Direct CD4 help provision following interaction of memory CD4 and CD8 T cells with distinct antigen-presenting dendritic cells.
Accumulating evidence suggests that CD4 help is needed at the memory stage to mount effective secondary CD8 T cell responses. In this paper, we report that memory CD4 T cells can provide efficient help to memory CD8 T cells after interaction of the two lymphocytes with distinct dendritic cells. Provision of help to CD8 T cells required direct cell-cell contact and involved both IL-2 and CD40 ligation, within a CD4-CD8 T cell synapse. Thus, following antigenic interaction with APCs, activated memory CD4 and CD8 T cells appear to separate from their respective APCs before meeting each other for help provision, regardless of their Ag specificity. CD4 help for memory CD8 T cells therefore appears to be conditioned primarily not by Ag specificity but by activation status.
de Goër de Herve
Marie-Ghislaine
MG
Institut National de la Santé et de la Recherche Médicale U-1012, Université Paris-Sud, Faculté de Médecine, 94276 Le Kremlin-Bicêtre, France.
Dembele
Bamory
B
Vallée
Mélissa
M
Herr
Florence
F
Cariou
Anne
A
Taoufik
Yassine
Y
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D019013:CD40 Antigens / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018827:Carcinoma, Lewis Lung / Q000276:immunology / Q000473:pathology; D002450:Cell Communication / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D053804:Granzymes / Q000378:metabolism; D007156:Immunologic Memory / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008285:Major Histocompatibility Complex / Q000235:genetics / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout
D019013:CD40 Antigens; D007376:Interleukin-2; D053804:Granzymes