Host response to treponema pallidum infection. II. Rabbit leukocyte migration inhibition in the presence of homologous organ extracts.

Peripheral leukocytes of 67 rabbits infected intratesticularly with Treponema pallidum, Nichols' strain for various lengths of time were examined by the migration inhibition test for their response to extracts of normal rabbit heart, skin, brain and T. pallidum antigen. A control group of 14 animals injected intratesticularly with extract of normal rabbit tests was similarly examined for the leukocyte response to the same antigens except the brain extract. The percentage of infected animals responding to T. pallidum antigen with significant migration inhibition varied from 13 to 31. Transitional cellular response to heart and skin but not brain was observed (12-28%). Leukocytes of all but 2 control rabbits responded to the organ extracts within the limit of 2 SD. The response of the infected animals to the homologous organ extracts may suggest that during infection, lymphocytes are activated by the host tissue antigens.