POSTER PRESENTATION Open Access Membrane-associated RING-CH (MARCH)

is a member of a recently discovered MARCH family of RING-finger E3 ubiquitin ligases, 11 members of which have been identified. MARCH8 downregulates several transmembrane proteins, such as MHC-II, CD86, TRAIL receptor 1, and CD98. We have recently reported that MARCH8 also negatively regulates cell-surface expression of transferrin receptor [1]. During the preparation of MARCH8-encoding lentiviral vector, we observed that the infectivity of the vector was considerably lower than that of the control vector, suggesting that MARCH8 might have the ability to reduce viral infectivity. Here, we have assessed the impact of MARCH8 expression on HIV-1 replication. Materials and methods Endogenous levels of MARCH8 expression were analyze