The supportive role of complement in HIV pathogenesis

This review focuses on interactions of HIV with the first-line defence of n ative immunity, the complement system. In all body compartments tested so f ar, HIV meets complement. Activation of the complement system results in de position of C3 fragments on the viral surface, but in contrast to other pat hogens, most of HIV is not or is only poorly lysed by membrane attack compl exes. To survive complement-mediated lysis, HIV has not only developed resi stance mechanisms, but uses opsonisation with complement fragments for its own advantage. Opsonised virions interact with complement receptor-expressi ng cells, which are either subsequently infected with high efficiency or re tain viral particles on their surface, which promotes transmission of virus to other permissive cells. Our knowledge of these mechanisms has increased enormously over the past few years. A complete understanding of these comp lex interactions of HIV with the complement system opens new perspectives f or development of alternative therapeutic strategies.