It has been reported that EPEC Cif induces cell damage and apoptosis of IEC-6 intestinal cells in a manner associated with LDH release and caspase-3 activation after infection. Similarly, Cif homologue in P. luminescens triggers apoptosis in insect cells, albeit this activity is not associated with virulence in an insect model. Consistent with these findings, the B. pseudomallei chbP mutant caused the release of lower levels of LDH in infected HeLa cells compared to the wild-type and complemented strain, despite intracellular net replication occurring at comparable levels. B. pseudomallei has recently been reported to induce expression of apoptosis-related genes including caspase-3, caspase -8, caspase -9, Bax, and Bcl-2 in NNC 63-0532 macrophages, and the role of CHBP in modulation of apoptosis during B. pseudomallei infection merits future study, ideally in murine models. A significant reduction in plaque formation was detected with the chbP mutant that could be restored by plasmid-mediated transcomplementation. Plaque formation reflects the outcome of multiple processes, including uptake, endosome escape, net intracellular replication and spread to adjacent cells via actinbased motility or cell fusion. While we did not detect a defect in the net intracellular replication, actin tail formation or multinucleated giant cell formation by the chbP mutant over short duration cell-based assays, it is possible that NNC 05-2090 hydrochloride subtle phenotypes are amplified over the longer duration and multiple cycles of infection required to form a plaque. It is noteworthy that despite marked cell-based phenotypes, Cif homologue in P. luminescens is not required for full virulence in an insect model and studies in murine melioidosis models are required before the relevance of the activities attributed to CHBP to date can be stated. Nevertheless, our study indicates a requirement for the Bsa apparatus for secretion of CHBP in host cells and indicates that distinct signals may regulate the expression or secretion of Bsa effectors. In order to activate immune responses that ward off invading microorganisms, plants utilize various types of receptors that recognize pathogen ligands of various nature. Appropriate recognition of these ligands by the immune receptors is crucial for the activation of immune responses. These immune receptors are either extracellular cell surface receptors that detect pathogen-associated molecular patterns or damage-associated modified self-patterns, or cytoplasmic receptors that recognize highly specific pathogen effectors either directly, or indirectly through recognition of their activities. Both types of receptors may activate an hypersensitive response, which is a rapid cell death surrounding the infection site that is thought to prevent further pathogen invasion. The Verticillium genus comprises vascular pathogens that cause Verticillium wilt diseases in over 200 plant species worldwide.