Immunohistochemical detection of B and T lymphocytes in mandibular lymph nodes of experimentally infected piglets with classical swine fever virus

Classical swine fever (CSF) is a highly contagious viral disease of domestic pigs and wild boars with severe consequences on animal welfare, livestock production, trade and national economy. We investigated if colostral antibodies in piglets, originating from sows vaccinated with Chine strain (C-strain) and challenged with CSF virus, affected the distribution of the B and T lymhocites in mandibular lymph nodes. Nineteen 45 days old cross breed pigs of both sexes were divided in three groups. All animals in the first group, originating from sows vaccinated with C-strain vaccine were serologically positive for the presence of specific colostral CSF virus antibodies. The second group consisted of pigs originating from unvaccinated sows serologically negative for CSF virus antibodies. Three healthy pigs serologically negative for the presence of CSF virus antibodies, originating from unvaccinated sows against CSF virus served as a control group. In the group of animals originating from unvaccinated sows against CSF, severe depletion of CD79 positive B lymphocytes was detected. In the group of pigs originating from sows vaccinated with C-strain (CSF virus antibody positive group of pigs), a reduced number of CD79 positive B lymphocytes was detected, but B cells were still present in the periphery of the germinative centres of secondary lymph follicles. There was an increase of the number of CD3 positive cells in the mandibular lymph nodes of pigs with or without maternal antibodies