The location of tick salivary antigens, complement and immunoglobulin in the skin of guinea-pigs infested with Dermacentor andersoni larvae.

Using indirect immunoflorescence techniques, tick salivary gland antigens (SGA) were demonstrable in cement deposited on the skin by ticks and in all layers of the epidermis of infested guinea-pigs close to the sites where ticks attached. The antigen remained in these sites for several days after ticks had detached. In tick-resistant but not in normal guinea-pigs, SGA, complement and IgG were deposited at the dermo-epidermal junction even at some distance from the attachment site. Complement was also demonstrable in epidermal vesicles which developed beneath larvae attached to resistant guinea-pigs. It is suggested that antigen-antibody reaction and complement activation at these sites may play a role in the development of skin lesions and the attraction of basophils to these areas in challenged tick-resistant guinea-pigs. Tick antigens were also found to be associated with dendritic suprabasal cells in the epidermis of resistant guinea-pigs. It has previously been proposed that such SGA-trapping cells are Langerhans cells. These cells, in the presence of specific antibody and complement, could also initiate epidermal lesions in resistant guinea-pigs.