Related Experiment Video

Updated: Jul 18, 2026

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae
09:12

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Published on: January 17, 2014

Toll-like receptor 2 and Toll-like receptor 4 polymorphisms in invasive pneumococcal disease

Leen Moens1, Jan Verhaegen, Marie Pierik

  • 1Department of Laboratory Medicine, University Hospital Leuven, Centraal Dienstengebouw, Herestraat 49, B-3000 Leuven, Belgium.

Microbes and Infection
|January 2, 2007
PubMed
Abstract

Insights

Genetic variations in Toll-like receptors (TLRs) 2 and 4 were not associated with invasive pneumococcal disease in Caucasian individuals. This study found no link between specific TLR polymorphisms and susceptibility to Streptococcus pneumoniae infection.

Area of Science:

  • Immunology
  • Genetics
  • Infectious Diseases

Background:

  • Toll-like receptors (TLRs) are crucial for innate immunity, recognizing pathogen-associated molecular patterns to initiate host defense.
  • TLR2 and TLR4 have demonstrated roles in combating Streptococcus pneumoniae infections in mouse models.
  • Polymorphisms in TLRs are linked to various human diseases, but their impact on pneumococcal defense is unexplored.

Purpose of the Study:

  • To investigate the association between specific polymorphisms in Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) and the risk of invasive pneumococcal disease in humans.
  • To determine if common TLR2 and TLR4 gene variants influence susceptibility or resistance to Streptococcus pneumoniae infections.

Main Methods:

  • Genotyping of 99 Caucasian patients with invasive pneumococcal disease and 178 Caucasian controls.
  • Analysis focused on known polymorphisms: R579H, P631H, and R753Q in TLR2, and D299G in TLR4.
  • Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for genotyping.

Main Results:

  • No significant differences in the distribution of TLR2 (R579H, P631H, R753Q) and TLR4 (D299G) variants were observed between patients and controls.
  • Stratification by age, sex, diagnosis, and mortality revealed no significant associations for TLR2 R753Q and TLR4 D299G genotypes within patient subgroups or compared to controls.
  • Homozygous mutant individuals for the studied TLR2 polymorphisms were absent in both patient and control groups.

Conclusions:

  • The studied polymorphisms in TLR2 and TLR4 are not associated with invasive pneumococcal infection in the Caucasian population.
  • These findings suggest that common variations in TLR2 and TLR4 do not play a significant role in human susceptibility to Streptococcus pneumoniae.

More Related Videos

Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling09:51

Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling

Published on: July 26, 2017

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Related Concept Videos

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters01:16

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase01:11

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Bacterial Meningitis II: Pathophysiology01:26

Bacterial Meningitis II: Pathophysiology

Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu01:29

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu

Genetic variations significantly influence drug response through pharmacokinetics, receptor interactions, and biologic milieu modifications. Pharmacokinetic alterations impact drug metabolism and clearance, affecting efficacy and toxicity. Variants in drug-metabolizing enzymes, such as CYP2C9 and CYP2C19, alter drug activation and elimination. For example, CYP2C9 loss-of-function variants require lower warfarin doses to prevent excessive bleeding, while CYP2C19 variants reduce clopidogrel...
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...