Study on effect of Sophora subprosrate polysaccharide on the inflammatory response and immunosuppression of immune cells in PCV2 infection through JAK-STAT/NF-κB signaling pathway.

The study was to investigate the modulatory effect of Sophora subprosrate polysaccharide (SSP) on inflammatory reaction and immunosuppression in PCV2-infected RAW264.7 cells. The PCV2-infected RAW264.7 cells were treated with SSP (100, 200 and 400 mg/L) for 16 h, the mRNA expression of signal transducer and activator of transcription 1, 2 ( STAT1, STAT2), janus kinase 1 (JAK1), tyrosine kinase 2 (TYK2), chemokine (C-C motif) ligand 3 (Ccl3), chemokine (C-X-C motif) ligand 2 (CXCL2), tumor necrosis factor alpha ( TNF-α), REL proto-oncogene, NF-κB subunit (Rel), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha and delta (Nfκbia, Nfκbid), and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor zeta (Nfκbiz) were measured. The protein expression levels of phospho-signal transducer and activator of transcription 1 and 2 (p-Stat1, p-Stat2), signal transducer and activator of transcription 1 and 2 (Stat1, Stat2), inhibitor of nuclear factor κB kinase subunit beta (IκB), phospho-inhibitor of nuclear factor κB kinase subunit beta (p-Iκ B), nuclear factor NF-κB p65 subunit (p65), phospho-nuclear factor NF-κB p65 subunit (p-p65), CXCL2, JAK1, phospho-Janus kinase 1 (p-JAK1) and TYK2 in the cells were detected. The levels of interleukin-1β (IL-1β), interferon-α (IFN-α), interferon-β (IFN-β), and TNF-α in cell supernatants were detected. The results showed that after the RAW264.7 cells were infected with PCV2 for 16 h, the mRNA expression levels of STAT1, STAT2, JAK1, TYK2 and Nfκbia were significantly upregulated (P<0.05), mRNA expression levels of Ccl3, CXCL2, TNF-α, Rel, Nfκbid and Nfκbiz were significantly downregulated ( P<0.05), the protein expression levels of Stat1, p-Stat1, Stat2, p-Stat2, JAK1, p-JAK1 and TYK2 were significantly upregulated ( P<0.05), protein expression levels of IκB, p-IκB, p65 and CXCL2 were significantly downregulated in RAW264.7 cells ( P<0.05), and SSP at 200 mg/L significantly regulated the imbalance in the expression levels of these factors (P<0.05). The study indicates that SSP modulates inflammatory response and immunosuppression induced by PCV2 infection through JAK-STAT/NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]