ARE BETA-CHEMOKINES THE ANSWER FOR CD8+ CELL FACTORS?
Recently, there are remarkable series of articles demonstrating the coreceptors for HIV-1 in various cell lines (4-9, 44-47). It has long been thought that HIV-1 may bind to its primary CD4 coreceptors, but coreceptors were certainly necessary for the viral entry (44-47). This was determined from data in murine and other animal cell-types, in which CD4-expression would not permit productive infection. Feng et al (46) demonstrated that a transmembrane chemokine receptor, CXCR4, serves as a cofactor for T-cell tropic, but not monocyte tropic, strains of HIV-1. Another coreceptor, CCR5 appears to be major co-receptor for macrophage /monocyte tropic strains of HIV-1 (45). These coreceptors bind variety of beta-chemokines i.e. RANTES, MIP-1 alpha and MIP-1beta and are secreted by variety of cell types. What these beta-chemokines do? Are they the suppressive factors scientists are looking for? It appears that they may not be the “elusive” CD8+ cell factors or CAF! Their effect is on pre-entr
