title: Immunization with live attenuated simian immunodeficiency virus induces strong type 1 T helper responses and beta-chemokine production.
abstract: Immunization with live attenuated simian immunodeficiency virus (SIV) strains has proved to be one of the most effective strategies to induce protective immunity in the SIV/macaque model. To better understand the role that CD4(+) T helper responses may play in mediating protection in this model, we characterized SIV-specific proliferative and cytokine responses in macaques immunized with live attenuated SIV strains. Macaques chronically infected with live attenuated SIV had strong proliferative responses to SIV proteins, with stimulation indices of up to 74. The magnitude of the proliferative response to SIV Gag varied inversely with the degree of attenuation; Gag-specific but not envelope-specific responses were lower in animals infected with more highly attenuated SIV strains. SIV-specific stimulation of lymphocytes from vaccinated macaques resulted in secretion of interferon-gamma, IL-2, regulated-upon-activation, normal T cells expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta but not IL-4 or IL-10. Intracellular flow cytometric analysis documented that, in macaques vaccinated with SIVmac239Deltanef, up to 2% of all CD4(+)T cells were specific for SIV p55. The ability of live attenuated SIV to induce a strong, sustained type 1 T helper response may play a role in the success of this vaccination approach to generate protection against challenge with wild-type SIV.
authors.affiliation: Division of Immunology, New England Regional Primate Research Center and Harvard Medical School, Southborough, MA 01772, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Gauduin
authors.forename: R L
authors.initials: RL
authors.lastname: Glickman
authors.forename: S
authors.initials: S
authors.lastname: Ahmad
authors.forename: T
authors.initials: T
authors.lastname: Yilma
authors.forename: R P
authors.initials: RP
authors.lastname: Johnson
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002455:Cell Division; D002478:Cells, Cultured; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000096:biosynthesis* / Q000378:metabolism; D015683:Gene Products, gag / Q000276:immunology; D015693:Gene Products, nef / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D007424:Intracellular Fluid / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008253:Macaca mulatta; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis* / Q000378:metabolism; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000502:physiology; D018417:Th1 Cells / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D015683:Gene Products, gag; D015693:Gene Products, nef; D007376:Interleukin-2; D019402:Macrophage Inflammatory Proteins; D014613:Vaccines, Attenuated; D014765:Viral Vaccines; C115853:simian immunodeficiency virus gag p55; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma