In addition to providing insights into the mechanism of viral entry, the identification of chemokine receptors as coreceptors of HIV may explain certain questions related to HIV transmission and AIDS pathogenesis. The importance of the CCR5 coreceptor in viral transmission is underscored by the observation that individuals who lack a functional CCR5 protein are largely protected from HIV-1 infection. Furthermore, regardless of the route of infection, R5 viruses are preferentially isolated from HIV-1 infected individuals during primary and acute infection. Despite the dominant role of R5 viruses in HIV-1 transmission and early infection, in about 50 percent of patients, CXCR4 using (X4) viruses emerge during late infection. The outgrowth of X4 viruses coincides with a loss in circulating CD4+ T cells and precedes the onset of AIDS. Indeed, studies in several in vitro and ex vivo tissue culture model systems, in addition to SCID-hu mouse models, revealed that X4 viruses are more cytopathic. Based on these findings, it has been widely presumed that R5 viral variants are selectively transmitted by sexual contact and that the phenotypic switch during HIV infection is the casual factor in acquired immunodeficiency. However, recent studies in the macaque model call into question this central belief. Using infection of rhesus macaques with SHIVs expressing R5 or X4 specific HIV-1 envelope as a model system, we find that both R5 (SHIVSF162P) and X4 (SHIVSF33A) SHIVs can establish systemic infection by the intravaginal (IVAG) route. Furthermore, both viruses are cytopathic, but they cause CD4+ T cell depletion in distinct anatomical compartment. Since these viruses appear to replicate with comparable kinetics and to similar titers in intravenous (IV) and IVAG infected animals, they provide the ideal setting for addressing the role of coreceptors in HIV2 transmission and pathogenesis. We propose that differential viral dissemination, rather that the ability of the virus to cross the mucosal barrier, is the major determinant for the apparent preferential transmission and early infection of R5 viruses. Furthermore, we hypothesize that AIDS pathogenesis will e influenced by coreceptor usage.
Four specific aims are proposed. (1) Compare the properties of the X4-specific SHIVSF33A and R5-specific SHIVSF162P in vitro. The replication kinetics, tropism and cytopathicity of the viruses will be determined. (2) Assess the role of coreceptor usage in defining the sites of virus replication and disease course in IV and IVAG inoculated animals. Viral loads, viral set points, compartments of virus replication and anti-viral immune responses in the infected animals will be assessed. T and B cell subset distribution in the bone marrow, gut, thymus, peripheral blood and lymph nodes will also be determined. (3) Perform IV and IVAG infection with mix inocula to determine whether there is preferential transmission of R5-utilizing virus and, if so, whether this preferential transmission is dependent on the route of infection. (4) Identify the first site and target cell of virus replication, and characterize the route of viral dissemination in R5 and X4 infected animals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI046980-03
Application #
6511215
Study Section
Special Emphasis Panel (ZRG1-AARR-1 (01))
Program Officer
Sharma, Opendra K
Project Start
2000-03-01
Project End
2005-02-28
Budget Start
2002-03-01
Budget End
2003-02-28
Support Year
3
Fiscal Year
2002
Total Cost
$568,926
Indirect Cost
Name
Aaron Diamond AIDS Research Center
Department
Type
DUNS #
786658872
City
New York
State
NY
Country
United States
Zip Code
10016
Ren, Wuze; Ma, Yingfei; Yang, Liying et al. (2015) Fast disease progression in simian HIV-infected female macaque is accompanied by a robust local inflammatory innate immune and microbial response. AIDS 29:F1-8
Harbison, Carole; Zhuang, Ke; Gettie, Agegnehu et al. (2014) Giant cell encephalitis and microglial infection with mucosally transmitted simian-human immunodeficiency virus SHIVSF162P3N in rhesus macaques. J Neurovirol 20:62-72
Tsai, Lily; Tasovski, Ivan; Leda, Ana Rachel et al. (2014) The number and genetic relatedness of transmitted/founder virus impact clinical outcome in vaginal R5 SHIVSF162P3N infection. Retrovirology 11:22
Ren, Wuze; Mumbauer, Alexandra; Gettie, Agegnehu et al. (2013) Generation of lineage-related, mucosally transmissible subtype C R5 simian-human immunodeficiency viruses capable of AIDS development, induction of neurological disease, and coreceptor switching in rhesus macaques. J Virol 87:6137-49
Ren, Wuze; Mumbauer, Alexandra; Zhuang, Ke et al. (2013) Mucosal transmissibility, disease induction and coreceptor switching of R5 SHIVSF162P3N molecular clones in rhesus macaques. Retrovirology 10:9
Shakirzyanova, Madina; Tsai, Lily; Ren, Wuze et al. (2012) Pathogenic consequences of vaginal infection with CCR5-tropic simian-human immunodeficiency virus SHIVSF162P3N. J Virol 86:9432-42
Tasca, Silvana; Zhuang, Ke; Gettie, Agegnehu et al. (2011) Effect of B-cell depletion on coreceptor switching in R5 simian-human immunodeficiency virus infection of rhesus macaques. J Virol 85:3086-94
Zhuang, Ke; Finzi, Andres; Tasca, Silvana et al. (2011) Adoption of an ""open"" envelope conformation facilitating CD4 binding and structural remodeling precedes coreceptor switch in R5 SHIV-infected macaques. PLoS One 6:e21350
Ren, Wuze; Tasca, Silvana; Zhuang, Ke et al. (2010) Different tempo and anatomic location of dual-tropic and X4 virus emergence in a model of R5 simian-human immunodeficiency virus infection. J Virol 84:340-51
Shakirzyanova, Madina; Ren, Wuze; Zhuang, Ke et al. (2010) Fitness disadvantage of transitional intermediates contributes to dynamic change in the infecting-virus population during coreceptor switch in R5 simian/human immunodeficiency virus-infected macaques. J Virol 84:12862-71

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