Related Experiment Video
Updated: Feb 26, 2026
12:16
Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells
Published on: December 17, 2015
27.1K
A CRISPR array orchestrates virulence and host response in Porphyromonas gingivalis.
Muhammad Irfan1, Ana Duran-Pinedo1, Jose Solbiati1
1Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA.
Microbiology Spectrum
|February 25, 2026
Summary
The CRISPR-Cas system in Porphyromonas gingivalis regulates biofilm formation and virulence. Deleting the CRISPR array 30.1 enhances bacterial growth and host immune evasion, revealing a novel regulatory role.
Area of Science:
- Microbiology
- Bacterial Genetics
- Host-Pathogen Interactions
Background:
- CRISPR-Cas systems are known for defense against foreign DNA.
- Non-coding CRISPR arrays in Porphyromonas gingivalis lack defined functions despite abundant spacers.
- Understanding CRISPR's role beyond immunity is crucial for bacterial pathogenesis research.
Purpose of the Study:
- Investigate the function of the non-coding CRISPR array 30.1 in Porphyromonas gingivalis ATCC 33277.
- Determine the impact of CRISPR array 30.1 deletion on bacterial physiology and host immune response.
- Elucidate the regulatory mechanism of CRISPR array 30.1.
Main Methods:
- CRISPR array 30.1 deletion mutant construction in P. gingivalis.
- Biofilm formation assays.
- Galleria mellonella infection model for virulence assessment.
- Dual RNA sequencing of infected THP-1 macrophages.
- Single-primer amplification (SPA) for identifying spacer-genome interactions.
Main Results:
- Deletion of CRISPR array 30.1 significantly increased biofilm formation and virulence in P. gingivalis.
- The mutant showed altered macrophage transcriptomic response, with increased pro-inflammatory cytokines and suppressed host immunity.
- SPA identified numerous self-genome loci bound by CRISPR 30.1 spacers, indicating direct regulatory activity.
- Loss of the array activated bacterial metabolic and secretion pathways.
Conclusions:
- CRISPR array 30.1 acts as a novel regulator of P. gingivalis physiology and virulence.
- CRISPR spacers directly modulate bacterial gene expression and host-pathogen interactions.
- This finding expands the known functions of CRISPR-Cas systems and suggests potential therapeutic targets.
Related Concept Videos
01:23The Antiviral System of Bacteria and Archaea: CRISPR
808
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...
808
02:53CRISPR and crRNAs
19.3K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
19.3K
01:28CRISPR/Cas9 Genome Editing
2.1K
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
2.1K
01:59CRISPR
58.2K
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
58.2K
01:28Gene Regulation in Microbial Communities: Quorum Sensing
762
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
762
01:29Immune Response Against Viral Pathogens
2.2K
The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses.
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
2.2K