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№3' 2021

INFECTIOUS DISEASES

International Medical Journal, Vol. 27., Iss. 3, 2021, P. 76−79.

DOI (https://doi.org/10.37436/2308-5274-2021-3-16)

GENERAL CHARACTERISTICS OF TOLL-LIKE RECEPTORS AND THEIR PARTICIPATION IN IMMUNE RESPONSE

V. N. Karazin Kharkiv National University, Ukraine

The innate immune response is the first step in protecting the body against pathogens. Cells of this response express various image recognition receptors, including Toll−like (TLR), which detect pathogen−associated molecular patterns and induce an inflammatory immune response. TLRs are involved into recognition of quite all pathogens, i.e. bacteria, viruses, fungi and protozoa. All TLRs are type 1 transmembrane proteins that contain leucine−rich repeats responsible for recognizing pathogen−associated molecular patterns and activating downlink signaling. The signaling cascade triggered by TLR type 9 depends on intracellular transport of the receptor and begins as soon as it and its ligand enter the endolysosomal system. Activation of this receptor, depending on the cell type, leads to the production of various mediators. The etiopathogenesis of most autoimmune diseases has not been fully studied, as their development may be facilitated by a large number of factors. A number of studies in TLR9−deficient mice prone to lupus have demonstrated a particular need for TLR9 to form the autoantibodies in vivo, indicating a critical role for innate immune activation in autoimmune processes. Previous studies of the involvement of TLR9 into signal transduction when pathogens enter the body have shown that activation of receptors occurs after their interaction with unmethylated CrG−DNA. However, recent studies have demonstrated an importance of these receptors in the case of RNA−containing viruses. Further in−depth study of the involvement of TLR in the body protection against both DNA and RNA−containing viruses will not only provide a better understanding of immune system damage, but also develop the methods and tools supporting and strengthening the immune response.

Key words: measles, Toll−like receptors, cytokines, interferon, autoimmune diseases.

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