Archive for February 28th, 2017

How papillomaviruses infect cells

28 February, 2017

We are presently hosting the 2017 Human Papillomaviirus Conference here in Cape Town, and we are experimenting with having a pre-conference Basic Science Workshop, in addition to the well-established Public Health and Clinical streams.

And it’s going…really well! We have a huge room for it, with double screens; it’s pretty full – and the kick-off was a masterful talk on HPV Entry by Michelle Ozbun.

She had a wonderfully illustrated close to 90 minute talk, with some very intriguing speculations: the theme of the Workshop is “Where Are The Gaps?”, and she pointed out a number of important gaps in our knowledge of the processes that  PVs engage with in order to get into cells.

One of the most intriguing was the fact that pseudo- or quasivirions made in and puriffied from mammalian cells, are not very infectious at all in keratinocyte raft cultures – which Martin Sapp pointed out from the audience can be hugely improved by using virions associated with cell matrix material rather than purified forms.

Michelle speculated that the natural state for PVs infecting susceptible cells – which most often probably occurs via transient wounding of cornified epithelia or mucous membranes – is in the context of squames, or exfoliated and disintegrating cells. Which means virions are associated with all of the molecules present in such a milieu, that may also serve as receptors – meaning that the virions may in fact be primed in terms of conformational changes associated with receptor binding, which could greatly facilitate binding of basal layer cells and entry into them.

How sensible is that as a concept: the natural milieu for PVs to infect other cells is in the context of debris from the cells in which they were produced.

I’m learning things by the minute B-) Michelle had a very useful set of questions (see below).

Other gaps for discussion will be posted later. #HPV2017