ABSTRACT
As an important micronutrient, selenium (Se) plays many essential roles in immune response and protection against pathogens in humans and animals, but underlying mechanisms of Se-based control of salmonella growth within macrophages remain poorly elucidated. In this study, using RNA-seq analyses, we demonstrate that Se treatment (at an appropriate concentration) can modulate the global transcriptome of chicken macrophages HD11. The bioinformatic analyses (KEGG pathway analysis) revealed that the differentially expressed genes (DEGs) were mainly enriched in retinol and glutathione metabolism, revealing that Se may be associated with retinol and glutathione metabolism. Meanwhile, Se treatment increased the number of salmonella invading the HD11 cells, but reduced the number of salmonella within HD11 cells, suggesting that enhanced clearance of salmonella within HD11 cells was potentially modulated by Se treatment. Furthermore, RNA-seq analyses also revealed that nine genes including SIVA1, FAS, and HMOX1 were differentially expressed in HD11 cells infected with salmonella following Se treatment, and GO enrichment analysis showed that these DEGs were mainly enriched in an extrinsic apoptotic signaling pathway. In summary, these results indicate that Se treatment may not only affect retinol and glutathione metabolism in macrophages, but could also inhibit salmonella-induced macrophage apoptosis via an extrinsic apoptotic signaling pathway involving SIVA1.
ABSTRACT
As key elements and targets for various intracellular pathogens, macrophages play an essential role in host defense. Although ovine peripheral blood monocyte-derived cell lines have been established, their phenotypic characteristics and functional properties remain unknown. We have established several ovine macrophage cell lines from peripheral blood adherent cells that can proliferate spontaneously in long-term culture in vitro. Characteristics of macrophages were shaped by cell morphology, cell adhesion, expression of cell surface markers, phagocytic activity and inflammatory response. Furthermore, the differences of genes expression (such as membrane proteins, pro-inflammatory cytokines and chemokine) were compared between blood macrophages (BMs) and alveolar macrophages (AMs), and between BMs and splenic macrophages (SMs), respectively. The expression of membrane genes (CD11b and CD80), pro-inflammatory cytokines (IL-1ß and TNFα) and chemokines (IL-8/CXCL8 and CCL-21) was lower than that in AMs or SMs, but not CD200. Moreover, BMs maintained lower expression level of M1 macrophage related genes (iNOS and IDO), but high expression levels of M2 macrophage related genes (ARG2 and TGFß1). BMs showed lower phagocytic ability than AMs and SMs. Compared with AMs, BMs showed higher salmonella proliferation rate within cells. Collectively, BMs could suppress inflammatory responses and possessed partly phenotypic characteristics of M2 macrophages.
