Staphylococcus aureus is responsible for a large number of hospital- and community-acquired infections worldwide. Therapeutic options to combat S. aureus infections are limited due to the high level of antibiotic resistance and lack of an effective vaccine. Thus, there is a significant need for the development of effective therapeutics against this organism. Critical to the pathogenic lifestyle of S. aureus is the killing of phagocytes; innate immune cells integral to the control of Staphylococcal infections. Thus, the long-term goal of this research program is to understand the mechanism employed by S. aureus to injure these critical immune cells. We have described that the leukocidin A/B (LukAB) plays an essential role in protecting S. aureus from phagocyte-mediated killing by targeting and eliminating these cells. Our work has established that LukAB is present in all clinical strains, yet is the most divergent member of the bi-component pore-forming family of toxins; is responsible for S. aureus-mediated demise of primary human phagocytes during ex vivo infections; targets the CD11b integrin; exhibits species specificity by preferentially targeting the human I-domain of CD11b over the murine I-domain; is produced in vivo during both murine and human infections; and kills human leukocytes when produced by S. aureus from both extracellular and intracellular environments. The primary goals of this application are to: elucidate the mechanism by which LukAB binds to human CD11b in order to define the species specificity determinants to develop an improved murine model for S. aureus infection (Aim 1); define the mechanism by which LukAB kills human phagocytes (Aim 2); and delineate the contribution of LukAB variants to the pathogenesis of other S. aureus clones (Aim 3). To accomplish these Aims, we propose to employ a multidisciplinary approach that combines molecular biology, genetics, cellular immunology, whole genome screens, and biochemistry, together with ex vivo and in vivo infection models. Understanding the molecular details of how LukAB mediates targeting and killing of phagocytes will provide insight into how S. aureus bi-component pore-forming toxins kill host cells and the importance of these toxins to S. aureus pathogenesis.

Public Health Relevance

This application aims to elucidate the mechanism of action of LukAB, a potent toxin produced by the bacterium Staphylococcus aureus, which targets and kills immune cells. Information obtained from the studies proposed in this application will pave the way for the development of specific inhibitors to target and block the activity of this toxin and thereby provide new methods for the treatment of infections caused by this important human pathogen.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI099394-08
Application #
9936356
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Huntley, Clayton C
Project Start
2013-06-04
Project End
2022-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
8
Fiscal Year
2020
Total Cost
Indirect Cost
Name
New York University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
121911077
City
New York
State
NY
Country
United States
Zip Code
10016
Copin, Richard; Shopsin, Bo; Torres, Victor J (2018) After the deluge: mining Staphylococcus aureus genomic data for clinical associations and host-pathogen interactions. Curr Opin Microbiol 41:43-50
Blake, Kimbria J; Baral, Pankaj; Voisin, Tiphaine et al. (2018) Staphylococcus aureus produces pain through pore-forming toxins and neuronal TRPV1 that is silenced by QX-314. Nat Commun 9:37
Harper, Lamia; Balasubramanian, Divya; Ohneck, Elizabeth A et al. (2018) Staphylococcus aureus Responds to the Central Metabolite Pyruvate To Regulate Virulence. MBio 9:
Mlynek, Kevin D; Sause, William E; Moormeier, Derek E et al. (2018) Nutritional Regulation of the Sae Two-Component System by CodY in Staphylococcus aureus. J Bacteriol 200:
Bhattacharya, Mohini; Berends, Evelien T M; Chan, Rita et al. (2018) Staphylococcus aureus biofilms release leukocidins to elicit extracellular trap formation and evade neutrophil-mediated killing. Proc Natl Acad Sci U S A 115:7416-7421
Lubkin, Ashira; Torres, Victor J (2017) Bacteria and endothelial cells: a toxic relationship. Curr Opin Microbiol 35:58-63
Roberts, Christina A; Al-Tameemi, Hassan M; Mashruwala, Ameya A et al. (2017) The Suf Iron-Sulfur Cluster Biosynthetic System Is Essential in Staphylococcus aureus, and Decreased Suf Function Results in Global Metabolic Defects and Reduced Survival in Human Neutrophils. Infect Immun 85:
Spaan, AndrĂ¡s N; van Strijp, Jos A G; Torres, Victor J (2017) Leukocidins: staphylococcal bi-component pore-forming toxins find their receptors. Nat Rev Microbiol 15:435-447
Thomsen, Isaac P; Sapparapu, Gopal; James, David B A et al. (2017) Monoclonal Antibodies Against the Staphylococcus aureus Bicomponent Leukotoxin AB Isolated Following Invasive Human Infection Reveal Diverse Binding and Modes of Action. J Infect Dis 215:1124-1131
Chapman, Jessica R; Balasubramanian, Divya; Tam, Kayan et al. (2017) Using Quantitative Spectrometry to Understand the Influence of Genetics and Nutritional Perturbations On the Virulence Potential of Staphylococcus aureus. Mol Cell Proteomics 16:S15-S28

Showing the most recent 10 out of 30 publications