This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Rose, M E Articles by Hesketh, P Search for Related Content PubMed PubMed Citation Articles by Rose, M E Articles by Hesketh, P

Immunity to coccidiosis: T-lymphocyte- or B-lymphocyte-deficient animals.

ABSTRACT

Comparisons were made between infections with Eimeria spp. in normal animals and in animals with functional deficiencies in either T-lymphocytes (athymic nude rats) or B-lymphocytes (bursectomized chickens). Approximately three times more oocysts of E. nieschulzi were passed during a primary infection in the nu/nu rats, and in contrast to the nu/+ rats, they were completely susceptible to reinfection. Nu/nu rats did not produce agglutinating antibodies to sporozoites, and injections of serum from immunized nu/+ rats caused a reduction of oocyst production during a primary infection in both nu/nu and nu/+ rats. In chickens, oocyst production in primary infections with E. maxima or with E. acervulina was increased 1.5 to 2-fold in the bursectomised (BX) groups, and the clinical effects of infection with E. maxima were greater than in controls. The BX birds were slightly more susceptible than the controls to challenge inoculations of oocysts, but nevertheless, they were very substantially immune. Tests for the functioning of B- and T-lymphocytes indicated that in the BX birds there was a severe deficiency of B-cell function, but near-normal T-cell function. The results show that T-lymphocytes are essential for immunity and that, although they may function partly as helper cells for immunoglobulin production, their major effect is exerted via some other mechanism.