Role of Basophilic Leukocytes in Cellular Immunity to Vaccinia Virus Infection

Abstract

Adult guinea pigs infected with an intradermal inoculum of vaccinia virus developed a long-lasting state of hypersensitivity associated with blast transformation in the draining lymph nodes, and characterized by delayed-onset, erythematous, non-indurated skin reactions rich in basophilic leukocytes. These reactions are similar to those of cutaneous basophil hypersensitivity to protein antigens, a contact allergen, and skin allografts in the guinea pig. By contrast, animals sensitized with the same dose of virus in complete Freund's adjuvant developed true delayed hypersensitivity with indurated skin reactions containing numerous mononuclear cells and only rare basophils. Thus, two morphologically distinct forms of cellular immunity may result following immunization with vaccinia virus. This heterogeneity will have to be considered in studies attempting to evaluate the role of cellular immunity in recovery from virus infection.