EXPERIMENTALLY INDUCED BOVINE SARCOCYSTOSIS - CORRELATION OF INVITRO LYMPHOCYTE FUNCTION WITH STRUCTURAL-CHANGES IN LYMPHOID-TISSUE

  • 1 January 1980
    • journal article
    • research article
    • Vol. 41  (8) , 1201-1207
Abstract
The effect of acute bovine sarcocystosis was studied by correlating in vitro lymphocyte blast transformation studies with morphologic and hematologic changes. Yearling calves inoculated with 900,000 sporocysts (large dose) had decreased responses to phytohemagglutinin and pokeweed mitogen and corresponding morphologic evidence of depletion of both T [thymus derived] and B [bone marrow derived] lymphocytes in all lymphoid organs examined during the 1st 4 wk. T-cell depletion was characterized by marked thymic atrophy. In lymph nodes denoting B-cell depletion, there was lymphoid follicular exhaustion and various degrees of follicular loss. Significant change in total circulating lymphocytes was not observed. All animals given this large dose died or were killed (in a moribund state) by 5 wk after they were inoculated. Changes in mitogen responsiveness were not significant during the 4 wk after yearling calves were inoculated with 90,000 sporocysts (small dose). The mitogenic effect of phytohemagglutinin was significantly greater than that of the control group during wk 4-18. During this period, thymic cortical regeneration occurred. Acute sarcocystosis may be accompanied by a lymphoid abnormality which could result in immunosuppression, adding to the severity of natural infection.