Coxiella burnetii Virulent Phase I and Avirulent Phase II Variants Differentially Manipulate Autophagy Pathway in Neutrophils
Venkatesh Kumaresan, Juexin Wang, Wendy Zhang, Yan Zhang, Dong Xu, Guoquan Zhang
Abstract
studies also demonstrated that although NMII exhibited a higher infection rate than NMI in mouse bone marrow neutrophils (BMNs), NMI-infected BMNs survived longer than NMII-infected BMNs. These results suggest that the differential interactions of NMI and NMII with neutrophils may be related to their ability to cause disease in animals. To understand the molecular mechanism underlying the differential interactions of NMI and NMII with neutrophils, global transcriptomic gene expressions were compared between NMI- and NMII-infected BMNs by RNA sequencing (RNA-seq) analysis. Interestingly, several genes involved in autophagy-related pathways, particularly membrane trafficking and lipid metabolism, are upregulated in NMII-infected BMNs but downregulated in NMI-infected BMNs. Immunofluorescence and immunoblot analyses indicate that compared to NMI-infected BMNs, vacuoles in NMII-infected-BMNs exhibit increased autophagic flux along with phosphatidylserine translocation in the cell membrane. Similar to neutrophils, NMII activated LC3-mediated autophagy in human macrophages. These findings suggest that the differential manipulation of autophagy of NMI and NMII may relate to their pathogenesis.