Accession Number : ADB080745

Title :   Togavirus-Specific Immune Effector Mechanisms.

Descriptive Note : Annual rept. 1 Jan-31 Dec 81,

Corporate Author : MARYLAND UNIV BALTIMORE SCHOOL OF MEDICINE

Personal Author(s) : Cole, G. A.

Report Date : DEC 1981

Pagination or Media Count : 31

Abstract : 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 C57BL/6J 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.

Descriptors :   *VIRUSES, *IMMUNITY, ANTIBODIES, SINDBIS VIRUS, MICE, HUMORAL IMMUNITY, SEROLOGY, IRRADIATION.

Subject Categories : Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE