The B lymphocyte differentiation factor (BAFF) is expressed in the airways of children with CF and in lungs of mice infected with Pseudomonas aeruginosa.
BACKGROUND
Chronic lung infection with Pseudomonas aeruginosa remains a major cause of mortality and morbidity among individuals with CF. Expression of mediators promoting recruitment and differentiation of B cells, or supporting antibody production is poorly understood yet could be key to controlling infection.


METHODS
BAFF was measured in BAL from children with CF, both with and without P. aeruginosa, and controls. Mice were intra-nasally infected with P. aeruginosa strain LESB65 for up to 7 days. Cellular infiltration and expression of B cell chemoattractants and B cell differentiation factor, BAFF were measured in lung tissue.


RESULTS
BAFF expression was elevated in both P. aeruginosa negative and positive CF patients and in P. aeruginosa infected mice post infection. Expression of the B cell chemoattractants CXCL13, CCL19 and CCL21 increased progressively post infection.


CONCLUSIONS
In a mouse model, infection with P. aeruginosa was associated with elevated expression of BAFF and other B cell chemoattractants suggesting a role for airway B cell recruitment and differentiation in the local adaptive immune response to P. aeruginosa. The paediatric CF airway, irrespective of pseudomonal infection, was found to be associated with an elevated level of BAFF implying that BAFF expression is not specific to pseudomonas infection and may be a feature of the CF airway. Despite the observed presence of a potent B cell activator, chronic colonisation is common suggesting that this response is ineffective.
Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Daniel R
DR
Neill
Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, United Kingdom.
Gemma L
GL
Saint
Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Laura
L
Bricio-Moreno
Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Joanne L
JL
Fothergill
Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, United Kingdom.
Kevin W
KW
Southern
Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Craig
C
Winstanley
Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Stephen E
SE
Christmas
Molecular and Clinical Cancer Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom.
Joseph R
JR
Slupsky
Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, United Kingdom.
Paul S
PS
McNamara
Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
Aras
A
Kadioglu
Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, United Kingdom.
Brian F
BF
Flanagan
D000818:Animals; D053264:B-Cell Activating Factor / Q000378:metabolism*; D016022:Case-Control Studies; D054415:Chemokine CCL19 / Q000378:metabolism; D054421:Chemokine CCL21 / Q000378:metabolism; D054382:Chemokine CXCL13 / Q000378:metabolism; D002648:Child; D003550:Cystic Fibrosis / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism* / Q000382:microbiology; D008807:Mice, Inbred BALB C; D011552:Pseudomonas Infections / Q000276:immunology / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000276:immunology*
D053264:B-Cell Activating Factor; C515460:CCL19 protein, human; C515478:CCL21 protein, human; C110663:CXCL13 protein, human; D054415:Chemokine CCL19; D054421:Chemokine CCL21; D054382:Chemokine CXCL13; C505719:TNFSF13B protein, human