DNA phasing by TA dinucleotide microsatellite length determines in vitro and in vivo expression of the gp91phox subunit of NADPH oxidase and mediates protection against severe malaria.
Reactive oxygen intermediates (ROIs) play a major role in the nonspecific innate immune response to invading microorganisms, such as Plasmodium falciparum. In a search for genetic markers that determine differences in production of ROI, we detected a highly polymorphic region of dinucleotide TA repeats approximately 550 bp upstream of the NADPH oxidase gp91(phox) subunit promoter. We genotyped 183 matched Gabonese children with severe or mild malaria. Repeat lengths TA(11) and TA(16) differed significantly in frequency between mild and severe infection, which suggests protection against severe malaria. Both repeat lengths showed lower levels of NADPH oxidase and promoter activities, which can be explained by a cyclic trend in TA repeat length with a period of approximately 5, which indicates the necessity of correct DNA phasing between 2 possible control regions in the promoter. We provide a molecular model of how DNA phasing generated by TA dinucleotide polymorphisms may influence the expression level and protect against severe malaria.
Uhlemann
Anne-Catrin
AC
Department of Parasitology, Institute of Tropical Medicine, University of Tubingen, Tubingen, Germany. a.uhlemann@sghms.ac.uk
Szlezák
Nicole A
NA
Vonthein
Reinhard
R
Tomiuk
Jürgen
J
Emmer
Stefanie A
SA
Lell
Bertrand
B
Kremsner
Peter G
PG
Kun
Jürgen F J
JF
D000818:Animals; D002648:Child; D004247:DNA / Q000737:chemistry*; D018900:Dinucleotide Repeats / Q000235:genetics*; D005260:Female; D005681:Gabon; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D006801:Humans; D016778:Malaria, Falciparum / Q000235:genetics* / Q000276:immunology / Q000469:parasitology / Q000503:physiopathology*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D010963:Plasmodium falciparum; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D017382:Reactive Oxygen Species / Q000378:metabolism; D012720:Severity of Illness Index; D014158:Transcription, Genetic
D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D004247:DNA; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases