Cell Proteins Interacting with the Human Immunodeficiency Virus in Immunoblotting can be Detected by R5- or X4- Tropic Human Immunodeficiency Virus Particles

INTRODUCTION: The present study reported a new immunoblot assay, with revelation by R5- or X4-whole free human immunodeficiency virus (HIV) particles or recombinant gp160. MATERIALS AND METHODS: The assay was optimized to identify cell proteins interacting with HIV. Whole cell lysates were prepared from peripheral blood lymphocytes (PBLs), dendritic cells (DC), monocyte-derived macrophage (MDM), and Henrietta Lacks (Hela, wild-type or transfected with DC-specific intracellular adhesion molecule-3-Grabbing Non-Integrin, HeLa) and Human endometrial cells (HEC-1A) lines; HIV particles used were the R5-tropic HIV-1(JRCSF) and the X4-tropic HIV-1(NDK). RESULTS: Experiments with PBL lysates and both viruses demonstrated different bands, including a unique band at 105–117 kDa in addition to nonspecific bands. The 105–117 kDa band migrated at the same level of that observed in controls using total PBL lysate and anti-CD4 mAb for detection and thus likely corresponds to the cluster difference (CD) 4 complex. Blots using lysates of DCs, MDM, HeLa cell line, and HEC-1A cell line allowed identifying several bands that positions were similar to that seen by recombinant gp160 or whole R5- or X4-HIV particles. CONCLUSION: Blot of whole lysates of various HIV target cells is recognized by free HIV particles and allows identifying a wide range of HIV-interacting cell proteins. Such optimized assay could be useful to recognize new cellular HIV attachment proteins.