Publications by authors named "Saswati S Lenka"

The molecular crosstalk of proximal innate immune receptor signaling mediated by Toll-like receptors (TLRs) is crucial in generating an adaptive immune response. The extracellular-signal regulated kinases (ERK) participate in propagating intracellular signals initiated by stimulated TLRs to transcription factors eliciting cytokine release. Although ERK signaling has been extensively studied in mammalian counterparts, very little is known about its existence in carps and its role in augmentation of immunoglobulin (Ig) synthesis.

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The high-mobility group box 1 (HMGB1) protein is a highly conserved nonhistone chromosomal protein ubiquitously present in almost all cell types. In the nucleus, it facilitates DNA repair and replication, V(D)J recombination, stabilization of nucleosome, and in the cytoplasm, it regulates autophagy and apoptosis. In addition to these intracellular functions, HMGB1 also facilitates activation of innate immune responses and plays key roles in host defense.

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The primordial immunoglobulin class, IgD, was the first non-IgM isotype discovered in teleosts. The crucial roles of IgM and IgZ in imparting systemic and mucosal immunity, respectively, in various fish species have been widely established. However, the putative function of a unique IgD isotype during pathogenic invasions has not been well explored.

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Toll-like receptors (TLRs) play key roles in innate immunity from lower to higher vertebrates. Among various TLR types, TLR4 was reported to recognize LPS in higher vertebrates resulting in the activation of down-stream signaling pathway. Except in some teleosts, function of TLR4 in most fish species including rohu (Labeo rohita) a commercially important fish species in the South-East Asian countries remained unknown.

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Immunoglobulins (Igs) play critical roles in protecting host against diverse pathogenic invasion and diseases. Among all Ig isotypes, IgD is the most recently-evolved and enigmatic molecule detected in all vertebrates species except birds. In South-East Asia, Labeo rohita (rohu) is the leading candidate fish species for freshwater aquaculture, and this article describes about IgD gene expression in rohu following viral, bacterial and parasitic antigenic challenges.

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B-cell activating factor (BAFF), an important member of the tumor necrosis factor superfamily, plays critical roles in the modulation of B-cell functions and enhancement of immune response in the host. Like higher vertebrates, the important role of BAFF in boosting immune response against diverse pathogens was also envisaged in fishes. We therefore, studied BAFF in rohu (Labeo rohita), a freshwater food fish species of highest economic importance in the Indian subcontinent.

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The damage-associated molecular patterns (DAMPs) released from the damaged tissue/cells are recently reported as endogenous ligands to activate toll-like receptors (TLRs) and nucleotide binding and oligomerization domain (NOD) receptors signaling pathways. In the aquatic environment, reduction in dissolved oxygen (DO) concentration causes hypoxic stress resulting in tissue damage and patho-biological changes in fish. We envisaged the critical role of TLR and NOD receptors in recognizing DAMPs as endogenous ligands during hypoxic stress in fish.

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Interferon gamma (IFN-γ) is one of the key cytokines that plays a major role against viral and intracellular bacterial infection. In addition to the IFN-γ gene, teleost fish possess a second copy known as IFN-γ-related (IFN-γrel) gene. This report describes structural and functional properties of IFN-γrel gene in the Indian major carp, rohu (Labeo rohita), a commercially important freshwater fish species in the Indian subcontinent.

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Toll-like receptors (TLRs) and nucleotide binding and oligomerization domain (NOD) receptors are pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) and play crucial role in innate immunity. In addition to PAMPs, PRRs recognize endogenous molecules released from damaged tissue or dead cells [damage-associated molecular patterns (DAMPs)] and activate signaling cascades to induce inflammatory processes. In the aquatic environment, large variation in seasonal and diurnal water temperature causes heat and cold stresses in fish, resulting in tissue injury and mortality of fish.

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Toll-like receptors (TLRs) are a class of innate immune receptors that sense pathogens or their molecular signatures and activate signaling cascades to induce a quick and non-specific immune response in the host. Among various types of TLRs, TLR22 is exclusively present in teleosts and amphibians and is expected to play the distinctive role in innate immunity. This report describes molecular cloning, three-dimensional (3D) modeling, and expression analysis of TLR22 in rohu (Labeo rohita), the most commercially important freshwater fish species in the Indian subcontinent.

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