Effects of antigen presentation of eosinophils on lung Th1/Th2 imbalance.
BACKGROUND
Antigen-loaded eosinophils (EOSs) instilled intratracheally into mice were capable of inducing Th2-type cytokine production in the draining lymph nodes. The aim of the present study was to evaluate whether EOSs within the tracheobronchial lumen can stimulate Th2 cell expansion in the lung tissues.


METHODS
Airway EOSs were recovered from ovalbumin-sensitized and -challenged BALB/c mice, these EOSs were then cocultured with CD4+ cells isolated from sensitized mice in the absence or presence of anti-CD80 or/and -CD86 monoclonal antibodies. Airway EOSs were instilled into the trachea of sensitized mice. At the day 3 thereafter, the lung tissues were removed and prepared into cell suspensions for culture. Cell-free culture supernatants were collected for detection of cytokines.


RESULTS
Airway EOSs functioned as CD80- and CD86-dependent antigen-presenting cells to stimulate lung CD4+ lymphocytes to produce interleukin-4, interleukin-5 and interleukin-13, but not interferon-gamma in in vitro assay. When instilled intratracheally in sensitized recipient mice, airway EOSs primed lung Th2 cells in vivo for interleukin-4, interleukin-5 and interleukin-13, but not interferon-gamma, production during the in vitro culture that was also CD80- and CD86-dependent.


CONCLUSIONS
EOSs within the lumina of airways could process inhaled antigen and function in vitro and in vivo as antigen-presenting cells to promote expansion of Th2 cells in the lungs.
Xie
Zheng-fu
ZF
Departments of Respiratory and Critical Care Medicine, First Affiliated Hospital, Guangxi Medical University, Nanning 530021, China.
Shi
Huan-zhong
HZ
Qin
Xue-jun
XJ
Kang
Lan-fu
LF
Huang
Chun-ping
CP
Chen
Yi-qiang
YQ
D000818:Animals; D017951:Antigen Presentation; D015703:Antigens, CD / Q000502:physiology; D018122:B7-1 Antigen / Q000502:physiology; D051940:B7-2 Antigen; D016207:Cytokines / Q000096:biosynthesis; D004804:Eosinophils / Q000502:physiology*; D005260:Female; D008168:Lung / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D016207:Cytokines; D008562:Membrane Glycoproteins