Cytokine and LL-37 gene expression levels in Bartonella spp. seropositive and seronegative patients of a rheumatology clinic

PurposeThe variation in the immune response to Bartonella spp. infection in humans remains unclear. The present study compares the expression of selected interleukins, cytokines and cathelicidin (LL-37) in rheumatology clinic patients suffering from musculoskeletal symptoms with healthy blood donors. The patients had previously been tested for the presence of Bartonella henselae antibodies.MethodsGene expression of LL-37, interleukin (IL)-2, IL-4, IL-6, IL-12, interferon-(IFN)-γ, and tumor necrosis factor (TNF-α)-α was determined in blood samples using quantitative Polymerase Chain Reaction (qPCR). Statistical analysis was prepared with STATISTICA.ResultsStatistically significant differences in the mRNA levels of the tested cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-12; p<0.0001) were observed between the healthy controls and patients; however, no difference was observed for LL37 mRNA (p ?= ?0.1974). No significant differences in mRNA expression were observed between IgG in anti-Bartonella seropositive and seronegative individuals (p>0.05). The only significant differences between the Bartonella spp. DNA positive and negative patients, indicated by PCR, were observed for TNF-α and IL-12 mRNA (p ?= ?0.0045 and p ?= ?0.0255, respectively).ConclusionA broadly similar immune response to the tested cytokines was observed among the participants irrespective of anti-Bartonella spp. IgG seropositivity. However, the Bartonella DNA-positive participants demonstrated significantly lower expression of IL-12 and TNF-α mRNA; this may indicate that these bacteria have a suppressive influence on the immune system.     

ArgD of Mycobacterium tuberculosis is a functional N-acetylornithine aminotransferase with moonlighting function as an effective immune modulator

Mycobacterium tuberculosis (M. tuberculosis) encodes an essential enzyme acetyl ornithine aminotransferase ArgD (Rv1655) of arginine biosynthetic pathway which plays crucial role in M. tuberculosis growth and survival. ArgD catalyzes the reversible conversion of N-acetylornithine and 2 oxoglutarate into glutamate-5-semialdehyde and L-glutamate. It also possesses succinyl diaminopimelate aminotransferase activity and can thus carry out the corresponding step in lysine biosynthesis. These essential roles played by ArgD in amino acid biosynthetic pathways highlight it as an important metabolic chokepoint thus an important drug target. We showed that M. tuberculosis ArgD rescues the growth of ΔargD E. coli grown in minimal media validating its functional importance. Phylogenetic analysis of M. tuberculosis ArgD showed homology with proteins in gram positive bacteria, pathogenic and non-pathogenic mycobacteria suggesting the essentiality of this protein. ArgD is a secretory protein that could be utilized by M. tuberculosis to modulate host innate immunity as its moonlighting function. In-silico analysis predicted it to be a highly antigenic protein. The recombinant ArgD protein when exposed to macrophage cells induced enhanced production of pro-inflammatory cytokines TNF, IL6 and IL12 in a dose dependent manner. ArgD also induced the increased production of innate immune effector molecule NOS2 and NO in macrophages. We also demonstrated ArgD mediated activation of the canonical NFkB pathway. Notably, we also show that ArgD is a specific TLR4 agonist involved in the activation of pro-inflammatory signaling for sustained production of effector cytokines. Intriguingly, ArgD protein treatment activated macrophages to acquire the M1 phenotype through the increased surface expression of MHCII and costimulatory molecules CD80 and CD86. ArgD induced robust B-cell response in immunized mice, validating its antigenicity potential as predicted by the in-silico analysis. These properties of M. tuberculosis ArgD signify its functional plasticity that could be exploited as a possible drug target to combat tuberculosis.     

细胞因子在分化型甲状腺癌诊疗中的应用进展北大核心

甲状腺癌是内分泌系统常见的恶性肿瘤之一,其发病率呈逐年上升趋势。甲状腺癌以分化型甲状腺癌(differentiated thyroid carcinoma, DTC)为主,尽管多数DTC患者经规范化治疗后预后良好,但由于部分肿瘤的病理类型侵袭性较高或肿瘤组织分化程度较低,病情进展迅速导致患者总生存时间显著缩短。近年来,有关炎症与肿瘤之间相关性的研究越来越多,炎性微环境的改变在肿瘤发病机制中的作用逐渐被证实,更多的证据表明细胞因子可作为肿瘤的良恶性鉴别、预后判断提示及诊疗方案选择等的重要参考依据。本文就部分细胞因子在DTC诊疗中的应用进展进行论述,旨在为DTC的诊疗与预后判断等提供参考依据。     

Different inflammatory cytokines release after open and endovascular reconstructions influences wound healing

Prodromal signs of a non‐healing wound after revascularisation, which might be strictly linked with impending failure of vascular reconstructions, are associated with an inflammatory response mediated by several circulating adhesion molecules, extracellular endopeptidases, and cytokines. The aim of our study was to investigate the role of selected plasma biomarkers in the prediction of both wound healing and failure of infrapopliteal vein graft or percutaneous trans‐luminal angioplasty (PTA) with selective stent positioning of the superficial femoral artery (SFA) in a population affected with critical limb ischaemia. A total of 68 patients who underwent either surgical or endovascular revascularisation of the inferior limb with autologous saphenous vein infrapopliteal bypass or PTA and selective stenting of the SFA were enrolled in our study. Patients were divided into two groups according to treatment: 41 patients were included in Group 1 (open surgery) and 27 in Group 2 (endovascular procedure). Plasma and blood samples were collected on the morning of surgery and every 6 months thereafter for up to 2 years of follow‐up or until an occlusion occurred of either the vein bypass graft or the vessel treated endovascularly. Fifteen age‐matched healthy male volunteers were considered a reference for biological parameters. Vascular cell adhesion molecule 1 [VCAM‐1]/CD106, inter‐cellular adhesion molecule‐1 [ICAM‐1]/CD54), interleukin‐1 (IL‐1), interleukin‐6 (IL‐6), tumour necrosis factor alpha (TNF‐α), and metalloproteinases (MMP)‐2 and ‐9 plasma levels were measured with enzyme‐linked immunosorbent assay (ELISA) kits. The mean observed time to heal of 54 wounds was 13 ± 4 months, with no statistically significant differences among the groups . The healing failure of the remaining wounds was strictly related to an unsuccessful open (n = 12) or endovascular (n = 8) treatment. The 2‐year primary patency rate was 65% (SE = .09) in Group 1 and 52% (SE = .1) in Group 2. When compared with mean concentration values of Group 1, VCAM‐1 and ICAM‐1 were always significantly higher during follow‐up in patients of Group 2 (P < .05). Furthermore, in the same group, IL‐6 and tumour necrosis factor alpha (TNF‐α) were found to be significantly higher at 6‐ and 12‐month (P < .05) when compared with surgically treated patients. Cox regression analysis showed that elevated plasma levels of VCAM‐1, ICAM‐1, IL‐6, and TNF‐α during follow up were strongly related to impaired wound healing and/or revascularisation failure (P < .05). Elevated plasma levels of inflammatory markers VCAM‐1, ICAM‐1, IL‐6, and TNF‐α may be related to the failure of wound healing and revascularisation procedures. Interestingly, we have observed that endovascular treatments cause a higher level of these inflammation biomarkers when compared with a vein graft, although wound‐healing and patency and limb salvage rates are not influenced.     

Differential expression of inflammatory cytokines and chemokines in lipopolysaccharide‐stimulated melanocytes from lightly and darkly pigmented skin

Increasing evidence suggests that human epidermal melanocytes play an important role in the skin immune system; however, a role of their pigmentation in immune and inflammatory responses is poorly examined. In the study, the expression of Toll‐like receptor 4 (TLR4) and inflammatory cytokines and chemokines by cultured normal melanocytes derived from lightly and darkly pigmented skin was investigated after cell stimulation with lipopolysaccharide (LPS). The basal TLR4 mRNA level in heavily pigmented cells was higher as compared to their lightly pigmented counterparts. Melanocyte exposure to LPS upregulated the expression of TLR4 mRNA and enhanced the DNA‐binding activity of NF‐κB p50 and p65. We found substantial differences in the LPS‐stimulated expression of numerous genes encoding inflammatory cytokines and chemokines between the cells with various melanin contents. In lightly pigmented melanocytes, the most significantly upregulated genes were nicotinamide phosphoribosyltransferase (NAMPT/visfatin), the chemokines CCL2 and CCL20, and IL6, while the genes for CXCL12, IL‐16 and the chemokine receptor CCR4 were the most significantly upregulated in heavily pigmented cells. Moreover, the lightly pigmented melanocytes secreted much more NAMPT, CCL2 and IL‐6. The results of our study suggest modulatory effect of melanogenesis on the immune properties of normal epidermal melanocytes.