High and low responsiveness of bovine lymphocytes to Trypanosoma brucei in vitro: Lack of correlation with resistance to trypano somiasis
Bovine peripheral blood lymphocytes (PBL) were stimulated to proliferate in vitro by live, irradiated or freeze-thawed Trypanosoma brucei but not by the isolated variant surface glycoprotein. The optimal dose was 10 exponent 5 trypanosomes per 5 X 10 exponent 5 lymphocytes in O.2 ml. Maximal proliferation was at day 5. Of the 98 cattle tested, 36 were high-responders (stimulation indexes 20-104), 49 were low or non-responders (SI 1-10) and 13 were intermediate. The responder status of individual animals did not change over a period of 1 year, nor did it after following deliberate trypanosome infection. The stimulation was dependent on macrophage/monocyte type accessory cells, and this co-operation did not seem to be MHC restricted. Lack of stimulation of non-responder PBL did not appear to be due to the activation of suppressor cells. Accessory cells from non-responder animals could complement PBL from responders, but accessory cells from responders could not complement non-responder PBL. Responsiveness is therefore a characteristic of lymphocytes. Analysis of the surface markers of these lymphocytes or the blast cells generated in culture showed that they were a subpopulation of T cells, possibly TH cells. Analysis of PBL from 98 animals, which had been selected for trypanoresistance or trypanosensitivity under natural tsetse fly challenge, failed to establish a correlation between resistance and level of lymphocyte stimulation by trypanosome in vitro
| Main Authors: | , , , , |
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| Format: | article biblioteca |
| Language: | eng |
| Subjects: | L73 - Maladies des animaux, L72 - Organismes nuisibles des animaux, bovin, lymphocyte, réponse immunitaire, Trypanosoma brucei, trypanosomose, résistance aux maladies, http://aims.fao.org/aos/agrovoc/c_1391, http://aims.fao.org/aos/agrovoc/c_4484, http://aims.fao.org/aos/agrovoc/c_3799, http://aims.fao.org/aos/agrovoc/c_27400, http://aims.fao.org/aos/agrovoc/c_7988, http://aims.fao.org/aos/agrovoc/c_2328, http://aims.fao.org/aos/agrovoc/c_8081, |
| Online Access: | http://agritrop.cirad.fr/446926/ |
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