Identification of the alpha6 integrin as a candidate receptor for papillomaviruses

Abstract

Papillomaviruses (PVs) bind in a specific and saturable fashion to a range of epithelial and other cell lines. Treatment of cells with trypsin markedly reduces their ability to bind virus particles, suggesting that binding is mediated via a cell membrane protein. We have investigated the interaction of human PV type 6b L1 virus-like particles (VLPs) with two epithelial cell lines, CV-1 and HaCaT, which bind VLPs, and a B-cell line (DG75) previously shown not to bind VLPs. Immunoprecipitation of a mixture of PV VLPs with [ 35 S]methionine-labeled cell extracts and with biotin-labeled cell surface proteins identified four proteins from CV-1 and HaCaT cells of 220, 120, 87, and 35 kDa that reacted with VLPs and were not present in DG75 cells. The ␣ 6 ␤ 4 integrin complex has subunits corresponding to the VLP precipitated proteins, and the tissue distribution of this complex suggested that it was a candidate human PV receptor. Monoclonal antibodies (MAbs) to the ␣ 6 or ␤ 4 integrin subunits precipitated VLPs from a mixture of CV-1 cell proteins and VLPs, whereas MAbs to other integrin subunits did not. An ␣ 6 integrin-specific MAb (GoH3) inhibited VLP binding to CV-1 and HaCaT cells, whereas an anti-␤ 4 integrin MAb and a range of integrin-specific and other MAbs did not. Furthermore, human laminin, the natural ligand for the ␣ 6 ␤ 4 integrin, was able to block VLP binding. By use of sections of monkey esophagus, the distribution of ␣ 6 integrin expression in the basal epithelium was shown to coincide with the distribution of bound VLPs. Taken together, these data suggest that VLPs bind specifically to the ␣ 6 integrin subunit and that integrin complexes containing ␣ 6 integrin complexed with either ␤ 1 or ␤ 4 integrins may act as a receptor for PV binding and entry into epithelial cells.

Evolution of Cell Recognition by Viruses: A Source of Biological Novelty with Medical Implications

“…PrV HS-GAG (Mettenleiter et al, 1990); nectin-1 alpha/Prr1/HveC ; nectin-2 alpha/Prr2/HveB (Warner et al, 1998); murine HveB (Shukla et al, 1999b); porcine HveC (Milne et al, 2001); murine HveC ; PVR/CD155 Herpesviridae, betaherpesvirinae HCMV/HHV-5 HS-GAG (Compton et al, 1993); APN/CD13 (Soderberg et al, 1993); MHC class I via 2 -microglobulin (Grundy et al, 1987) HHV-6 CD46 (Santoro et al, 1999) HHV-7 HS-GAG (Secchiero et al, 1997;Skrincosky et al, 2000); CD4 (Lusso et al, 1994) KSHV/HHV-8 HS-GAG Birkmann et al, 2001;Wang et al, 2001); integrin 3 1 (Akula et al, 2002) MCMV MHC class I (H-2Dd and Kb) (Wykes et al, 1993) Herpesviridae, gammaherpesvirinae EBV/HHV-4 CD21/CR2 (Fingeroth et al, 1984;Frade et al, 1985;Nemerow et al, 1985); MHC class II (HLA-DR, -DP, -DQ) (Reisert et al, 1985;Li et al, 1997; BHV-4 HS-GAG (Vanderplasschen et al, 1993) Papovaviridae Papillomavirus 6 integrins (Evander et al, 1997;McMillan et al, 1999); HS-GAG (Giroglou et al, 2001) Murine polyomavirus Sialic acid (N-acetyl neuraminic acid) (Stehle et al, 1994;Stehle and Harrison, 1996);integrin 41 (Caruso et al, 2003) SV40 MHC class I (Atwood and Norkin, 1989;Breau et al, 1992) Poxviridae Vaccinia virus HS-GAG and CS-GAG (Chung et al, 1998;Hsiao et al, 1999) Myxoma virus CCR1, CCR5, CXCR4 (Lalani et al, 1999) Single-stranded DNA viruses Parvoviridae AAV2 HS-GAG (Summerford and Samulski, 199...…”

The role of NH4Cl and cysteine proteases in Human Papillomavirus type 16 infection

“…Although the virion-cell binding process is still unclear it is thought to occur by initial binding of the L1 protein on the virion capsid to heparan sulfate (a cell surface proteoglycan), followed by binding to a secondary receptor, putatively an integrin complex [16][17][18]. α6β4 has been shown to be able to mediate cell binding in studies showing that antibodies against α6 could block virion binding to the epithelial cells CV-1 and HaCaT keratinocytes [19]. However, α6β4 integrin may not be a necessary requirement for infection since studies also indicate that some PVs can infect cells such as BO-SV keratinocytes that lack this complex [20].…”

Anatomy of a viral entry platform differentially functionalized by integrins α3 and α6

“…Candidates comprise members of the integrin family of cell-adhesion-receptors that (i) interact with CD151, (ii) have a connection to HPV infection, and (iii) are integral part of TEMs. Integrin α6 is a strong candidate as it interacts directly with CD151 10 and, among others, is one of the direct receptors for HPV binding [11][12][13] . Hence, integrin α6 may be organized into TEMs for virus binding.…”

“…www.nature.com/scientificreports www.nature.com/scientificreports/ Roles of integrin α6 and integrin α3. Studies employing co-immunoprecipitation and flow cytometry indicate that HPV binds directly to integrin α6 [11][12][13] . On the other hand, it is also assumed that the HPV capsid protein binds to a set of primary receptors different from integrin α6 16,39 , undergoes conformational changes and is then transferred to a secondary receptor complex 34,[48][49][50] which could be part of a TEM.…”