CEP55 and HIV-1 infection: Additionally, because MARCH8, another member of the MARCH protein family, potently inhibits HIV-1 infection in MDMs [9], we generated THP-1 cells depleted with either a control shRNA, a MARCH8 (shM8) specific shRNA, or shRNAs for both MARCH2 and MARCH8 (shM8/2) followed by selection for geneticin (G418) resistant cells.