Ca²⁺ signals triggered by bacterial pathogens and microdomains

Area of Science:

• Cellular microbiology
• Host-pathogen interactions
• Calcium signaling

Background:

• Calcium ions (Ca2+) play a critical role in host cell responses during bacterial infections.
• Bacterial pore-forming toxins (PFTs) are key effectors that can disrupt host cell homeostasis.
• Type III secretion systems (T3SS) deliver bacterial effectors directly into host cells.

Purpose of the Study:

• To review how bacterial PFTs induce global Ca2+ signals in host cells.
• To discuss the role of bacterial effectors and host factors in Ca2+ microdomain formation during specific infections (Shigella, Chlamydia).
• To explore how modeling can elucidate Ca2+ response dynamics.

Main Methods:

• Literature review of recent reports on bacterial PFTs and Ca2+ signaling.
• Analysis of studies involving type III secretion systems (T3SS) in bacterial invasion and extrusion.
• Discussion of computational modeling approaches for Ca2+ dynamics.

Main Results:

• Bacterial PFTs trigger significant Ca2+ signals that regulate cell adhesion, inflammation, and death.
• Bacterial effectors and host cell components contribute to Ca2+ microdomain formation during Shigella and Chlamydia infections.
• Comparative analysis of bacterial-induced and physiological Ca2+ microdomains offers insights into response regulation.

Conclusions:

• Bacterial PFTs are potent modulators of host cell Ca2+ signaling pathways.
• Understanding the interplay between bacterial factors and host Ca2+ dynamics is essential for deciphering infection mechanisms.
• Modeling provides a valuable tool for dissecting the parameters governing local Ca2+ responses in host-pathogen interactions.