Analysis of T-cell responses in cattle immunized against heartwater by vaccination with killed elementary bodies of Cowdria ruminantium.
Cattle were successfully immunized against heartwater with a lysate of Cowdria ruminantium formulated in Freund's adjuvant. Vaccinated animals proved fully resistant to virulent challenge 3 and 10 months after vaccination. For the first time a helper T lymphocyte response to Cowdria antigens was observed and characterized. Cowdria-specific T-cell lines generated from vaccinated animals by in vitro restimulation with Cowdria lysates are 95 to 100% CD4+, are MHC class II restricted, and produce gamma interferon. They proliferate in response to autologous monocytes infected with live Cowdria but not in response to uninfected monocytes. These T-cell lines will facilitate the search for Cowdria antigens that are immunogenic for T cells and will therefore be of relevance in the development of a subunit vaccine against the disease.
Totté
P
P
CIRAD-EMVT, Montpellier, France. P.TOTTE@cgnet.com
McKeever
D
D
Martinez
D
D
Bensaid
A
A
D000818:Animals; D000942:Antigens, Bacterial / Q000627:therapeutic use; D001428:Bacterial Vaccines / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control*; D002460:Cell Line; D005434:Flow Cytometry; D005620:Freund's Adjuvant; D006357:Heartwater Disease / Q000276:immunology / Q000401:mortality / Q000517:prevention & control*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007371:Interferon-gamma / Q000032:analysis; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex / Q000276:immunology; D013347:Subcellular Fractions / Q000276:immunology; D014611:Vaccination; D015164:Vaccines, Inactivated / Q000627:therapeutic use*
D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D000949:Histocompatibility Antigens Class II; D015164:Vaccines, Inactivated; D007371:Interferon-gamma; D005620:Freund's Adjuvant