Mechanism of Innate Resistance to Viral Encephalitis.
Final rept. 1 Mar 74-31 Dec 76,
YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE
Pagination or Media Count:
Factors that influence the phenotypic expression of genetic resistance or susceptibility to lethal flavivirus infection were investigated in 2 congenic strains of mice C3HRV resistant to lethal infection and C3HHe susceptible to lethal infection. C3HHe and C3HRV mice were equally susceptible to infection by Banzi virus when inoculated intraperitoneally IP. Encephalitis developed in both strains after IP inoculation and mortality was high in C3HHe mice whereas mortality was low in C3HRV mice. The difference in susceptibility between the 2 strains, based on mortality, ranged from 10 to the 4th power to 10 to the 6th power LD sub 50. Resistance of C3HRV mice to lethal encephalitis developed postnatally and did not reach significant levels until mice were 4 weeks old. Resistance was abrogated by cyclophosphamide-treatment, sublethal x-irradiation 400R and T-cell depletion. Virus yields, distribution of viral antigen and lesions in brain of immunologically crippled C3HRV mice closely resembled those in untreated C3HHe mice. Infected, cyclophosphamide-treated C3HRV mice also developed severe pancreatitis. Intracerebral IC inoculation of Banzi virus produced high mortality in both strains and virus titers and lesions in brains were also similar.
- Medicine and Medical Research