Publications by authors named "Palash Bhattacharya"

We have previously shown GM-CSF derived bone-marrow dendritic cells (G-BMDCs) can induce the selective expansion of Tregs through the surface-bound molecule OX40L; however, the physiological role of this ex vivo derived DC subset remained to be elucidated. We determined GM-CSF administration to mice induced the generation of in vivo derived OX40L DCs, phenotypically similar to ex vivo OX40LG-BMDCs, in the spleen, brachial lymph nodes and liver. The generation of OX40L DCs correlated with increased percentages of functionally suppressive Tregs in the spleen, brachial lymph nodes, and liver of GM-CSF treated mice.

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The immune system ensures optimum T-effector (Teff) immune responses against invading microbes and tumor antigens while preventing inappropriate autoimmune responses against self-antigens with the help of T-regulatory (Treg) cells. Thus, Treg and Teff cells help maintain immune homeostasis through mutual regulation. While Tregs can contribute to tumor immune evasion by suppressing anti-tumor Teff response, loss of Treg function can result in Teff responses against self-antigens leading to autoimmune disease.

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Regulatory T cells (Tregs) play a pivotal role in immune-tolerance, and loss of Treg function can lead to the development of autoimmunity. Natural Tregs generated in the thymus substantially contribute to the Treg pool in the periphery, where they suppress self-reactive effector T cells (Teff) responses. Recently, we showed that OX40L (TNFSF4) is able to drive selective proliferation of peripheral Tregs independent of canonical antigen presentation (CAP-independent) in the presence of low-dose IL-2.

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We have previously shown that OX40L/OX40 interaction is critical for TCR-independent selective proliferation of Foxp3 Tregs, but not Foxp3 effector T-cells (Teff), when CD4 T-cells are co-cultured with GM-CSF derived bone marrow dendritic cells (G-BMDCs). Events downstream of OX40L/OX40 interaction in Tregs responsible for this novel mechanism are not understood. Earlier, OX40L/OX40 interaction has been shown to stimulate CD4 T-cells through the formation of a signalosome involving TRAF2/PKC-Ѳ leading to NF-kB activation.

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Regulatory T-cells (Tregs) play a pivotal role in maintaining peripheral tolerance. Increasing Treg numbers/functions has been shown to ameliorate autoimmune diseases. However, common Treg expansion approaches use T-Cell Receptor (TCR)-mediated stimulation which also causes proliferation of effector T-cells (Teff).

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Earlier, we have shown that GM-CSF derived bone marrow (BM) dendritic cells (G-BMDCs) can expand Foxp3(+) regulatory T-cells (Tregs) through a TCR-independent, but IL-2 dependent mechanism that required OX40L/OX40 interaction. While some reports have shown suppression of autoimmunity upon treatment with an OX40 agonist, others have shown exacerbation of autoimmune disease instead. To better understand the basis for these differing outcomes, we compared the effects of OX40L treatment in 6-week-old pre-diabetic and 12-week-old near diabetic NOD mice.

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Virtually all efforts to generate an effective protection against the life-long, recurrent genital infections caused by HSV-2 have failed. Apart from sexual transmission, the virus can also be transmitted from mothers to neonates, and it is a key facilitator of HIV coacquisition. In this article, we uncover a nanoimmunotherapy using specially designed zinc oxide tetrapod nanoparticles (ZOTEN) with engineered oxygen vacancies.

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GM-CSF was originally identified as a colony stimulating factor (CSF) because of its ability to induce granulocyte and macrophage populations from precursor cells. Multiple studies have demonstrated that GM-CSF is also an immune-modulatory cytokine, capable of affecting not only the phenotype of myeloid lineage cells, but also T-cell activation through various myeloid intermediaries. This property has been implicated in the sustenance of several autoimmune diseases like arthritis and multiple sclerosis.

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Granulocyte macrophage colony stimulating factor (GM-CSF) is generally recognized as an inflammatory cytokine. Its inflammatory activity is primarily due its role as a growth and differentiation factor for granulocyte and macrophage populations. In this capacity, among other clinical applications, it has been used to bolster anti-tumor immune responses.

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To prepare a novel Bispecific Antibody (BsAb) as a potential targeted therapy for T1D, we produced a "functionally inert" monoclonal antibody (mAb) against Glucose transporter-2 (GLUT-2) expressed on β-cells to serve as an anchoring antibody. The therapeutic arm is an agonistic mAb against Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4), a negative regulator of T-cell activation expressed on activated CD4+ T-cells. A BsAb was prepared by chemically coupling an anti-GLUT2 mAb to an agonistic anti-CTLA-4 mAb.

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Multilocular cystic renal cell carcinoma (MCRCC), also known as multilocular clear cell renal cell carcinoma (RCC), is a rare cystic tumor of the kidney with an excellent outcome. It occurs in about 3.1-6% of the conventional RCC.

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Adenoid cystic carcinoma is a relatively rare epithelial tumor of the salivary glands accounting for about 5-10% of all salivary gland neoplasms. Approximately, 31% of salivary gland neoplasms affect minor salivary glands particularly the palate. It involves tongue in only 19.

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Earlier, we had demonstrated that treatment with low dose of GM-CSF can prevent the development of experimental autoimmune thyroiditis (EAT), experimental autoimmune myasthenia gravis, and type 1 diabetes, and could also reverse ongoing EAT and experimental autoimmune myasthenia gravis. The protective effect was mediated through the induction of tolerogenic CD11C(+)CD8α(-) dendritic cells (DCs) and consequent expansion of Foxp3(+) regulatory T cells (Tregs). Subsequently, we showed that GM-CSF acted specifically on bone marrow precursors and facilitated their differentiation into tolerogenic dendritic cells (DCs; GM-CSF-induced bone marrow-derived DCs [GM-BMDCs]), which directed Treg expansion in a contact-dependent manner.

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It is difficult to predict which urothelial neoplasm would subsequently recur or progress to muscle invasive tumours or produce metastasis.The aim and objective of the study were to evaluate the scope of immunohistochemical expression of p53 in human urothelial neoplasms with regard to grade, stage and outcome of the patients. Eighteen consecutive patients were taken and urothelial tumour samples were obtained from transurethral resection or surgical excision.

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The optimal upper limit of the normal range for prostate specific antigen (PSA) is suggested, but review of literature reveals that, malignancy of prostate can occur below that range and some benign prostatic diseases are occasionally associated with higher levels. The aim of the study is for early detection of prostatic malignancy. We tried to evaluate digital rectal examination (DRE), estimation of PSA and transrectal ultrasound (TRUS) guided core needle biopsy and histopathological examination in the patients.

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The enforcement of sphingosine-1-phosphate (S1P) signaling network protects from radiation-induced pneumonitis. We now demonstrate that, in contrast to early postirradiation period, late postirradiation sphingosine kinase-1 (SphK1) and sphingoid base-1-phosphates are associated with radiation-induced pulmonary fibrosis (RIF). Using the mouse model, we demonstrate that RIF is characterized by a marked upregulation of S1P and dihydrosphingosine-1-phosphate (DHS1P) levels in the lung tissue and in circulation accompanied by increased lung SphK1 expression and activity.

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Autoimmune thyroid diseases (AITD) are one of the most common organ-specific autoimmune disorders, of which Hashimoto's thyroiditis (HT) and Graves' disease (GD) are 2 of the most common clinical expressions. HT is characterized by hypothyroidism that results from the destruction of the thyroid by thyroglobulin-specific T cell-mediated autoimmune response. In contrast, GD is characterized by hyperthyroidism due to excessive production of thyroid hormone induced by thyrotropin receptor-specific stimulatory autoantibodies.

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Earlier, we have shown that GM-CSF-exposed CD8α- DCs that express low levels of pro-inflammatory cytokines IL-12 and IL-1β can induce Foxp3+ Tregs leading to suppression of autoimmunity. Here, we examined the differential effects of IL-12 and IL-1β on Foxp3 expression in T cells when activated in the presence and absence of DCs. Exogenous IL-12 abolished, but IL-1β enhanced, the ability of GM-CSF-exposed tolerogenic DCs to promote Foxp3 expression.

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In our earlier work, we had shown that GM-CSF treatment of CBA/J mice can suppress ongoing thyroiditis by inducing tolerogenic CD8α(-) DCs, which helped expand and/or induce CD4(+)Foxp3(+) Tregs. To identify the primary cell type that was affected by the GM-CSF treatment and understand the mechanism by which Tregs were induced, we compared the effect of GM-CSF on matured spDCs and BMDC precursors in vitro. Matured spDCs exposed to GM-CSF ex vivo induced only a modest increase in the percentage of Foxp3-expressing T cells in cocultures.

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Autoantibodies directed against the skeletal muscle acetylcholine receptor (AChR) play a critical role in the pathogenesis of the autoimmune disease, myasthenia gravis (MG). The pathogenic importance of anti-AChR antibodies is substantiated clinically by the often dramatic clinical improvement that follows removal of circulating antibodies utilizing extracorporeal plasma exchange (PE). Unfortunately, the effects of PE are non-specific as immunoglobulins (IgG) and other plasma proteins are removed in addition to anti-AChR IgG.

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Ig class switch recombination (CSR) is regulated through long-range intrachromosomal interactions between germline transcript promoters and enhancers to initiate transcription and create chromatin accessible to activation-induced deaminase attack. CSR occurs between switch (S) regions that flank Cmu and downstream C(H) regions and functions via an intrachromosomal deletional event between the donor Smicro region and a downstream S region. It is unclear to what extent S region primary sequence influences differential targeting of CSR to specific isotypes.

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Every year, influenza virus infection causes significant mortality and morbidity in human populations. Although egg-based inactivated viral vaccines are available, their effectiveness depends on the correct prediction of the circulating viral strains and is limited by the time constraint of the manufacturing process. Recombinant subunit vaccines are easier to manufacture with a relatively short lead time but are limited in their efficacy partly because the purified recombinant membrane proteins in the soluble form most likely do not retain their native membrane-bound structure.

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Aim: The aim of the study was to investigate the expression and function of the IG20 gene in thyroid cancer cell survival, proliferation, and apoptosis.

Methods: We determined the expression levels of the major isoforms of IG20 by quantitative RT-PCR in normal and thyroid tumor tissues/cell lines. We evaluated the functional consequence of IG20 knockdown in WRO (follicular carcinoma) and FRO (anaplastic carcinoma) thyroid cancer cell lines by measuring spontaneous, TNFalpha-related apoptosis-inducing ligand (TRAIL), and TNFalpha-induced apoptosis.

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Activation-induced deaminase (AID) is the master regulator of class switch recombination (CSR) and somatic hypermutation (SHM), but the mechanisms regulating AID function are obscure. The differential pattern of switch plasmid activity in three IgM(+)/AID(+) and two IgG(+)/AID(+) B cell lines prompted an analysis of global gene expression to discover the origin of these cells. Gene profiling suggested that the IgG(+)/AID(+) B cell lines derived from germinal center B cells.

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