Genetic Polymorphisms of TLR4 and MICA are Associated with Severity of Trachoma Disease in Tanzania

Muneer Abbas; Noureddine Berka; Mozna Khraiwesh; Ali Ramadan; Victor Apprey; Paulette Furbert-Harris; Thomas Quinn; Hassan Brim; Georgia Dunston

doi:10.16966/2470-1025.116

Genetic Polymorphisms of TLR4 and MICA are Associated with Severity of Trachoma Disease in Tanzania

Autoimmune Infect Dis. 2016 Jun;2(3):10.16966/2470-1025.116. doi: 10.16966/2470-1025.116. Epub 2016 Jun 3.

Authors

Muneer Abbas¹, Noureddine Berka², Mozna Khraiwesh³, Ali Ramadan⁴, Victor Apprey⁵, Paulette Furbert-Harris¹, Thomas Quinn⁶, Hassan Brim⁴, Georgia Dunston¹

Affiliations

¹ Department of Microbiology, Howard University, Washington, DC, USA.
² Calgary Laboratory Services, Tissue Typing Laboratory, Canada.
³ Division of Experimental Therapeutics, Department of Drug Discovery, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
⁴ Department of Pathology, Howard University Hospital, Washington, DC, USA.
⁵ Department of Microbiology, Howard University, Washington, DC, USA; Department of Community Health and Family Medicine, Howard University, Washington DC, USA.
⁶ International Health, School of Medicine, Johns Hopkins University, Baltimore Maryland, USA.

Abstract

Aim: To examine the association of TLR4 Asp299Gly and MICA exon 5 microsatellites polymorphisms with severity of trachoma in a sub-Saharan East Africa population of Tanzanian villagers.

Methods: The samples were genotyped for MICA exon 5 microsatellites and the TLR4 299 A/G polymorphism by Restriction Fragment Length Polymorphism (RFLP), and GeneScan^®, respectively. The association of TLR4 Asp299Gly and MICA exon 5 microsatellites with inflammatory trachoma (TI) and trichiasis (TI) were examined.

Results: The results showed an association between TLR4 and MICA polymorphisms and trachoma disease severity, as well as with protection. TLR4 an allele was significantly associated with inflammatory trachoma (p=0.0410), while the G allele (p=0.0410) was associated with protection.

Conclusion: TLR4 and MICA may modulate the risk of severity to trachoma disease by modulating the immune response to Ct. In addition; the increased frequency of MICA-A9 heterozygote in controls may suggest a positive selection of these alleles in adaptation to environments where Ct is endemic.

Keywords: Chlamydia trachomatis; Inflammation; MICA; Major histocompatibility complex (MHC) class I chain related gene A; Microsatellite polymorphism; Single nucleotide polymorphism; Toll like receptor 4; Trachoma; Trichiasis.

Grants and funding

G12 RR003048/RR/NCRR NIH HHS/United States