As one of the first cells to contact HIV, dendritic cells (DCs) are believed to play a central role in establishing infection and subsequent viral dissemination. All currently defined interactions between HIV and DCs rely upon the HIV Env. Previous work from our lab has demonstrated that HIV is capable of establishing robust interactions with DCs in an Env-independent manner and that the virus is capable of trans infection through this mechanism. This proposal seeks to define the DC receptor that mediates Env-independent binding and to investigate the role that this interaction has on HIV pathogenesis.
Specific Aim I is to identify the DC receptor that mediates Env-independent HIV binding. Preliminary data suggests that HIV binds to a DC glycosphingolipid (GSL). In order to specifically identify the type of GSL that is acting as a DC receptor, two separate but complimentary approaches will be used. As GSLs are highly conserved between murine and humans, and murine DCs can bind and transfer HIV in an Env-independent manner, a murine DC model will be utilized. This approach allows for identification of the DC receptor through existing GSL knockout mouse models and species polymorphisms. In addition, primary human DCs will be treated with RNAi to target specific regions of the GSL biosynthesis pathway and subsequently test the effects on Env-independent binding and transfer.
In specific Aim II, the way in which Env-independent binding impacts the fate of the virus will be characterized. Our lab has previously demonstrated that HIV traffics through a DC and reaches the T lymphocyte infectious synapse irrespective of the presence of Env. Using fluorescently labeled virions and deconvolution microscopy, this aim will define the relative contribution of Env-independent binding to efficient transfer of the virus. Identification of an Env-independent DC receptor is an important development in our understanding of HIV transmission. As DC interactions are particularly important in the establishment of early infection, an Env-independent DC receptor may be uniquely amenable to the efficient design of small molecule inhibitors that could serve as microbicides. In addition, this pathway may define a common mode of interaction between DCs and RNA viruses that bud from lipid rafts and share host-derived membrane compositions similar to HIV.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32AI084558-02
Application #
7945362
Study Section
Special Emphasis Panel (ZRG1-AARR-C (22))
Program Officer
Embry, Alan C
Project Start
2009-09-15
Project End
2011-08-30
Budget Start
2010-09-15
Budget End
2011-08-30
Support Year
2
Fiscal Year
2010
Total Cost
$50,404
Indirect Cost
Name
Boston University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Puryear, Wendy Blay; Akiyama, Hisashi; Geer, Suzanne D et al. (2013) Interferon-inducible mechanism of dendritic cell-mediated HIV-1 dissemination is dependent on Siglec-1/CD169. PLoS Pathog 9:e1003291
Puryear, Wendy Blay; Gummuluru, Suryaram (2013) Role of glycosphingolipids in dendritic cell-mediated HIV-1 trans-infection. Adv Exp Med Biol 762:131-53
Puryear, Wendy Blay; Yu, Xinwei; Ramirez, Nora P et al. (2012) HIV-1 incorporation of host-cell-derived glycosphingolipid GM3 allows for capture by mature dendritic cells. Proc Natl Acad Sci U S A 109:7475-80
Hanley, Timothy M; Blay Puryear, Wendy; Gummuluru, Suryaram et al. (2010) PPARgamma and LXR signaling inhibit dendritic cell-mediated HIV-1 capture and trans-infection. PLoS Pathog 6:e1000981