Interleukin 1 alpha mRNA-expressing cells on the local inflammatory response in feline infectious peritonitis

Area of Science:

• Veterinary Pathology
• Immunology
• Molecular Biology

Background:

• Feline infectious peritonitis (FIP) is a significant disease in cats.
• The role of specific cytokines, like interleukin-1 alpha (IL-1 alpha), in FIP pathogenesis is not fully understood.

Purpose of the Study:

• To investigate the distribution and cellular localization of IL-1 alpha mRNA in tissues affected by FIP.
• To explore the potential role of IL-1 alpha in the inflammatory processes of FIP.

Main Methods:

• In situ hybridization using a biotinylated human IL-1 alpha cDNA probe.
• Examination of tissues from 49 pathologically diagnosed FIP cases.
• Morphological assessment of IL-1 alpha mRNA-expressing cells.

Main Results:

• IL-1 alpha mRNA-expressing cells were identified in various tissues, including peritoneum, lymphoid organs, liver, kidney, and brain.
• Hybridization signals were concentrated in inflammatory lesions on serosal surfaces, particularly in FIP-affected areas.
• The majority of these cells were morphologically consistent with infiltrated macrophages.

Conclusions:

• Macrophages expressing IL-1 alpha mRNA are present in FIP inflammatory lesions.
• IL-1 alpha produced by macrophages at local inflammatory sites may play a role in the development of visceral peritoneal lesions in FIP.