The Relationship of TLR2 Polymorphisms with Infectious Diseases

Abstract

The proinflammatory response induced by Toll-Like receptors (TLR) is considered the host's first defense line. Single nucleotide polymorphisms (SNPs) correspond to the most frequent type of variation in the human genome, and due to the importance of TLR2 in the immune response, SNPs in the TLR gene are related to susceptibility or resistance to various diseases. Thus, the objective of the present study was to identify the polymorphisms existing in the TLR2 gene that may cause susceptibility or protection against infectious diseases. We conducted a systematic review of the literature in the databases Science Direct, National Library of Medicine National Institutes of Health of the USA (PUBMED), Cochrane Collaboration and Medical Literature Analysis and Retrieval System Online (MEDLINE) between 2000 to 2020. The search resulted in 32 articles, all of which in English. Thus, it was demonstrated that the related polymorphisms are extremely important for the identification of related pathologies, whether for the susceptibility or protection of the individual to the diseases, also being essential for the mechanisms of signal generation and immune responses, and finally indicating that a balance between activation and inactivating these receptors to prevent an excessive inflammatory or immune response.

Analysis of Epidemiological Factors and SNP rs3804100 of TLR2 for COVID-19 in a Cohort of Professionals Who Worked in the First Pandemic Wave in Belém-PA, Brazil

“…The presence of TLR2 SNPs in each population can functionally affect the production of the receptor and therefore impact the generation of an effective immune response [21]. Despite having been predicted in this present work about the benign nature and the reduction in the protein stability of TLR2 related to the presence of the SNP rs3804100 and the literary scenario more related to the patient's worse prognosis when this gene is more expressed, in the case of the Amazonian population, significant associations for any investigated COVID-19 phenotype were not observed.…”

“…TLRs play a key role in generating and maintaining the innate immune response, in addition to guiding the adaptive immune response in infections. Therefore, SNPs in these genes can generate different levels of receptor expression, generating uncoordinated immune responses through excessive or reduced cytokine production [21][22][23].…”

“…Tuberculosis (TB), an essentially lung disease, was the disease most studied for the SNP rs3804100 in the TLR2 gene in different populations [21]. This may be linked to the fact that the highlighted gene is the main receptor for lipoproteins in mammals, derived from a variety of bacteria, such as the agent Mycobacterium tuberculosis.…”