Cell biology of HIV spread

Date Commenced:
05/2011
Project Status
Ongoing
Expected Date of Completion:
Ongoing
Project Supporters

NHMRC

Currently recruiting
Yes
image - Cell Biology Of Hiv Spread

About the Project

This image shows the use of cellular structures for HIV spread. Finger like projections  known as filopodia (red) propel HIV virions (white) to neighbouring cells. The cell nucleus here is stained in blue.

Rationale

For persistent HIV infections, efficient spread to permissive targets is paramount. Spread of HIV is either through cell-free virions or by cell-to-cell transfer.  Cell-to-cell transfer of virus is orders of magnitude more efficient. Our previous and present aims are broadly based around how HIV can highjack structures to enable cell-cell spread of the virus.

Aims
  1. Generate genetically modified HIV that can be visualised in live infected cells
  2. Determine cellular structures corrupted by HIV to aid cell-cell spread
  3. Determine the role of F-actin pathways on HIV spread
Design & Method

Labelling of bacteria and large complex viral families can be readily achieved by insertion of fluorescent proteins genes into their genome. The same cannot be said for HIV as this leads to significant attenuation.  We and others have for the last decade aimed to generate HIV which incorporates visible tags/beacons that can be utilized in high/super-resolution fluorescent microscopy and in live cell imaging. Presently we have succeeded in creating labels that permit imaging of HIV in infected live cells. At present we utilize two complementary imaging strategies for HIV in live cells, thus controlling for the observations of tag specific artefacts.

Progress/Update

By observing the real-time dynamics of HIV spread between infected cells, we have identified a novel pathogenic structure that combines the biogenesis of newly budding HIV virions with that of long filopodia (finger-like structures that protrude from the cell membrane). Long HIV filopodia work in unison to tether future targets and later converge to the lamellipodial contacts of the virological synapse- a bridge like structure that is the product of HIV accumulation at the cell-cell contact point).

Benefits

Observations that map the processes of cell-to-cell viral spread will provide critical new information on “Achille’s heel” moments of the HIV life cycle that could lead to the discovery of and development of new drug targets for the treatment of HIV.

Output

Turville, S. G.; Aravantinou, M.; Stossel, H.; Romani, N.; Robbiani, M.  Resolution of de novo HIV production and trafficking in immature dendritic cells  Nat Methods  (2008)  5 1  75-85

Aggarwal, A.; Iemma, T.L.; Shih, I; Newsome, T.P.; McAllery, S.; Cunningham, A.L.; Turville, S.G.  Mobilization of HIV spread by dendritic cells via diaphanous 2 dependent filopodia  PLoS Pathog  (2012)  In Press

Project Members
image - Tina Iemma1
Ms Tina Hitchen
PhD Student
Other Investigators

Timothy Newsome, Dept of Microbiology, University of Sydney

Project Research Area

Project Contacts

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