Significance of Host Cell Kinesin in the Development of Chlamydia psittaci

Abstract

The influence of the microtubule-associated motor protein kinesin on Chlamydia psittaci inclusion development in epithelial and fibroblast cell lines was addressed. Kinesin was blocked early after chlamydial internalization (4 h postinfection [p.i.]) and before the initiation of active chlamydial multiplication (8 h p.i.). Chlamydia development was monitored by fluorescence and transmission electron microscopy at different times during the cycle. In both host cell lines, kinesin blockage restricted mitochondria from the chlamydial vacuole. The effects of kinesin blockage on the C. psittaci replication cycle included the presence of multiple inclusions up to late in the cycle, the presence of enlarged pleomorphic reticulate bodies, and a delayed reappearance of elementary bodies. The last effect seems to be greater when kinesin is blocked early after infection. Our results show that kinesin activity is required for optimal development of these microorganisms, most probably acting through the apposition of mitochondria to the C. psittaci inclusions.

Molecular motors hijacking by intracellular pathogens

“…Indeed, intracellular delivery of antibodies against kinesin after host cell permeabilization has been shown to inhibit C. psittaci replication. However, this may only result from the loss of the close apposition of mitochondria to the C. psittaci inclusions (Escalante‐Ochoa et al ., 1999). All in all, little is known about diversion of molecular motor functions by intracellular bacteria and Salmonella has given the most striking illustration of such a phenomenon.…”

Chlamydia–host cell interaction not only from a bird's eye view: some lessons from Chlamydia psittaci

“…This kind of mitochondrial recruitment may allow C. psittaci to acquire high‐energy storage substrates (such as ATP) from the host cell. Interestingly, mitochondria and the GA also interact with the microtubule motor proteins dynein and kinesin . Dynein is critically involved in the intracellular translocation and positioning of the chlamydial vacuole near the GA, whereas kinesin probably acts through the characteristic recruitment of host cell mitochondria to the PVs of C. psittaci .…”

“…Interestingly, mitochondria and the GA also interact with the microtubule motor proteins dynein and kinesin . Dynein is critically involved in the intracellular translocation and positioning of the chlamydial vacuole near the GA, whereas kinesin probably acts through the characteristic recruitment of host cell mitochondria to the PVs of C. psittaci . 24–72 hours post infection, chlamydial RBs retransform into EBs in response to an as yet unidentified signaling mechanism, and bacteria are released by cell lysis (Fig.…”

Psittacosis

“…From eight to ten hours of cycle, the reticular bodies start to replicate by binary fission, remaining in contact with the inclusion membrane [20,65]. In this moment, it's possible to see numerous mitochondria surrounding the inclusion [18,20], possibly due to protein motors function as kinesins [81]. Cp.…”