scholarly journals Antigen-reactive T cell clones. I. Transcomplementing hybrid I-A-region gene products function effectively in antigen presentation.

1980 ◽  
Vol 152 (4) ◽  
pp. 759-770 ◽  
Author(s):  
M Kimoto ◽  
C G Fathman

Studies in our laboratory and elsewhere have shown that it is possible to propagate antigen-specific murine T cells in vitro with resultant specific stepwise enrichment of antigen-induced proliferative cells. The proliferative responses of these T cells are antigen specific and dependent upon the presence of antigen-presenting cells (spleen cells) that share the I-A subregion with the proliferating T cell. Using techniques of soft-agar cloning, it has been further possible to isolate clones of antigen-reactive T lymphocytes from such long-term cultures. Data suggesting that these were clones of antigen-reactive T cells were obtained by studying the recognition of antigen in association with antigen-presenting cells with a panel of such clones of antigen-reactive T cells. Proof of clonality was obtained by subcloning. Clones derived from F1-immune mice can be divided into three separate categories: one clone recognizes antigen in association with antigen-presenting determinants of parent A and the F1; the second type recognizes antigen in association with antigen-presenting determinants of parent B and the F1; and the third type recognizes antigen only in association with antigen-presenting determinants of the F1 mouse. Genetic studies on the major histocompatibility complex requirements for antigen presentation to such F1-reactive T cell clones suggests that the hybrid antigen-presenting determinant in this system results from transcomplementation of products of the I-A region of haplotypes a and b. These studies support the concept developed in our laboratory that there exist unique F1 hybrid determinants on (A/J X C57BL/6) F1 cells and suggest that these determinants can be utilized physiologically by hybrid mice in immunocompetent cellular interactions.

1981 ◽  
Vol 154 (3) ◽  
pp. 883-891 ◽  
Author(s):  
M Kimoto ◽  
T J Krenz ◽  
C G Fathman

Long-term-cultured poly(Tyr, Glu)-poly-D,L,-Ala-poly-Lys [(T,G)-A--L]-reactive T cells and clones derived from (high responder x low responder)F1 [(C57BL/6 x A/J)F1] mice were shown to recognize (T,G)-A--L presented by cells from low responder strain A/J mice. The antigen-presenting determinant(s) that allowed recognition of (T,G)-A--L by such T cell clones was controlled by the I-A subregion of the major histocompatibility complex. These results suggest that there is no functional defect in the ability of low responder Ir gene products (I-A antigens) to associate with (T,G)-A--L for effective recognition by T cells. Although these results might tentatively be interpreted to suggest that Ir gene-controlled low responsiveness is due to the inability of the T cell to recognize the association between (T,G)-A--L and low responder I-A gene products, it is similarly possible that there might be a defect in the functional capabilities of low responder antigen-presenting cells to effectively process (T,G)-A--L into immunodominant epitopes.


1992 ◽  
Vol 176 (3) ◽  
pp. 875-880 ◽  
Author(s):  
S Sidhu ◽  
S Deacock ◽  
V Bal ◽  
J R Batchelor ◽  
G Lombardi ◽  
...  

The ability of two HLA-DR-expressing human T cell clones to function as antigen-presenting cells (APC) was investigated using highly purified T cells. The results demonstrated that these T cell clones are unable to act as autonomous APC, and that recognition of nominal or alloantigens on the surface of T cells leads to a state of nonresponsiveness. The first observation was that a T cell clone with specificity for the 306-324 peptide of influenza hemagglutinin (HA), and raised from a DR1 responder, exhibited apparent degeneracy of major histocompatibility complex restriction when cultured with peptide in the presence of peripheral blood mononuclear cells (PBMC) expressing a wide variety of structurally unrelated DR types. However, when the PBMC were pulsed with peptide and washed before coculture with the clone, peptide was exclusively recognized with DR1Dw1. This implied that in the presence of soluble peptide the T cells were displaying ligand to each other, and that the third-party APC were providing costimulatory signals. To test the ability of T cells to act as autonomous APC, accessory cell-free preparations of two DR1-restricted clones were cultured with peptide in the presence or the absence of added B cell APC. T cell purity was established by the absence of proliferation in response to the mitogen phytohemagglutinin (PHA). PHA-nonresponsive T cells were completely unable to proliferate in response to peptide alone; furthermore, preculture of the HA-specific clone, in the complete absence of accessory cells, with the same concentration of peptide (1 microgram/ml) that induced optimal proliferation when presented by conventional APC, led to profound nonresponsiveness. The same phenomenon was also observed when two of three anti-DR1 alloreactive T cell clones were precultured with a DR1-expressing T cell clone. The ability of the DR1-expressing clone to induce nonresponsiveness in anti-DR1 clones correlated with recognition of the DR1 alloantigen on the DR1-expressing clone.


1998 ◽  
Vol 187 (10) ◽  
pp. 1611-1621 ◽  
Author(s):  
Sarah E. Townsend ◽  
Christopher C. Goodnow

Antigen-specific B cells are implicated as antigen-presenting cells in memory and tolerance responses because they capture antigens efficiently and localize to T cell zones after antigen capture. It has not been possible, however, to visualize the effect of specific B cells on specific CD4+ helper T cells under physiological conditions. We demonstrate here that rare T cells are activated in vivo by minute quantities of antigen captured by antigen-specific B cells. Antigen-activated B cells are helped under these conditions, whereas antigen-tolerant B cells are killed. The T cells proliferate and then disappear regardless of whether the B cells are activated or tolerant. We show genetically that T cell activation, proliferation, and disappearance can be mediated either by transfer of antigen from antigen-specific B cells to endogenous antigen-presenting cells or by direct B–T cell interactions. These results identify a novel antigen presentation route, and demonstrate that B cell presentation of antigen has profound effects on T cell fate that could not be predicted from in vitro studies.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Eytan Breman ◽  
Jurjen M. Ruben ◽  
Kees L. Franken ◽  
Mirjam H. M. Heemskerk ◽  
Dave L. Roelen ◽  
...  

In organ transplantation, alloantigens are taken up by antigen presenting cells and presented via the indirect pathway to T-cells which in turn can induce allograft rejection. Monitoring of these T-cells is of major importance; however no reliable assay is available to routinely monitor indirect allorecognition. Recently we showed that HLA monomers can be successfully used to monitor indirect allorecognition. Targeting antigens to endocytic receptors on antigen presenting cells may further enhance the presentation of antigens via HLA class II and improve the efficiency of this assay. In the current study we explored targeting of HLA monomers to either CD89 expressing monocytes or mannose receptor expressing dendritic cells. Monomer-antibody complexes were generated using biotin-labeled monomers and avidin labeling of the antibodies. We demonstrate that targeting the complexes to these receptors resulted in a dose-dependent HLA class II mediated presentation to a T-cell clone. The immune-complexes were efficiently taken up and presented to T-cells. However, the level of T-cell reactivity was similar to that when only exogenous antigen was added. We conclude that HLA-A2 monomers targeted for presentation through CD89 on monocytes or mannose receptor on dendritic cells lead to proper antigen presentation but do not enhance indirect allorecognition via HLA-DR.


2021 ◽  
Vol 23 (1) ◽  
pp. 137
Author(s):  
Tom J. Harryvan ◽  
Sabine de Lange ◽  
Lukas J. A. C. Hawinkels ◽  
Els M. E. Verdegaal

Professional antigen-presenting cells (APCs), such as dendritic cells and macrophages, are known for their ability to present exogenous antigens to T cells. However, many other cell types, including endothelial cells, fibroblasts, and lymph node stromal cells, are also capable of presenting exogenous antigens to either CD8+ or CD4+ T cells via cross-presentation or major histocompatibility complex (MHC) class II-mediated presentation, respectively. Antigen presentation by these stromal nonprofessional APCs differentially affect T cell function, depending on the type of cells that present the antigen, as well as the local (inflammatory) micro-environment. It has been recently appreciated that nonprofessional APCs can, as such, orchestrate immunity against pathogens, tumor survival, or rejection, and aid in the progression of various auto-immune pathologies. Therefore, the interest for these nonprofessional APCs is growing as they might be an important target for enhancing various immunotherapies. In this review, the different nonprofessional APCs are discussed, as well as their functional consequences on the T cell response, with a focus on immuno-oncology.


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