Table 3

The functions of vitamin D-binding protein (VDBP)

FunctionRelevance to lung and/or systemic diseaseMechanism
Vitamin D transportationPotential influence of levels of vitamin D on host defence and regulation of cell proliferationDelivery of vitamin D to lung parenchyma and to alveolar macrophages
Actin bindingPrevents systemic vascular occlusion following cellular damage. Potential relevance in sepsis and acute lung injuryPrevents formation of F-actin networks in the systemic circulation
Neutrophil chemotaxisNeutrophilic inflammation is a recognised part of COPD and ALI pathogenesis. Neutrophil recruitment is a key part of host defence.Enhances chemotactic effect of complement-derived peptides
Macrophage activationMacrophage activity is a key part of host defence, and contributes to COPD and ALI pathogenesisVDBP is converted to macrophage-activating factor by enzymes derived from lymphocytes
  • ALI, acute lung injury; COPD, chronic obstructive pulmonary disease.