title: Maintenance of CD8(+) T-cell memory following infection with recombinant sindbis and vaccinia viruses.
abstract: CD8(+) T-cell memory is critical for protection against pathogens poorly controlled by humoral immunity. To characterize two distinct vaccine vectors, the acute and memory CD8(+) T-cell responses to an HIV-1 epitope (p18) expressed by recombinant vaccinia (vp18) and Sindbis (SINp18) viruses were compared. Whereas 9 to 13% of CD8(+) splenocytes were p18 specific during the acute response to vp18, 4% were induced by SINp18 as revealed by class I tetramer staining. Increased T-cell activation by vp18 was confirmed by higher numbers of both p18-specific IFN-gamma-secreting splenocytes and activated CD8(+) and CD4(+) T cells. Although higher frequencies of p18-specific CD8(+) T cells during primary responses correlated with higher frequencies during memory, the overall decline was only two- to threefold during the transition to memory, demonstrating equally efficient maintenance of memory in SINp18- as in vp18-immune mice. Despite modest in vivo activation, SINp18-induced CD4(+) T cells secreted substantial amounts of IFN-gamma and IL-2, potentially contributing to sustained CD8(+) memory. Collectively the data indicate that Sindbis virus recombinants provide effective vaccines for inducing protective memory CD8(+) T cells in the absence of the extensive inflammation and replication associated with vaccinia virus.
authors.affiliation: Department of Neurology, University of Southern California Keck School of Medicine, Los Angeles, California 90033, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Villacres
authors.forename: J
authors.initials: J
authors.lastname: Zuo
authors.forename: C C
authors.initials: CC
authors.lastname: Bergmann
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology; D005260:Female; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; 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; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014779:Virus Replication
chemical_list: D000956:Antigens, Viral; D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D015699:HIV Envelope Protein gp120; D014614:Vaccines, Synthetic; D014765:Viral Vaccines