Molecular and Functional Analysis of TLR 1, 2 and 6 in Peripheral Blood Monocytes of Patients with Schizophrenia: A Pilot Study.

Schizophrenia (SZ) is a chronic disabling mental disorder with high heritability, and several immune-regulating genes have been implicated in its pathophysiology In this study, we investigated the expression of Toll-like receptors (TLRs) 1, 2, and 6 in peripheral blood monocytes from SZ patients and healthy control subjects (HCSs) in the Mexican population, focusing on specific SZ-associated gene variants. Gene expressions were assessed by qPCR, and protein expression was measured using flow cytometry. The secretory profiles of MALP2-stimulated monocytes were evaluated through immunoproteomic arrays. Our results indicate that patients with SZ carrying the rs4833093/ GG genotype exhibited significantly lower gene expression compared to TT carriers. Notably, HCSs with the TT genotype showed markedly higher protein expression, while all patients with SZ exhibited significantly reduced protein levels regardless of genotype. Furthermore, monocytes from patients with SZ displayed altered secretion profiles upon TLR stimulation, with significant elevations in IL-18, uPAR, angiopoietin-2, and serpin E1, alongside reductions in MCP-1, IL-17A, IL-24, MIF, and myeloperoxidase compared to HCSs. These findings suggest a dysfunctional TLR-mediated innate immune response in SZ.