RIGI, TLR7, and TLR3 Genes Were Predicted to Have Immune Response Against Avian Influenza in Indigenous Ducks.

Aruna Pal,Pradyumna Baviskar,Abantika Pal

doi:10.3389/fmolb.2021.633283

Abstract

Avian influenza is a disease with every possibility to evolve as a human-to-human pandemic arising out of frequent mutations and genetic reassortment or recombination of avian influenza (AI) virus. The greatest concern is that till date, no satisfactory medicine or vaccines are available, leading to massive culling of poultry birds, causing huge economic loss and ban on export of chicken products, which emphasizes the need to develop an alternative strategy for control of AI. In the current study, we attempt to explore the molecular mechanism of innate immune potential of ducks against avian influenza. In the present study, we have characterized immune response molecules such as duck TLR3, TLR7, and RIGI that are predicted to have potent antiviral activities against the identified strain of avian influenza through in silico studies (molecular docking) followed by experimental validation with differential mRNA expression analysis. Future exploitation may include immunomodulation with the recombinant protein, and transgenic or gene-edited chicken resistant to bird flu.

Highlights

Ducks are reported to be relatively resistant to common poultry diseases, including viral disease, compared to chicken (Pal et al, 2017), and are commonly asymptomatic to avian influenza virus infection (Kim et al, 2009; Fleming-Canepa et al, 2019; CDC, Centre for Disease control and Prevention, 2021)
TLR3 gene of indigenous ducks has been characterized with 2688 bp nucleotide (Gene bank accession number KX865107, NCBI) and derived protein as ASW23003.1
TLR7 expression profiling was observed to be significantly better in duck than in chicken and other poultry species, indicative of better antiviral immunity in ducks. 53 nonsynonymous mutations with amino acid variations were observed while comparing amino acid sequence of duck with other poultry species, including chicken, most of which are confined to the leucine-rich repeats (LRRs) domain

Summary

Introduction

Ducks are reported to be relatively resistant to common poultry diseases, including viral disease, compared to chicken (Pal et al, 2017), and are commonly asymptomatic to avian influenza virus infection (Kim et al, 2009; Fleming-Canepa et al, 2019; CDC, Centre for Disease control and Prevention, 2021). Avian influenza is caused by single-stranded RNA virus, which is negatively stranded, and belongs to Orthomyxoviridae family (WHO, 2019). It is commonly known as bird flu since birds are the main host. Most of the H5 and H7 subtypes were regarded as highly pathogenic avian influenza (HPAI) virus, owing to the higher incidence and mortality of birds. The greatest concern is the lack of definite treatment or vaccination due to frequent mutation and reassortment of viral strain, regarded as antigenic shift and antigenic drift

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Discussion

Conclusion