The CD8-Derived Chemokine XCL1/Lymphotactin Is a Conformation-Dependent, Broad-Spectrum Inhibitor of HIV-1
Figure 2
XCL1 inhibits HIV-1 infection irrespective of coreceptor usage.
(A) Dose-dependent inhibition of prototypic X4 (magenta) and R5 (blue) HIV-1 strains (IIIB and BaL) by recombinant XCL1 (Peprotech) in PBMC. Virus replication was assessed by measuring the amount of p24 Gag antigen in culture supernatants via AlphaLISA immunoassay. Data were normalized to the amount of viral replication observed in control cultures (not treated with XCL1). Data represent the mean values (±SD) of replicate wells, representative of at least 5 independent experiments performed on separate PBMC donors. (B) Similar infection protocols were performed on a larger panel of primary HIV-1 isolates with different coreceptor specificity. Inhibition curves in magenta represent CXCR4- and CXCR4/CCR5-tropic isolates, while those in blue represent CCR5-tropic viruses.