Increased Susceptibility of Humanized NSG Mice to Panton-Valentine Leukocidin and Staphylococcus aureus Skin Infection

PLoS Pathogens

Maria D. Rodriguez¹  Juan Carlos Biancotti²  Stacey L. Kolar²  Terrence Town²  Xuemo Fan²  David O. Beenhouwer³  David Gate³  George Y. Liu³  Ching Wen Tseng³  Kavon Rezai-Zadeh³  Bethany L. Berg⁴  Sabrina Müller⁴ 

[1] Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, United States of America;Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America;Division of Pediatric Infectious Diseases and the Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America;Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America

关键词: Mouse models;    Staphylococcus aureus;    Lesions;    Skin infections;    Cytokines;    Flow cytometry;    Staphylococcal infection;    Neutrophils;   

DOI  :  10.1371/journal.ppat.1005292

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Staphylococcus aureus is a leading cause of skin and soft-tissue infections worldwide. Mice are the most commonly used animals for modeling human staphylococcal infections. However a supra-physiologic S. aureus inoculum is required to establish gross murine skin pathology. Moreover, many staphylococcal factors, including Panton-Valentine leukocidin (PVL) elaborated by community-associated methicillin-resistant S. aureus (CA-MRSA), exhibit selective human tropism and cannot be adequately studied in mice. To overcome these deficiencies, we investigated S. aureus infection in non-obese diabetic (NOD)/severe combined immune deficiency (SCID)/IL2rγnull (NSG) mice engrafted with human CD34+ umbilical cord blood cells. These “humanized” NSG mice require one to two log lower inoculum to induce consistent skin lesions compared with control mice, and exhibit larger cutaneous lesions upon infection with PVL+ versus isogenic PVL- S. aureus. Neutrophils appear important for PVL pathology as adoptive transfer of human neutrophils alone to NSG mice was sufficient to induce dermonecrosis following challenge with PVL+ S. aureus but not PVL- S. aureus. PMX53, a human C5aR inhibitor, blocked PVL-induced cellular cytotoxicity in vitro and reduced the size difference of lesions induced by the PVL+ and PVL- S. aureus, but PMX53 also reduced recruitment of neutrophils and exacerbated the infection. Overall, our findings establish humanized mice as an important translational tool for the study of S. aureus infection and provide strong evidence that PVL is a human virulence factor.

【 授权许可】

CC BY