Influence of LTB4 on CD4-, CD8- thymocytes. Evidence that LTB4 plus IL-2 generate CD8+ suppressor thymocytes involved in tolerance to self. Effect of LTB4 and IL-2 on double negative thymocytes.
Leukotriene B4 (LTB4) is produced by a large variety of cells involved in immune response and it has been demonstrated that this arachidonic acid metabolite acts as an immunomodulator. Because LTB4 and IL-2 both influence the physiology of immature cells we studied the effects of the leukotriene on double negative thymocytes. For that purpose C57 Bl/6 double negative thymocytes were treated by LTB4 plus IL-2 in the presence of either autologous or allogenic red blood cells (RBC). Then, preincubated CD4- CD8- thymocytes were cocultured with red blood cells stimulated fresh splenocytes. We observed that fresh splenocytes responding to autologous RBC were CD4+ cells and that the proliferative response of spleen lymphocytes driven by RBC was inhibited by preincubated double negative thymocytes. On the other hand a majority of double negative thymocytes overnight preincubated in vitro in the presence of both IL-2 and LTB4 give rise to CD8+ CD4- cells. Therefore we speculate that LTB4 plus IL-2 generate CD8+ suppressor thymocytes among double negative thymocytes and that these suppressive T cells are involved in tolerance to self.
Gualde
N
N
Fondation Bergonié, Université de Bordeaux II, France.
Cogny van Weydevelt
F
F
Buffière
F
F
Jauberteau
M O
MO
Daculsi
R
R
Vaillier
D
D
D000818:Animals; D015704:CD4 Antigens / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D016827:CD8 Antigens / Q000032:analysis*; D002478:Cells, Cultured; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D007376:Interleukin-2 / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology
D015704:CD4 Antigens; D016827:CD8 Antigens; D007376:Interleukin-2; D007975:Leukotriene B4