The
molecular and cellular events necessary for the assembly and release of human
T-cell leukemia virus type 1 (HTLV-1) in infected cells and for the entry and
replication of virions in target cells are not well defined. Recent work from
other laboratories suggests that the directed transmission of HTLV-1 between T
lymphocytes is coordinated with development of an intercellular synapse, and occurs
at the cell-cell interface. This scenario predicts that various steps in the virus
infectious cycle would be integrated with and enhanced by formation of specific
cell-cell contacts. We are examining the molecular mechanisms underlying the individual
steps in the HTLV-1 infectious cycle with the long-term objective of understanding
the concerted production, transfer, and replication of the virus in the context
of cell to cell transmission.
To this end, we are developing in vitro
methods to analyze cellular and viral events when HTLV-1-infected cells engage
uninfected target cells. The figure shows an example of preliminary studies in
which Jurkat T-cells were cotransfected with an HTLV-1 provirus clone in combination
with a Tax-eYFP expression plasmid and subsequently incubated with an equal number
of untransfected Jurkat cells for 1 hr to allow formation of stable cell-cell
contacts. Cells were then collected, fixed, and stained with fluorescent-labeled
antibodies that recognize HTLV-1 Gag matrix protein (red) and a-tubulin
(blue); nuclear-localized Tax-eYFP is shown in green. In individual transfected
cells, HTLV-1 Gag is randomly dispersed, but in conjugated cells, Gag is concentrated
at the cell-cell interface.
Last
modified: 12 January 2009 |