[Identification of mouse dentritic cells expanded in vivo by combined over-expression of Flt3-L with GM-CSF].
OBJECTIVE
To establish a method to expand dentritic cells (DC) in vivo by combined Flt3-L-expressing plasmid with GM-CSF-expressing plasmid and to analyze their function in antigen presenting.


METHODS
Flt3-L and GM-CSF expressing DNAs were injected into the tail veins of BALB/c mice on day 0 and day 10 respectively. The spleens were harvested on day 15 and the splenocytes were prepared to analyze the percentage of CD11c, CD11b, B220, CD8, and NK1. 1 positive cells by FACS. The splenocytes from HBsAg-vaccinated mice were simulated in vitro with DC pre-incubated with HBsAg and then IFN-gamma in supernatant after simulation was detected by ELISA.


RESULTS
Combined injection of Flt3-L-expressing plasmid with GM-CSF-expressing plasmid resulted in dramatic plednomegaly in mice. Averagely 4 x 10(8) splenocytes were harvested from the expanded spleen of each mouse, more than 20% of which were CD11c(+) DC. Among CD11C(+) splenocytes, 17% of CD11B(+) cells, 10% of CD11b(-) cells, 26% of B220(+) cells, 16% of CD8(+) cells and 7% of NK1.1(+) cells were detected respectively. When loaded with HBsAg, Flt3-L/GM-GSF DC could stimulate HBsAg-primed splenocytes to secrete much higher IFN-gamma than DC or HBsAg alone.


CONCLUSIONS
Combined intravenous injection of Flt3-L-expressing plasmid with GM-CSF-expressing plasmid could in vivo expand dentritic cells which seemed to have many subsets and were able to present antigens to antigen special T cells in vitro.
Su
Shu
S
Department of Microbiology and Immunology, School of Medical Science, Southeast University, Nanjing 210009, China.
Xue
Meng
M
Cao
Meng
M
Wang
Li-xin
LX
D000818:Animals; D000950:Antigens, Ly / Q000276:immunology; D039481:CD11b Antigen / Q000276:immunology; D039521:CD11c Antigen / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism*; D017493:Leukocyte Common Antigens / Q000276:immunology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D055651:NK Cell Lectin-Like Receptor Subfamily B / Q000276:immunology; D010957:Plasmids
D000950:Antigens, Ly; D039481:CD11b Antigen; D039521:CD11c Antigen; D016827:CD8 Antigens; C527211:Klrb1c protein, mouse; D008565:Membrane Proteins; D055651:NK Cell Lectin-Like Receptor Subfamily B; C084881:flt3 ligand protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D017493:Leukocyte Common Antigens