IL-15-independent antiviral function of primary and memory CD8+ T cells.
Memory CD8+ T cells are comprised of CD122hi IL-15-dependent and CD122lo IL-15-independent subsets. Induction and retention of IL-15-independent memory CD8+ T cells was assessed in IL-15-/- and wild-type (wt) mice immunized with recombinant vaccinia virus (rVV) or Sindbis virus (rSIN) vectors expressing the identical foreign epitope. Both vectors induced epitope-specific CD8+ T cell expansion and function, independent of IL-15. Similar kinetics of rVV clearance confirmed effective CD8+ T cell function in IL-15-/- mice. CD44hi CD122hi CD8+ T cells, mainly of the CD62L-/lo phenotype, increased more dramatically and declined more rapidly in IL-15-/- mice, independent of the vector. Rapid IL-15-independent memory CD8+ T cell expansion following challenge of immune mice compensated for the limited memory CD8+ populations in IL-15-/- mice. However, despite expansion and expression of potent effector function, viral clearance was delayed in the absence of IL-15, coinciding with a rapid loss in cytolytic function.
Zuo
Jun
J
Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, CA 90033, USA.
Stohlman
Stephen A
SA
Bergmann
Cornelia C
CC
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D007156:Immunologic Memory / Q000276:immunology*; D019409:Interleukin-15 / Q000172:deficiency / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D012845:Sindbis Virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology
D000939:Epitopes; D018984:Epitopes, T-Lymphocyte; D019409:Interleukin-15; D014614:Vaccines, Synthetic