Cellular response in bovine limph nodes inoculated with Anaplasma marginale
The immune response against the pathogen Anaplasma marginale was evaluated after the inoculation, in calves, with the strain AUFV1 2nd passage. For this, routine coloration techniques and immunohistochemistry techniques were performed in slides of superficial limph nodes. In the first week post inoculation, a proliferative response was observed in the paracortical areas and, in the third week, a great number of germinal centers. With the TUNEL technique, many cells in apoptosis were observed, in a number statistically significant six and 13 days post inoculation. Antigens of A. marginale presented by dendritic cells were detected with the Indirect Immunoperoxidase technique six days post inoculation, and these were not observed in the limph node of the negative control animal. The same technique was also performed with the purpose of identifying the surface antigens CD4, CD8 and WC1, and a little augment was observed only on the population of lymphocytes CD4+. Another experiment evolved the isolation of peripheral blood mononuclear cells (PBMCs), wich were isolated in the same days the limph nodes were coleted, for studies of proliferation and production of cytokines after reestimulation ex vivo. The mitogen Con A and initial bodies of A. marginale were utilized as positive controls. The PBMCs were estimulated wiht two synthetic peptides based on the structure of the surface protein of A. marginale MSP-2, named 13590 and 13591. A negative control was also utilized, were was added incomplete medium only. On the proliferative tests, only six days post inoculation the peptides were better than the negative control, with numbers statistically significants (plt;0,05). On this way, we could conclude that the inoculated animals developed an adaptative immune response against A. marginale, probably evolving T helper cells. In relation to the synthetic peptides tested, we can only afirm that they are good candidates for the development of a vaccine against bovine anaplasmosis, but more studies have to be performed in this area.
Advisor:Marlene Isabel Vargas Viloria; Jackson Victor de Araújo; Lygia Maria Friche Passos; Múcio Flávio Barbosa Ribeiro; Joaquín Hernán Patarroyo Salcedo
School:Universidade Federal de Viçosa
Source Type:Master's Thesis
Keywords:Anaplasmose Anaplasma marginale Anaplasmosis Control Synthetic vaccine
Date of Publication:02/28/2003