Journal article
Specific immune responses are required to control parasitemia in Babesia equi infection
Infection and immunity, Vol.62(5), pp.1909-1913
05/1994
Handle:
https://hdl.handle.net/2376/107980
PMCID: PMC186438
PMID: 8168957
Abstract
Horses possessing a normal immune system and spleen often control infection caused by Babesia equi. However, splenectomized horses are unable to control B. equi infection and usually succumb to the infection. To investigate the role of the spleen in the control of B. equi infection in the absence of specific immune responses, two 1-month-old foals with severe combined immunodeficiency (SCID) and two age-matched normal foals were inoculated with B. equi. The SCID foals became febrile seven days postinoculation and developed terminal parasitemias of 41 and 29%. The SCID foals had greater than 50% decreases in indices of total erythrocytes, packed-cell volumes, and hemoglobin concentrations. Both SCID foals were euthanized in extremis at 10 days postinoculation. As expected, the serum of the SCID foals lacked detectable antibodies to B. equi antigens. In contrast, the normal foals inoculated with B. equi produced detectable anti-erythrocyte-stage parasite antibodies by 7 days and controlled clinical disease by 12 days postinoculation. Although SCID foals lack functional T and B lymphocytes, they do possess complement, macrophages, granulocytes, and natural killer cells, as well as a spleen. Therefore, the data indicate that specific immune responses are required to control B. equi parasitemia but are not required for erythrocyte lysis in infected horses. Furthermore, the spleen is not able to control B. equi parasitemia in the absence of specific immune responses to parasite antigens.
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Details
- Title
- Specific immune responses are required to control parasitemia in Babesia equi infection
- Creators
- D P Knowles - Animal Disease Research Unit, Agricultural Research Service, Pullman, Washington 99164-7030L S Kappmeyer - Animal Disease Research Unit, Agricultural Research Service, Pullman, Washington 99164-7030L E Perryman - Animal Disease Research Unit, Agricultural Research Service, Pullman, Washington 99164-7030
- Publication Details
- Infection and immunity, Vol.62(5), pp.1909-1913
- Academic Unit
- Veterinary Microbiology and Pathology, Department of
- Identifiers
- 99900547500301842
- Language
- English
- Resource Type
- Journal article