Study Shows How Antibody Class Inhibits HIV Infection
Antiphospholipid antibodies bind to monocytes, spur chemokines that interfere with CCR5 receptor
WEDNESDAY, April 7 (HealthDay News) -- Naturally occurring antibodies that can block a method of HIV entry into cells point to a possible new approach for designing HIV vaccines, according to research published online April 5 in the Journal of Experimental Medicine.
M. Anthony Moody, M.D., of the Duke University Medical Center in Durham, N.C., and colleagues performed a series of laboratory tests using blood samples from healthy controls and individuals with HIV.
The researchers found that the antiphospholipid monoclonal antibodies PGN632, P1, IS4 and CL1 can bind to monocytes and trigger the production of chemokines that prevent the virus from attaching to the CCR5 receptor. The researchers found antiviral activity in the presence of monocytes only, and the antiphospholipid antibodies had an inhibitory effect in only 85 percent of peripheral blood mononuclear cells (PBMC) tested.
"In HIV-1 vaccine development, recent studies have demonstrated the extremely early destruction of the immune system, and early induction of immunosuppression and apoptosis, signaling the need for a vaccine that can prime for a very early salutary immune response within days of infection. The novel mechanism outlined here of antiphospholipid antibody modulation of anti-HIV-1 chemokines accounts for the selective activity of lipid antibodies in PBMC but not epithelial-based cultures. These results suggest that a vaccine could potentially harness the adaptive immune system to trigger innate immunity for an anti-viral response, in effect, reversing the traditional path of protection of innate to adaptive immunity," the authors conclude.
Some authors disclosed patent applications or royalties related to these monoclonal antibodies. The Duke Human Vaccine Institute has received a grant from Peregrine Pharmaceuticals, which employs two of the authors.