Tetraspanin CD9 affects HPV16 infection by modulating ADAM17 activity and the ERK signalling pathway.

Human papillomaviruses (HPV) are causative agents of various tumours such as cervical cancer. HPV binding to the cell surface of keratinocytes leads to virus endocytosis at tetraspanin enriched microdomains. Complex interactions of the capsid proteins with host proteins as well as ADAM17-dependent ERK1/2 signal transduction enable the entry platform assembly of the oncogenic HPV type 16.

The CD63-Syntenin-1 Complex Controls Post-Endocytic Trafficking of Oncogenic Human Papillomaviruses.

Human papillomaviruses enter host cells via a clathrin-independent endocytic pathway involving tetraspanin proteins. However, post-endocytic trafficking required for virus capsid disassembly remains unclear. Here we demonstrate that the early trafficking pathway of internalised HPV particles involves tetraspanin CD63, syntenin-1 and ESCRT-associated adaptor protein ALIX.

The extracellular δ-domain is essential for the formation of CD81 tetraspanin webs.

CD81 is a ubiquitously expressed member of the tetraspanin family. It forms large molecular platforms, so-called tetraspanin webs that play physiological roles in a variety of cellular functions and are involved in viral and parasite infections. We have investigated which part of the CD81 molecule is required for the formation of domains in the cell membranes of T-cells and hepatocytes.

Inhibition by cellular vacuolar ATPase impairs human papillomavirus uncoating and infection.

Several viruses, including human papillomaviruses, depend on endosomal acidification for successful infection. Hence, the multisubunit enzyme vacuolar ATPase (V-ATPase), which is mainly responsible for endosome acidification in the cell, represents an attractive target for antiviral strategies. In the present study, we show that V-ATPase is required for human papillomavirus (HPV) infection and that uncoating/disassembly but not endocytosis is affected by V-ATPase inhibition.

The tetraspanin CD151 in papillomavirus infection.

Human papillomaviruses (HPV) are non-enveloped DNA tumor viruses that infect skin and mucosa. The most oncogenic subtype, HPV16, causes various types of cancer, including cervical, anal, and head and neck cancers. During the multistep process of infection, numerous host proteins are required for the delivery of virus genetic information into the nucleus of target cells.

Isolation and characterization of pathogen-bearing endosomes enable analysis of endosomal escape and identification of new cellular cofactors of infection.

Many pathogens, including viruses, bacteria, as well as bacterial toxins, enter their target cells by endocytosis leading to accumulation of pathogenic and cellular proteins in endosomes. Here, we present detailed experimental instructions on isolation of endosomes after virus infection and their subsequent biomolecular characterization. The isolation of endosomes is based on discontinuous sucrose gradient centrifugation, where different endosomal compartments accumulate at a specific sucrose interface.

The transcription factors TBX2 and TBX3 interact with human papillomavirus 16 (HPV16) L2 and repress the long control region of HPVs.

The minor capsid protein L2 of human papillomaviruses (HPVs) has multiple functions during the viral life cycle. Although L2 is required for effective invasion and morphogenesis, only a few cellular interaction partners are known so far. Using yeast two-hybrid screening, we identified the transcription factor TBX2 as a novel interaction partner of HPV type 16 (HPV16) L2.

Tetraspanin CD151 mediates papillomavirus type 16 endocytosis.

Human papillomavirus type 16 (HPV16) is the primary etiologic agent for cervical cancer. The infectious entry of HPV16 into cells occurs via a so-far poorly characterized clathrin- and caveolin-independent endocytic pathway, which involves tetraspanin proteins and actin. In this study, we investigated the specific role of the tetraspanin CD151 in the early steps of HPV16 infection.