"Most human cells are short lived, so it has been unclear how HIV manages to stick around for decades in spite of very effective antiviral treatment," says Mathias Lichterfeld, MD, of the MGH Infectious Disease Division, corresponding author of the report receiving advance online publication in Nature Medicine. "This question led to the hypothesis that HIV might infect stem cells — the most long-lasting cells in the body — but traditional organ-specific stem cells, even those that give rise to all immune and blood cells, are resistant to HIV infection. We have discovered that a new group of T cells, called T memory stem cells, are susceptible to HIV and likely represent the longest lasting cellular niche for the virus." HIV has such a devastating impact on the human immune system because it infects the CD4-positive T cells that normally direct and support the infection-fighting activities of other immune cells. Several subtypes of CD4 T cells have different functions; and all are capable of being infected by HIV, although antiviral treatment keeps the virus in those cells from replicating…

Scientists make advance in cancer research

The most advanced version of vβ3-integrin antagonists failed clinical trials to treat aggressive forms of brain cancer. But research published today in the American Heart Association’s journal Circulation Research shows that targeting the protein in question could still be vital in stopping the growth of tumors. Not least because the drugs targeting it cause minimal side effects compared to other drugs — which can cause bleeding in the gut and high blood pressure. tumors must recruit their own blood supply to grow beyond a very small size…

New Models of Drug-Resistant Breast Cancer Point to Better Treatments

The transplanted tumors maintain the genetic errors that caused the original cancer, even though they are growing in mice. …