Related Experiment Video
Updated: Sep 10, 2025
07:18
An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines
Published on: October 11, 2022
1.9K
The host calcium system contributes to intracellular Rickettsia pathogenesis
Jinyi C Zhu1,2, Jack H Cook2, Mustapha Dahmani2
1Biological Sciences Training Program, University of Maryland College Park, College Park, Maryland, USA.
Infection and Immunity
|August 21, 2025
Summary
Calcium channel blockers (CCBs) show potential against Rickettsia bacteria by disrupting their actin polymerization. This host-targeted approach exploits the bacteria
Area of Science:
- Microbiology
- Cell Biology
- Pharmacology
Background:
- Rickettsia bacteria are obligate intracellular parasites dependent on host cell functions for proliferation.
- This dependence offers a therapeutic strategy using host-targeted drugs.
- Calcium channel blockers (CCBs) previously showed inhibitory effects on Rickettsia conorii.
Purpose of the Study:
- To investigate the anti-Rickettsia activity of CCBs.
- To define the interaction between Rickettsia and the host calcium (Ca2+) system.
- To elucidate the mechanism of CCB action against Rickettsia.
Main Methods:
- Screening of host-targeted compounds, specifically CCBs.
- Assessing Rickettsia proliferation in endothelial cells under CCB treatment.
- Analyzing the effect of host Ca2+ disruption on Rickettsia growth.
- Investigating rickettsial adherence, apoptosis, and actin polymerization.
Main Results:
- CCBs inhibit Rickettsia proliferation in endothelial cells.
- Disruption of the host Ca2+ gradient impairs Rickettsia growth.
- Rickettsia infection causes persistent disruption of host Ca2+ equilibrium.
- CCBs universally inhibit Rickettsia actin polymerization, with minor effects on adherence or apoptosis.
Conclusions:
- CCBs possess anti-Rickettsia properties.
- The primary mechanism of CCB action is the disruption of rickettsial actin polymerization.
- These findings highlight the intricate interdependence between Rickettsia and host cell biology.
Keywords:
Rickettsiacalciumhost-pathogen interactionshost-targeted therapeuticsobligate intracellular bacteriaMore Related Videos
08:01Author Spotlight: Investigating Viral Disruption of Intestinal Epithelial Signaling – Research Insights and Future Directions
Published on: January 19, 2024
1.5K
08:46A "Dual-Addition" Calcium Fluorescence Assay for the High-Throughput Screening of Recombinant G Protein-Coupled Receptors
Published on: December 2, 2022
2.4K
Related Concept Videos
01:10Intracellular Movement of Viruses and Bacteria
2.9K
Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a...
2.9K
01:29Bacterial Phylum Chlamydiae
109
The phylum Chlamydiae or Chlamydiota is composed of a single order, Chlamydiales. This phylum consists entirely of obligate intracellular parasites that infect eukaryotic hosts. While human pathogens within this group have been studied extensively, the phylum encompasses many species capable of interacting with various eukaryotic organisms. Members of Chlamydiae are typically small cocci, approximately 0.5 μm in diameter, and exhibit a distinctive developmental cycle. As is characteristic...
109
01:21Skeleton and Calcium Homeostasis
4.8K
Calcium is not only the most abundant mineral in bone but also the most abundant mineral in the human body. Calcium ions are needed for bone mineralization, tooth health, heart rate regulation and strength of contraction, blood coagulation, the contraction of smooth and skeletal muscle cells, and the regulation of nerve impulse conduction. The average calcium level in the blood is about 10 mg/dL. When the body cannot maintain this level, a person will experience hypo or hypercalcemia.
4.8K
01:27Feedback Regulation of Calcium Concentration
3.5K
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
3.5K
01:16Calmodulin-dependent Signaling
5.3K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.3K
01:23Rheumatic Heart Disease I: Introduction
39
Rheumatic heart disease or RHD is a chronic condition that results from rheumatic fever, causing permanent damage to the heart valves.Etiology and Risk FactorsIt primarily arises from rheumatic fever, an inflammatory disease that can develop after untreated or inadequately treated group A streptococcal (GAS) pharyngitis. Streptococcus spreads through direct contact with oral or respiratory secretions. While the bacteria are the causative agents, factors like malnutrition, overcrowding, poor...
39