crossm Articles of Signiﬁcant Interest Selected from This Issue by the Editor Modulation of Macrophage Polarization as a Potential Adjunctive Therapy for Pneumocystis Pneumonia Pneumocystis pneumonia is best treated using antibiotics. However, mortality and morbidity resulting from inﬂammatory injury to the lungs, rather than from the fungal burden alone, remain a concern. In that light, Nandakumar et al. (e00939-16) examine the lung immune polarization kinetics of macrophages by using a rat model of chronic Pneumocystis pneumonia. Intratracheal adoptive transfer of differentially polarized macrophages improves the immunopathogenesis associated with Pneumocystis infection. This work emphasizes the plastic nature of macrophage polarization during Pneumocystis pneumonia and the potential beneﬁt of M2 macrophages in facilitating the clearance of Pneumocystis and reducing lung inﬂammation during infection. Dectin-1 Mediates Macrophage Immune Response to the Fungal Pathogen Exserohilum rostratum An effective innate immune response, driven by cells such as macrophages, is key in the clearance of fungal pathogens. Exserohilum rostratum is a dematiaceous mold that caused 753 infections and 64 deaths during a multistate outbreak due to injection of a contaminated steroid. Reedy et al. (e00903-16) show that a cell surface receptor on macrophages, Dectin-1, is required for production of proinﬂammatory signals in response to Exserohilum. In addition, coadministration of Exserohilum and steroids potently decrease the immune response and increase fungal growth in a mouse model of infection. Genomic Data Support Conclusions from an Animal Model of Invasive Pneumococcal Disease Previous work published in Infection and Immunity provided evidence for the involvement of two proteins of Streptococcus pneumoniae in the pathogenesis of infection in a murine model (L. E. Cron et al., Infect Immun 79:3697–3710, 2011, https://doi.org/10.1128/IAI.01383-10). Such proteins are of interest because they may be candidates for the development of protein vaccines. Lees et al. (e01061-16) present an analysis of genomic data from humans with culture-proven pneumococcal meningitis. This analysis determined that positive selection is acting on one of the proteins originally identiﬁed in the murine model during human disease, providing further evidence for a role in pathogenesis.
Copyright © 2017 American Society for Microbiology. All Rights Reserved. https://doi.org/10.1128/IAI.00052-17
March 2017 Volume 85 Issue 3 e00052-17
Infection and Immunity