Immunogenicity and Quantitation of Soluble Anaplasma Marginale Antigens From Cell Cultures and Blood

224 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.Short-term Anaplasma marginale cultures were initiated utilizing infected bovine blood from a splenectomized calf at various periods during acute parasitaemia employing Medium 199 supplemented with 10% adult bovine serum and 25 mM HEPES buffer. Better growth was observed in cultures initiated with lower percentage of parasitized erythrocytes (PPE) than those at higher PPE. Mineral supplementation (KCl and or MgSO(,4)) did not improve the ability of medium to support anaplasmal growth and appeared to be deleterious.Immunization of cattle with selected supernatants administered along with an adjuvant resulted in production of specific antibody as measured by the indirect fluorescent antibody test. Some of the immunized cattle were partially protected from parasitaemia following challenge with virulent Anaplasma marginale but not from anaemia associated with the disease.Soluble A marginale antigens from plasma of a splenectomized calf during acute infection, water and sonic energy lysates of infected bovine and ovine erythrocytes, hydrochloric acid ('HCl') precipitated antigens and those derived from culture supernatants demonstrated identity in immunodiffusion tests.Specific antibodies against soluble 'HCl' precipitated antigen from a water lysate of A marginale infected bovine erythrocytes were detected from convalescent sera of immunized and nonimmunized animals challenged with a virulent strain of A marginale by an indirect enzyme linked-immunosorbent assay (ELISA).An ELISA inhibition test was used for quantitation of soluble A marginale antigens derived from cultures and blood. The quantity of soluble antigen was expressed in arbitrary units, with one unit defined as the amount of antigen capable of producing 50% inhibition of positive reference serum diluted 1:320. Supernatants obtained early in culture of A marginale appeared to yield more soluble antigens than those obtained late. Similarly those from cultures initiated at lower PPE had more antigens as compared with those initiated at higher PPE.Evidence is presented which suggests that A marginale soluble antigen prepared from a sonic lysate of infected erythrocytes is complexed with a normal erythrocyte component.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD