ELife: to reveal how subperiosteal sinus macrophages help HIV-1 spread in immune organs

December 18, 2019 / Biovalley BIOON / - -- as a retrovirus, HIV can destroy immune cells and inhibit the host's ability to resist daily infections and diseases During HIV-1 infection, follicular dendritic cells will act as a reservoir of the virus and become an obstacle to cure the infection, but how these cells are initially infected and conserve HIV-1 is not clear In a new study, John kehrl and Chung Park of the National Institute of allergy and infectious diseases (NIAID) found in mice that, as the first layer of cells in draining lymph nodes, the macrophages of the subcapsular sinuses act as the "shuttle" vector of HIV-1 virus like particles These cells help them spread by loading the virus like particles into two types of immune cells - follicle dendritic cells and B cells The picture is from John kehrl and Chung Park (CC by 4.0) In this new study, kehrl and park visualized possible early events in the transmission of HIV-1 like particles in mice They studied how the virus is transferred from lymph and blood through macrophages on the walls of the sinuses, and then into the underlying network of follicular dendritic cells Their study focused on a subgroup of macrophages in the sinusoid wall of the lymphoid organs, which provides an entry point for cell-cell contact, thus shuttling HIV-1 particles to follicular dendritic cells and B cells in the lymph nodes and spleen They found that a protein called mfg-e8 is essential for the normal function of this entry, because its absence severely limits the spread of HIV-1 to the follicular dendritic cell network Kehrl and park also found that the HIV-1 envelope, which encapsulates the virus particles and assists the virus to enter the cells, provides a way for mfg-e8 to bind Mfg-e8 can connect HIV-1 granules with the integrin of α V β 3 expressed in host cells These integrins assist cells in ingesting these viral particles, making them available to other types of cells, or in some cases targeting them for subsequent destruction They say further research is needed to see if this process involving mfg-e8 is beneficial to the host or virus Immune.html