Influence of an anti-integrin α6 monoclonal antibody on the in vitro infection of human HaCaT keratinocytes with human papillomavirus (HPV) 6/11 virus particles

Objective To investigate the influence of an anti-integrin α6 monoclonal antibody (GoH3) on the in vitro infection of a human keratinocyte cell line HaCaT with HPV6/11 virus particles (VP). Methods HaCaT cells were infected in vitro with 4 different concentrations of HPV6/11 VP alone, HPV6/11 VP of 106 copies/ml after incubation with 6 different dilutions of GoH3, or 8 clinical isolates of HPV6/11 VP of 106 copies/ml before or after the incubation with 1∶ 100 dilution of GoH3. After additional culture, the infected HaCaT cells were collected and fluorescence quantitative (FQ)-PCR was performed to detect the HPV DNA load in cells. The inhibition rate of CoH3 on the infection was calculated. Results The viral load was different among the HaCaT cells infected with different concentrations of HPV6/11 VP (P < 0.01). The inhibition rate on the infection positively correlated with the concentration of CoH3 when the dilution was more than 1∶ 100; however, when the dilution was less than 1∶ 100, the increase in CoH3 concentration had no influence on the inhibition rate. The average viral load in HaCaT cells infected with clinical isolates of HPV6/11 VP was (5.81 ± 2.51) × 104 copies/ml in the absence of GoH3, (3.02 ± 1.21) × 104 copies/ml with the presence of CoH3, and the average inhibition rate of GoH3 was (46.9 ± 4.7)%. Conclusions GoH3 could partially suppress the adhesion of HPV6/11 VP to HaCaT cells, hinting that integrin a6 is an important HPV6/11 VP receptor on host cells.