Chlamydia trachomatis causes centrosomal defects resulting in chromosomal segregation abnormalities

Area of Science:

• Microbiology
• Cell Biology
• Genetics

Background:

• Chlamydiae are obligate intracellular bacteria that establish a niche within host cells by trafficking along microtubules to the microtubule organizing center (MTOC).
• This intracellular trafficking is dynein-dependent, but the precise mechanisms, particularly the role of the dynactin complex, are not fully understood and appear to be subverted by chlamydial factors.

Purpose of the Study:

• To investigate the interaction of Chlamydiae with the host cell centrosome after trafficking to the MTOC.
• To determine the consequences of this interaction on host cell mitosis and genomic stability.

Main Methods:

• Live-cell imaging to track Chlamydiae localization and centrosome dynamics.
• Immunofluorescence microscopy to assess centrosome number, spindle formation, and chromosome segregation.
• Analysis of chromosomal instability in infected cells post-infection.

Main Results:

• Chlamydial inclusions localize to and associate tightly with host cell centrosomes.
• This association persists through mitosis, leading to an increase in supernumerary centrosomes.
• Infected cells exhibit abnormal spindle poles and significant chromosomal segregation defects.

Conclusions:

• Chlamydial infection disrupts normal centrosome function and mitotic progression.
• The persistent association of chlamydial inclusions with centrosomes induces genomic instability in host cells.
• Chlamydial infection can lead to lasting chromosome instability in cells that survive the infection.