PBMCs of Hainan Black goats mediating immune response to resist the infection of Mannheimia haemolytica.

Abstract

Mannheimia haemolytica (M. haemolytica) can cause pneumonia in domestic ruminants, resulting in substantial economic losses in animal husbandry. Peripheral blood mononuclear cells (PBMCs) play an important role in anti-infection by mediating innate and adaptive immune responses. In this study, we established an in vitro model of PBMCs infected with M. haemolytica to explore the immune regulation mechanism of PBMCs during infection. In the experimental group (mh), PBMCs were infected with M. haemolytica at a multiplicity of infection (MOI) of 10, and the PBS treatment group (ck) was used as a control. RNA was extracted and transcriptome sequencing was performed, and 2617 differentially expressed genes (DEGs) were obtained. The protein-protein interaction (PPI) network was constructed, and 11 DEGs were screened for RT-qPCR verification. The results were consistent with the sequencing results. DEGs were significantly enriched in immune response and inflammatory response-related signaling pathways according to pathway and gene set analysis. The differentially expressed genes were enriched in JAK-STAT and other pathways, and CCL20 was the common gene among the five significantly enriched immune-related pathways. TNF, IL-6, and TLR4 were identified as the core nodes by MCODE. Therefore, TNF, IL-6, and TLR4 were the key genes of immune regulation after PBMCs infection with M. haemolytica. This study provides a new experimental basis and reference for elucidating the pathogenic mechanism and host immune response characteristics of M. haemolytica-infected goats.