NEW YORK (Reuters Health) - Intranasal administration of nanospheres carrying HIV antigens on their surface can induce both antibody and cellular immune responses, apparently mediated by dendritic cells, a new study in mice shows.
These findings suggest that HIV-1 nanospheres (HIV-NS) “may provide a novel and promising approach for the induction of humoral and cellular immune responses to HIV-1,” Dr. Masanori Baba of Kagoshima University in Japan and colleagues write in the May issue of the Journal of Medical Virology.
The researchers used concanavalin A (con A)-immobilized polystyrene nanospheres designed to capture gp120 and HIV-1 particles on their surface. Past studies by the team have shown that HIV-NS produced antibodies to HIV in the genital tract when administered intranasally.
In this study they investigated the interaction of HIV-NS with dendritic cells. The researchers began by examining the capacity of murine bone marrow-derived dendritic cells to take up several antigens, as well as nanospheres both with and without antigens.
While it had been assumed that the nanospheres would adhere to dendritic cell surfaces via con A’s affinity for mannose, the researchers found nanosphere uptake was not hampered by blocking con A mannose binding. Phagocytosis was at least in part responsible for dendritic cell take-up of the nanospheres; dendritic cells took up gp120 nanospheres at a 100-fold greater rate than gp120 alone.
The researchers also found that pulmonary dendritic cells took up HIV-1-NS administered intranasally. They identified antigens to the virus in vaginal samples from the animals, and found that the animals’ spleen cells showed HIV-specific cytolytic activity after administration.
“The results also suggest the Con A-NS have potential to enhance the immune responses through the increase of antigen uptake and presentation by dendritic cells,” the researchers conclude.
Source: J Med Virol 2005;76:7-15. [ Google search on this article ]
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