ABSTRACT
Toll-like receptors (TLRs) are pathogen recognition receptors, and primitive sources of innate immune response that also play key roles in the defense mechanism against infectious diseases. About 10 different TLRs have been discovered in chicken that recognize ligands and participate in TLR signaling pathways. Research findings related to TLRs revealed new approaches to understand the fundamental mechanisms of the immune system, patterns of resistance against diseases, and the role of TLR-specific pathways in nutrient metabolism in chicken. In particular, the uses of specific feed ingredients encourage molecular biologists to exploit the relationship between nutrients (including different phytochemicals) and TLRs to modulate immunity in chicken. Phytonutrients and prebiotics are noteworthy dietary components to promote immunity and the production of disease-resistant chicken. Supplementations of yeast-derived products have also been extensively studied to enhance innate immunity during the last decade. Such interventions pave the way to explore nutrigenomic approaches for healthy and profitable chicken production. Additionally, single-nucleotide polymorphisms in TLRs have shown potential association with few disease outbreaks in chickens. This review aimed to provide insights into the key roles of TLRs in the immune response and discuss the potential applications of these TLRs for genomic and nutritional interventions to improve health, and resistance against different fatal diseases in chicken.
ABSTRACT
In this review, we focused on the origins of the novel coronavirus (SARS-CoV-2), origin, pathogenesis, immune responses, genes and genetic variations, phylogenetic analyses, and potential therapeutic strategies to summarize approaches for developing broadly effective preventions and vaccines to cope COVID-19. Towards the end of 2019, SARS-CoV-2 has emerged in association with the SARS, later was named COVID-19 caused an environment of chaos worldwide and infected a massive number of lives. Since these epidemics or pandemics had spread to 210 countries and territories around the world and 2 international conveyances with 6,467,229 confirmed cases, including, 382,766 deaths, as of June 03, 2020 (https://www.worldometers.info/coronavirus/), hence the World Health Organization declared it as a global Public Health Emergency. There are no clinically approved vaccines or antiviral drugs available for either of new or old corona infections; thus, the development of effective therapeutic and preventive strategies that can be readily available to cope with these strains.
