Expression and function of 4-1BB during CD4 versus CD8 T cell responses in vivo.
4-1BBL(-/-) mice have a defect in recall CD8+ T cell responses to viruses, whereas CD4+ T cell responses to virus are unimpaired in these mice. In contrast, both CD4+ and CD8+ T cells respond to 4-1BB ligand (4-1BBL) in vitro. To clarify the role of 4-1BB/4-1BBL in CD4+ versus CD8+ T cell responses in vivo, we compared CD4 (OT-II) and CD8 (OT-I) TCR transgenic T cells responding to the same antigen in an in vivo adoptive transfer model in 4-1BBL(+/+) versus 4-1BBL(-/-) mice. During primary and secondary responses, expression of 4-1BB on in vivo-activated TCR transgenic T cells was earlier and more transient than previously observed in vitro, correlating with expression of the early activation antigen CD69 and preceding the transition to the CD44hi state. Although 4-1BB is expressed early in the primary response, there was no effect of 4-1BBL deficiency on initial CD8 T cell expansion and only a minor effect on initial CD4 T cell expansion. The major effect of 4-1BB/4-1BBL interaction is on the T cell recall response. This is due to effects of 4-1BBL on maintenance of T cell numbers at the end of the primary response with additional effects of 4-1BBL on secondary expansion of T cells.
Department of Immunology, University of Toronto, Toronto, Canada.
Wojciech
W
Dawicki
Department of Immunology, University of Toronto, Toronto, Canada.
Tania H
TH
Watts
D053330:4-1BB Ligand; D019264:Adoptive Transfer; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D019672:Genes, T-Cell Receptor; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D053330:4-1BB Ligand; C505975:Tnfsf9 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D010047:Ovalbumin