Response to Matters Arising

Abstract

The proposed mechanism for HIV-1 coreceptor selectivity (Sharon et al., 2003) has been greeted with great interest. Nevertheless, several investigators have raised concerns regarding the validity of the model (Hartley et al., 2005; Lusso, 2003). Hartley and coworkers base their challenge of our model on their view that the homology between V3 and chemokines is too low to be of biological significance. We are pleased to have the opportunity to clarify certain aspects of our hypothesis and to provide additional information not present in our earlier publication (Sharon et al., 2003).