The sensitivity to gamma-irradiation of the phases of the virus-host interaction: studies with strains of Semliki forest virus in mice

A convenient and quantifiable model system, Semliki Forest virus (SFV) in the mouse, has been used to probe the wider problem of the radiation sensitivity of the distinct phases of the virus-host interaction. This has been investigated through the suppression and recovery of the several host defence mechanisms and cellular compartments involved. Direct observations have been made, following whole-body gamma-irradiation at up to 600 R, of the sequential modifications imposed upon the efficiency of primary infection, the stimulation of regulatory immunity (pre-challenge) and the stimulation or boosting of protective immunity (post-challenge). These phases of the virus-host interaction show distinct sensitivities to gamma-radiation which are discussed in terms of the impairment and recovery of the lymphocyte compartments probably involved.