TITLE:
The effect of Panton Valentin Leukocidin (PVL) on the airway smooth muscle viability
AUTHORS:
Rodopi Stamatiou, Efthimia Petinaki, Apostolia Hatziefthimiou
KEYWORDS:
Staphylococcus Aureus; PVL; Airway Smooth Muscle Cells
JOURNAL NAME:
Open Journal of Molecular and Integrative Physiology,
Vol.3 No.1,
February
22,
2013
ABSTRACT: Methicillin-resistant Staphylococcus aureus (MRSA) is
recognized as a worldwide pathogen, and the incidence of community-acquired
infections (CA-MRSA) is increased. A virulence factor has been found in most
CA-MRSA infections, the Panton-Valentin leukocidin (PVL), which causes
polymorphonuclear leukocytes lysis and acute uncontrolled inflammation and tissue injury. In this study we investigated the effect of bacterial supernatant of PVL
positive or negative strains on airway smooth muscle obtained from rabbit trachea.
MRSA that carry the PVL-gene, confirmed by PCR, is cultured on GP agar and colonies were transferred into casein casein yeast extract medium. The culture
supernatants were removed after centrifugation and the presence of PVL was
confirmed using an immunochromatographic test. Rabbit tracheal ASMC were isolated and incubated with
PVL positive or negative bacterial supernatant (1:20 - 1:2000)
for 1 - 3 days. The effect of PVL on the ASMC morphology or viability
was estimated using microscope observations or indirect immunofluores- cence
with anti-Smooth muscle α-actin antibody and Dapi for DNA staining, and Trypan
blue staining, respectively. ASMC incubated with PVL exhibit increased cell
size, granular cytoplasm, and ruptured nuclei. Furthermore, PVL reduces cell
number mainly in ASMC incubated in the presence of 10% FBS, therefore actively
proliferating cells. These results show that apart from the known effect of
PVL on immune cells and inflammation process, PVL has a direct toxic effect on
airway smooth muscle cells.