Recombinant Attenuated Vaccine Displaying Regulated Lysis to Confer Biological Containment and Protect Catfish against Edwardsiellosis.

We implemented a unique strategy to construct a recombinant attenuated vaccine (RAEV) with a biological containment phenotype that causes regulated bacterial cell wall lysis. This process ensures that the vaccine strain is not able to persist in the environment. The gene is responsible for the catalysis of one of the first steps in the biosynthesis of muramic acid, which is a crucial component of the bacterial cell wall.

Construction and Evaluation of Recombinant Attenuated Vaccine (RAEV) Vector System Encoding (Ich) Antigen IAG52B.

We have successfully designed and constructed a RAEV vector system with regulated-delayed attenuation attributes that synthesizes (Ich) protective antigen IAG52B to enable vaccination of fish susceptible to edwardsiellosis and white spot disease. The first feature of this vaccine delivery system is an strain carrying genomic deletions of . AsdA is an enzyme necessary for the synthesis of diaminopimelic acid (DAP), which is an essential component of the peptidoglycan layer of the cell wall of Gram-negative bacteria.

Virulence, immunogenicity and live vaccine potential of aroA and phoP mutants of Edwardsiella piscicida in zebrafish.

Vaccination remains the most effective approach for prevention and control of infectious diseases in aquaculture. Edwardsiella piscicida is a causative agent of edwardsiellosis leading to mass mortality in a variety of fish species, leading to huge economic losses in the aquaculture industry. In this study, we have deleted the aroA and phoP genes in E.

Pathogenicity and immunogenicity of Edwardsiella piscicida ferric uptake regulator (fur) mutations in zebrafish.

Edwardsiella piscicida is the etiological agent of edwardsiellosis in fish and causes severe economic losses in global aquaculture. Vaccination would be the most effective method to prevent infectious diseases and their associated economic losses. The ferric uptake regulator (Fur) is an important transcriptional global regulator of Gram-negative bacteria.

Molecular cloning and characterization of LrTLR4, analysis of its inductive expression and associated down-stream signaling molecules following lipopolysaccharide stimulation and Gram-negative bacterial infection.

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.

Immunoglobulin (Ig) D in Labeo rohita is widely expressed and differentially modulated in viral, bacterial and parasitic antigenic challenges.

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.

Characterization and Inductive Expression Analysis of Interferon Gamma-Related Gene in the Indian Major Carp, Rohu (Labeo rohita).

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.

Modulation of TLR2, TLR4, TLR5, NOD1 and NOD2 receptor gene expressions and their downstream signaling molecules following thermal stress in the Indian major carp catla (Catla catla).

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.

LRRsearch: An asynchronous server-based application for the prediction of leucine-rich repeat motifs and an integrative database of NOD-like receptors.

The leucine-rich repeat (LRR) motifs of the nucleotide-binding oligomerization domain like receptors (NLRs) play key roles in recognizing and binding various pathogen associated molecular patterns (PAMPs) resulting in the activation of downstream signaling and innate immunity. Therefore, identification of LRR motifs is very important to study ligand-receptor interaction. To date, available resources pose restrictions including both false negative and false positive prediction of LRR motifs from the primary protein sequence as their algorithms are relied either only on sequence based comparison or alignment techniques or are over biased for a particular LRR containing protein family.

Toll-like receptor 22 in Labeo rohita: molecular cloning, characterization, 3D modeling, and expression analysis following ligands stimulation and bacterial infection.

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.

Elucidation of novel structural scaffold in rohu TLR2 and its binding site analysis with peptidoglycan, lipoteichoic acid and zymosan ligands, and downstream MyD88 adaptor protein.

Toll-like receptors (TLRs) play key roles in sensing wide array of microbial signatures and induction of innate immunity. TLR2 in fish resembles higher eukaryotes by sensing peptidoglycan (PGN) and lipoteichoic acid (LTA) of bacterial cell wall and zymosan of yeasts. However, in fish TLR2, no study yet describes the ligand binding motifs in the leucine rich repeat regions (LRRs) of the extracellular domain (ECD) and important amino acids in TLR2-TIR (toll/interleukin-1 receptor) domain that could be engaged in transmitting downstream signaling.

NOD1 and NOD2 receptors in mrigal (Cirrhinus mrigala): inductive expression and downstream signalling in ligand stimulation and bacterial infections.

Nucleotide binding and oligomerization domain (NOD)1 and NOD2 are important cytoplasmic pattern recognition receptors (PRRs) and key members of the NOD-like receptor (NLR) family. They sense a wide range of bacteria or their products and play a key role in inducing innate immunity. This report describes the role of NOD1 and NOD2 receptors signalling in innate immunity in the Indian major carp, mrigal (Cirrhinus mrigala).

Activation of nucleotide-binding oligomerization domain 1 (NOD1) receptor signaling in Labeo rohita by iE-DAP and identification of ligand-binding key motifs in NOD1 by molecular modeling and docking.

The nucleotide-binding oligomerization domain 1 (NOD1) receptor recognizes various pattern-associated structures of microbes through its leucine-rich repeat (LRR) domain and activates signaling cascades to induce innate immunity. This report describes the activation of NOD1 receptor signaling by gamma-D-glutamyl-meso-diaminopimelic acid (or γ-D-Glu-mDAP [iE-DAP]) in a commercially important fish species, rohu (Labeo rohita). It also described critical motifs in the NOD1-LRR domain that could be involved in binding iE-DAP, lipopolysaccharide (LPS), and polyinosinic:polycytidylic acid (poly I:C).

Identification of MDP (muramyl dipeptide)-binding key domains in NOD2 (nucleotide-binding and oligomerization domain-2) receptor of Labeo rohita.

In lower eukaryotes-like fish, innate immunity contributed by various pattern recognition receptor (PRR) plays an essential role in protection against diseases. Nucleotide-binding and oligomerization domain (NOD)-2 is a cytoplasmic PRR that recognizes MDP (muramyl dipeptide) of the Gram positive and Gram negative bacteria as ligand and activates signalling to induce innate immunity. Hypothesizing a similar NOD2 signalling pathway of higher eukaryotes, the peripheral blood leucocytes (PBLs) of rohu (Labeo rohita) was stimulated with MDP.

Molecular cloning and characterization of Toll-like receptor 3, and inductive expression analysis of type I IFN, Mx and pro-inflammatory cytokines in the Indian carp, rohu (Labeo rohita).

Toll-like receptors (TLRs) are one of the key components of innate or non-specific immunity. Among various types of TLRs, TLR3 recognizes dsRNA, the genetic material or replicative intermediate of many RNA viruses and triggers TIR-domain-containing adapter-inducing interferon-β dependent signalling pathway to induce type I interferon (IFN) and pro-inflammatory cytokines. In this study, we cloned and characterized full-length TLR3 cDNA in rohu (Labeo rohita), that comprised of 2,619 bp nucleotides encoding a putative protein of 873 amino acid with the estimated molecular mass of 98.

Structural insights of rohu TLR3, its binding site analysis with fish reovirus dsRNA, poly I:C and zebrafish TRIF.

In response to double stranded RNA (dsRNA) viruses, toll-like receptor 3 (TLR3) in fish activates signaling like human, and induces innate immunity. This suggested the existence of dsRNA binding domains in fish TLR3 as reported in higher vertebrates. In in silico analysis, leucine rich repeat (LRR) regions (4-6, 13-14, 20-22), and LRR (8-15, 17-24) were identified as key domains in rohu TLR3 as poly I:C and dsRNA of fish reovirus (AGCRV,VHSV and IHNV) binding regions.

Molecular cloning and characterization of nucleotide binding and oligomerization domain-1 (NOD1) receptor in the Indian Major Carp, rohu (Labeo rohita), and analysis of its inductive expression and down-stream signalling molecules following ligands exposure and Gram-negative bacterial infections.

Nucleotide binding and oligomerization domain-1 (NOD1) is a cytoplasmic pattern recognition receptor (PRR), and is a member of the NOD-like receptor (NLR) family. It senses a wide range of bacteria and viruses or their products, and plays a key role in inducing innate immunity. In this report, NOD1 gene was cloned and characterized in rohu (Labeo rohita), a fish species of highest commercial importance in the Indian subcontinent.

Induction of toll-like receptor (TLR) 2, and MyD88-dependent TLR- signaling in response to ligand stimulation and bacterial infections in the Indian major carp, mrigal (Cirrhinus mrigala).

Toll-like receptor 2 (TLR2) is a member of TLR family. It recognizes a wide range of bacteria and their products, and is involved in inducing innate immune responses. In this article, we reported inductive expression of TLR2 and myeloid differentiation primary response gene 88 (MyD88)-dependent signaling in the Indian major carp, mrigal (Cirrhinus mrigala) which is highly commercially important fish species in the Indian subcontinent.

Molecular characterization of toll-like receptor 2 (TLR2), analysis of its inductive expression and associated down-stream signaling molecules following ligands exposure and bacterial infection in the Indian major carp, rohu (Labeo rohita).

Toll-like receptors (TLRs) are one of the key components of innate immunity. Among various TLR types, TLR2 is involved in recognizing specific microbial structures such as peptidoglycan (PGN), lipoteichoic acid (LTA), zymosan etc., and after binding them it triggers myeloid differentiation primary response gene 88 (MyD88)-dependent signaling pathway to induce various cytokines.

3D modeling and molecular dynamics simulation of an immune-regulatory cytokine, interleukin-10, from the Indian major carp, Catla catla.

Interleukin-10 (IL-10) is a pleiotropic immune-regulatory cytokine that is expressed in various species of fish and higher vertebrates, and is activated during infection. In spite of its important role, IL-10 has not been well characterized either functionally or structurally in fish. To analyze its properties and function, we constructed a 3D model of IL-10 in the Indian major carp, the catla (Catla catla), which is a highly preferred fish species and the most commercially important one in the Indian subcontinent.