¹Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Campus Universidad Autónoma Cantoblanco, E-28049 Madrid, Spain

Correspondence: Antonio Bernad, E-mail: abernad@cnb.uam.es.

^*Present address: Genetrix S.L., Centro Nacional de Biotecnología/CSIC, Campus Universidad Autónoma Cantoblanco, E-28049 Madrid, Spain.

^†These authors contributed equally to the work.

Received 14 February 2003; Accepted 1 June 2003.

Abstract

CCR5 is the major coreceptor for the HIV-1 strains responsible for primary infection. Individuals homozygous for a 32-bp deletion in the CCR5 coding region are resistant to HIV-1 infection. Strategies to delete CCR5 functionally could thus be of substantial benefit in preventing HIV-1 infection or delaying disease. We evaluated new molecules for their ability to inhibit cell membrane CCR5 expression and to prevent HIV-1 infection. These inhibitors include several truncated forms of CCR5 that may act as negative transdominants, as well as bifunctional molecules resulting from the combination of a previously described anti-CCR5 ribozyme or a truncated CCR5 variant with an intracellular chemokine (RANTES-KDEL). These constructs efficiently blocked membrane CCR5 expression when cotransfected into HEK 293 cells. When expressed by retroviral transduction, some of these molecules significantly inhibited CCR5-dependent chemotaxis in the MCF-7 cell line and reduced CCR5 expression and HIV-1 infection in human T cells. Analysis of inhibitors with different efficiencies showed a strong linear correlation between CCR5 expression inhibition and prevention of HIV-1 infection. This study indicates the potential clinical application of several new CCR5 inhibitory molecules for HIV-1 gene therapy.