SAIM resident Colorado State University Fort Collins, Colorado, United States
Abstract: Background – The pathogenesis of feline infectious peritonitis (FIP) is still poorly understood, and transcriptome analysis can help to identify new insights into immunological mechanisms in cats with effusive FIP. Hypothesis/Objectives – To analyze the transcriptome of peritoneal cells of healthy cats and cats with effusive FIP. We hypothesize that there would be a significant difference between healthy cats and cats with effusive FIP. Animals – Two healthy research colony cats and two client owned cats diagnosed with effusive FIP. Methods – Peritoneal lavage samples were obtained from healthy cats during routine ovariectomy and from abdominocentesis in cats with FIP. The RNA was extracted and subjected to Illumina sequencing. Sequence files were aligned with the reference cat genome and assembled using Partek flow software. Gene set enrichment analysis (GSEA) was used for comparison. Results – Expression of 558 genes was significantly upregulated and expression of 732 genes was significantly downregulated in cats with FIP. Using GSEA, multiple pathways associated with Th1 T cell responses, including the interferon gamma, interferon alpha, TNF-α, and STAT3 signaling pathways were identified. There was also a significant downregulation of the epithelial to mesenchymal transitional pathway. Conclusions and clinical importance – This study provides new insights into the normal peritoneal fluid transcriptome in cats as well as transcriptome analysis of peritoneal fluid of cats with effusive FIP which shows the importance of T cell activation and signaling in these patients. These findings suggest additional immune targets in cats with FIP including activation of Th1 pathway responses.
