The measurement of antigens released by radiation-attenuated Trichinella spiralis larvae

Abstract

A radioimmunoassay was developed that uses antisera raised to different excretory-secretory antigens of infective larvae of T. spiralis (LESA) [in guinea pigs] to measure accurately the output of these antigens following irradiation at doses from 10-120 Krads. In the lower range (up to 20 Krads) irradiation results in the increased export of antigens to the culture supernatant in a subsequent 3 h period, without obvious or gross damage to the worms. Higher doses (> 40 Krads) suppress antigen release over the same period compared with the activity of untreated (control) cultures. This work makes 2 contributions. It describes a sensitive assay system which detects and measures parasite antigens that may be important both in protection and in serodiagnosis, and it offers for the 1st time an explanation of the special properties of the lower dose range larval irradiation-attenuated vaccine in inducing a high degree of reinfection resistance, as previously reported and recently confirmed.