title: Interleukin 2/interleukin 4-independent T helper cell generation during an in vitro antigenic stimulation of mouse spleen cells in the presence of cyclosporin A.
abstract: Cyclosporin A (CsA), an immunosuppressive drug which completely suppresses the humoral response to thymus-dependent antigens, does not affect the generation of T helper (Th) cells during an in vitro stimulation of murine spleen cells with sheep red blood cells. The appearance of Th cells depends on time and their development can be prevented by X-ray irradiation performed at the onset of the culture and up to 3-4 days later; however, beyond this time, irradiation is ineffective, suggesting that cell proliferation is essentially completed by this time. The activity of Th cells generated in the presence of CsA is resistant to irradiation, indicating that the effector cells belong to a memory subset. Limiting dilution analysis has shown that the frequency of the Th cells recovered from 6-day sheep red blood cell-stimulated and CsA-treated cultures is of approximately 1.4 X 10(-3), representing an increment of about 500-fold compared to naive spleen cells. The increased frequency of Th cells and the sensitivity to irradiation of the generation of these cells demonstrate that Th cell precursors proliferate in the presence of CsA. Lymphokine genes transcription analysis confirms that the inhibition of interleukin (IL) 2/IL 4 gene expression is one target of CsA action. That the generation of Th memory cells can nevertheless take place strongly argues in favor of the existence of an IL 2/IL 4-independent pathway for murine T cell proliferation. Our finding that the transcription of the IL 7 gene is not inhibited by CsA raises the possibility for a role of this T cell growth factor in the generation of memory Th cells.
authors.affiliation: Unité d'Immunophysiologie Moléculaire, Institut Pasteur, Paris, France.
authors.forename: I
authors.initials: I
authors.lastname: Motta
authors.forename: J H
authors.initials: JH
authors.lastname: Colle
authors.forename: B
authors.initials: B
authors.lastname: Shidani
authors.forename: P
authors.initials: P
authors.lastname: Truffa-Bachi
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens; D003524:Cyclosporins / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D007156:Immunologic Memory / Q000187:drug effects; D007376:Interleukin-2 / Q000502:physiology*; D015847:Interleukin-4 / Q000502:physiology*; D015848:Interleukin-5 / Q000235:genetics; D015851:Interleukin-7 / Q000235:genetics; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D003524:Cyclosporins; D007376:Interleukin-2; D015848:Interleukin-5; D015851:Interleukin-7; D009841:Oligonucleotides; D015847:Interleukin-4