In vitro effects of 4-hydroperoxycyclophosphamide on concanavalin A-induced human suppressor T cells

1984 ◽  
Vol 18 (2) ◽  
Author(s):  
Abraham Klajman ◽  
Ilana Drucker ◽  
Yosef Manor ◽  
Shlomo Ben-Efraim
1982 ◽  
Vol 156 (3) ◽  
pp. 918-923 ◽  
Author(s):  
M S Sy ◽  
S H Lee ◽  
M Tsurufuji ◽  
K L Rock ◽  
B Benacerraf ◽  
...  

Treatment of responder cells with monoclonal anti-Ly-1,2 antibodies plus complement in vitro completely eliminated their ability to generate azobenzenearsonate (ABA)-specific cytolytic T lymphocytes (CTL). However, addition of the concanavalin A-stimulated supernatants of rat spleen cells (Con A-Sup) can fully reconstitute the response. Therefore, Lyt-1,2-bearing T cells are required for the generation of ABA-specific CTL, and such requirement can be replaced by factors present in the Con A- sup. Suppressor T cells (Ts), when adoptively transferred into naive recipients, will inhibit the in vivo priming of CTL. This inhibition can also be reversed by in vitro addition of Con A-Sup. furthermore, mice serving as donors of Ts also show profound unresponsiveness when primed and restimulated in vitro. In contrast to the Ts-mediated inhibition, in vitro addition of Con A-Sup was unable to abolish the unresponsiveness observed in these cultures. Thus, we identified two unresponsive states in a hapten-specific killing system that differ in their ability to be reconstituted by Con A-Sup.


1976 ◽  
Vol 143 (4) ◽  
pp. 919-936 ◽  
Author(s):  
D Redelman ◽  
C B Scott ◽  
H W Sheppard ◽  
S Sell

The late B-cell proliferative phase of the in vitro antibody response by rabbit spleen cells is highly susceptible to suppression by activated T cells. The in vitro antisheep erythrocyte plaque-forming cell (PFC) response by spleen cells from normal or primed rabbits can be suppressed by adding concanavalin A (Con A), Con A-prestimulated peripheral blood or spleen lymphocytes, or supernates from Con A-prestimulated peripheral blood lymphocytes. The suppression is not mediated by a direct interaction of Con A with responding cells as shown by the effectiveness of prestimulated cells. Primed spleen cultures remain sensitive to Con A suppression as late as 72 h after initiation, and the addition of Con A after 24-72 h rapidly stops the increase in the number of PFC. T cells are required for Con A addition to be effective but the suppression can be induced at a time when T-helper cells are no longer necessary. Further, the suppressive effect of Con A addition is abrogated by specific antisera to rabbit T cells. We propose that Con A activates suppressor T cells which then exert their effects on proliferating PFC or their immediate precursor B cells. The early inductive or recruitment phase of the response is probably not blocked by suppressor cells. Also, there is an apparent relationship between the number of proliferating B cells and the number of suppressor cells required. Finally, the difficulties in inducing a stimulatory effect by Con A and the prolonged period that Con A addition is suppressive suggests that the rabbit has relatively more and/or longer-lived suppressor cells than the mouse and may be a particularly useful species for studying suppressive phenomena and their mechanisms.


1981 ◽  
Vol 3 (2) ◽  
pp. 75-84 ◽  
Author(s):  
T. Fuchs ◽  
L. Hammarström ◽  
C.I.E. Smith ◽  
J. Brundin

1979 ◽  
Vol 149 (6) ◽  
pp. 1371-1378 ◽  
Author(s):  
B S Kim

Normal BALB/c spleen cells are unresponsive in vitro to the phosphorylcholine (PC) determinant in the presence of anti-idiotype antibodies specific for the TEPC-15 myeloma protein (T15) which carries an idiotypic determinant indistinguishable from that of most anti-PC antibodies in BALB/c mice. The possibility that idiotype-specific suppressor cells may be generated during the culture period was examined by coculturing the cells with untreated syngeneic spleen cells. Cells that had been preincubated with anti-T15 idiotype (anti-T15id) antibodies and a PC-containing antigen, R36a for 3 d, were capable of specifically suppressing the anti-PC response of fresh normal spleen cells, indicating that idiotype-specific suppressor cells were generated during the culture period. The presence of specific antigen also appeared to be necessary because anti-T15id antibodies and a control antigen, DNP-Lys-Ficoll, were not capable of generating such suppressor cells. Suppressor cells were induced only in the population of spleen cells nonadherent to nylon wool and the suppressive activity was abrogated by treatment with anti-Thy 1.2 serum and complement. These results indicate that anti-idiotype antibodies and specific antigen can generate idiotype-specific suppressor T cells in vitro. These in vitro results may reflect in vivo mechanisms of idiotype suppression.


1983 ◽  
Vol 6 (1) ◽  
pp. 23-31
Author(s):  
Morihiro Ohara ◽  
Satoshi Igarashi ◽  
Chikara Kobashi ◽  
Masami Shirato ◽  
Masayuki Miyata ◽  
...  

1977 ◽  
Vol 145 (1) ◽  
pp. 163-174 ◽  
Author(s):  
A S Kong ◽  
S I Morse

The mitogenic response of murine lymphocytes to the lymphocytosis-promoting factor of Bordetella pertussis has been shown to be due to activation of T cells. The selectivity of responsiveness to LPF with respect to the population of T cells which is stimllated, differs from that of PHA as well as Con A, and the surface receptors are different. A population of adherent cells, which does not appear to consist of macrophages or other phagocytic cells, is required for the T-cell response.


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