The CC-chemokines RANTES, macrophage inflammatory protein 1α (MIP-1α), and MIP-1β are natural ligands for the CC-chemokine receptor CCR5. This receptor is used by human immunodeficiency virus type 1 (HIV-1) to infect human macrophages. In May Journal of Virology, Stefano Aquaro and colleagues from Katholieke Universiteit, Leuven, Belgium show that the LD78β isoform of MIP-1α is the most potent chemokine in inhibiting HIV replication in human macrophages.

Aquaro et al compared the antiviral efficacy in purified macrophages of LD78β with that of the LD78α isoform of MIP-1α, RANTES and MIP-1β. LD78β at 100 ng/ml almost completely blocked HIV-1 replication; at the same concentration LD78α had only weak antiviral activity. In addition, when HIV-1 infection in macrophages was monitored by a flow cytometric analysis using p24 antigen intracellular staining, LD78β proved to be the most antivirally active of the chemokines (J Virol 2001, 75:4402-4406).

This data can explain...