complex. A variety of criteria implicate B cells as the subpopulation of lymphocytes bearing this antigen. In view of these data and the recent report by others of a T-cell alloantigen determined by gene(s) in the major histocompatibility complex, it seems possible that there may be a variety of H-2-linked alloantigens expressed preferentially on subclasses of lymphocytes.

scholarly journals Protection against graft vs. host-associated immunosuppression in F1 mice. I. Activation of F1 regulatory cells by host-specific anti-major histocompatibility complex antibodies.

1981 ◽  
Vol 154 (6) ◽  
pp. 1922-1934 ◽  
Author(s):  
U Hurtenbach ◽  
D H Sachs ◽  
G M Shearer
Keyword(s):  
Major Histocompatibility Complex ◽  
Cytotoxic T Lymphocyte ◽  
Major Histocompatibility ◽  
Spleen Cells ◽  
Cell Surface Antigens ◽  
F1 Hybrid ◽  
Histocompatibility Complex ◽  
Parental Haplotype ◽  
Ctl Responses

Injection of parental spleen cells into unirradiated F1 hybrid mice results in suppression of the potential to generate cytotoxic T lymphocyte (CTL) responses in vitro. In an attempt to protect the F1 mice from immunosuppression, the recipients were injected with antibodies specific for major histocompatibility complex (MHC)-encoded antigens of the F1 mice 24 h before inoculation of the parental spleen cells. 8-14 d later, the generation of CTL responses in vitro against H-2 alloantigens was tested. Alloantiserum directed against either parental haplotype of the F1 strain markedly diminished the suppression of CTL activity. Furthermore, monoclonal antibodies recognizing H-2 or Ia antigens protected the F2 mice from parental spleen cell-induced suppression. Although this study has been limited to reagents that recognize host H-2 determinants, these findings do not necessarily imply that protection against graft vs. host (GvH) can be achieved only with anti-MHC antibodies. However, protection was observed only by antibodies reactive with F1 antigens, and small amounts of the alloantibodies were sufficient to diminish CTL suppression. Adoptive transfer of spleen cells from syngeneic F1 mice treated with anti-h-2a alloantiserum 24 h previously provided protection equal to that of injection of the recipients with alloantibodies. The cells necessary for this effect were shown to be T cells and to be radiosensitive to 2000 rad. This cell population is induced by antisera against F1 cell surface antigens and effectively counteracts GvH-associated immuno-suppression.

scholarly journals T cells specific for alpha-beta interface regions of hemoglobin recognize the isolated subunit but not the tetramer and indicate presentation without processing

1989 ◽  
Vol 86 (17) ◽  
pp. 6729-6733 ◽  
Author(s):  
M Z Atassi ◽  
M Yoshioka ◽  
G S Bixler
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Lines ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Oligomeric Protein ◽  
T Cell Lines ◽  
Antigen Presenting

Processing of a protein antigen into fragments is believed to be a prerequisite for its presentation by the antigen-presenting cell to the T cell. This model would predict that, in oligomeric proteins, T cells prepared with specificity for regions that are buried within subunit association surfaces should recognize the respective regions in vitro equally well on the isolated subunit or on the oligomer. Three hemoglobin (Hb) alpha-chain synthetic peptides, corresponding to areas that are situated either completely [alpha-(31-45)] or partially [alpha-(41-45) and alpha-(81-95)] within the interface between the alpha and beta subunits of Hb, and a fourth peptide representing a completely exposed area in tetrameric Hb were used as immunogens in SJL/J (H-2s) mice. Peptide-primed T cells were passaged in vitro with the respective peptide to obtain peptide-specific T-lymphocyte lines. T-cell clones were isolated from these lines by limiting dilution. T-cell lines and clones that were specific for buried regions in the subunit association surfaces recognized the free peptide and the isolated subunit but not the Hb tetramer. On the other hand, T cells with specificity against regions that are not involved in subunit interaction and are completely exposed in the tetramer recognized the peptide, the isolated subunit, and the oligomeric protein equally well. The responses of the T-cell lines and clones were major histocompatibility complex-restricted. Since the same x-irradiated antigen-presenting cells were employed, the results could not be attributed to differences or defects in Hb processing. The findings indicate that in vitro the native (unprocessed and undissociated) oligomeric protein was the trigger of major histocompatibility complex-restricted T-cell responses.

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