Researchers get closer to malaria vaccine

The hunt for an anti-malaria vaccine is hotting up thanks to Australian researchers who have shown for the first time that T-cells can provide cell-based immunity in humans against the red blood cell stage of malaria.

Based at the Queensland Institute for Medical Research (QIMR), Australia's largest medical research centre, the research team has also identified a target antigen for T-cells.

Most vaccine research until now has concentrated on the liver-based first stage of the Plasmodium falciparum malaria parasite.

However disease symptoms only appear at the red blood cell stage which adds value to a vaccine able to control that part of the cycle.

A paper outlining the latest results from the team led by QIMR director Prof Michael Good has been accepted for publication in a prestigious US journal.

It follows a major article published in The Lancet in August where the team demonstrated that cell-based immunity can be induced in humans and that it provides protection against malaria.

That paper did not delve into which molecules were targeted by T-cells but the team's latest results identify the purine salvage enzyme HGXPRT at the major target antigen.

The teams suggests localisation of HGXPRT within the infected red cell may be significant in regulating malaria immunity both in newborn and adult humans.

An abstract of the paper claims the research provides both "the first demonstration of cell-based immunity (CMI) protecting humans from the erythrocytic (red blood cell) stage of malaria and the first definition of target antigens for CMI."

Identification of a target antigen for T-cells opens up new strategies for malaria vaccine researchers, Good said.

The research was publicly unveiled in the last few weeks month at two specialist meetings including the world's largest malaria conference to date which took place in late November in Kenya.