背景资料： Bonzo (also designated STRL33.3) and BOB (brother of Bonzo; also designated GRP15) are seven-transmembrane, G protein-coupled receptors that are closely related to chemokine receptor family members. In conjunction with CD4, several chemokine receptors are known to serve as receptors for HIV-1 entry into cells. Bonzo and BOB are utilized by simian immunodeficiency virus (SIV), HIV-2 and M-tropic HIV-1 for cell entry. Bonzo and BOB are both expressed in lymphoid tissues, and BOB is also expressed in colon.