Cutting edge: CD4+ T cell help can be essential for primary CD8+ T cell responses in vivo.
Recent studies have shown that CD4(+) T cell help is required for the generation of memory CD8(+) T cells that can proliferate and differentiate into effector cells on Ag restimulation. The importance of help for primary CD8(+) T cell responses remains controversial. It has been suggested that help is not required for the initial proliferation and differentiation of CD8(+) T cells in vivo and that classical models of helper-dependent responses describe impaired secondary responses to Ag in vitro. We have measured primary CD8(+) T cell responses to peptide-pulsed dendritic cells in mice by cytokine ELISPOT and tetramer staining. No responses were detected in the absence of help, either when normal dendritic cells were injected into MHC II-deficient mice or when MHC II-deficient dendritic cells were injected into normal mice. Thus, the primary in vivo CD8(+) T cell response depends absolutely on help from CD4(+) T cells in our experimental system.
Wang
Jyh-Chiang E
JC
David H. Smith Center for Vaccine Biology and Immunology, Aab Institute of Biomedical Sciences, and Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA.
Livingstone
Alexandra M
AM
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism / Q000637:transplantation; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D007111:Immunity, Cellular / Q000235:genetics; D007156:Immunologic Memory / Q000235:genetics; D007371:Interferon-gamma / Q000096:biosynthesis / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000637:transplantation
D018984:Epitopes, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; D007371:Interferon-gamma; D010047:Ovalbumin