Demonstration of antibodies against human papillomavirus type-11 E6 and L2 proteins in patients with recurrent respiratory papillomatosis.

Recurrent respiratory papillomatosis (RRP) is highly prevalent in Thailand, with the human papillomavirus (HPV) type-11 being the most widespread. In this study, we isolated the HPV type-11 (HPV-11) genome from subjects with RRP and subcloned the E6 and L2 open reading frames (ORFs) with the expression vectors pEX1 and pEX3. The recombinant E6/beta-gal and L2/beta-gal fusion proteins were expressed in E. coli. Using the recombinant proteins, we demonstrated the presence of antibodies against HPV-11 E6 and L2 in RRP patients by Western blot analysis. The prevalence of seropositivity for HPV-11 E6 and L2 were 5% (1/20) and 10% (2/20), respectively. Although RRP is caused by infection on the mucosal surface, it appears that an immune response occurs against viral proteins expressed in the epithelial lesions.