Distribution Of Canine Distemper Virus Receptor SLAM In Minks And The Regulation By Virus Loading

Signaling lymphocyte activation molecule (SLAM), the cellular receptors for Canine distemper virus (CDV), was amplified from pMD18-T-SLAM plasmid, and inserted to the EcoR I/Sal Isites of pGEX-6p-1prokaryotic expression vector. The recombinant plasmid pGEX-6p-1-SLAM was transformed to the competent E.coli BL21for expression, and the induced protein was detected by SDS-PAGE and western blot.The purified SLAM protein was used as antigen to immunize New Zealand White rabbits and thepolyclonal anti-SLAM serum was prepared after the immunity period. Indirect immunofluorescence assay was performed using Vero cells expressing mSLAM (Vero-mSLAM) as antigen, polyclonal anti-SLAM serum as primary antibody to confirm the specificity of anti-SLAM serum. The distribution of SLAM in different tissues and organs of mink was investigated using immunohistochemistry technique. We further compared the receptor distribution and the CDV antigen expression as well as viral load in different tissues and organs on CDV infected mink. The results showed that the target gene was inserted into the exact location and the reading frame was correct, an recombinant protein about63.2kd was induced successfully, the recombinant protein showed good reaction with the GST-tag monoclonal antibody. Indirect immunofluorescence assays showed that the prepared rabbit anti SLAM protein serum contains SLAM protein antibodies, Immunohistochemistry assay results indicated that the distribution of receptor SLAM in healthy minks is different, the positive cells in the lung and brain were more than those in the liver and spleen, and less positive cells in the kidney were observed. The expression level of receptor SLAM was increased in CDV infected mink compared to healthy minks. Virus loading test showed that distribution of CDV in different tissues in the minks infected CDV is different, the distribution of CDV in the lung and brain is more than that in the liver and spleen, and less in the kidney. The distribution of receptor SLAM in different tissues in the minks infected CDV is similar to the distribution of CDV in the infected minks.This study provided important basis for understanding the combination mechanism between CDV and receptor SLAM.