Cellular antacids give vaccines a boost

ROME, Sep 12, 2005 (United Press International via COMTEX) -- Italian scientists say they've found a drug that blocks acid buildup inside cells and increases the immune response to vaccines.

Vincenzo Barnaba and his team at the University of Rome found people receiving booster shots against hepatitis B virus developed more robust immune responses if given a widely used anti-malaria drug called chloroquine.

Many vaccines are made up of soluble proteins derived from dangerous viruses or bacteria. But because of the way the proteins are broken down by cells, they do a poor job of prodding killer cells called cytolytic T cells into action.

Cytolytic T cells identify and execute infected cells, so finding ways to activate more of those cells is an important goal for vaccine developers.

The demonstration that a single dose of chloroquine boosted hepatitis B virus-specific T cell responses in up to 70 percent of vaccine recipients suggests the readily available, oral drug might be a promising vaccine supplement, scientists said.

The study is detailed in the Sept. 19 issue of The Journal of Experimental Medicine.