Antibody Responses of Cattle Immunized with the Tf190 Adhesin of Tritrichomonas foetus

Abstract

The antibody response patterns of cattle after subcutaneous and intranasal immunizations with adhesin Tf190 of Tritrichomonas foetus were investigated. Reactions of antibody from cattle parenterally immunized with Tf190 revealed antigen specificity and Tf190 sensitization in the majority of the animals, as determined by Western blotting. The results also demonstrated strong preimmune immunoglobulin G2 (IgG2) binding to T. foetus antigens not seen in IgG1 profiles. Subcutaneous injections of Tf190 resulted in significant (P < 0.05) increases in serum IgG1 and IgG2 titers over time, as determined by parasite specific enzyme-linked immunosorbent assay. Immune sera also significantly inhibited parasite adhesion to mammalian cell lines compared to the level of inhibition obtained with preimmune sera (P < 0.05). Intranasal immunization with Tf190 failed to produce measurable parasite-specific antibody in serum; however, this immunization route did result in significant (P < 0.05) increases in parasite-specific IgA titers in cervical mucus secretions from immunized animals that were more resistant to intravaginal challenge with T. foetus than controls. These results suggest that systemic immunization with Tf190 results in serum antibody production and antiparasitic adhesin antibodies. Additionally, the results of challenge experiments with intranasally immunized animals suggests that Tf190 primes protective immune responses that lead to lower rates of infection among these animals.The sexually transmitted parasitic protozoan Tritrichomonas foetus, the causative agent of bovine trichomoniasis, results in fetal loss due to abortion and increased management costs due to unproductive cows. It is often found on the mucosal surfaces of the female reproductive tract or in the epithelial glands of the penis of the bull (20,21,23,28). There is no approved chemotherapy in the United States, and infected animals are usually culled to control disease in the herd (14). Infected animals can often self-cure, perhaps as a consequence of infection-induced acquired immunity; however, reinfection is common and infected bulls can carry the infection for life, serving as a reservoir for the disease and suggesting that immunity from natural infection rarely protects against challenge. Therefore, the reported herd incidence remains near 10%, despite the availability of a commercial vaccine (15). The present vaccine is also problematic because of its incomplete efficacy, since its use results in only an approximately 30% rate of reduction in the incidence of abortion (15).Advancements in chemotherapy and vaccine development are complicated by a general lack of knowledge of the immune effector functions that contribute to protection and insufficient understanding of the pathogenesis of trichomoniasis. Parasitespecific antibody responses in cattle to natural T. foetus infection (immunoglobulin G1 [IgG1], IgG2, and IgA isotypes) have been demonstrated by a variety of assays and with a variety of parasite antigens (3,9,15,17,25) and in experiment...

CD4+ T Cell Responses to Pathogens in Cattle

“…More specifically, Trichomonas foetus upregulates both IgG1 and IgG2 in the serum but only IgG1 in local secretions from cervix, vagina, and uterus [220,221]. Furthermore, animals immunized with specific antigen of Trichomonas foetus showed resistance to the experimental challenge, which was associated with the upregulation of both antigen-specific IgG1 and IgG2 in the serum [222,223]. Trichomonas foetus seems to induce a Th0 response in the circulation, but a Th2 response in the mucosa.…”

Detection of Trichomoniasis in cattle in Nineveh province

“…(6). Further, the serological test can be used for diagnosis of the parasite such as mucus agglutination test and ELISA test, but these tests have limited use because of low sensitivity, the specificity of tests, and in bulls do not develop tangible immune responses (7). The polymerase chain reaction is widely used to detect T. foetus DNA using different types of primers TF1, TF2, TF3, and TF4.…”

A new inactivated Tritrichomonas foetus vaccine that improves genital clearance of the infection and calving intervals in cattle

“…The main objective of vaccines against bovine trichomonosis is to eliminate T. foetus infection from the reproductive tract of the cow before foetal loss occurs. Whole-parasite-based vaccines ( 22 – 26 , 30 , 31 , 35 – 39 ), vaccines formulated with membrane antigens of T. foetus or subunit vaccines ( 29 , 35 , 40 – 42 ) have been developed. Additional work has been also done to identify T. foetus surface antigens such as TF1.17 and TF190 ( 29 , 42 ).…”