[Enhancement of antigen presenting function of dendritic cells by IL-2 gene modification and its mechanism].
OBJECTIVE
To investigate the effects of IL-2 gene modification enhancement of the antigen-presenting function of the mouse bone marrow derived dendritic cells and on the activation of CTL induced by MHC class I molecule restricted antigen peptides as well as the related immunological mechanisms.


METHODS
DCs were prepared from mouse bone marrow and modified by recombinant IL-2 adenovirus (DC-IL-2). The IL-12 and IFN-gamma levels in culture supernatant of DC and CTL were examined by ELISA, the expression of costimulatory molecules and fluorescent intensity of endocytosis of OVA-FITC in DC by FACS, the capacity of presenting 3LL cell tumor antigen by (3)H-TdR incorporation method, the MHC class I-restricted tumor-antigen-peptide Mut1 of 3LL cells pulsed DC-IL-2 to induce CTL cytotoxicity by (51)Cr 4-hr releasing assay.


RESULTS
After IL-2 gene modification, DC-IL-2 could produce high level of IL-12 [(78.4 +/- 6.6) pg.(1 x 10(6) cells)(-1).ml(-1)]. The expression of costimulatory molecules on DC-IL-2 was increased, the fluorescent intensity of DC captured OVA-FITC was enhanced, and the proliferation of allo-T cells from 3LL bearing mouse pulsed with Mut1 was also enhanced. Mut1 antigen peptide pulsed DC-IL-2 could induce more potent antigen-specific CTL cytotoxicity and excrete high concentration of IFN-gamma [(1 168 +/- 58.4) pg/ml] in vivo.


CONCLUSIONS
IL-2 gene modification of DC can activate second signal for DC presenting antigen, and enhance the function for capturing and presenting tumor antigen. DC-IL-2 pulsed with MHC class I restricted tumor-antigen-peptide can induce specific anti-tumor immune response more effectively. Owing to IL-2 gene modification, the functions of IL-12 excretion and T cell activation of DC were promoted, so that the capacity of CTL excreting IFN-gamma was enhanced, which are relevant to the immune mechanism.
No. 148 Hospital, Tumor Treatment Center of Jinan Military Area, Zibo 255300, China.
Lifei
L
Sun
Jiang
J
Liu
Xuetao
X
Cao
Minghui
M
Zhang
Yihong
Y
Zhou
Bin
B
Liu
Hua
H
Shi
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D018122:B7-1 Antigen / Q000235:genetics / Q000378:metabolism*; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005260:Female; D018664:Interleukin-12 / Q000378:metabolism*; D007376:Interleukin-2 / Q000235:genetics*; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D011995:Recombination, Genetic / Q000235:genetics* / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology
D018122:B7-1 Antigen; D007376:Interleukin-2; D018664:Interleukin-12