STANFORD, Calif--Researchers at Stanford University Medical Center have found profound shortages of naïve T cells among individuals infected with HIV. In contrast, previous studies have suggested that naïve T cells remain stable with the progression of HIV disease.
"This study forces us to re-evaluate all of the experiments that have been done in the past 10 to 12 years on T cell function with cells from HIV patients," said lead investigator Mario Roederer, PhD.
He believes that the findings should also prompt a rethinking of some proposed treatment strategies and could lead to improved means of tracking disease progression in individual patients.
Naïve T cells, so called because they have not yet encountered an antigen, are responsible for the body's initial response to infections. Once they encounter their first foreign molecule, they turn into memory T cells, long-lived cells that protect against subsequent attacks.
Using a more precise identification method than in previous studies, the Stanford research team measured naïve T cells in blood samples from 266 HIV-infected adults with CD4 counts less than 500/mL and from 44 uninfected controls.
The study found that whereas naïve cells represent about 50% of all T cells in healthy adults, they make up less than 10% in adults with advanced AIDS (J Clin Invest 95:2061-2066, 1995). The shortfall of naïve cells was seen in both CD4 and CD8 cells.