[Effect of CD40 on Foxp3(+) Treg cell in the lung of cigarette smoke exposure mice].
OBJECTIVE
To evaluate the effect of CD40 on Foxp3(+) Treg cell in the lung of cigarette smoke exposure mice.


METHODS
According to the random number table, 20 wild type (WT) C57 BL/6 mice and 20 CD40(-/-)C57 BL/6 mice were randomly divided into two groups: WT control group, WT smoke-exposure group (24 weeks) and CD40(-/-) control group, CD40(-/-) smoke-exposure group (24 weeks) (n=10 each). Alveolar airspace enlargement was observed by HE staining. Morphological change was evaluated by mean linear intercepts (MLI). Immunohistochemical method was used to detect the quantity of Foxp3(+) cell in the lung. The mRNA expression of Foxp3 was measured by fluorescence quantitative real-time polymerase chain reaction (qRT-PCR). The protein level of Foxp3 was measured by Western blot. Interleukin (IL)-10 and IL-35 levels in the lung were tested by enzyme-linked immunosorbent assay (ELISA).


RESULTS
The MLI in CD40(-/-) smoke-exposure group was significantly lower than the WT smoke-exposure group[(30.0±1.7) vs (37.3±3.7) μm], but higher than the CD40(-/-) control group[(23.2±2.5) μm], WT smoke-exposure group was significantly higher than the WT control group[(22.2±1.7) μm](all P<0.05). The percentage of Foxp3(+) cell in the lungs of CD40(-/-) smoke-exposure group was significantly higher than the WT smoke-exposure group and CD40(-/-) control group[(16.89±0.75)% vs (9.65±0.74)% and (13.58±0.51)%], WT smoke-exposure group was significantly lower than WT control group[(12.13±0.81)%](all P<0.05). In the lungs, Foxp3 mRNA and protein expression in CD40(-/-) smoke-exposure group were increased compared to WT-smoke-exposure group and CD40(-/-) control group, WT smoke-exposure group were decreased compared to WT control group (all P<0.05). In the lungs, the level of IL-10 in CD40(-/-) smoke-exposure group was higher than the WT smoke-exposure group and CD40(-/-) control group[(231±25) vs (80±31) and (183±29) ng/L], WT smoke-exposure group was lower than the WT control group[(192±37) ng/L](all P<0.05). The level of IL-35 in CD40(-/-) smoke-exposure group was higher than the CD40(-/-) control group, WT control group and WT smoke-exposure group[(208±29) vs (118±29) , (148±36), (137±37) ng/L, all P<0.05].


CONCLUSIONS
Knockout the CD40 gene can promote the differentiation of Foxp3(+) Treg cell in the lung of cigarette smoke exposure mice, indicating that blocking the CD40-CD40 ligand pathway may contribute to alleviate the smoking-induced pulmonary emphysema.
Department of Respiratory Diseases, First Affiliated Hospital, Guangxi Medical University, Nanning 530021, China.
T T
TT
Deng
X N
XN
Zhong
Q
Q
Wang
L J
LJ
Kuang
S L
SL
Qiu
Y
Y
Liang
Z Y
ZY
He
J Q
JQ
Zhang
J
J
Bai
D000818:Animals; D019013:CD40 Antigens; D002454:Cell Differentiation; D004797:Enzyme-Linked Immunosorbent Assay; D051858:Forkhead Transcription Factors / Q000235:genetics* / Q000378:metabolism; D016753:Interleukin-10 / Q000097:blood / Q000378:metabolism; D008168:Lung / Q000503:physiopathology; D051379:Mice; D018345:Mice, Knockout; D011656:Pulmonary Emphysema / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction; D012906:Smoke; D012907:Smoking / Q000009:adverse effects; D050378:T-Lymphocytes, Regulatory; D014026:Nicotiana; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D019013:CD40 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; C508609:IL10 protein, human; D012906:Smoke; D014028:Tobacco Smoke Pollution; D016753:Interleukin-10