gms | German Medical Science

Introduction: Dendritic Cell-Specific Intercellular adhesion molecule-3 Grabbing Non-Intergrin (DC SIGN), a C-type lectin receptor present on macrophages and dendritic cells, recognizes an array of microbes including HIV. Ethnicities worldwide exhibit genetic variations in the DC SIGN receptor for which ethnically predominant pathogens have been suggested to be the driving force. DC SIGN promoter region possesses different binding sites for its different transcription factors; thus, polymorphisms in this region may affect transcription and subsequently protein expression. Involvement of DC SIGN in vertical transmission of HIV is evident from its increased expression in the placental tissue.

Methodology: In this study we analyzed genetic polymorphisms spanning the promoter region in Carbohydrate Recognition Domain (CRD) of DC SIGN receptor gene. Our study group comprised HIV negative (n=53) and HIV positive infants (n=65) born to HIV-infected mothers and HIV-infected pregnant women (n=61), from North India. Six polymorphisms at position -116, -139, -190, -336, -871 and -939 were analyzed in infant samples using DNA sequencing.

Results: DC SIGN promoter polymorphisms -871AA was present in 50.8% of the pregnant women sequences, -871GG (36%) and AG (12.3%), and at position 939 GG and AA genotypes were present in equal percentage (39.3%), AG (21.3%). Genetic analysis of DC-SIGN promoter polymorphisms in infants born to HIV infected mothers revealed -871GG and -939GG to be associated significantly with HIV infected infants (P value <0.001).

Conclusion: In conclusion, these preliminary studies illustrate a significant role of DC SIGN in perinatal transmission of HIV. DC SIGN promoter polymorphisms may be crucial in protection or susceptibility against HIV, by affecting protein expression. Further studies are required to elucidate the protective or susceptible mechanisms of these DC SIGN promoter polymorphisms.