Kinetics of cytokine gene expression during the in vitro CTL induction against a murine nonimmunogenic tumor.
BACKGROUND
The study of the local environment around tumors, including cellular and endogenous cytokine kinetics may improve our understanding of the biological process occurring during the CTL induction.


METHODS
The expression kinetics of ten cytokine genes and immune cell subsets were examined by a RT-PCR and immunohistochemistry using a nonimmunogenic murine tumor and its immunogenic variant (A7).


RESULTS
In a mixed lymphocyte-parent tumor cell culture (MLTC) using in vivo A7-immunized spleen cells, where CTL induction was confirmed on day 5 of cultivation, IL-6 gene expression was promptly activated at 12 h, IL-2 and IL-4 gene expression was prominently up-regulated on days 1 and 2, and then IL-10 and TGF-beta gene expression was down-regulated from day 2 onward. In contrast, in a MLTC using non-immunized spleen cells (a CTL non-induction model), no prominent upregulation of the IL-6, IL-2 or IL-4 gene was detected, and expression of the IL-10 and TGF-beta genes increased steadily. Although numerous dendritic cells were observed in the A7 immunized spleen tissue, lower numbers of dendritic cells were evident in the non-immunized spleen tissue.


CONCLUSIONS
A cellular environment that includes the presence of dendritic cells and a cytokine environment that involves the timely production of IL-6, IL-2, and IL-4, and subsequent inhibition of the immunosuppressive cytokines IL-10 and TGF-beta, appear to play an important role in induction of CTL in this model.
Murata
S
S
First Department of Surgery, Shiga University of Medical Science, Japan. satoshi1@belle.shiga-med.ac.jp
Eguchi
Y
Y
Mekata
E
E
Tani
T
T
Kodama
M
M
D000818:Animals; D019496:Cancer Vaccines / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D005354:Fibrosarcoma / Q000276:immunology* / Q000473:pathology; D005786:Gene Expression Regulation / Q000276:immunology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D007114:Immunization; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000235:genetics; D007378:Interleukins / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation / Q000235:genetics*; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000276:immunology
D019496:Cancer Vaccines; D016207:Cytokines; D007378:Interleukins; D016212:Transforming Growth Factor beta; D008769:Methylnitronitrosoguanidine; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor