HLA-G 14-bp insertion/deletion polymorphism is a risk factor for HTLV-1 infection.
About 95% of HTLV-1 infected patients remain asymptomatic throughout life, and the risk factors associated with the development of related diseases, such as HAM/TSP and ATL, are not fully understood. The human leukocyte antigen-G molecule (HLA-G), a nonclassical HLA class I molecule encoded by MHC, is expressed in several pathological conditions, including viral infection, and is related to immunosuppressive effects that allow the virus-infected cells to escape the antiviral defense of the host. The 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene influences the stability of the transcripts and could be related to HTLV-1-infected cell protection and to the increase of proviral load. The present study analyzed by conventional PCR the 14-bp insertion/deletion polymorphism of exon 8 HLA-G gene in 150 unrelated healthy subjects, 82 HTLV-1 infected patients with symptoms (33 ATL and 49 HAM), and 56 asymptomatic HTLV-1 infected patients (HAC). In addition, the proviral load was determined by quantitative real-time PCR in all infected groups and correlated with 14-bp insertion/deletion genotypes. The heterozygote genotype frequencies were significantly higher in HAM, in the symptomatic group, and in infected patients compared to control (p < 0.05). The proviral load was higher in the symptomatic group than the HAC group (p < 0.0005). The comparison of proviral load and genotypes showed that -14-bp/-14-bp genotype had a higher proviral load than +14-bp/-14-bp and +14-bp/+14-bp genotypes. Although HLA-G 14-bp polymorphism does not appear to be associated with HTLV-1 related disease development, it could be a genetic risk factor for susceptibility to infection.
Hemocentro de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Rodrigo
R
Haddad
Daiani Cristina
DC
Cilião Alves
Maurício Cristiano
MC
Rocha-Junior
Rochele
R
Azevedo
Maria do Socorro
MS
Pombo-de-Oliveira
Oswaldo Massaiti
OM
Takayanagui
Eduardo Antônio
EA
Donadi
Dimas Tadeu
DT
Covas
Simone
S
Kashima
D000293:Adolescent; D000328:Adult; D000368:Aged; D004279:DNA, Viral / Q000235:genetics; D006800:Deltaretrovirus Infections / Q000235:genetics*; D004198:Disease Susceptibility; D005260:Female; D005838:Genotype; D006680:HLA Antigens / Q000235:genetics*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology; D006801:Humans; D054643:INDEL Mutation; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012307:Risk Factors; D019562:Viral Load / Q000235:genetics
D004279:DNA, Viral; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I