The immunological response of mice infected with Trichinella spiralis: Biological and physico-chemical distinction of two homocytotropic antibodies

(1) Infection of mice with Trichinella spiralis induced the appearance in serum of two homocytotropic antibodies that could be distinguished by their biological and chromatographic behaviour.

(2) Biologically, the antibodies could be distinguished by their ability to persist in homologous skin after passive transfer. One antibody was able to induce PCA only when a short latent period was used, whereas the other was able to induce PCA even after 72 hours.

(3) They could also be separated when antiserum was passed through a DEAE-cellulose column. Antibody present in the first eluates was able to induce PCA only if a short latent period was used whereas antibody present in the subsequent eluates was able to induce PCA 72 hours after sensitization.

(4) Both antibodies appeared in the circulation 5 weeks after infection and reached their highest levels around the 9th week. Later, the 72-hour PCA antibody disappeared from the serum in some animals, whereas the 4-hour PCA antibody remained.

(5) Re-infection resulted in an increase in the levels of both antibodies.

(6) In animals subjected to repeated reinfections the reagin-like antibody either decreased or disappeared from the serum. On the other hand, the 4-hour PCA antibody increased.

(7) Immunization with `dead' T. spiralis antigen led to the appearance of both antibodies in the serum. A second dose of antigen resulted in increases in the levels of both antibodies, but further injections resulted in a high level of 4-hour PCA antibody and in the disappearance of the reagin-like antibody.