Healthy Uninfected Individuals Research Articles

Exercise Capacity, Muscle Function, Functional Balance, and Cognitive Status in Patients with Post COVID-19 Syndrome Compared to Healthy Controls

Objective: There is limited data on the effect of post-COVID-19 syndrome on functional outcomes compared with healthy uninfected individuals. This study aimed to compare the muscle function, exercise capacity, and quality of life of patients with post-COVID-19 syndrome with that of healthy controls. Methods: Twenty patients with post-COVID-19 syndrome and twenty healthy controls participated in the study. The Incremental Shuttle Walk Test (ISWT) was used to measure exercise capacity, and the Timed Up and Go Test (TUG) was used to assess functional balance. Quadriceps muscle strength (QMS) and handgrip strength (HGS) were measured. Assessment tools included the McGill Pain Questionnaire (SF-MPQ) for pain, the Tampa Scale for Kinesiophobia (TSK) for movement fear, the Modified Medical Research Council Dyspnea Scale (mMRC) for dyspnea, the Fatigue Severity Scale (FSS) for fatigue perception, and the Cognitive Failures Questionnaire (CFQ) for cognitive status. Results: The mMRC dyspnea, TSK, FSS, SF-MPQ total scores, and pain severity of patients with post-COVID-19 syndrome were higher than those of healthy controls (p

Altered plasma metabolites and inflammatory networks in HIV-1 infected patients with different immunological responses after long-term antiretroviral therapy.

Chronic metabolic changes relevant to human immunodeficiency virus type 1 (HIV-1) infection and in response to antiretroviral therapy (ART) remain undetermined. Moreover, links between metabolic dysfunction caused by HIV and immunological inflammation in long-term treated individuals have been poorly studied. Untargeted metabolomics and inflammatory cytokine levels were assessed in 47 HIV-infected individuals including 22 immunological responders (IRs) and 25 non-responders (INRs) before and after ART. The IRs and INRs were matched by age, gender, baseline viral load, and baseline CD4+T cell counts. Another 25 age-matched uninfected healthy individuals were also included as controls. Among the 770 plasma compounds detected in the current study, significant changes were identified in lipids, nucleotides, and biogenic amino acids between HIV-infected patients and healthy controls. Principal Component Analysis (PCA) and the Random Forest (RF) model suggested that levels of selected metabolites could differentiate HIV-infected patients clearly from healthy controls. However, the metabolite profiles identified in our patients were similar, and only three metabolites, maltotetraose, N, N-dimethyl-5-aminovalerate, and decadienedioic acid (C10:2-DC), were different between IRs and INRs following long-term ART. The pathway enrichment analysis results revealed that disturbances in pyrimidine metabolism, sphingolipid metabolism, and purine metabolism after HIV infection and these changes did not recover to normal levels in healthy controls even with suppressive ART. Correlation analysis of the metabolism-immune network indicated that interleukin (IL)-10, D-dimer, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), and TNF-RII were positively correlated with most of the significantly changed lipid and amino acid metabolites but negatively correlated with metabolites in nucleotide metabolism. Significant changes in many metabolites were observed in HIV-infected individuals before and after ART regardless of their immunological recovery status. The disturbed metabolic profiles of lipids and nucleotides in HIV infection did not recover to normal levels even after long-term ART. These changes are correlated with modified cytokines and biomarkers of chronic non-AIDS events, warranting tryout of interventions other than ART.

Circulating platelets and malaria severity: two sides of the same coin among inhabitants of a tropical savannah region, Nigeria.

Changes in circulating platelets during different grades of malaria are of major concerns, and its etiology is poorly understood. We appraised and evaluated the role of circulating platelets in the determination of the severity of malaria among a cohort of outpatients living in Ilorin, Nigeria. A hospital-based case-control study of outpatients visiting public health facilities within the locality voluntarily enrolled for this study. Blood samples from 1162 malaise patients were screened using routine microscopy for Plasmodium parasite species identification, and their respective circulating platelet levels were determined. Seven hundred and seventy-five individuals (775, 66.7%, p<0.001) were malaria-positive. Samples from 387 (33.3%) uninfected healthy individuals were used as controls. Individuals with uncomplicated malaria (UCM) and complicated malaria (CM) across age group were notable (p<0.05). Children ≤5 years had the highest number of individuals with CM (103, 45.2%) with a relative risk ratio of 4.005 (95% CI: 2.964-5.413). UCM (471, 40.5%) occurred more than CM (304, 26.2%) (p>0.05) across the groups. The geometric mean, 95% CI, median, and IQR of populations with malaria thrombocytopenia were higher (181, 110.94±2.207, 106.59-115.30, 118.00, and 39.00) than thrombocytosis (78, 624.64±13.131, 598.49-650.79, 623.00, and 208). Seemingly, health controls recorded insignificant morbidity with respect to platelet counts. High P. falciparum parasitemia is inversely correlated with platelet count, and its' morbidity is associated with the manifestation of several malaria pathogenesis. Thrombocytopenia is a silent pathophysiological attribute that can trigger other cofactors during severe malaria disease. Although further studies are pertinent in order to specifically clarify its relevance to clinical disease spectrum.

Differing natural killer cell, T cell and antibody profiles in antiretroviral-naive HIV-1 viraemic controllers with and without protective HLA alleles.

Previous work suggests that HIV controllers with protective human leukocyte antigen class I alleles (VC+) possess a high breadth of Gag-specific CD8+ T cell responses, while controllers without protective alleles (VC-) have a different unknown mechanism of control. We aimed to gain further insight into potential mechanisms of control in VC+ and VC-. We studied 15 VC+, 12 VC- and 4 healthy uninfected individuals (UI). CD8+ T cell responses were measured by ELISpot. Flow cytometry was performed to analyse surface markers for activation, maturation, and exhaustion on natural killer (NK) cell and T cells, as well as cytokine secretion from stimulated NK cells. We measured plasma neutralization activity against a panel of 18 Env-pseudotyped viruses using the TZM-bl neutralization assay. We found no significant differences in the magnitude and breadth of CD8+ T cell responses between VC+ and VC-. However, NK cells from VC- had higher levels of activation markers (HLA-DR and CD38) (p = 0.03), and lower cytokine expression (MIP-1β and TNF-α) (p = 0.05 and p = 0.04, respectively) than NK cells from VC+. T cells from VC- had higher levels of activation (CD38 and HLA-DR co-expression) (p = 0.05), as well as a trend towards higher expression of the terminal differentiation marker CD57 (p = 0.09) when compared to VC+. There was no difference in overall neutralization breadth between VC+ and VC- groups, although there was a trend for higher neutralization potency in the VC- group (p = 0.09). Altogether, these results suggest that VC- have a more activated NK cell profile with lower cytokine expression, and a more terminally differentiated and activated T cell profile than VC+. VC- also showed a trend of more potent neutralizing antibody responses that may enhance viral clearance. Further studies are required to understand how these NK, T cell and antibody profiles may contribute to differing mechanisms of control in VC+ and VC-.

Antibody isotype epitope mapping of SARS-CoV-2 Spike RBD protein: Targets for COVID-19 symptomatology and disease control.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) still poses a challenge for biomedicine and public health. To advance the development of effective diagnostic, prognostic, and preventive interventions, our study focused on high-throughput antibody binding epitope mapping of the SARS-CoV-2 spike RBD protein by IgA, IgM and IgG antibodies in saliva and sera of different cohorts from healthy uninfected individuals to SARS-CoV-2-infected unvaccinated and vaccinated asymptomatic, recovered, nonsevere, and severe patients. Identified candidate diagnostic (455-LFRKSNLKPFERD-467), prognostic (395-VYADSFVIRGDEV-407-C-KLH, 332-ITNLCPFGEV-342-C-KLH, 352-AWNRKRI-358-C-KLH, 524-VCGPKKSTNLVKN-536-KLH), and protective (MKLLE-487-NCYFPLQSYGFQPTNGVG-504-GGGGS-446-GGNYNYLYRLFRKSNLKPFERD-467) epitopes were validated with sera from prevaccine and postvaccine cohorts. The results identified neutralizing epitopes and support that antibody recognition of linear B-cell epitopes in RBD protein is associated with antibody isotype and disease symptomatology. The findings in asymptomatic individuals suggest a role for anti-RBD antibodies in the protective response against SARS-CoV-2. The possibility of translating results into diagnostic interventions for the early diagnosis of asymptomatic individuals and prognosis of disease severity provides new tools for COVID-19 surveillance and evaluation of risks in hospitalized patients. These results, together with other approaches, may contribute to the development of new vaccines for the control of COVID-19 and other coronavirus-related diseases using a quantum vaccinomics approach through the combination of protective epitopes.

Effect of aging on immune cells in male HIV-infected and -uninfected healthy individuals.

HIV induces immunologic dysfunction in T cells of infected individuals. However, the impact of aging on T cell phenotypes in HIV-infected individuals receiving antiretroviral therapy (ART) has not been fully delineated. We evaluated the relationship between aging and the expression of immune activation and exhaustion markers on CD8 + T cells of age-matched HIV-infected and -uninfected male participants. Levels of immune activation and exhaustion markers on peripheral blood CD8 + T cells of HIV-infected and -uninfected participants were examined. 110 HIV-infected aviremic male participants receiving ART and 146 HIV-uninfected male participants were studied. The levels of TIGIT, PD-1, CD38, and CD226 on CD8 + T cells of the study participants were determined by flow cytometry. The level of TIGIT on CD8 + T cells was higher in aviremic HIV-infected compared to uninfected participants ( P < 0.0001). In contrast, no significant differences were found in the levels of PD-1 and CD38 on CD8 + T cells between the two groups. Statistically significant correlations were observed between age and the levels of TIGIT + and CD38 + CD8 + T cells in both groups; however, no correlation was found between age and the level of PD-1 + CD8 + T cells in HIV-infected participants. Age-stratification of HIV-infected and -uninfected groups did not show any significant differences in the level of PD-1 expression on CD8 + T cells. The findings of our study highlight the role of aging in the expression of immune markers on CD8 + T cells and have important implications for therapies that target immune checkpoints in HIV-infected individuals.

Therapeutic potential of 5-aminolevulinic acid and sodium-ferrous citrate for viral insults: relevance to the COVID-19 crisis

ABSTRACT Introduction : 5-Aminolevulinic acid (5-ALA) is a naturally synthesized amino acid present in most plants as well as animals, and it is routinely consumed by humans. This brief report sought to describe the potential of 5-ALA and sodium-ferrous citrate (5-ALA/SFC) to ameliorate the course of coronavirus disease 2019 (COVID-19). Areas covered : Studies have shown that 5-ALA is converted to protoporphyrin IX (PPIX), then to heme. Recent studies have demonstrated that PPIX has antiviral effects against several viruses, including Zika virus, dengue virus, and influenza A virus. The anti-inflammatory effects of 5-ALA have also been reported in humans. Preliminary in vitro and clinical studies have shown that the combination of 5-ALA/SFC could reduce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-mediated insults. The SARS-CoV-2 genome contains guanine-quadruplex sequences, and the administration of 5-ALA/SFC can lead to the generation of porphyrins that have the ability to bind to guanine-quadruplexes and reduce the replication of SARS-CoV-2. Furthermore, 5-ALA is a metabolic precursor of heme, which is a potent inducer of the enzyme heme oxygenase-1, the levels of which are decreased in patients with severe COVID-19. Oral administration of 5-ALA/SFC induced heme oxygenase-1 in the peripheral blood of uninfected healthy individuals. Expert opinion : Based on the available information, it appears likely that 5-ALA/SFC has therapeutic value in clinically controlling SARS-CoV-2-mediated insults in COVID-19 patients. Multicenter randomized controlled trials are needed for determining the long-term clinical utility of 5-ALA/SFC.

Loss of p53 Expression in Gastric Epithelial Cells of Helicobacter pylori-Infected Jordanian Patients.

Background Around half of the global population is chronically infected with the stomach bacterium Helicobacter pylori, making it one of the most common chronic infections worldwide. H. pylori induces the production of reactive oxygen species, DNA damage, and accelerates the degradation of the tumor suppressor protein p53, which may lead to cancer development. In this study, we investigated the relationship between H. pylori infection and the expression of p53 in gastric mucosa in a group of patients from Jordan. Methods In this retrospective case-control study, the epithelium of gastric glands in subjects chronically infected with H. pylori was examined for the expression of p53. Paraffin-embedded gastric biopsy samples from the archives for 50 Jordanian patients diagnosed with chronic H. pylori infection and 25 samples free of H. pylori infection and any other gastric abnormalities were selected. Samples were analyzed for the presence of H. pylori as well as p53 expression levels in the mucosa and submucosa by immunohistochemical analyses and Western blotting. Results H. pylori was detected in the gastric tissues of infected individuals (n = 50); whereas, no H. pylori infection was detected in uninfected healthy individuals (n = 25) using immunohistochemistry. In contrast to the noninfected samples of gastric mucosa, no nuclear p53 expression was detected in the infected samples using immunohistochemistry. In addition, the levels of p53 in H. pylori-positive samples detected by Western blotting were significantly lower than those in the negative individuals. Conclusion Our data reveal that p53 protein expression decreased in gastric mucosa of patients infected with H. pylori. The loss of this tumor suppressor may play a role in the increased risk for tumor initiation associated with H. pylori carriage.

Estimation of Variations in the Erythrocyte Sedimentation Rate in COVID-19 Recovered Patients

Background: A cluster of patients with pneumonia and severe acute respiratory syndrome developed in Wuhan, China in December 2019, and infection with a novel coronavirus virus called COVID -19 was later verified. Although fever and cough were the most common early signs and symptoms of COVID -19, extrapulmonary symptoms have also been reported. Many studies demonstrate that called COVID -19 swiftly progresses to acute respiratory distress syndrome and even multiple organ dysfunction.&#x0D; Aim:The study aims to evaluate the erythrocyte sedimentation rate count in COVID -19 recovered individuals and compare it with healthy controls.&#x0D; Materials &amp; Methods: A cross-sectional pilot study in 5 healthy COVID -19 uninfected and 5 COVID -19 recovered individuals was conducted, the blood samples were collected and the erythrocyte sedimentation rate was calculated for each set of controls and samples. Statistical analysis was performed using SPSS software. An independent t-test was done to compare the results.&#x0D; Results: The mean value of the control participants was found to be 8.08 ± 4.38 and the mean value of COVID -19 recovered patients was 20.60 ± 1.81. The difference in Erythrocyte Sedimentation Rate (ESR) values between control individuals and COVID -19 recovered patients was statistically significant with p value of less than 0.005.&#x0D; Conclusion: Within the limitations of the study, we conclude that the COVID -19 recovered patients has higher ESR values compared to the healthy uninfected individuals.

Lactobacillus plantarum induces innate cytokine responses that potentially provide a protective benefit against COVID-19: A single-arm, double-blind, prospective trial combined with an in vitro cytokine response assay.

Intestinal microbiota can indirectly modulate airway physiology and immunity through the gut-lung axis. Recent microbiome studies indicate that patients with coronavirus disease 2019 (COVID-19) exhibit a specific intestinal dysbiosis that is closely associated with the disease pathophysiology. Therefore, rebalancing the intestinal microbiome using probiotics may be effective for controlling COVID-19. However, the rationale for using probiotics in COVID-19 remains unclear. In the present study, an in vitro cytokine response assay was conducted, followed by a single-arm, double-blind, prospective trial to evaluate the immunological efficacy of probiotic lactic acid bacteria against COVID-19. The present study focused on Lactobacillus plantarum (L. plantarum), Bifidobacterium longum and Lactococcus lactis ssp. lactis, which exhibit robust protective effects against infection with respiratory RNA viruses. Considering the feasibility of long-term daily intake for prophylactic purposes, healthy uninfected individuals were enrolled as subjects. Our previous pilot trial demonstrated that oral Qingfei Paidu decoction (QFPD), a Chinese herbal medicine formulated specifically against COVID-19, upregulates plasma TNF-α, IL-1β, IL-18 and IL-8. Therefore, the present study utilized the cytokine changes induced by QFPD to define the innate cytokine index QICI [=(TNF-α) x (IL-1β) x (IL-18) x (IL-8)/(IL-6)] as an indicator of the anti-COVID-19 immunomodulatory potential of the lactic acid bacteria. A total of 20 eligible volunteers were enrolled, 18 of whom completed the intervention. L. plantarum demonstrated a strikingly high innate cytokine index in all subjects in the in vitro cytokine response assay. In the subsequent trial, oral intake of L. plantarum significantly increased the innate cytokine index (mean fold change, 17-fold; P=0.0138) and decreased the plasma level of IL-6 (P=0.0128), a key driver of complex immune dysregulation in COVID-19, as compared with the baseline. The cytokine index increased in 16 of 18 subjects (88.9%) with considerable individual differences in the fold change (1- to 128-fold). In line with these innate cytokine changes, L. plantarum ingestion significantly enhanced the activity of natural killer cells. By contrast, oral B. longum failed to induce a significant increase in the innate cytokine index (mean fold change, 2-fold; P=0.474) as compared with the baseline. In conclusion, L. plantarum demonstrated superior QFPD-like immunomodulatory ability and mimicked the blood cytokine environment produced by early immune responses to viral infection. Daily consumption of L. plantarum as an anti-COVID-19 probiotic may be a possible option for preventing COVID-19 during the pandemic. The present study was prospectively registered in the University Hospital Medical Information Network-Clinical Trials Registry under the trial number UMIN000040479 on 22 May 2020 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046202).

Naturally induced humoral response against Plasmodium vivax reticulocyte binding protein 2P1

BackgroundPlasmodium vivax is the most prevalent malaria parasite in many countries. A better understanding of human immunity to this parasite can provide new insights for vaccine development. Plasmodium vivax Reticulocyte Binding Proteins (RBPs) are key parasite proteins that interact with human proteins during erythrocyte invasion and are targets of the human immune response. The aim of this study is to characterize the human antibody response to RBP2P1, the most recently described member of the RBP family.MethodsThe levels of total IgG and IgM against RBP2P1 were measured using plasmas from 68 P. vivax malaria patients and 525 villagers in a malarious village of western Thailand. The latter group comprises asymptomatic carriers and healthy uninfected individuals. Subsets of plasma samples were evaluated for anti-RBP2P1 IgG subtypes and complement-fixing activity.ResultsAs age increased, it was found that the level of anti-RBP2P1 IgG increased while the level of IgM decreased. The main anti-RBP2P1 IgG subtypes were IgG1 and IgG3. The IgG3-seropositive rate was higher in asymptomatic carriers than in patients. The higher level of IgG3 was correlated with higher in vitro RBP2P1-mediated complement fixing activity.ConclusionsIn natural infection, the primary IgG response to RBP2P1 was IgG1 and IgG3. The predominance of these cytophilic subtypes and the elevated level of IgG3 correlating with complement fixing activity, suggest a possible role of anti-RBP2P1 antibodies in immunity against P. vivax.

Qingfei Paidu decoction, a Chinese herbal medicine against COVID‑19, elevates the blood levels of pro‑inflammatory cytokines: An open‑label, single‑arm pilot study

Qingfei Paidu decoction (QFPD) is a Chinese herbal medicine newly formulated for the treatment of COVID‑19. QFPD significantly enhances the therapeutic effects of standard pharmacotherapy in mild to critically ill patients with COVID‑19. However, limited information is available on the immunological mechanisms underlying the efficacy of QFPD. In addition, the feasibility of the prophylactic administration of QFPD to uninfected individuals remains unconfirmed. To obtain insight into these issues, an open‑label, single‑arm pilot study was conducted using 19 healthy uninfected individuals as subjects, and the effects of QFPD ingestion at a dose lower than that recommended for therapeutic use on hematological and immunological parameters were examined. QFPD was prepared according to the Chinese official clinical guideline, except that the dose of each herb was reduced to 1/30 and administered orally to the participants twice daily for 3 days. Low‑dose QFPD ingestion significantly increased the plasma levels of pro‑inflammatory cytokines, tumor necrosis factor (TNF)‑α (P=0.000107), interleukin (IL)‑1β (P=0.000982), IL‑18 (P=0.00105), IL‑2 (P=0.0483) and IL‑8 (P=0.000191), key mediators of a broad spectrum of antiviral immunity. No apparent adverse effects were observed during the trial. These findings suggest that the clinical efficacy of QFPD against COVID‑19 is, at least in part, associated with its immunological activity to mimic the blood cytokine environment produced by early antiviral immune responses, which are shown to be profoundly suppressed during the early stages of COVID‑19. The daily ingestion of low‑dose QFPD may thus be a possible option for the prevention of COVID‑19 during the epidemic. The present study was prospectively registered at the University Hospital Medical Information Network‑Clinical Trials Registry (UMIN‑CTR) under the trial no. UMIN000040341 on May 9, 2020.

Longitudinal profiling of plasma cytokines in melioidosis and their association with mortality: a prospective cohort study

ObjectivesTo characterize plasma cytokine responses in melioidosis and analyse their association with mortality. MethodsA prospective longitudinal study was conducted in two hospitals in Northeast Thailand to enrol 161 individuals with melioidosis, plus 13 uninfected healthy individuals and 11 uninfected individuals with diabetes to act as controls. Blood was obtained from all individuals at enrolment (day 0), and at days 5, 12 and 28 from surviving melioidosis patients. Interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-17A, IL-23, and tumour necrosis factor-α (TNF-α) were assayed in plasma. The association of each cytokine and its dynamics with 28-day mortality was determined. ResultsOf the individuals with melioidosis, 131/161 (81%) were bacteraemic, and 68/161 (42%) died. On enrolment, median levels of IFN-γ, IL-6, IL-8, IL-10, IL-23 and TNF-α were higher in individuals with melioidosis compared with uninfected healthy individuals and all but IFN-γ were positively associated with 28-day mortality. Interleukin-8 provided the best discrimination of mortality (area under the receiver operating characteristic curve 0.78, 95% CI 0.71–0.85). Over time, non-survivors had increasing IL-6, IL-8 and IL-17A levels, in contrast to survivors. In joint modelling, temporal trajectories of IFN-γ, IL-6, IL-8, IL-10 and TNF-α predicted survival. ConclusionsIn a severely ill cohort of individuals with melioidosis, specific pro- and anti-inflammatory and T helper type 17 cytokines were associated with survival from melioidosis, at enrolment and over time. Persistent inflammation preceded death. These findings support further evaluation of these mediators as prognostic biomarkers and to guide targeted immunotherapeutic development for severe melioidosis.

Association between Inflammatory Cytokine Levels and Thrombocytopenia during Plasmodium falciparum and P. vivax Infections in South-Western Coastal Region of India.

Background Thrombocytopenia is a most commonly observed complication during malaria infections. Inflammatory cytokines such as IL-1, IL-6, and IL-10 have been documented in malaria induced thrombocytopaenia. This study was aimed to understand the possible relationship between inflammatory cytokines across varying degrees of thrombocytopenia during P. vivax, P. falciparum, and mixed infections. Methods A hospital-based cross sectional study was conducted at District Wenlock Hospital in Mangaluru, a city situated along the south-western coastal region of Arabian Sea in India. In this study, blood samples from 627 malaria patients were analyzed for infected parasite species, clinical conditions, platelet levels, and key cytokines that are produced in response to infection; samples from 176 uninfected healthy individuals were used as controls. Results The results of our study showed a high prevalence of malarial thrombocytopenia (platelets <150 ×103/μl) in this endemic settings. About 62.7% patients had mild-to-moderate levels of thrombocytopenia and 16% patients had severe thrombocytopenia (platelets <50 × 103/μl). Upon comparison of cytokines across varying degrees of thrombocytopenia, irrespective of infecting species, the levels of TNF-α and IL-10 were significantly higher during thrombocytopenia, whereas IL-6 levels were considerably lower in severe thrombocytopenia patients suffering from P. vivax or P. falciparum infections. The severe clinical complications observed in patients with malarial thrombocytopenia included severe anemia (17.5%), acute renal failure (12.7%), jaundice (27.0%), metabolic acidosis (36.5%), spontaneous bleeding (3.2%), hypoglycemia (25.4%), hyperparasitemia (4.8%), acute respiratory distress syndrome (1.6%), pulmonary edema (19.0%), and cerebral malaria (1.6%) in various combinations. Conclusion Overall, the results of our study suggest that inflammatory cytokines influence the transformation of mild forms of thrombocytopenia into severe forms during malarial infections. Further studies are needed to understand the association of inflammatory cytokine responses with severe malaria complications and thrombocytopenia.

N-acetyl-cysteine exhibits potent anti-mycobacterial activity in addition to its known anti-oxidative functions.

Background Mycobacterium tuberculosis infection is thought to induce oxidative stress. N-acetyl-cysteine (NAC) is widely used in patients with chronic pulmonary diseases including tuberculosis due to its mucolytic and anti-oxidant activities. Here, we tested whether NAC exerts a direct antibiotic activity against mycobacteria.MethodsOxidative stress status in plasma was compared between pulmonary TB (PTB) patients and those with latent M. tuberculosis infection (LTBI) or healthy uninfected individuals. Lipid peroxidation, DNA oxidation and cell death, as well as accumulation of reactive oxygen species (ROS) were measured in cultures of primary human monocyte-derived macrophages infected with M. tuberculosis and treated or not with NAC. M. tuberculosis, M. avium and M. bovis BCG cultures were also exposed to different doses of NAC with or without medium pH adjustment to control for acidity. The anti-mycobacterial effect of NAC was assessed in M. tuberculosis infected human THP-1 cells and bone marrow-derived macrophages from mice lacking a fully functional NADPH oxidase system. The capacity of NAC to control M. tuberculosis infection was further tested in vivo in a mouse (C57BL/6) model.ResultsPTB patients exhibited elevated levels of oxidation products and a reduction of anti-oxidants compared with LTBI cases or uninfected controls. NAC treatment in M. tuberculosis-infected human macrophages resulted in a decrease of oxidative stress and cell death evoked by mycobacteria. Importantly, we observed a dose-dependent reduction in metabolic activity and in vitro growth of NAC treated M. tuberculosis, M. avium and M. bovis BCG. Furthermore, anti-mycobacterial activity in infected macrophages was shown to be independent of the effects of NAC on the host NADPH oxidase system in vitro. Short-term NAC treatment of M. tuberculosis infected mice in vivo resulted in a significant reduction of mycobacterial loads in the lungs.ConclusionsNAC exhibits potent anti-mycobacterial effects and may limit M. tuberculosis infection and disease both through suppression of the host oxidative response and through direct antimicrobial activity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0872-7) contains supplementary material, which is available to authorized users.

T cell receptor signaling pathway is overexpressed in CD4+ T cells from HAM/TSP individuals

Human T-lymphotropic virus type 1 (HTLV-1) is a human retrovirus related to the chronic neuroinflammatory disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). CD4+ T cells activation appears to play a key role on HTLV-1 infection. Here we investigated the expression of genes associated to T cell activation CD3e molecule, epsilon (CD3ɛ), lymphocyte-specific protein tyrosine kinase (LCK), vav 1 guanine nucleotide exchange factor (VAV1), and zeta-chain (TCR) associated protein kinase 70kDa (ZAP70) on T lymphocytes of HTLV-1-infected individuals and compared to healthy uninfected individuals (CT). We observed that CD3ɛ, LCK, ZAP70, and VAV1 gene expression were increased in CD4+ T cells from HAM/TSP group compared to HTLV-1 asymptomatic patients (HAC). Moreover, ZAP70 and VAV1 were also upregulated in HAM/TSP compared to CT group. We detected a positive correlation among all these genes. We also observed that CD3ɛ, LCK, and VAV1 genes had a positive correlation with the proviral load (PVL) and Tax expression. These results suggest that PVL and Tax protein could drive CD3ɛ, LCK, and VAV1 gene expression in CD4+ T cells, and these genes function on a synchronized way on the CD4+ T cell activation. The elucidation of the mechanisms underlying T cell receptor signaling pathway is of considerable interest and might lead to new insights into the mechanism of HAM/TSP.

Understanding immune protection against tuberculosis using RNA expression profiling

A major limitation in the development and testing of new tuberculosis (TB) vaccines is the current inadequate understanding of the nature of the immune response required for protection against either infection with Mycobacterium tuberculosis (MTB) or progression to disease. Genome wide RNA expression analysis has provided a new tool with which to study the inflammatory and immunological response to mycobacteria. To explore how currently available transcriptomic data might be used to understand the basis of protective immunity to MTB, we analysed and reviewed published RNA expression studies to (1) identify a “susceptible” immune response in patients with acquired defects in the interferon gamma pathway; (2) identify the “failing” transcriptomic response in patients with TB as compared with latent TB infection (LTBI); and (3) identify elements of the “protective” response in healthy latently infected and healthy uninfected individuals.

Alteration or adaptation, the two roads for human gastric mucin glycosylation infected by Helicobacter pylori.

Helicobacter pylori is a Gram-negative bacterium that colonizes the mucus niche of the gastric mucosa and infects more than half of the world's human population. Chronic infection may cause gastritis, duodenal ulcer, intestinal metaplasia or gastric cancer. In the stomach, H. pylori interacts with O-glycans of gastric mucins but the mechanism by which the bacteria succeed in altering the mucosa remains mainly unknown. To better understand the physiopathology of the infection, inhibitory adhesion assays were performed with various O-glycans expressed by human gastric mucins, and topographic expression of gastric mucins MUC5AC and MUC6 was analyzed for healthy uninfected individuals, for infected asymptomatic individuals and for patients infected by H. pylori and having the incomplete type of intestinal metaplasia. The glycosylation of the gastric mucosa of asymptomatic individuals infected by H. pylori was determined and compared with the glycosylation pattern found for patients with the incomplete type of intestinal metaplasia. Results show that H. pylori manages to modulate host's glycosylation during the course of infection in order to create a favorable niche, whereas asymptomatic infected individuals seem to counteract further steps of infection development by adapting their mucus glycosylation.

Clinical Severity of Visceral Leishmaniasis Is Associated with Changes in Immunoglobulin G Fc N-Glycosylation

ABSTRACT Visceral leishmaniasis (VL) has a high fatality rate if not treated; nevertheless, the majority of human infections with the causative agent, Leishmania infantum chagasi, are asymptomatic. Although VL patients often present with increased levels of serum immunoglobulins, the contribution of antibodies to resistance or progression to disease remains unknown. Effector and regulatory functions of antibodies rely on their interactions with type I and II Fc receptors, and these interactions are tuned by the patterns of antibody Fc N-glycosylation. In view of these facts, we applied a robust method of IgG Fc N-glycopeptide profiling of serum samples from 187 patients with VL, 177 asymptomatic individuals, 116 endemic controls (individuals residing in areas where VL is endemic) and 43 nonendemic controls (individuals living in an area where VL is not endemic). We show that, in comparison to the overall IgG Fc N-glycan profiles of asymptomatic or uninfected healthy individuals, those of patients with VL are profoundly altered. These changes correlate with levels of serum cytokines and the inflammation marker C-reactive protein. We also fitted univariate and multivariate ordinal logistic regression models to demonstrate the ability of IgG Fc N-glycosylation features and immunity regulators present in serum to predict disease severity in VL patients. Importantly, we show that Fc N-glycosylation profiles change after treatment of VL. This study introduces important concepts contributing to the understanding of antibody responses in infections with Leishmania parasites and provides new insights into the pathology of human VL.

High-mobility group box-1, promising serological biomarker for the distinction of human WNV disease severity

The recent increase of West Nile neuroinvasive disease (WNND) incidence in southern Europe made this change in epidemiology a major concern for public health. The lack of a vaccine or specific treatment against human WNV infection imposes the need to discover biological markers associated with disease severity for diagnostic and/or therapeutic purposes. Recently, using a brain proteomic study from a mouse model of West Nile virus (WNV) infection with neuronal involvement, we reported the kinetic up-regulation of high-mobility group box-1 (HMGB1) and peroxiredoxin-6 (PRDX6), before and after onset of clinical symptoms, respectively. To evaluate whether these proteins could be useful biomarkers for the distinction of WNV disease severity in humans, HMBG1 and PRDX6 concentrations in serum from WNV-infected patients (n=49) diagnosed for either WNF (n=22) or WNND (n=27), were measured by ELISA and compared to concentrations in serum from uninfected healthy individuals (n=30). HMGB1 concentrations were significantly higher in WNND than in either WNF patients (p<0.05) or healthy individuals (p<0.001). In contrast, PRDX6 levels were significantly higher in healthy individuals compared with WNV-infected patients (p<0.001), regardless of clinical symptoms. The present study highlighted the deregulation of HMGB1 and PRDX6 serum level in WNV-infected patients and provided HMGB1 as candidate biomarker distinguishing disease severity. Further investigation in larger cohorts could confirm HMGB1 and PRDX6 as auxiliary biomarkers in confirmed cases of WNV infection and validate the usefulness of measuring HMBG1 for prediction of detrimental clinical outcome.