Dynamics and efficacy of viral interference in HIV infection

     Viral interference is a phenomenon by which a virus infected cell displays reduced susceptibility to infection by a virus of the same species. This phenomenon, also called superinfection resistance, is generally due to occupation or down-regulation of cellular proteins that are required for virus replication. In this respect, the principal mechanism of HIV superinfection resistance is down-modulation of the CD4 receptor from the cell surface. Recent data, however, strongly suggest that HIV superinfection resistance involves several CD4-independent mechanisms that remain to be fully understood.
     In spite of the well-documented ability of HIV to interfere with superinfection, cells harboring multiple HIV genomes are readily observed both in infected subjects and in tissue culture. Double infection allows genetic recombination, a key mechanisms contributing to HIV diversity and evolution, and potentially implicated in pathogenesis. Thus, while HIV can clearly induce superinfection resistance under some circumstances, this phenomenon appears to be regulated.
     We will discuss our recent data on the delay after which viral interference is effective, its magnitude and modification of its potency over time.