VPS29 and infection: Using HeLa cells as an important model for infection, various host cell vesicular trafficking pathways have been shown to facilitate CCV development and contribute to the infection cycle of Coxiella. The retromer trafficking process, required for retrograde transport from endosomes to the trans-Golgi network [21], has been shown to contribute to the maturation of the CCV with retromer subunits VPS35 and VPS29 and sorting nexins all required for expansion of the CCV [22].