Distinct expression profile and histological distribution of NLRP3 inflammasome components in the tissues of Hainan black goat suggest a site-specific role in the inflammatory response.

The NOD-like receptor protein 3 (NLRP3) inflammasome comprised of NLRP3, ASC and caspase-1 plays an important role in the inflammatory and innate immune response. However, little is known about the expression pattern and histological distribution of these genes in goat. Here, we first cloned the fulllength cDNAs of the NLRP3, ASC and caspase-1 genes of Hainan black goat and produced their polyclonal antibodies. Tissue-specific expression and histological distribution of these genes were analysed. Phylogenetic analysis revealed that these three goat genes had high homology with Bos taurus genes and low homology with avian or fish genes. After immunisations with these recombinant Histagged proteins, the titres of antiserum were higher than 1:1024 and purified IgG was obtained. These three genes were expressed in all examined tissues, the mRNA expression level of NLRP3 and caspase-1 was most abundant in the spleen and mesenteric lymph nodes (MLNs), while ASC was primary expressed in the liver, spleen and kidney. The histological distribution of NLRP3, ASC and caspase-1 was detected in myocardial cells, hepatocytes, focal lymphocytes, bronchiolar epithelial cells, renal tubular epithelial cells, cortical neurons and endothelial cells of the germinal centres in the MLNs. These results will be helpful in further investigations into the function of the NLRP3 inflammasome and in elucidating its role in caprine inflammatory diseases.