Expression Pattern of Immune-Related Genes in the Liver of Rohu, <i>Labeo rohita</i> (Hamilton) Exposed to Carbon Tetrachloride Toxicity

Abstract

Immune responses in the liver play a crucial role in the detoxification process and renderingprotection against different diseases. The present study was targeted to analyze the expressionkinetics of few immune genes (pro-inflammatory, immune receptors, anti-microbial and innateimmunity-related) using qPCR in liver tissue of carbon tetrachloride (CCl4) treated rohu (Labeorohita). Rohu juveniles were injected with single intraperitoneal toxic dose of 30% CCl4 to induce liver damage. Histopathological findings showed the presence of focal necrosis and vaccuolation of hepatocytes. Increase in the level of pro-inflammatory cytokine (interleukin-6, IL-8 and IL-15) transcripts was observed immediately after CCl4 post-exposure (from 6 h to 120 h), thus indicating the role of enhanced level of cytokines inducing liver damage. The degree of liver damage was also reflected by reduction in expression of immune related molecules (viz., TLR 22, transferrin and hepcidin), which are mostly synthesized in liver tissue. No effect was noticed in synthesis of mitochondrial antiviral-signaling protein (MAVS) transcripts with the current level of CCl4 exposure. These results suggest that there is a critical balance between immune molecules that may play essential roles in the orchestration of immune defense in fish during liver dysfunction.