Leukotrienes Are Upregulated and Associated with Human T-Lymphotropic Virus Type 1 (HTLV-1)-Associated Neuroinflammatory Disease

Leukotrienes (LTs) are lipid mediators involved in several inflammatory disorders. We investigated the LT pathway in human T-lymphotropic virus type 1 (HTLV-1) infection by evaluating LT levels in HTLV-1-infected patients classified according to the clinical status as asymptomatic carriers (HACs) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Bioactive LTB4 and CysLTs were both increased in the plasma and in the supernatant of peripheral blood mononuclear cell cultures of HTLV-1-infected when compared to non-infected. Interestingly, CysLT concentrations were increased in HAM/TSP patients. Also, the concentration of plasma LTB4 and LTC4 positively correlated with the HTLV-1 proviral load in HTLV-1-infected individuals. The gene expression levels of LT receptors were differentially modulated in CD4(+) and CD8(+) T cells of HTLV-1-infected patients. Analysis of the overall plasma signature of immune mediators demonstrated that LT and chemokine amounts were elevated during HTLV-1 infection. Importantly, in addition to CysLTs, IP-10 was also identified as a biomarker for HAM/TSP activity. These data suggest that LTs are likely to be associated with HTLV-1 infection and HAM/TSP development, suggesting their putative use for clinical monitoring.Fundacao de Amparo a Pesquisa do Estado de Sao PauloFundacao de Amparo a Pesquisa do Estado de Sao PauloFundacao de Amparo a Pesquisa do Estado de Minas GeraisFundacao de Amparo a Pesquisa do Estado de Minas GeraisConselho Nacional de Desenvolvimento Cientifico e TecnologicoConselho Nacional de Desenvolvimento Cientifico e TecnologicoFundacao Hemocentro de Ribeirao PretoFundacao Hemocentro de Ribeirao PretoCNPqCNP

Participação do gene Alc11a1 na infecção por Paracoccidioides brasiliensis em linhagens de camundongos selecionados segundo a alta ou baixa reatividade inflamatória aguda

Camundongos selecionados para a máxima (AIRmax) ou mínima (AIRmin) reação inflamatória aguda apresentam desvio de freqüência do gene Slc11a1. Este gene está envolvido no transporte de íons divalentes no compartimento endossomal/lisossomal de macrófagos e neutrófilos, interferindo na sua ativação e suscetibilidade a infecções. Neste estudo, nós investigamos a interação dos alelos Slc11a1 R (Slc11a1rGly169) e S (expressão nula da proteína Slc11a1, Slc11a1sAsp169) com os loci de características quantitativas (QTL) moduladores da inflamação, durante a paracoccidioidomicose (PCM) em linhagens AIRmaxRR, AIRmaxSS, AIRminRR and AIRminSS homozigotas para o gene Slc11a1, produzidas por acasalamentos assistidos por genotipagem. Nós verificamos que o alelo R em homozigose foi responsável por um maior influxo neutrofílico em camundongos com background AIRmax. Observamos ainda, que as linhagens AIRmaxRR e AIRmaxSS foram mais resistentes enquanto a linhagem AIRmin portadora do alelo R foi implicada em uma maior recuperação de UFC de P. brasiliensis. Desta forma, apesar de não observarmos diferença na recuperação de UFC entre as sublinhagens AIRmax, um aumento no influxo de neutrófilos para o pulmão dos animais AIRmaxRR pode ter compensado a influência do alelo Slc11a1 R na multiplicação do fungo. Nós também mostramos que o número de UFC nos pulmões foi relacionado a síntese de IL-4 e IL-10 neste órgão, mas a produção de óxido nítrico foi semelhante em ambas as linhagens mostrando que este metabólito não foi o fator determinante de resistência/suscetibilidade nas linhagens analisadas. Quanto a análise de diferentes citocinas em sobrenadante de cultura de células do baço e no pulmão das linhagens utilizadas, mostramos que o gene modula a síntese de várias citocinas, porém...Mice selected for the maximum (AIRmax) or minimum (AIRmin) acute inflammatory reaction show disequilibrium of the Slc11a1 gene. This gene is involved in the transport of divalent ions at the endosomal/lysosomal compartment within macrophages and neutrophils, interfering in their activation and susceptibility to infections. In this study, we investigated the interaction of the Slc11a1 R (Slc11a1rGly169) and S (null Slc11a1 protein expression, Slc11a1sAsp169) alleles with the Quantitative Trait Loci (QTL) modulated-inflammation during paracoccidioidomycosis in homozygous AIRmaxRR, AIRmaxSS, AIRminRR and AIRminSS lines produced by genotype-assisted breedings. It could be verified that R allele in homozygosis is associated with a more intense neutrophil influx in AIRmax background. The AIRmax lines showed to be more resistant wile AIRmin bearing allele R implicated in a higher recovered P. brasiliensis CFU. Although, the increase of neutrophil influx to the lungs in AIRmaxRR mice can be compensating the influence of Slc11a1 R allele in P. brasilinsis multiplication. We have also observed that the number of CFU in lungs was not related to NO production but instead to modulation of IL-4 and IL-10 synthesis in the lungs. Moreover, we present the effect of Slc11a1 modulating the release of differents cytokines in both supernatant of spleen cells and lungs, but this effect was time-dependent and change in accordance of host genetic background and microenviroment produced by immune response during P. brasiliensis infection. In conclusion, these findings suggest that the lower PMN leukocyte infiltration to the lungs and Slc11a1 R genotype seemed to be a decisive factor in determining the susceptibility profiles in P.brasiliensis infection.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Serum 25-hydroxyvitamin D levels are not associated with adverse outcomes in Clostridium difficile infection

<em>Clostridium difficile</em> infection (CDI) is a significant source of healthcare-associated morbidity and mortality. This study investigated whether serum 25-hydroxyvitamin D is associated with adverse outcomes from CDI. Patients with CDI were prospectively enrolled. Charts were reviewed and serum 25-hydroxyvitamin D was measured. The primary outcome was a composite definition of severe disease: fever (temperature &gt;38°C), acute organ dysfunction, or serum white blood cell count &gt;15,000 cells/μL within 24-48 hours of diagnosis; lack of response to therapy by day 5; and intensive care unit admission; colectomy; or death within 30 days. Sixty-seven patients were included in the final analysis. Mean (±SD) serum 25- hydroxyvitamin D was 26.1 (±18.54) ng/mL. Severe disease, which occurred in 26 (39%) participants, was not associated with serum 25-hydroxyvitamin D [odds ratio (OR) 1.00; 95% confidence interval (CI) 0.96-1.04]. In the adjusted model for severe disease only serum albumin (OR 0.12; 95%CI 0.02-0.64) and diagnosis by detection of stool toxin (OR 5.87; 95%CI 1.09-31.7) remained independent predictors. We conclude that serum 25-hydroxyvitamin D is not associated with the development of severe disease in patients with CDI

Celecoxib Improves Host Defense through Prostaglandin Inhibition during Histoplasma capsulatum Infection

Prostaglandins act as mediators of inflammation and, similar to cytokines, function as immune modulators during innate and adaptive immune responses. Therefore, using a pharmacological inhibitor, celecoxib, we investigated the role of prostaglandins in host defense against Histoplasma capsulatum infection in C57BL/6 mice. Our results showed that treatment with celecoxib inhibited cyclooxygenase 2, reduced the total fungal burden, and reduced the concentration of PGE2, cytokines, lymphocytes, neutrophils, and mononuclear cells in the bronchoalveolar space and lung parenchyma. In addition, celecoxib treatment increased the synthesis of nitric oxide, IFN-γ, LTB4, and the phagocytic capacity of alveolar macrophages. Moreover, celecoxib treatment increased the survival of mice after infection with a lethal inoculum of H. capsulatum. These results suggest that prostaglandins alter the host immune response and play an important role in the pathogenesis of histoplasmosis. Thus, the inhibition of prostaglandins could be a valuable immunomodulatory strategy and antifungal therapy for histoplasmosis treatment

Demographical and Clinical Characteristics of the Study Groups.

<p><b>Note.</b>^aM/F: male/female;</p>b<p>N/A: not applicable;</p>c<p>HAC: HTLV-1 asymptomatic carriers;</p>d<p>HAM/TSP: HTLV-1 associated myelopathy/tropical spastic paraparesis.</p

Signature curves of high biomarker producers during HTLV-1 infection.

<p>(A) Representative scattergraphs were used to establish the concept of low biomarker producers (white) and high biomarker producers (black). The results from all groups studied (non-infected donors, HACs and HAM/TSP patients) were assembled to calculate the global median for each biomarker. Low biomarker producers were defined as having values lower than the global median, whereas high biomarker producers were defined as having values greater than or equal to the global median cut-off. Data from 3 of 18 molecules analyzed are shown. (B–D) The diagrams were plotted using the global median index of plasma biomarkers (measured by ELISA) as the cut-off to identify each volunteer as a low (□) or high (▪) producer. The ascendant frequency of high producers found in the NI group was established as a reference curve (–□–) to identify changes in the overall biomarker signature of the other groups. Significant differences were defined as a shift to a distinct 25% quartile interval between the studied groups. *, significantly different values compared with NI donors; ^#, significantly different values compared with HACs. NI – non-infected healthy donors; HAC – HTLV-1 asymptomatic carriers; HAM – HAM/TSP subjects.</p

Leukotriene receptor mRNA expression in lymphocytes of HTLV-1 patients.

<p>Quantitative PCR (qPCR) was performed for BLT₁ (A, C) and CysLT₁ (B, D), and their relative expression levels were determined in CD4⁺ (A, B) and CD8⁺ (C, D) T cells from twenty non-infected healthy donors (NI), twenty asymptomatic carriers (HAC) and seventeen HAM/TSP patients (HAM). Gene expression levels were normalized to the gene expression levels of <i>ACTB, GAPDH, B2M</i> and <i>RPL13a</i> for CD4⁺ T cells and of <i>ACTB</i> for CD8⁺ T cells in the same real-time PCR reaction. The data are presented as means ± SEM. *<i>p</i><0.05, compared with NI donors; ^#<i>p</i><0.05, compared with HACs (one-way ANOVA).</p