title: Induction of CD8+ cells able to suppress CCR5-tropic simian immunodeficiency virus SIVmac239 replication by controlled infection of CXCR4-tropic simian-human immunodeficiency virus in vaccinated rhesus macaques.
abstract: Recent recombinant viral vector-based AIDS vaccine trials inducing cellular immune responses have shown control of CXCR4-tropic simian-human immunodeficiency virus (SHIV) replication but difficulty in containment of pathogenic CCR5-tropic simian immunodeficiency virus (SIV) in rhesus macaques. In contrast, controlled infection of live attenuated SIV/SHIV can confer the ability to contain SIV superchallenge in macaques. The specific immune responses responsible for this control may be induced by live virus infection but not consistently by viral vector vaccination, although those responses have not been determined. Here, we have examined in vitro anti-SIV efficacy of CD8+ cells in rhesus macaques that showed prophylactic viral vector vaccine-based control of CXCR4-tropic SHIV89.6PD replication. Analysis of the effect of CD8+ cells obtained at several time points from these macaques on CCR5-tropic SIVmac239 replication in vitro revealed that CD8+ cells in the chronic phase after SHIV challenge suppressed SIV replication more efficiently than those before challenge. SIVmac239 superchallenge of two of these macaques at 3 or 4 years post-SHIV challenge was contained, and the following anti-CD8 antibody administration resulted in transient CD8+ T-cell depletion and appearance of plasma SIVmac239 viremia in both of them. Our results indicate that CD8+ cells acquired the ability to efficiently suppress SIV replication by controlled SHIV infection, suggesting the contribution of CD8+ cell responses induced by controlled live virus infection to containment of HIV/SIV superinfection.
authors.affiliation: International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yuasa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Miki
authors.initials: M
authors.lastname: Kawada
authors.forename: Akiko
authors.initials: A
authors.lastname: Takeda
authors.forename: Hiroko
authors.initials: H
authors.lastname: Igarashi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Matano
mesh_terms: D016915:AIDS Vaccines / Q000737:chemistry; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism / Q000821:virology*; D018920:Coculture Techniques; D006678:HIV / Q000378:metabolism; D008253:Macaca mulatta; D019713:Receptors, CCR5 / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000378:metabolism*; D018449:SAIDS Vaccines / Q000737:chemistry; D016097:Simian Acquired Immunodeficiency Syndrome / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000378:metabolism*; D013997:Time Factors; D019562:Viral Load; D014765:Viral Vaccines; D014779:Virus Replication
chemical_list: D016915:AIDS Vaccines; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; D018449:SAIDS Vaccines; D014765:Viral Vaccines