In silico analysis of molecular interactions between HIV-1 glycoprotein gp120 and TNF receptors

Abstract

Proinflammatory microenvironmental is crucial for the Human Immunodeficiency Virus Type 1 (HIV-1) pathogenesis. The viral glycoprotein 120 (gp120) must interact with the CD4+ T cell chemokine receptor (CCR5) and a co-receptor C-X-C chemokine receptor type 4 (CXCR4) to let the virus entry into the host cells. However, the interaction of the viral particle with other cell surface receptors is mandatory for its attachment and subsequently entry. Tumor Necrosis Factor receptor type I (TNFR1), type II (TNFR2) and Fas are a superfamily of transmembrane proteins involved in canonical inflammatory pathway and cell death by apoptosis as responses against viral pathogens. In our study, we performed an in silico evaluation of the molecular interactions between viral protein gp120 and TNF receptors (TNFR1, TNFR2 and Fas). Protein structures were retrieved from Protein Databank (PDB), and Molecular Docking and dynamics were performed using ClusPro 2.0 server and GROMACS software, respectively. We observed that gp120 is able to bind TNFR1, TNFR2 and Fas receptors, although only the TNFR2-gp120 complex demonstrated to produce a stable and durable binding. Our findings suggest that gp120 may act as an agonist to TNF-α and also function as an attachment factor in HIV-1 entry process. These molecular interaction by gp120 may be the key to HIV-1 immunopathogenesis. In conclusion, gp120 may stimulate pro-inflammatory and apoptotic signaling transduction pathways mediated by TNFR2 and may act as an attachment factor retaining HIV-1 viral particles on the host cell surface.