In vitro modulation of viral cell surface glycoproteins by anti-viral antibody in the presence of complement.

In the presence of optimal concentrations of both anti-viral IgG and complement, cells persistently infected with either measles virus (DS6-PI) or canine distemper virus (CDV-PI) could be lysed. In contrast, in the presence of adequate concentrations of anti-viral IgG but no complement the viral antigens expressed on the cell surface of DS6-PI and CDV-PI cells were lost, i.e. the cells were modulated. It was however possible to show that with critical concentrations of anti-viral IgG but with only moderately depressed levels of complement, modulation of the cells rather than lysis could occur. The implication that this may have in the generation of persistent viral infections in vivo is discussed.