The study shows that the fatty tissue in the abdomen (the omentum) naturally makes the antimicrobial peptide LL‑37 and other immune‑boosting molecules, and that their production spikes when there’s an infection after surgery.

Introduction Omentum can secrete out biological agents like different growth factors, cytokines, and antimicrobial peptides. The aim of our study was to determine the expression of antimicrobial peptides and cytokines in human omentum tissue and its response to intra-abdominal infection. Methodology Omentum tissue was obtained from 60 patients: control (n=20) and cases (n=40). mRNA expression of antimicrobial peptides (LL-37, HBD-1, HBD-2, HNP1-3) and cytokines (TNF- α, IL-8, IL-10, IL1β) was evaluated using Real-Time PCR. Protein quantification was done by Immunoblotting and ELISA. Results Significantly higher expression of antimicrobial peptides (LL-37, HBD-1, HBD-2, HNP1-3) and cytokines (TNF- α, IL-8, IL-10, IL1β) was observed in cases as compared to control at both the transcriptional and translational level (p<0.0001). Conclusion Omentum governs a population of antimicrobial peptides with potent immunologic functions. The expression of antimicrobial peptides and cytokines is inducible and increases with the severity of infection. Omentum is thus an immunologically active and adaptable organ but its complete regulatory mechanism is still elusive.