Non-typeable Haemophilus influenzae decreases cilia beating via protein kinase Cε.
BACKGROUND
Haemophilus influenzae infection of the nasal epithelium has long been associated with observations of decreased nasal ciliary beat frequency (CBF) and injury to the ciliated epithelium. Previously, we have reported that several agents that slow CBF also have the effect of activating protein kinase C epsilon (PKCε) activity in bronchial epithelial cells. The subsequent auto-downregulation of PKCε or the direct inhibition of PKCε leads to the specific detachment of the ciliated cells.


METHODS
Primary cultures of ciliated bovine bronchial epithelial cells were exposed to filtered conditioned media supernatants from non-typeable H. influenzae (NTHi) cultures. CBF and motile points were measured and PKCε activity assayed.


RESULTS
NTHi supernatant exposure significantly and rapidly decreased CBF in a dose-dependent manner within 10 minutes of exposure. After 3 hours of exposure, the number of motile ciliated cells significantly decreased. Direct measurement of PKCε activity revealed a dose-dependent activation of PKCε in response to NTHi supernatant exposure. Both CBF and PKCε activity changes were only observed in fresh NTHi culture supernatant and not observed in exposures to heat-inactivated or frozen supernatants.


CONCLUSIONS
Our results suggest that CBF slowing observed in response to NTHi is consistent with the stimulated activation of PKCε. Ciliated cell detachment is associated with PKCε autodownregulation.
Department of Epidemiology, College of Public Health, University of Nebraska Medical Center, Omaha, NE 68198-5910, USA.
Kristina L
KL
Bailey
Tricia D
TD
LeVan
Daniel A
DA
Yanov
Jaqueline A
JA
Pavlik
Jane M
JM
DeVasure
Joseph H
JH
Sisson
Todd A
TA
Wyatt
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002923:Cilia / Q000187:drug effects / Q000201:enzymology* / Q000821:virology; D017077:Culture Media, Conditioned / Q000494:pharmacology; D015536:Down-Regulation / Q000502:physiology*; D006193:Haemophilus influenzae; D006801:Humans; D051744:Protein Kinase C-epsilon / Q000502:physiology*; D020545:Respiratory Mucosa / Q000201:enzymology* / Q000821:virology
D017077:Culture Media, Conditioned; D051744:Protein Kinase C-epsilon