Background information
Human Immunodeficiency Virus (HIV) and Simian Immunodeficiency Virus (SIV) require coreceptors to enter and infect target cells. They are dependent upon an interaction between the viral envelope glycoprotein with T cell antigen T4 (CD4) and a G protein coupled receptor (GPCR). HIV1 infection relies upon interaction with a chemokine receptor, usually chemokine (C-C) receptor 5 (CCR5). During progression of the infection, the virus tends to rely upon chemokine (C-X-C) receptor 4 (CXCR4). SIV also utilizes CCR5 in the early stages of infection, but during progression it tends to rely on two orphan GPCR's named chemokine (C-X-C) receptor 6 (Bonzo) and G protein coupled receptor 15 (BOB/GRP15). Bonzo mRNA expression has been localized to lymphoid tissues and activated peripheral blood lymphocytes.
