Work

Chlamydia psittaci inclusion membrane protein CPSIT_0844 elicits inflammatory IL-6 and IL-8 production in human monocytes via TLR2/TLR4 signaling pathways

Year: 2026

Type: article

Abstract: The respiratory disease caused by Chlamydia psittaci (C. psittaci) infection is often characterized by significant inflammation. In the present study, we demonstrated that the C. psittaci inclusion membrane protein CPSIT_0844 induced THP-1 cells to express IL-6 and IL-8. However, silencing of the Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) genes by using small interfering RNA (siRNA) and transfection with the dominant negative plasmid encoding MyD88 (pDeNy-hMyD88) were found to reduce the expression of IL-6 and IL-8 in THP-1 cells stimulated with CPSIT_0844. Furthermore, CPSIT_0844 induces IL-6 and IL-8 production by signaling pathways involving JNK, p38, and NF-κB in monocytes. Collectively, our findings identify CPSIT_0844 as a proinflammatory virulence factor that triggers IL-6 and IL-8 expression via a TLR2/TLR4-MyD88-dependent mechanism, culminating in the activation of MAPK and NF-κB pathways. This work provides crucial molecular insight into the inflammatory pathogenesis of C. psittaci infection.

Source: Immunobiology

DOI: 10.1016/j.imbio.2026.153160