Attenuation of toll-like receptor 2-mediated innate immune response in patients with alcoholic chronic liver disease.
BACKGROUND
Alcoholic chronic liver disease (ACLD) is a common form of acquired immunodeficiency.


OBJECTIVE
To evaluate ex vivo toll-like receptor (TLR) 2 and TLR4 innate immune response in stable ACLD.


METHODS
Blood was collected from 26 males with stable ACLD and from 17 controls. Serum was used for lipopolysaccharide (LPS), sCD14, LPS-binding protein (LBP), tumour necrosis factor-alpha (TNF-alpha) and interleukin 10 (IL-10) quantification. Peripheral blood monocytes (PBM) protein expression of TLR2 and TLR4 was determined by flow cytometry. Primary cultures of anti-CD11b positive selected PBM were stimulated with the TLR2/TLR6 ligand zymosan (Zym), with TLR2/TLR1 ligand lipopeptide (Lp) and with TLR4 ligand LPS. PBM TLR1, TLR2, TLR4, TLR6, MD2, CD14, TNF-alpha and IL-10 gene expression was evaluated by reverse transcription-polymerase chain reaction.


RESULTS
Stable ACLD patients showed increased circulating LPS (+22.5+/-4.1%), LBP (+60.6+/-12.2%) and sCD14 (+23.5+/-4.6%), with no differences in TNF-alpha and IL-10. Zym and Lp, but not LPS, induced TNF-alpha production by monocytes was blunted in ACLD (-66+/-20.4% Zym; -40.1+/-13.5% Lp; P<0.05). Basal TNF-alpha mRNA expression was decreased in PBM from ACLD patients (-50.1+/-21.0%; P<0.05), with no significant differences in the other studied genes. Results were similar in Child-Pugh A and B/C patients.


CONCLUSIONS
Patients with stable ACLD show an attenuation of TLR2-mediated innate immune response in PBM, which may represent an important mechanism for acquired immunodeficiency. This was neither related with decreased TLR2 or its co-receptors expression nor with impaired TLR4 activation, being already present in the early stages of disease.
Pimentel-Nunes
Pedro
P
Department of Physiology, Cardiovascular Research & Development Unit, Faculty of Medicine, University of Porto, Porto, Portugal.
Roncon-Albuquerque
Roberto
R
Gonçalves
Nádia
N
Fernandes-Cerqueira
Cátia
C
Cardoso
Hélder
H
Bastos
Rui Pedro
RP
Marques
Margarida
M
Marques
Cristina
C
Alexandre Sarmento
José
J
Costa-Santos
Carlos
C
Macedo
Guilherme
G
Pestana
Manuel
M
Dinis-Ribeiro
Mário
M
Leite-Moreira
Adelino F
AF
D000209:Acute-Phase Proteins; D002352:Carrier Proteins / Q000097:blood; D016022:Case-Control Studies; D002478:Cells, Cultured; D002908:Chronic Disease; D015536:Down-Regulation; D020869:Gene Expression Profiling; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D016753:Interleukin-10 / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology*; D055666:Lipopeptides / Q000494:pharmacology; D018950:Lipopolysaccharide Receptors / Q000097:blood; D008070:Lipopolysaccharides / Q000494:pharmacology; D008108:Liver Diseases, Alcoholic / Q000276:immunology*; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood; D008875:Middle Aged; D011174:Portugal; D012333:RNA, Messenger / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000819:agonists / Q000097:blood* / Q000235:genetics; D051197:Toll-Like Receptor 4 / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D015054:Zymosan / Q000494:pharmacology; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D016753:Interleukin-10; D055666:Lipopeptides; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D015054:Zymosan; D000099231:Lipopolysaccharide-Binding Protein; C508609:IL10 protein, human; C495342:TLR2 protein, human; C495345:TLR4 protein, human