Mycobacterium tuberculosis directs T helper 2 cell differentiation by inducing interleukin-1β production in dendritic cells

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), resides and replicates within phagocytes and persists in susceptible hosts by modulating protective innate immune responses. Furthermore, M. tb promotes T helper 2(Th2) immune responses by altering the balance of T cell polarising cytokines in infected cells. However, cytokines that regulate Th2 cell differentiation during TB infection remain unknown. Here we show that IL-1β produced by phagocytes infected by virulent M. tb strain H37Rv directs Th2 cell differentiation. In sharp contrast, the vaccine strain BCG as well as RD-1 and ESAT-6 mutants of H37Rv failed to induce IL-1β and promote Th2 cell differentiation. Furthermore, ESAT-6 induced IL-1β production in dendritic cells, and CD4+ T cells co-cultured with infected DCs differentiated into Th2 cells. Taken together our findings indicate that IL-1β induced by RD-1/ESAT-6 plays an important role in the differentiation of Th2 cells, which in turn facilitates progression of TB by inhibiting host protective Th1 responses

Inhibition of NO2, PGE2, TNF-α, and iNOS EXpression by Shorea robusta L.: An Ethnomedicine Used for Anti-Inflammatory and Analgesic Activity

This paper is an attempt to evaluate the anti-inflammatory and analgesic activities and the possible mechanism of action of tender leaf extracts of Shorea robusta, traditionally used in ailments related to inflammation. The acetic-acid-induced writhing and tail flick tests were carried out for analgesic activity, while the anti-inflammatory activity was evaluated in carrageenan-and dextran- induced paw edema and cotton-pellet-induced granuloma model. The acetic-acid-induced vascular permeability, erythrocyte membrane stabilization, release of proinflammatory mediators (nitric oxide and prostaglandin E2), and cytokines (tumor necrosis factor-α, and interleukins-1β and -6) from lipopolysaccharide-stimulated human monocytic cell lines were assessed to understand the mechanism of action. The results revealed that both aqueous and methanol extract (400 mg/kg) caused significant reduction of writhing and tail flick, paw edema, granuloma tissue formation (P < 0.01), vascular permeability, and membrane stabilization. Interestingly, the aqueous extract at 40 μg/mL significantly inhibited the production of NO and release of PGE2, TNF-α, IL-1β, and IL-6. Chemically the extract contains flavonoids and triterpenes and toxicity study showed that the extract is safe. Thus, our study validated the scientific rationale of ethnomedicinal use of S. robusta and unveils its mechanism of action. However, chronic toxicological studies with active constituents are needed before its use

CAIC anjur kolokium memperkasa program pengajaran dan pembelajaran

Seramai 180 dalam kalangan tenaga akademik dan pensyarah dari Universiti Malaysia Pahang (UMP) dan institut pengajian tinggi hadir menyertai Kolokium Pengajaran dan Pembelajaran 2014 bertemakan `Innovation Towards Creative Pedagogy’ anjuran Pusat Inovasi dan Daya Saing Akademik (CAIC) universiti ini

Spectroscopic characterization, antimicrobial activity and molecular docking study of novel azo-imine functionalized sulphamethoxazoles

Financial support from University Grants Commission (F.42-333/2013(SR)) and the Council of Scientific and Industrial Research (01(2894)/09/EMR-II), New Delhi are gratefully acknowledged.[SMX—N=N—C6H3—(p-OH)(m—CHO)] ( 1 ) reacts with ArNH2 to synthesize Schiff bases, [SMX—N=N—C6H3—(pOH)(m—HC=N—Ar)] (Ar =—C6H5 ( 2a ), —C6H4—p—CH3 ( 2b ), —C6H4—p—OCH3 ( 2c ), —C6H4—p—Cl ( 2d ), —C6H4—p—NO2 ( 2e ), —C10H7 ( 2f )) and the products have been assessed for antibacterial properties against Gram positive bacteria, B. subtillis: IC50 (μg/ml): 39.2 ( 1 ), 60.1 ( 2a ), 64.0 ( 2b ), 85.6 ( 2c ), 55.1 ( 2d ), 88.4 ( 2e ) and 65.1 ( 2f ); and Gram negative bacteria, E. coli: IC50 (μg/ml): 159.0 ( 1 ), 151.4 ( 2a ), 155.3 ( 2b ), 140 ( 2c ), 156.0 ( 2d ), 153.5 ( 2e ) and 157 ( 2f ). The cell line toxicity (Vero cells) has also been evaluated with these compounds and EC50 (μg/ml) values are 129.9 ( 1 ), 74.2 ( 2a ) and 93.0 ( 2b ), 191.9 ( 2c ), 99.1 ( 2d ), 93.2 ( 2e ) and 62.0 ( 2f ). The anti-viral efficiency against harpies virus (HSV1F ATCC-733) infection demonstrates that the compound 1 has highest selectivity index (CC50/EC50), 5.06 than the compounds 2a-f (CC50/EC50: 1.18 ( 2a ), 1.42 ( 2b ), 3.50 ( 2c ), 1.45 ( 2d ), 1.58 ( 2e ), 1.29 ( 2f )). The compounds have been spectroscopically characterized and the structural confirmation has been established in one case by single crystal X-ray diffraction studies of 2c . In silico Molecular Docking study has been done using optimized geometries of the compounds to search the most favored binding mode of these drugs and hence useful to explain their competitive drug efficiency.PostprintPeer reviewe

Early Secreted Antigen ESAT-6 of Mycobacterium tuberculosis Promotes Protective T Helper 17 Cell Responses in a Toll-Like Receptor-2-dependent Manner

Despite its relatively poor efficacy, Bacillus Calmette-Guérin (BCG) has been used as a tuberculosis (TB) vaccine since its development in 1921. BCG induces robust T helper 1 (Th1) immune responses but, for many individuals, this is not sufficient for host resistance against Mycobacterium tuberculosis (M. tb) infection. Here we provide evidence that early secreted antigenic target protein 6 (ESAT-6), expressed by the virulent M. tb strain H37Rv but not by BCG, promotes vaccine-enhancing Th17 cell responses. These activities of ESAT-6 were dependent on TLR-2/MyD88 signalling and involved IL-6 and TGF-β production by dendritic cells. Thus, animals that were previously infected with H37Rv or recombinant BCG containing the RD1 region (BCG::RD1) exhibited improved protection upon re-challenge with virulent H37Rv compared with mice previously infected with BCG or RD1-deficient H37Rv (H37RvΔRD1). However, TLR-2 knockout (TLR-2-/-) animals neither showed Th17 responses nor exhibited improved protection in response to immunization with H37Rv. Furthermore, H37Rv and BCG::RD1 infection had little effect on the expression of the anti-inflammatory microRNA-146a (miR146a) in dendritic cells (DCs), whereas BCG and H37RvΔRD1 profoundly induced its expression in DCs. Consistent with these findings, ESAT-6 had no effect on miR146a expression in uninfected DCs, but dramatically inhibited its upregulation in BCG-infected or LPS-treated DCs. Collectively, our findings indicate that, in addition to Th1 immunity induced by BCG, RD1/ESAT-6-induced Th17 immune responses are essential for optimal vaccine efficacy

Effect of L-arginine on the growth of Plasmodium falciparum and immune modulation of host cells

Background & objectives: Malaria is a life-threatening disease caused by Plasmodium parasites. The life-cycle of Plasmodium species involves several stages both in mosquito and the vertebrate host. In the erythrocytic stage, Plasmodium resides inside the red blood cells (RBCs), where it meets most of its nutritional requirement by degrad- ing host′s haemoglobin. L-arginine is required for growth and division of cells. The present study was aimed to demonstrate the effect of supplementation of different concentrations of L-arginine and L-citrulline on the growth of parasite, and effect of the culture supernatant on the host′s peripheral blood mononuclear cells (PBMCs). Methods: To examine the effect of supplementation of L-arginine and L-citrulline, Plasmodium falciparum (3D7 strain) was cultured in RPMI 1640, L-arginine deficient RPMI 1640, and in different concentrations of L-arginine, and L-citrulline supplemented in arginine deficient RPMI 1640 medium. To have a holistic view of in vivo cell activation, the PBMCs isolated from healthy human host were cultured in the supernatant collected from P. falciparum culture. Results: Growth of the parasite was greatly enhanced in L-arginine supplemented media and was found to be concentration dependent. However, parasite growth was compromised in L-citrulline supplemented and L-arginine deficient media. The supernatant collected from L-arginine supplemented parasite media (sArg) showed increased FOXP3 and interleukin-10 (IL-10) expression as compared to the supernatant collected from L-citrulline supple- mented parasite media (sCit). Interpretation & conclusion: The in vitro culture results showed, decreased parasite growth, and decreased expression of programmed cell death-1 (PD-1) (a coinhibitory molecule) and IL-10 in the L-citrulline supplemented media as compared to L-arginine supplemented media. Hence, it was concluded that L-citrulline supplementation would be a better alternative than L-arginine to inhibit the parasite growth

Seroprevalence of Herpes Simplex Virus Infection in HIV Coinfected Individuals in Eastern India with Risk Factor Analysis

Herpes simplex virus type 2 (HSV-2) is the cause of most genital herpes while HSV-1 is responsible for orolabial and facial lesions. In immunocompromised individuals, like HIV patients, impaired immunity leads to more frequent symptomatic and asymptomatic HSV infection. Fifty-two blood samples from HIV patients with clinically diagnosed HSV infection were taken as cases, while 45 blood samples each from HIV-infected (HIV control) and noninfected patients without any herpetic lesion (non-HIV control) were taken as control. Serum was tested for IgM and IgG antibodies of both HSV-1 and HSV-2 by ELISA. The seroprevalence was compared among the three groups of study population, considering the demographic and socioeconomic parameters. The HSV-2 IgM was significantly higher (p<0.005) in the HIV patient group (34.6%) than the HIV control (2.2%) and non-HIV control (2.2%) groups, whereas HSV-2 IgG seroprevalence was higher in both HIV patient (61.5%) and HIV control (57.8%) groups than the non-HIV control group (17.8%). The prevalence of HSV-2 was significantly higher in persons with multiple partners and in the reproductive age group. The overall seroprevalence of HSV-1 IgM was too low (<5%), whereas it was too high (about 90%) with HSV-1 IgG in all three study groups