Publications by authors named "Nabanita Biswas"

Poor translatability of animal disease models has hampered the development of new inflammatory bowel disorder (IBD) therapeutics. We describe a preclinical, ex vivo system using freshly obtained and well-characterized human colorectal tissue from patients with ulcerative colitis (UC) and healthy control (HC) participants to test potential therapeutics for efficacy and target engagement, using the JAK/STAT inhibitor tofacitinib (TOFA) as a model therapeutic. Colorectal biopsies from HC participants and patients with UC were cultured and stimulated with multiple mitogens ± TOFA.

View Article and Find Full Text PDF

Authenticity of dried aromatic herbs and herbal powders for the ASU (ayurvedic, siddha, unani) drug formulations is a key of their clinical success. The DNA based authentication is an answer; however, extraction of PCR quality DNA from such material is often problematic due to the presence of various co-extracted PCR inhibitors. Here, we report a novel DNA isolation and purification method utilizing cow skim milk that successfully yields PCR quality DNA from the aromatic herbs and dried herbal powders.

View Article and Find Full Text PDF

Background: There are limited data on the immunological responsiveness of healthy intestinal tissue when it is cultured and stimulated ex vivo. Such an ex vivo model has the potential to be a valuable tool in understanding disease pathogenesis and as a preclinical tool for the assessment of candidate therapeutic agents used to treat inflammatory bowel disease (IBD).

Aim: We undertook a comprehensive study to evaluate ex vivo immunological responses of intestinal tissue and isolated mucosal mononuclear cells (MMC) to a broad range of stimuli.

View Article and Find Full Text PDF

Tenofovir (TFV) is a reverse transcriptase inhibitor used in microbicide preexposure prophylaxis trials to prevent HIV infection. Recognizing that changes in cytokine/chemokine secretion and nucleotidase biological activity can influence female reproductive tract (FRT) immune protection against HIV infection, we tested the hypothesis that TFV regulates immune protection in the FRT. Epithelial cells, fibroblasts, CD4(+) T cells, and CD14(+) cells were isolated from the endometrium (Em), endocervix (Cx), and ectocervix (Ecx) following hysterectomy.

View Article and Find Full Text PDF

Tenofovir (TFV) has been widely used for pre-exposure prophylaxis of HIV-1 infection with mixed results. While the use of TFV in uninfected individuals for prevention of HIV-1 acquisition is actively being investigated, the possible consequences of TFV exposure for the HIV-target cells and the mucosal microenvironment are unknown. In the current study, we evaluated the effects of TFV treatment on blood-derived CD4⁺ T cells, monocyte-derived macrophages and dendritic cells (DC).

View Article and Find Full Text PDF

The magnitude of the HIV epidemic in women requires urgent efforts to find effective preventive methods. Even though sex hormones have been described to influence HIV infection in epidemiological studies and regulate different immune responses that may affect HIV infection, the direct role that female sex hormones play in altering the susceptibility of target cells to HIV-infection is largely unknown. Here we evaluated the direct effect of 17-β-estradiol (E2) and ethinyl estradiol (EE) in HIV-infection of CD4(+) T-cells and macrophages.

View Article and Find Full Text PDF

We examined the antiviral activity of ADAR1 against HIV-1. Our results indicated that ADAR1 in a transfection system inhibited production of viral proteins and infectious HIV-1 in various cell lines including 293T, HeLa, Jurkat T and primary CD4+ T cells, and was active against a number of X4 and R5 HIV-1 of different clades. Further analysis showed that ADAR1 inhibited viral protein synthesis without any effect on viral RNA synthesis.

View Article and Find Full Text PDF

Background: The innate immune responses to virus infection are initiated by either Toll-like receptors (TLR3/7/8/9) or cytoplasmic double-stranded RNA (dsRNA)-recognizing RNA helicases RIG-I and MDA5. To avoid causing injury to the host, these signaling pathways must be switched off in time by negative regulators.

Methodology/principal Findings: Through yeast-two hybrid screening, we found that an ubiquitin-like protein named protein linking integrin-associated protein to cytoskeleton 1(PLIC-1 or Ubiquilin 1) interacted with the Toll/interleukin-1 receptor (TIR) domain of TLR4.

View Article and Find Full Text PDF

Claudin-1 (CLDN1), a tight junction (TJ) protein, has recently been identified as an entry co-receptor for hepatitis C virus (HCV). Ectopic expression of CLDN1 rendered several non-hepatic cell lines permissive to HCV infection. However, little is known about the mechanism by which CLDN1 mediates HCV entry.

View Article and Find Full Text PDF