Study of the lymphocyte fractions in the mixed lymphocyte culture in vitro

1967 ◽  
Vol 23 (10) ◽  
pp. 848-849 ◽  
Author(s):  
D. C. Viza

In Vitro ◽  
1977 ◽  
Vol 13 (11) ◽  
pp. 806-807 ◽  
Author(s):  
Ram S. Verma ◽  
Carole Rubenstein ◽  
Harvey Dosik


1975 ◽  
Vol 141 (2) ◽  
pp. 508-512 ◽  
Author(s):  
P Häyry ◽  
L C Andersson

T cells triggered to blast transformation and proliferation by histoincompatible cells have the capacity of reverting "back" to lymphocytes. These "secondary" lymphocytes and their progeny cells are able to respond repeatedly to the same allogeneic stimulus in vitro.



1983 ◽  
Vol 157 (1) ◽  
pp. 141-154 ◽  
Author(s):  
P J Fink ◽  
I L Weissman ◽  
M J Bevan

To detect a strong cytotoxic T lymphocyte (CTL) response to minor histocompatibility (H) antigens in a 5-d mixed lymphocyte culture, it is necessary to use a responder that has been primed in vivo with antigen-bearing cells. It has previously been shown that minor-H-specific CTL can be primed in vivo both directly by foreign spleen cells and by presentation of foreign minor H antigens on host antigen-presenting cells. This latter route is evident in the phenomenon of cross-priming, in which H-2 heterozygous (A x B)F1 mice injected 2 wk previously with minor H-different H-2A (A') spleen cells generate both H-2A- and H-2B-restricted minor-H-specific CTL. In a study of the kinetics of direct- vs. cross-priming to minors in F1 mice, we have found that minor H-different T cells actually suppress the induction of virgin CTL capable of recognizing them. CTL activity measured from F1 mice 3-6 d after injection with viable A' spleen cells is largely H-2B restricted. The H-2A-restricted response recovers such that roughly equal A- and B-restricted activity is detected in mice as early as 8-10 d postinjection. This temporary hyporeactivity does not result from generalized immunosuppression--it is specific for those CTL that recognize the foreign minor H antigen in the context of the H-2 antigens on the injected spleen cells. The injected spleen cells that mediate this suppression are radiosensitive T cells; Lyt-2+ T cells are highly efficient at suppressing the induction of CTL in vivo. No graft vs. host reaction by the injected T cells appears to be required, as suppression of direct primed CTL can be mediated by spleen cells that are wholly tolerant of both host H-2 and minor H antigens. Suppression cannot be demonstrated by in vitro mixing experiments. Several possible mechanisms for haplotype-specific suppression are discussed, including inactivation of responding CTL by veto cells and in vivo sequestration of responding CTL by the injected spleen cells.



1975 ◽  
Vol 142 (6) ◽  
pp. 1477-1487 ◽  
Author(s):  
H Wagner ◽  
D Götze ◽  
L Ptschelinzew ◽  
M Röllinghoff

Determinants controlled by the I region of the murine H-2 complex provoked the generation of cytotoxic T lymphocytes (CTL) in both a secondary and primary mixed lymphocyte culture. The stimulating determinants appeared to be controlled by loci within the I-A subregion. The target antigens of the CTL generated were present on both lipopolysaccharide- and concanavalin-induced blast lymphocytes, but were barely detectable on phytohemagglutinin-induced blast cells. The stimulating capacity for CTL induction of a complete H-2 complex incompatibility by far exceeded the sum of H-2D/K-region and I-region incompatibility, respectively.



1974 ◽  
Vol 140 (6) ◽  
pp. 1646-1659 ◽  
Author(s):  
Richard J. Hodes ◽  
Barry S. Handwerger ◽  
William D. Terry

Two subpopulations separated from normal spleen have been shown to synergize as responding cells in the in vitro induction of specific cell-mediated cytotoxicity during the mixed lymphocyte culture (MLC). The synergizing populations are a nylon wool column-adherent and a nylon wool column-nonadherent fraction, enriched for B lymphocytes and T lymphocytes, respectively. When a mixture of these fractions is used as the responding cell population in MLC, greater cytotoxicity is generated than would be expected from the sum of activities generated in the two subpopulations sensitized separately. The synergy appears to occur at the sensitization rather than the effector phase. The synergizing cell which is contained in the nylon-adherent subpopulation is distinct from the cytotoxic effector T lymphocyte, is resistant to lysis by rabbit antimouse brain serum, and is unresponsive to phytohemagglutinin; its synergizing function could not be replaced by either plastic-adherent spleen cells or peritoneal exudate cells. These results suggest a role of a non-T-cell nonmacrophage population in the generation of cytotoxic activity.



2002 ◽  
Vol 196 (3) ◽  
pp. 379-387 ◽  
Author(s):  
Francesco Annunziato ◽  
Lorenzo Cosmi ◽  
Francesco Liotta ◽  
Elena Lazzeri ◽  
Roberto Manetti ◽  
...  

Phenotypic markers, localization, functional activities, and mechanisms of action in vitro of CD4+CD25+ T cells, purified from postnatal human thymuses, were investigated. These cells showed poor or no proliferation in mixed lymphocyte culture (MLC), and suppressed in a dose-dependent fashion the proliferative response to allogeneic stimulation of CD4+CD25− thymocytes. Virtually all CD4+CD25+ thymocytes constitutively expressed cytoplasmic T lymphocyte antigen (CTLA)-4, surface tumor necrosis factor type 2 receptor (TNFR2), and CCR8. They prevalently localized to perivascular areas of fibrous septa and responded to the chemoattractant activity of CCL1/I-309, which was found to be produced by either thymic medullary macrophages or fibrous septa epithelial cells. After polyclonal activation, CD4+CD25+ thymocytes did not produce the cytokines interleukin (IL)-2, IL-4, IL-5, IL-13, interferon γ, and only a very few produced IL-10, but all they expressed on their surface CTLA-4 and the majority of them also transforming growth factor (TGF)-β1. The suppressive activity of these cells was contact dependent and associated with the lack of IL-2 receptor (IL-2R) α-chain (CD25) expression in target cells. Such a suppressive activity was partially inhibited by either anti–CTLA-4 or anti–TGF-β1, and was completely blocked by a mixture of these monoclonal antibodies, which were also able to restore in target T cells the expression of IL-2R α-chain and, therefore, their responsiveness to IL-2. These data demonstrate that CD4+CD25+ human thymocytes represent a population of regulatory cells that migrate in response to the chemokine CCL1/I-309 and exert their suppressive function via the inhibition of IL-2R α-chain in target T cells, induced by the combined activity of CTLA-4 and membrane TGF-β1.



1979 ◽  
Vol 149 (4) ◽  
pp. 824-836 ◽  
Author(s):  
J A McIntyre ◽  
W P Faulk

This report describes the inhibition of human mixed lymphocyte culture (MLC) reactions by rabbit antisera to intact and detergent solubilized, fractionated, human trophoblast membranes. Heat-inactivated antisera were passed through solid-phase immunoabsorption columns of normal human serum and extensively absorbed with human erythrocytes, lymphocytes and liver powder. Immunohistological experiments with these absorbed antisera showed that they reacted brilliantly with syncytiotrophoblast in cryostat sections of human but not baboon or monkey placentae, and not with other normal adult tissues including peripheral blood lymphocytes (PBL). Addition of these antisera to MLC reactions produced significant and reproducible suppression of responses without affecting cell viability. Absorption studies demonstrated complete removal of MLC inhibition and trophoblast membranes but not with PBL or suspensions of HEp-2 cells. Timed experiments showed that optimal inhibition occurred when the antisera were added between 2 and 6 h after culture initiation, and that little suppression was achieved after 18 h. Lymphocytes harvested from MLC reactions after 2 h showed that 3--5% of the cells reacted with PBL/liver-absorbed anti-trophoblast sera, and that unstimulated PBL were negative. Cultures of subhuman primate lymphocytes in the presence of heterologous antisera to human trophoblast membranes showed total inhibition of rhesus:human and human:rhesus MLC, and no suppression of baboon:human or human:baboon reactions, whereas human lymphocytes responded in an exagerated manner when stimulated by baboon cells. Modulated MLC responses to human, rhesus, or baboon lymphocytes, in the presence of anti-trophoblast sera indicate that the antisera recognize trophoblast cross-reactive lymphocytes antigens. We propose that these antigens are reaction products of cell-cell interactions, and that the nature of the antigens is determined by the specificity of the recognition signals which initiate the reaction.



1998 ◽  
Vol 30 (7) ◽  
pp. 2974
Author(s):  
S Agrawal ◽  
A.K Singh ◽  
R.K Sharma ◽  
A Gupta ◽  
A Kumar ◽  
...  


Blood ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 1143-1147 ◽  
Author(s):  
M Harada ◽  
S Nakao ◽  
K Kondo ◽  
K Odaka ◽  
M Ueda ◽  
...  

Abstract Autologous mixed lymphocyte culture (AMLR) is an immunologic response with memory and specificity and plays a role in immune regulation. Effects of T cells activated by AMLR were studied in the regulation of in vitro erythropoiesis. AMLR-activated T cells were cocultured with autologous non-T, nonphagocytic peripheral blood mononuclear cells for assaying erythroid progenitor cells (BFU-E). T cells activated for 3 days in AMLR showed significant enhancement of in vitro colony growth by BFU-E. In contrast, activated T cells from day 7 AMLR caused significant suppression of BFU-E growth. Both enhancing and suppressing activities of AMLR-activated T cells were mediated by an la-positive and radiosensitive population within the OKT4+ subset. These observations suggest that AMLR-activated T cells may play a role in the immune-mediated regulation of in vitro erythropoiesis. It is also suggested that heterogeneous T-cell subsets may exert regulatory functions in the regulation of in vitro hematopoiesis.



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