Togavirus-Specific Immune Effector Mechanisms.
Annual rept. 1 Jan-31 Dec 81,
MARYLAND UNIV BALTIMORE SCHOOL OF MEDICINE
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Monoclonal MC antibodies specific for the E1 and E2 envelope glycoproteins of AR 339 strain Sindbis virus SV have been tested individually for their ability to passively protect adult C57BL6J mice from fatal paralytic disease produced by a neuroadapted variant na-SV of the non-lethal parent p strain. To date, protection has been obtained with 3 anti-E1 MC antibodies and is associated with their capacity to neutralize infectivity of na-SV, in addition to that of p-SV three others which neutralize only p-SV are non-protective. In the presence of complement C, anti-E2 IgG2a MC antibodies exhibit greater virus-neutralizing activity and they also mediate C-dependent lysis of cultured SV-infected cells. Results suggested at least two specific humoral mechanisms of alphavirus elimination in vivo 1 neutralization of infectivity by antibodies binding to E2 determinants on free virions, a process enhanced by, but not requiring C, and 2 C-dependent lysis of virus-infected cells mediated by antibodies which bind to either E1 or E2 determinants expressed on cell surfaces during viral morphogenesis. On the other hand, the possibility that a waning humoral immunity may increase host-susceptibility to reinfection is suggested by the ability of low concentrations of E2-specific antibodies to enhance SV infectivity in vitro.
- Medicine and Medical Research