Aims: To identify the presence of mouse beta-defensin 3 (Mbd3) (the human homologue of beta-defensin 2) in different tissues and to define the antimicrobial properties of recombinant MBD3 (rMBD3) against a panel of human pathogens.
Methods and results: Mbd3 gene expression in different mouse tissues before or after lipopolysaccharide (LPS) injection was compared by semi-quantitative RT-PCR. This analysis demonstrated that epithelial and mucosal tissues expressed Mbd3 independent of LPS stimulation. Evaluation of the antimicrobial properties of recombinant rMBD3 was determined by assessing the median inhibition concentration (IC(50)), minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)/minimal fungicidal concentration (MFC) against various human pathogens.
Conclusion: Mbd3 gene expression by epithelial and mucosal tissues suggested that MBD3 likely plays an early defensive role against microbial infections. This activity was most significant against filamentous fungi.
Significance and impact of the study: The data presented in this report suggested that formulations containing rMBD3 and related molecules could serve to treat fungal and bacterial infections.