Ryan Zurakowski, assistant professor of electrical and computer
engineering at the University of Delaware, Mathias Lichterfeld, Ragon Institute of MGH, the Massachusetts
Institute of Technology and Harvard University and researchers from
Massachusetts General Hospital (MGH), together have presented a paper titled as
"HIV-1 Persistence in CD4+ T-Cells with Stem Cell-Like Properties,"
which throws light on how a particular T-cell type may provide a better
understanding of how HIV can persist despite treatment. It has been explained
that treatment does not kill the infected cells, but stop the infection of new
cells. It is upon virus itself to kill the infected cells. However memory
T-cells which have been infected by the virus do not get killed by virus.
T-cells are
lymphocytes, which are produced by the thymus gland and they actively
participates in the body's immune response. "Memory" T-cells can live
for years, or even decades, providing life-long immunity to previously
encountered diseases. They can form "dormant" infections, which last
for years, and cause HIV to ricochet whenever a patient stops treatment.
Researchers
discovered a subgroup of memory T-cells calles “Stem-Cell Memory T-cells"
(Tscm), are different, particularly in their ability to produce daughter cells.
These cells decayed more slowly than any other type of T-cells and if HIV
infected, they could even persist after years of therapy. As a result, after 10
years of therapy, the Tscm cells represented 24 percent of the total HIV
infected cell population, despite being only 1 percent of the total T-cell
population. This is a significant finding as this slowest decaying portion of
HIV infected cells play an increasingly significant role in sustaining HIV
infection in patients that have remained on therapy according to Zurakowski.
Credit for this
finding goes to to the diligence of Lichterfeld and the researchers at the
Ragon Institute in cautiously following the same HIV patients for a decade that
proved to be a source of a high fidelity data set for the Team of Zurakowski ,
that would not otherwise have been possible
Work is
currently going on in developing Drugs for cancer therapy that target stem-cell
metabolic pathways and may be able to
target this cell type as well, due to the "stem-cell like" nature of
the Tscm cells. For developing better clinical strategies for HIV treatment, it
is better to understand how the HIV virus leverages a cell's stem cell-like
properties of cellular immune memory to stay alive.
Zurakowski
concludes that if ways are developed to selectively eliminate the HIV-infected
Tscm cells, it will be a major step in developing a true 'cure' for HIV
infection.