Table of Contents Author Guidelines Submit a Manuscript
Journal of Immunology Research
Volume 2016, Article ID 7515687, 9 pages
http://dx.doi.org/10.1155/2016/7515687
Review Article

Defensins: The Case for Their Use against Mycobacterial Infections

1National Animal Transmissible Spongiform Encephalopathy Laboratory, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Lab of Agrobiotechnology, China Agricultural University, Beijing, China
2School of Veterinary Medicine, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire Le12SRD, UK

Received 4 July 2016; Accepted 30 August 2016

Academic Editor: Margarete D. Bagatini

Copyright © 2016 Haodi Dong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Human tuberculosis remains a huge global public health problem with an estimated 1/3rd of the population being infected. Defensins are antibacterial cationic peptides produced by a number of cell types, most notably neutrophil granulocytes and epithelial cells. All three defensin types (α-, β-, and θ-defensins) have antibacterial activities, mainly through bacterial membrane permeabilization. Defensins are effective against Gram-negative and Gram-positive bacteria including mycobacteria and are active both intra- and extracellularly. Mycobacterial resistance has never been demonstrated although the mprF gene encoding resistance in Staphylococcus aureus is present in the Mycobacterium tuberculosis genome. In addition to their antibacterial effect, defensins are chemoattractants for macrophages and neutrophils. There are many cases for their use for therapy or prophylaxis in tuberculosis as well. In conclusion, we propose that there is considerable scope and potential for exploring their use as therapeutic/prophylactic agents and more comprehensive survey of defensins from different species and their bioactivity is timely.