The Immunological Response of the Rat to Infection with <em>Taenia taeniaeformis</em> I. IMMUNOGLOBULIN CLASSES INVOLVED IN PASSIVE TRANSFER OF RESISTANCE*.

Passive transfer of immunity to Taenza taeniaeformis infection in the rat was achieved with serum taken 14, 21 and 28 days after infection, with maximal activity at 28 days4 The protective capacity resided in the globulin fraction, which was further fractionated by gel filtration and anion exchange chromatography. The immunoglobulins present in each passively transferred fraction were detected with specific antisera to 7Sγ2, 7Sγl, γM and γA. Protective activity was confined to those fractions containing 7S immunoglobulirn. Fractions enriched for γM were unable to confer protection and it was possible to protect recipient rats against challenge with fractions devoid of γA and reaginic antibody activity. 7Sγ2a antibodies were able to confer passive protection when given alone, and probably contributed to the protective capacity of mixtures containing 7Sγ2 and 7Sγl immunoglobulins. A mechanism for specific acquired resistance to T. taeniaeformis is proposed based upon the recently established biological properties of 7Sγ2a, Absorption of protective activity from immune rat serum was unsuccessful using a variety of techniques, and an explanation is offered for this finding. The results are discussed in relation to the current understanding of acquired resistance in cysticercosis and hydatid disease in domesticated food animals. [ABSTRACT FROM AUTHOR]