ANPEP and infection: To define the relevance of CD13 to A. phagocytophilum infectivity, HEK-293T cells transfected to express Flag-tagged CD13 or bacterial alkaline phosphatase (BAP) were incubated with A. phagocytophilum organisms followed by immunofluorescence microscopy at 24 h to assess infection and the number of ApVs per cell.