Lipooligosacharide(LOS) of Neisseria gonorrhoeae(gonococci, GC) is involved in the interaction of GC with host cells. Deletion of the alpha-oligosaccharide(alpha-OS) moiety of LOS(lgt F mutant) significantly impairs invasion of GC into epithelial cell lines. GC opacity(Opa) proteins, such as Opa I, mediate phagocytosis and stimulate chemiluminescence responses in neutrophils in part through interaction with members of the carcinoembryonic antigen(CEA) family, which includes CEACAM3(CD66d), a human neutrophil specific receptor for phagocytosis of bacteria. In the present work, we examined the effects of Opa I-expressing lgt F mutant on phagocytosis by He La-CEACAM3 cells and chemiluminescence responses in neutrophils. The results showed that lgt F mutant even expressing Opa I completely lost the ability to promote either phagocytosis mediated by CEACAM3 interaction in He La cells or chemiluminescence responses in neutrophils. These data indicated that Opa proteins in the lgt F mutant, which might result from the conformational change, cannot be functional.
Liopxin A4(LXA4) is considered to be a crucial modulator in the inflammatory responses. In the present study, we aimed to study the effect of LXA4 on the inflammatory cytokines production induced by lipopolysaccharide(LPS) and the possible mechanism in normal human epidermal keratinocytes(NHEKs). NHEKs were isolated and cultured. The expression of toll-like receptor 4(TLR4), LXA4 receptor(ALXR) and aryl hydrocarbon receptor(Ah R) in NHEKs was detected by reverse transcription polymerase chain reaction(RT-PCR). The m RNA and protein levels of tumor necrosis factor-alpha(TNF-α) and interleukin-1β(IL-1β) were determined in NHEKs stimulated by LPS(10 μg/m L) with or without preincubation with LXA4(100 nmol/L) for 30 min by real-time quantitative PCR(real-time q PCR) and enzyme-linked immunosorbent assay(ELISA), respectively. The expression levels of tumor necrosis factor receptor-associated factor 6(TRAF6) and suppressors of cytokine signaling 2(SOCS2) m RNAs and proteins, and nuclear translocation of NF-k B-p65 were measured by real-time q PCR and Western blotting, respectively. The results showed that NHEKs expressed TLR4, ALXR and Ah R. LXA4 significantly inhibited the m RNA and protein expression levels of TNF-α, IL-1β and TRAF6 induced by LPS in NHEKs, and LXA4 obviously increased the expression of SOCS2 at m RNA and protein levels. The nuclear NF-k B-p65 protein expression induced by LPS was inhibited after preincubation with LXA4 in NHEKs. It was concluded that LXA4 inhibits the LPS-induced production of TNF-α and IL-1β in NHEKs by up-regulating SOCS2 and down-regulating TRAF6.
The expression of the interferon regulatory factor 4 (IRF-4) and the IRF-4-binding pro-tein (IBP) in psoriatic skin lesions was investigated. The expression of IRF-4 and IBP in skin lesions of 20 patients with psoriasis vulgaris were immunohistochemically dectected. Normal skin from 10 healthy people was used as normal control. The study showed that expression of IRF-4 was increased significantly in keratinocytes and inflammatory cells in the lesions of psoriasis vulgaris than that in the normal control. The detection revealed that IBP expression in keratinocytes, lymphocytes, hair follicles, and sebaceous glands in normal skin was significantly lower than that in the lesions of pso-riasis vulgaris (P<0.05). Both IRF-4 and IBP might be involved in the pathogenesis of psoriasis vul-garis.
This study examined the correlation of the expression of interleukin-36 (IL-36),a novel member of interleukin-1 (IL-1) family,with p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor-kappa B (NF-κB) pathways in psoriasis vulgaris skin lesions.The expression levels of IL-36α,IL-36β,IL-36γ,phosphorylated p38 MAPK,and NF-κBp65 were detected in the skin tissues of 38 psoriasis patients and 17 healthy control subjects by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting.The cytokine expression levels were compared between the psoriasis group and the control group.A correlation analysis between cytokine proteins was performed in the psoriasis group.Results showed that the expression levels of IL-36a,IL-36β,IL-36γ,phosphorylated p38 MAPK and NF-κBp65 in the psoriasis group were significantly higher than those in the control group (P<0.001).In the psoriasis group,the IL-36 cytokine expression was positively correlated with phosphorylated p38 MAPK and NF-κBp65 expression (P<0.05).A significant positive correlation was also found between the phosphorylated p38 MAPK and NF-κBp65 expression (P<0.01).It was concluded that the increased IL-36 expression is correlated with p38 MAPK and NF-κB pathways in psoriasis vulgaris skin lesions.All the three factors may be jointly involved in the pathogenesis and local inflammatory response of psoriasis.
