Browsing by Author "Pearson, T.W."
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Item Cell-Mediated Immunity to Theileria-Transformed Cell Lines(1979) Pearson, T.W.; Lundin, L.B.; Dolan, T.T.; Stagg, D.A.; International Laboratory For Research in Animal Diseases Kenya Agricultural Research Institute Veterinary Research MugugaIn East and Central Africa, the protozoan parasite Theileria parva causes a disease of cattle called East Coast fever (ECF). In Kenya alone between 60,000 and 85,000 cattle die from ECF every year1. Infected animals can recover from ECF either naturally2 or after treatment with tetracyclines3 or menoctone4 and are subsequently able to resist challenge with the homologous strain of parasite. That this acquired resistance is due to cell-mediated rather than humoral immunity has been suspected5,6 but never decisively shown. A major difficulty in studying immunity to ECF has been the lack of inbred animals for studying Theileria-specific immunity in the absence of allogeneic histocompatibility barriers. We have avoided this problem by measuring cell-mediated immune responses in a syngeneic system in vitro. Unidirectional mixed lymphocyte cultures (MLC) were set up using bovine peripheral blood lymphocytes (PBL) as responder cells and autologous cell lines transformed in vitro by T. parva as stimulator cells. In these cultures, DNA synthesis was induced in PBL from both normal and Theileria-immune animals. However, cytotoxic lymphocytes were induced only in cultures containing responder lymphocytes from Theileria-immune cattle. The results show that Theileria-transformed cells express antigens which are recognised by effector cells and provide evidence that cell-mediated cytotoxic mechanisms function in immunity to ECF.Item Use of procyclic trypanosomes for detection of antibodies in sera from vervet monkeys infected with Trypanosoma rhodesiense: an immunodiagnostic test for African sleeping sickness(1986) Pearson, T.W.; Liu, M.; Gardiner, I.C.; Longridge, D.; Beecroft, R.P.; Sayer, P.D.; Gould, S.S.; Waitumbi, J.N.; Njogu, A.R.; Kenya Trypanosomiasis Research Institute; Department of Biochemistry and Microbiology of Victoria, Canada, Kenya Trypanosomiasis Research Institute MugugaUncoated procyclic culture forms of African trypanosomes were used in immunofluorescence and simple agglutination assays to detect antibodies in the sera of vervet monkeys infected with T. b. rhodesiense. Antibodies to procyclic surface antigens were found in sera from animals with active, untreated infections or sera taken soon after treatment with trypanocidal drugs. The antibodies were detectable within 7 days of infection. No specific antibodies were detected in sera prior to infection or long after drug cure. The results indicate that antigens expressed on the surface of pro cyclic culture forms of T. brucei spp. Are useful for the detection of antibodies produced in response to infection with T. b. rhodesiense and may allow the development of a simple immunodiagnostic test for African sleeping sickness. In addition, the use of a form of the trypanosome of a different differentiation state from the infecting organism illustrates the utility of this approach for detection of antibodies to common antigens.Item Use of Procyclic Trypanosomes for Detection of Antibodies in Sera from Vervet Monkeys Infected with Trypanosoma Rhodesiense: an Immunodiagnostic Test for African Sleeping Sickness(veterinary Record, 1986) Pearson, T.W.; Liu, M.; Gardiner, I.C.; Longridge, D.; Beecroft, R.P.; Sayer, P.D.; Gould, S.S.; Waitumbi, J.N.; Njogu, A.R.; Department of Biochemistry and Microbiology, University of Victoria, Canada, Kenya Trypanosomiasis Research Institute, Muguga, KenyaUncoated procyclic culture forms of African trypanosomes were used in immunofluorescence and simple agglutination assays to detect antibodies in the sera of vervet monkeys infected with T. b. rhodesiense. Antibodies to procyclic surface antigens were found in sera from animals with active, untreated infections or sera taken soon after treatment with trypanocidal drugs. The antibodies were detectable within 7 days of infection. No specific antibodies were detected in sera prior to infection or long after drug cure. The results indicate that antigens expressed on the surface of procyclic culture forms of T. brucei spp. Are useful for the detection of antibodies produced in response to infection with T. b. rhodesiense and may allow the development of a simple immunodiagnostic test for African sleeping sickness. In addition, the use of a form of the trypanosome of a different differentiation state from the infecting organism illustrates the utility of this approach for detection of antibodies to common antigens.
