Statins protect against fulminant pneumococcal infection and cytolysin toxicity in a mouse model of sickle cell disease

J Clin Invest. 2010 Feb;120(2):627-35. doi: 10.1172/JCI39843. Epub 2010 Jan 19.

Abstract

Sickle cell disease (SCD) is characterized by intravascular hemolysis and inflammation coupled to a 400-fold greater incidence of invasive pneumococcal infection resulting in fulminant, lethal pneumococcal sepsis. Mechanistically, invasive infection is facilitated by a proinflammatory state that enhances receptor-mediated endocytosis of pneumococci into epithelial and endothelial cells. As statins reduce chronic inflammation, in addition to their serum cholesterol-lowering effects, we hypothesized that statin therapy might improve the outcome of pneumococcal infection in SCD. In this study, we tested this hypothesis in an experimental SCD mouse model and found that statin therapy prolonged survival following pneumococcal challenge. The protective effect resulted in part from decreased platelet-activating factor receptor expression on endothelia and epithelia, which led to reduced bacterial invasion. An additional protective effect resulted from inhibition of host cell lysis by pneumococcal cholesterol-dependent cytotoxins (CDCs), including pneumolysin. We conclude therefore that statins may be of prophylactic benefit against invasive pneumococcal disease in patients with SCD and, more broadly, in settings of bacterial pathogenesis driven by receptor-mediated endocytosis and the CDC class of toxins produced by Gram-positive invasive bacteria.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anemia, Sickle Cell / microbiology*
  • Anemia, Sickle Cell / pathology
  • Animals
  • Anti-Inflammatory Agents / therapeutic use
  • Bacterial Proteins / therapeutic use
  • Cytotoxins / antagonists & inhibitors
  • Cytotoxins / toxicity
  • Disease Models, Animal
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / therapeutic use*
  • Lung / drug effects
  • Lung / pathology
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Platelet Membrane Glycoproteins / drug effects
  • Platelet Membrane Glycoproteins / physiology
  • Pneumococcal Infections / pathology
  • Pneumococcal Infections / physiopathology
  • Pneumococcal Infections / prevention & control*
  • Receptors, G-Protein-Coupled / drug effects
  • Receptors, G-Protein-Coupled / physiology
  • Streptolysins / therapeutic use

Substances

  • Anti-Inflammatory Agents
  • Bacterial Proteins
  • Cytotoxins
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Platelet Membrane Glycoproteins
  • Receptors, G-Protein-Coupled
  • Streptolysins
  • plY protein, Streptococcus pneumoniae
  • platelet activating factor receptor