October 14, 2005

IMMUNOLOGY: Special Delivery Brings Fats to Immune System
Proteins access the immune system by well-known pathways of antigen presentation, but work by Michael Brenner and colleagues reveals that fat-containing antigens, including those from pathogens like the tuberculosis bacterium, take a different and rather unexpected route. In a paper published in the Oct. 6 Nature, the researchers show that the immune system coopts apolipoproteins, best known as blood cholesterol carriers, to procure lipid antigens for presentation to T cells. The convergence of two previously unrelated systems—the transfer of dietary fats and cholesterol and the delivery of lipid antigens to the immune system—has profound implications for the understanding of a host of diseases from atherosclerosis to asthma.

NEUROLOGY: Vaccine May Clear Alzheimer’s Brain Plaques
Many researchers believe that clearing the waxy amyloid plaques that fill the brains of Alzheimer’s patients is the key to improving their cognitive function. In the September Journal of Clinical Investigation, a team including (from left) Dan Frenkel, Howard Weiner, and Ruth Maron unveils a novel vaccine strategy for Alzheimer’s that clears the buildup of amyloid plaques in a mouse model. The new strategy triggers cells of the immune system to gobble up amyloid-beta. It is delivered as a simple nasal spray and consists of two FDA-approved drugs already in use for other conditions.

PATHOLOGY: Brain Injury Reversed in Animal Model of AIDS
Drugs that cannot breach the blood–brain barrier can reverse signs of AIDS-related neurological damage in monkeys by suppressing infected immune cells in the blood that continually assault the brain, report Kenneth Williams and colleagues in the September Journal of Clinical Investigation. Born as monocytes in the blood, the infected cells transform into dysfunctional macrophages in the brain at the interface of blood vessels and nerves, where they presumably spew destructive chemicals. The research may lead to strategies for treating the severe neurological problems that affect about one third of people in this country who have AIDS.