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.

scholarly journals A pathway of costimulation that prevents anergy in CD28- T cells: B7-independent costimulation of CD1-restricted T cells.

1995 ◽  
Vol 182 (6) ◽  
pp. 2007-2018 ◽  
Author(s):  
S M Behar ◽  
S A Porcelli ◽  
E M Beckman ◽  
M B Brenner
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Lines ◽  
Cd8 T Cells ◽  
Major Histocompatibility ◽  
Costimulatory Signal ◽  
Histocompatibility Complex ◽  
Costimulatory Signals ◽  
T Cell Lines

A class of molecules that is expressed on antigen presenting cells, exemplified by CD80 (B7), has been found to provide a necessary costimulatory signal for T cell activation and proliferation. CD28 and CTLA4 are the B7 counterreceptors and are expressed on the majority of human CD4+ T cells and many CD8+ T cells. The signal these molecules mediate is distinguished from other costimulatory signals by the finding that T cell recognition of antigen results in a prolonged state of T cell unresponsiveness or anergy, unless these costimulatory molecules are engaged. However, nearly half of the CD8+ and CD4-CD8- T cells lack CD28, and the costimulatory signals required for the activation of such cells are unknown. To understand the pathways of activation used by CD28- T cells, we have examined the costimulatory requirements of antigen-specific CD4-CD8- TCR(+)-alpha/beta circulating T cells that lack the expression of CD28. We have characterized two T cell lines, DN1 and DN6, that recognize a mycobacterial antigen, and are restricted not by major histocompatibility complex class I or II, but by CD1b or CD1c, two members of a family of major histocompatibility complex-related molecules that have been recently implicated in a distinct pathway for antigen presentation. Comparison of antigen-specific cytolytic responses of the DN1 and DN6 T cell lines against antigen-pulsed CD1+ monocytes or CD1+ B lymphoblastoid cell lines (B-LCL) demonstrated that these T cells recognized antigen presented by both types of cells. However, T cell proliferation occurred only when antigen was presented by CD1+ monocytes, indicating that the CD1+ monocytes expressed a costimulatory molecule that the B-LCL transfectants lacked. This hypothesis was confirmed by demonstrating that the T cells became anergic when incubated with the CD1(+)-transfected B-LCL in the presence of antigen, but not in the absence of antigen. The required costimulatory signal occurred by a CD28-independent mechanism since both the CD1+ monocytes and CD1+ B-LCL transfectants expressed B7-1 and B7-2, and DN1 and DN6 lacked surface expression of CD28. We propose that these data define a previously unrecognized pathway of costimulation for T cells distinct from that involving CD28 and its counterreceptors. We suggest that this B7-independent pathway plays a crucial role in the activation and maintenance of tolerance of at least a subset of CD28- T cells.

scholarly journals H2-M3 Major Histocompatibility Complex Class Ib-Restricted CD8 T Cells Induced by Salmonella enterica Serovar Typhimurium Infection Recognize Proteins Released by Salmonella Serovar Typhimurium

2005 ◽  
Vol 73 (12) ◽  
pp. 8002-8008 ◽  
Author(s):  
S. Ugrinovic ◽  
C. G. Brooks ◽  
J. Robson ◽  
B. A. Blacklaws ◽  
C. E. Hormaeche ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Lines ◽  
Cd8 T Cells ◽  
Histocompatibility Complex ◽  
Serovar Typhimurium ◽  
T Cell Lines ◽  
Culture Supernatants ◽  
Class Ib

ABSTRACT Salmonella enterica serovar Typhimurium causes a typhoid-like disease in mice which has been studied extensively as a model for typhoid fever in humans. CD8 T cells contribute to protection against S. enterica serovar Typhimurium in mice, but little is known about the specificity and major histocompatibility complex (MHC) restriction of the response. We report here that CD8 T-cell lines derived from S. enterica serovar Typhimurium-infected BALB/c mice lysed bone marrow macrophages infected with S. enterica serovar Typhimurium or pulsed with proteins from S. enterica serovar Typhimurium culture supernatants. Cytoxicity was beta-2-microglobulin dependent and largely TAP dependent, although not MHC class Ia restricted, as target cells of several different MHC haplotypes were lysed. The data suggested the participation of class Ib MHC molecules although no evidence for the presence of Qa1-restricted T cells could be found, unlike in previous reports. Instead, the T-cell lines lysed H2-M3-transfected fibroblasts infected with S. enterica serovar Typhimurium SL3261 or treated with Salmonella culture supernatants. Thus, this report increases the number of MHC class Ib antigen-presenting molecules known for Salmonella antigens to three: Qa-1, HLA-E, and now H2-M3. It also expands the range of pathogens that induce H2-M3-restricted CD8 T cells to include an example of gram-negative bacteria.

scholarly journals Major histocompatibility complex-restricted, polyclonal B cell responses resulting from helper T cell recognition of antiimmunoglobulin presented by small B lymphocytes.

1985 ◽  
Vol 161 (1) ◽  
pp. 223-241 ◽  
Author(s):  
H P Tony ◽  
D C Parker
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Lines ◽  
Major Histocompatibility ◽  
Helper T Cell ◽  
Histocompatibility Complex ◽  
T Cell Lines

Anti-Ig has been widely used as a model for antigen receptor-mediated B cell activation. B cells activated with mitogenic concentrations of anti-Ig (approximately 10 micrograms/ml) become responsive to a set of T cell-derived, antigen-nonspecific helper factors that enable the B cells to proliferate, and, in some cases, mature to Ig secretion. In the present experiments, we show that anti-Ig can also be used as a model for major histocompatibility complex (MHC)-restricted, antigen-specific T-B cell collaboration. We used murine helper T cell lines and T cell hybridomas specific for a protein antigen, the F(ab')2 fragment of normal rabbit IgG. Small B cells are very efficient at presenting rabbit anti-IgM or rabbit anti-IgD to these rabbit Ig-specific T cell lines and hybridomas, and the responding (initially) small B cells, appear to be the only antigen-presenting cells required. Efficient presentation depends upon binding of rabbit antibody to mIg on the B cell surface. MHC-restricted recognition of rabbit Ig determinants on the B cell surface results in a polyclonal B cell response. This response is qualitatively different from the well-studied response to blastogenic concentrations of anti-Ig plus stable, T cell-derived helper factors, since it (a) requires 1,000-fold lower concentrations of anti-Ig, (b) involves helper T cell functions other than, or in addition to, the local production of the same stable helper factors, and (c) is largely MHC-restricted at the T-B cell level.

scholarly journals Immunoglobulin E–independent Major Histocompatibility Complex–restricted T Cell Peptide Epitope–induced Late Asthmatic Reactions

1999 ◽  
Vol 189 (12) ◽  
pp. 1885-1894 ◽  
Author(s):  
Brigitte M. Haselden ◽  
A. Barry Kay ◽  
Mark Larché
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Lines ◽  
Fibroblast Cell ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Fel D 1 ◽  
Cat Allergen ◽  
Fibroblast Cell Lines

Intradermal administration of short overlapping peptides derived from chain 1 of the cat allergen Fel d 1 (FC1P) that did not cross-link IgE, elicited isolated late asthmatic reactions with no visible early or late cutaneous response in 9/40 cat-allergic asthmatics. Four of the nine were human histocompatibility leukocyte antigen DR13–positive, as compared with only 1/31 nonreactors. The other five reactors expressed either DR1 or DR4. To confirm major histocompatibility complex restriction, fibroblast cell lines transfected with HLA-DR molecules were used to present FC1Ps to cat allergen–specific T cell lines derived from subjects before peptide injection. FC1P3 (peptide 28–44 of Fel d 1 chain 1) was recognized in the context of DR13 alleles (DRB1*1301, 1302) and induced specific T cell proliferation and IL-5 production. T cells from a DR1+ responder proliferated and produced IL-5 in the presence of FC1P3 and DR1 (DRB1*0101) fibroblast cell lines, whereas T cells from a DR4+ subject recognized FC1P2 (peptide 22–37) when presented by DRB1*0405. We conclude that short, allergen-derived peptides can directly initiate a major histocompatibility complex–restricted, T cell–dependent late asthmatic reaction, without the requirement for an early IgE/mast cell–dependent response, in sensitized asthmatic subjects.

Generation of Autologous Pre-B Acute Lymphocytic Leukemia (ALL) Reactive T Cell Lines Using ALL Blasts as Antigen Presenting Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2035-2035
Author(s):  
Rui-kun Zhong ◽  
Thomas A. Lane ◽  
Edward D Ball
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Acute Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Cd40 Expression ◽  
T Cell Lines ◽  
Antigen Presenting ◽  
Cytokine Combination

Abstract 2035 Poster Board II-12 Although hematologic remissions can be achieved in the majority of patients with adult acute lymphocytic leukemia (ALL) by chemotherapy, long term survival is only 30–40%. The inability of the immune system to recognize and eliminate residual malignant leukemia cells may be an important mechanism contributing to relapse. In this study, we investigated the possibility of using pre-B-ALL cells as antigen presenting cells in an in vitro culture to induce autologous ALL reactive T cells. After 7 day culture of Pre-B-ALL peripheral blood mononuclear cells (CD19+ 93±4%) in 96 well culture plates in culture medium supplemented with a cytokine combination of IL-2/IL-3/IL-4/IL-7/GM-CSF, CD80, CD86, CD83, CD54, HLA-Dr and CD40 expression was analyzed. Significant enhancement of CD80, CD86, CD83 and CD40 on ALL cells was observed (n=8, P≦0.001-0.02). Addition of lipopolysaccharide (LPS) to the cytokine combination further increased CD80, CD86 or CD40 expression by 3 of 8 ALL samples above the baseline enhancement by cytokines (Figure), while CD40 ligand (CD40L) enhanced expression of the co-stimulatory molecules in 4 of 8 cases. Autologous T cells remaining in the culture after day 7 were then expanded with high dose IL-2 and autologous ALL reactive T cell lines were identified by IFN-g release by T cells in response to autologous ALL cells. Autologous ALL reactive T cells were generated from 5 of 8 pre-B ALL samples studied. The data from 3 experiments demonstrated that although the cytokine combination plus LPS or CD40L could effectively induce ALL cell expression of co-stimulatory molecules, the presence of CD40L and LPS in the culture induced significantly greater activation of autologous ALL-reactive T cells than did the cytokine combination plus LPS alone, as assessed by average IFN-g release of 24-48 culture wells (P≦0.004). ALL-reactive T cell lines selected by high IFN-g release response showed effective elimination of autologous ALL cells in a 2 day co-culture assay with an E:T ratio of 1:1 by flow cytometry analysis. Average residual CD19+ cells was 2.0±1.4% for highly reactive T cell lines (n=17) vs 16.5±25.9% for the less reactive control T cell lines (n=9) (P<0.02). Conclusion: Autologous ALL-reactive T cells can be induced from most ALL patients in an in vitro culture with a cytokine combination. Adoptive transfer of these anti-ALL CTL to patients is a possible therapeutic approach for further study. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The major histocompatibility complex-restricted antigen receptor on T cells. II. Role of the L3T4 product.

1983 ◽  
Vol 158 (4) ◽  
pp. 1077-1091 ◽  
Author(s):  
P Marrack ◽  
R Endres ◽  
R Shimonkevitz ◽  
A Zlotnik ◽  
D Dialynas ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Receptor ◽  
Surface Expression ◽  
High Avidity ◽  
Low Doses ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

We have examined the role of the murine homologue of Leu-3 T4, L3T4, in recognition of antigen in association with products of the major histocompatibility complex (Ag/MHC) by murine T cell hybridomas. A series of ovalbumin (OVA)/I-Ad-specific T cell hybridomas were ranked in their sensitivity to Ag/I by measuring their ability to respond to low doses of OVA, or their sensitivity to inhibition by anti-I-Ad antibodies. T cell hybridomas with low apparent avidity for OVA/I-Ad, i.e. that did not respond well to low concentrations of OVA and were easily inhibited by anti-I-Ad, were also easily inhibited by anti-L3T4 antibodies. The reverse was true for T cell hybridomas with apparent high avidity for Ag/MHC. We found that the presence of low doses of anti-L3T4 antibodies caused T cell hybridomas to respond less well to low doses of Ag, and to be more easily inhibited by anti-I-Ad antibodies. These results suggested that the role of the L3T4 molecule is to increase the overall avidity of the reaction between T cells and Ag-presenting cells. In support of this idea was the discovery of several L3T4- subclones of one of our L3T4+ T cell hybridomas, D0.11.10. The L3T4- subclones had the same amount of receptor for OVA/I-Ad as their L3T4+ parent, as detected by an anti-receptor monoclonal antibody. The L3T4- subclones, however, responded less well to low doses of OVA, and were more easily inhibited by anti-I-Ad antibodies than their L3T4/ parent. These results showed that the L3T4 molecule was not required for surface expression of, or functional activity of, the T cell receptor for Ag/MHC. The L3T4 molecule did, however, increase the sensitivity with which the T cell reacted with Ag/MHC on Ag-presenting cells.

scholarly journals The Role of Peptides in T Cell Alloreactivity Is Determined by Self–Major Histocompatibility Complex Molecules

2000 ◽  
Vol 191 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Reinhard Obst ◽  
Nikolai Netuschil ◽  
Karsten Klopfer ◽  
Stefan Stevanović ◽  
Hans-Georg Rammensee
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Target Cells ◽  
Major Histocompatibility ◽  
Complex Molecules ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
Alloreactive T Cells

By analyzing T cell responses against foreign major histocompatibility complex (MHC) molecules loaded with peptide libraries and defined self- and viral peptides, we demonstrate a profound influence of self-MHC molecules on the repertoire of alloreactive T cells: the closer the foreign MHC molecule is related to the T cell's MHC, the higher is the proportion of peptide-specific, alloreactive (“allorestricted”) T cells versus T cells recognizing the foreign MHC molecule without regard to the peptide in the groove. Thus, the peptide repertoire of alloreactive T cells must be influenced by self-MHC molecules during positive or negative thymic selection or peripheral survival, much like the repertoire of the self-restricted T cells. In consequence, allorestricted, peptide-specific T cells (that are of interest for clinical applications) are easier to obtain if T cells and target cells express related MHC molecules.

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