Transport of Streptococcus pneumoniae Capsular Polysaccharide in MHC Class II Tubules

Bacterial capsular polysaccharides are virulence factors and are considered T cell–independent antigens. However, the capsular polysaccharide Sp1 from Streptococcus pneumoniae serotype 1 has been shown to activate CD4(+) T cells in a major histocompatibility complex (MHC) class II–dependent manner. The mechanism of carbohydrate presentation to CD4(+) T cells is unknown. We show in live murine dendritic cells (DCs) that Sp1 translocates from lysosomal compartments to the plasma membrane in MHCII-positive tubules. Sp1 cell surface presentation results in reduction of self-peptide presentation without alteration of the MHCII self peptide repertoire. In DM-deficient mice, retrograde transport of Sp1/MHCII complexes resulting in T cell–dependent immune responses to the polysaccharide in vitro and in vivo is significantly reduced. The results demonstrate the capacity of a bacterial capsular polysaccharide antigen to use DC tubules as a vehicle for its transport as an MHCII/saccharide complex to the cell surface for the induction of T cell activation. Furthermore, retrograde transport requires the functional role of DM in self peptide–carbohydrate exchange. These observations open new opportunities for the design of vaccines against microbial encapsulated pathogens

IL-17A/F-Signaling Does Not Contribute to the Initial Phase of Mucosal Inflammation Triggered by S. Typhimurium

Salmonella enterica subspecies 1 serovar Typhimurium (S. Typhimurium) causes diarrhea and acute inflammation of the intestinal mucosa. The pro-inflammatory cytokines IL-17A and IL-17F are strongly induced in the infected mucosa but their contribution in driving the tissue inflammation is not understood. We have used the streptomycin mouse model to analyze the role of IL-17A and IL-17F and their cognate receptor IL-17RA in S. Typhimurium enterocolitis. Neutralization of IL-17A and IL-17F did not affect mucosal inflammation triggered by infection or spread of S. Typhimurium to systemic sites by 48 h p.i. Similarly, Il17ra−/− mice did not display any reduction in infection or inflammation by 12 h p.i. The same results were obtained using S. Typhimurium variants infecting via the TTSS1 type III secretion system, the TTSS1 effector SipA or the TTSS1 effector SopE. Moreover, the expression pattern of 45 genes encoding chemokines/cytokines (including CXCL1, CXCL2, IL-17A, IL-17F, IL-1α, IL-1β, IFNγ, CXCL-10, CXCL-9, IL-6, CCL3, CCL4) and antibacterial molecules was not affected by Il17ra deficiency by 12 h p.i. Thus, in spite of the strong increase in Il17a/Il17f mRNA in the infected mucosa, IL-17RA signaling seems to be dispensable for eliciting the acute disease. Future work will have to address whether this is attributable to redundancy in the cytokine signaling network

What causes hidradenitis suppurativa? - 15 years after

The 14 authors of the first review article on hidradenitis suppurativa (HS) pathogenesis published 2008 in EXPERIMENTAL DERMATOLOGY cumulating from the 1st International Hidradenitis Suppurativa Research Symposium held March 30?April 2, 2006 in Dessau, Germany with 33 participants were prophetic when they wrote "Hopefully, this heralds a welcome new tradition: to get to the molecular heart of HS pathogenesis, which can only be achieved by a renaissance of solid basic HS research, as the key to developing more effective HS therapy." (Kurzen et al. What causes hidradenitis suppurativa? Exp Dermatol 2008;17:455). Fifteen years later, there is no doubt that the desired renaissance of solid basic HS research is progressing with rapid steps and that HS has developed deep roots among inflammatory diseases in Dermatology and beyond, recognized as ?the only inflammatory skin disease than can be healed?. This anniversary article of 43 research-performing authors from all around the globe in the official journal of the European Hidradenitis Suppurativa Foundation e.V. (EHSF e.V.) and the Hidradenitis Suppurativa Foundation, Inc (HSF USA) summarizes the evidence of the intense HS clinical and experimental research during the last 15 years in all aspects of the disease and provides information of the developments to come in the near future

What causes hidradenitis suppurativa ?—15 years after

The 14 authors of the first review article on hidradenitis suppurativa (HS) pathogenesis published 2008 in EXPERIMENTAL DERMATOLOGY cumulating from the 1st International Hidradenitis Suppurativa Research Symposium held March 30–April 2, 2006 in Dessau, Germany with 33 participants were prophetic when they wrote “Hopefully, this heralds a welcome new tradition: to get to the molecular heart of HS pathogenesis, which can only be achieved by a renaissance of solid basic HS research, as the key to developing more effective HS therapy.” (Kurzen et al. What causes hidradenitis suppurativa? Exp Dermatol 2008;17:455). Fifteen years later, th

A Virus-Like particle-based anti-nerve growth factor vaccine reduces inflammatory hyperalgesia: potential long-term therapy for chronic pain

Chronic pain resulting from inflammatory and neuropathic disorders causes considerable economic and social burden. For a substantial proportion of patients, conventional drug treatments do not provide adequate pain relief. Consequently, novel approaches to pain management, involving alternative targets and new therapeutic modalities compatible with chronic use, are being sought. Nerve growth factor (NGF) is a major mediator of chronic pain. Clinical testing of NGF antagonists is ongoing, and clinical proof of concept has been established with a neutralizing mAb. Active immunization, with the goal of inducing therapeutically effective neutralizing autoreactive Abs, is recognized as a potential treatment option for chronic diseases. We have sought to determine if such a strategy could be applied to chronic pain by targeting NGF with a virus-like particle (VLP)-based vaccine. A vaccine comprising recombinant murine NGF conjugated to VLPs from the bacteriophage Qβ (NGFQβ) was produced. Immunization of mice with NGFQβ induced anti-NGF-specific IgG Abs capable of neutralizing NGF. Titers could be sustained over 1 y by periodic immunization but declined in the absence of boosting. Vaccination with NGFQβ substantially reduced hyperalgesia in collagen-induced arthritis or postinjection of zymosan A, two models of inflammatory pain. Long-term NGFQβ immunization did not change sensory or sympathetic innervation patterns or induce cholinergic deficits in the forebrain, nor did it interfere with blood-brain barrier integrity. Thus, autovaccination targeting NGF using a VLP-based approach may represent a novel modality for the treatment of chronic pain

Body growth and blood metabolite concentrations in Boran and Boran x Friesian bulls grazed on natural pastures: Effect of dry season dietary supplementation

Twenty-seven Boran and 37 Boran x Friesian bulls, weaned at six months of age, were allocated to either receive supplementary diet (16 percent crude protein and 10.8 MJ/kg DM energy) during the dry season or to serve as unsupplemented controls until 21 months of age. Body weight measurements were taken monthly and two sets of blood samples were collected from all bulls during each of the two dry seasons and one intervening wet season during the 15-month study period. Plasma samples were used for determination of plasma total protein, albumin, globulin, blood urea nitrogen (BUN) and glucose concentrations. Over the study period, overall body weight gain was positive for all treatment groups, but was higher in supplemented than in control bulls and in Boran x Friesian than in Boran bulls. Within genotype, supplementary feeding increased overall body growth by 2.2- and 1.6-fold in Boran and Boran x Friesian bulls, respectively. Within genotype, supplemented bulls had higher total protein and albumin levels, while plasma globulin, BUN and glucose were not affected. On average, Boran bulls had lower concentrations of total protein and globulin, but higher albumin and BUN levels than the Boran x Friesian bulls. Blood glucose concentrations were not influenced by dietary supplementation, did not differ between genotypes and showed no consistent trends over time in the two genotypes. Body weight was positively correlated with plasma total protein (0.54) and globulin (0.49) concentrations, but negatively related with albumin/globulin ration (-0.48) and blood urea nitrogen (-0.57). It was concluded that the body growth of young bulls grazing natural pastures during the wet season was adequate and dry season dietary supplementation improved growth in both Boran and Boran x Friesian bulls. Determination of blood metabolites considered in this study did not assist in assessing the nutritional status of young Boran and Boran x Friesian bulls using the types of feeds and at the level of supplementation provided

LTA4H inhibitor LYS006: Clinical PK/PD and safety in a randomized phase I clinical trial

Abstract LYS006 is a novel, highly potent and selective, new‐generation leukotriene A4 hydrolase (LTA4H) inhibitor in clinical development for the treatment of neutrophil‐driven inflammatory diseases. We describe the complex pharmacokinetic to pharmacodynamic (PD) relationship in blood, plasma, and skin of LYS006‐treated nonclinical species and healthy human participants. In a randomized first in human study, participants were exposed to single ascending doses up to 100 mg and multiple ascending doses up to 80 mg b.i.d.. LYS006 showed rapid absorption, overall dose proportional plasma exposure and nonlinear blood to plasma distribution caused by saturable target binding. The compound efficiently inhibited LTB4 production in human blood and skin blister cells, leading to greater than 90% predose target inhibition from day 1 after treatment initiation at doses of 20 mg b.i.d. and above. Slow re‐distribution from target expressing cells resulted in a long terminal half‐life and a long‐lasting PD effect in ex vivo stimulated blood and skin cells despite low plasma exposures. LYS006 was well‐tolerated and demonstrated a favorable safety profile up to highest doses tested, without any dose‐limiting toxicity. This supported further clinical development in phase II studies in predominantly neutrophil‐driven inflammatory conditions, such as hidradenitis suppurativa, inflammatory acne, and ulcerative colitis

Effect of IL-17A and/or F immunization on the <i>S.</i>Typhimurium infection.

<p>C57BL/6 mice were vaccinated three times (50 µg each, s.c.) with IL-17A-VLP, IL-17F-VLP, either reagents or unconjugated control VLPs. A–C) αIL-17A and αIL-17F titers were analyzed two weeks after the last immunization by ELISA and compared to unconjugated-VLP immunized controls (B,C; OD450 nm values +/− SEM). D,E) Neutralization was tested by ELISA. D) ELISA plates were coated with 1 µg/ml IL-17RA and binding of 10 ng/ml biotinylated IL-17A to IL-17RA was tested in the presence of serum of mice immunized with IL-17A-VLPs, IL-17F-VLPs or VLPs alone (OD450 nm values +/− SEM). E) ELISA plates were coated with 1 µg/ml IL-17RC and binding of 200 ng/ml biotinylated IL-17F to IL-17RC was tested in the presence of serum of mice immunized with IL-17A-VLPs, IL-17F-VLPs or VLPs alone; OD450 nm values +/− SEM. F–J) Subsequent analysis in <i>S</i>. Typhimurium challenge infections. Animals were pretreated with streptomycin and infected for 2 days with wt <i>S</i>. Typhimurium. PBS immunization and PBS treatment served as control. We analyzed colonization levels in the gut lumen (F), the mLN (G), the liver (H) and the spleen (I), as well as the degree of inflammation of the cecum mucosa (J). Comparison with the control VLPs immunized mice did not reveal any significant differences in any of the parameters of the infection, analyzed (J: Mann-Whitney U test was not significant as well as ANOVA with Bonferroni (p = 0.0841)). Stippled line: minimal detectable value.</p

<i>Il17ra</i> expression in the gut of control and <i>S</i>.Tm^*-infected C57BL/6 mice.

<p>(A) <i>Il17a</i>, <i>Il17f</i> and <i>Il17ra</i> expression in the intestinal tissues of naïve mice (n = 3 per group). Relative levels of mRNA in 20 ng total RNA were normalized to <i>house keeping genes</i>. ΔCt values do not strictly correlate to the difference in gene expression between various genes. However, ΔCt values <19 represent detectable levels of expression, demonstrating thereby that all three genes are expressed in the various tissue segments. (B) Induction of <i>Il17ra</i> expression in <i>Salmonella</i>-infected animals. <i>Salmonella</i>-infected animals (n = 3; 12 h p.i. with <i>S</i>.Tm*; open circles) were from the experiment shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013804#pone-0013804-g002" target="_blank">Fig. 2</a>. Non-infected, stereptomycin pretreated C57BL/6 mice (n = 3; black circles) served as a contol. Samples of gut tissues (A, as indicated; B, cecum tissue) were taken for RNA isolation and mRNA levels were analyzed by real time PCR. <i>S</i>.Tm^* infected C57BL/6 mice showed a significant up-regulation of <i>Il17ra</i> in comparision to non-infected C57BL/6 mice (p<0.05; t-test unpaired, two-tailed). Sm: Streptomycin. Line: median.</p