Cellular immune responses in the lungs of pigs infected in utero with PRRSV: an immunohistochemical study.

The cellular response in the lungs of pigs transplacentally infected with porcine reproductive and respiratory syndrome virus (PRRSV) was examined by immunohistochemistry. Double staining for the T-cell marker antigen CD3 and PRRSV demonstrated that the appearance and distribution of T-cells homing to the lungs of infected pigs correlated well with the presence and location of virusinfected cells. Single stainings showed that cells positive for the CD2 and CD8 antigen were almost as numerous in pneumonic lesions as CD3 positive cells whereas cells expressing the CD4 antigen were rare.

Immunohistochemical detection of SWC3, CD2, CD3, CD4 and CD8 antigens in paraformaldehyde fixed and paraffin embedded porcine lymphoid tissue.

Identification of the different cell types of the immune system is important for in situ studies on the pathogenesis of infectious diseases in various animals, including the pig. Unfortunately, many monoclonal anti-leukocyte antibodies are only useful for staining frozen tissue sections with inherent poor tissue morphology, and are not readily adapted to formaldehyde fixed and paraffin embedded tissue with well preserved morphology. Seven well characterised monoclonal antibodies against porcine leukocyte antigens were tested on neutral buffered paraformaldehyde fixed and paraffin embedded porcine tissue sections using the highly sensitive tyramide signal amplification system.