Received December 1, 2006
Accepted on December 29, 2006

BASIC SCIENCE: Basic Immunology and Pathology

DEC-205-Mediated Internalization of HIV-1 Results in the Establishment of Silent Infection in Renal Tubular Cells

Ikusuke Hatsukari ^*, Priyanka Singh ^*, Naoko Hitosugi ^*, Davorka Messmer ^*, Elsa Valderrama , Saul Teichberg ^*, Wayne Chaung ^*, Eleanore Gross ^*, Helena Schmidtmayerova ^*1, and Pravin C. Singhal ^*1

*Center for Immunology and Inflammation, The Feinstein Institute for Medical Research, Manhasset, and Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, New York

¹ To whom correspondence should be addressed. E-mail: hschmidt{at}nshs.edu.

	Abstract

HIV-1 infection of renal cells has been proposed to play a role in HIV-1-associated nephropathy. Renal biopsy data further suggest that renal tubular cells may serve as reservoir for HIV-1. The mechanism by which HIV-1 enters these cells has not been identified. Renal tubular cells do not express any of the known HIV-1 receptors, and our results confirmed lack of the expression of CD4, CCR5, CXCR4, DC-SIGN, or mannose receptors in tubular cells. The aim of this study, therefore, was to determine the mechanism that enables viral entry into renal tubular cells. An in vitro model was used to study the HIV-1 infection of human kidney tubular (HK2) cells and to identify the receptor that enables the virus to enter these cells. Results of these studies demonstrate that the C-type lectin DEC-205 acts as an HIV-1 receptor in HK2 cells. Interaction of HIV-1 with DEC-205 results in the internalization of the virus and establishment of a nonproductive infection. HIV-1-specific strong-stop DNA is detected in the infected HK2 cells for at least 7 d, and the virus can be transmitted in trans to sensitive target cells. HIV-1 entry is blocked by pretreatment with specific anti-DEC-205 antibody. Moreover, expression of DEC-205 in cells that lack the DEC-205 receptors renders them susceptible to HIV-1 infection. These findings suggest that DEC-205 acts as an HIV-1 receptor that mediates internalization of the virus into renal tubular cells, from which the virus can be rescued and disseminated by encountering immune cells.