[Analysis of in vitro delivering CD8+ T epitopes by attenuated bacteria].
OBJECTIVE
To analyze the efficiency of delivery for CD8(+) T cell epitopes by recombinant bacteria vectors.


METHODS
The recombinant E. coli strain 13A or 25A and recombinant Salmonella typhimurium strain SL7207 expressing CD8(+) T cell epitopes of Lymphocytic Choriomeningitis Virus (LCMV) and Ovalbumin (OVA), which were fused with green fluorescent protein (GFP) marker at the C-terminal, were infected into LK(b) cells, LL(d) cells or bone marrow dendritic cells (BMDC). The efficiency of presentation for CD8(+) T cell epitopes by recombinant bacteria was analyzed by in vitro antigen presentation assay.


RESULTS
After the infection of LK(b) cells, LL(d) cells or BMDC by recombinant bacteria, about 90% of cells were GFP positive. The results indicated that attenuated strain 13A, 25A and SL7207 had better invasive capacity to LK(b) and LL(d) cells, while BMDC had stronger capacity for uptaking recombinant bacteria. At 2 h post infection, CD8(+) T cell epitopes presented on the surface of those LK(b), LL(d) and BMDC cells infected by 13A (ptG2F) and SL7207(ptG2F) could be recognized by B3Z or nV1H7 T hybridoma cells, which were specific for OVA peptide p257-264 or LCMV peptide p118-132, respectively. But the efficiency of presentation for OVA or LCMV CD8(+) T cell epitope was decreased or increased respectively at 48 h post infection. However, LK(b), LL(d) and BMDC cells infected by 25A (ptG2F) did not effectively stimulate the specific B3Z or nV1H7 T cells. Furthermore, the presentation efficiency of BMDC was higher than those of LK(b) and LL(d) cells under the same condition.


CONCLUSIONS
CD8(+) T cell epitopes can be delivered and presented to T lymphocytes by APC by attenuated bacteria in vitro.
Pan
Zhi-Ming
ZM
Animal Infectious Diseases Laboratory of Ministry of Agriculture, Yangzhou University, Yangzhou 225009, China. zmpan@yzu.edu.cn
Zhang
Xiao-Ming
XM
Jiao
Xin-An
XA
Lo-Man
Richard
R
Leclerc
Claude
C
Liu
Xiu-Fan
XF
D000818:Animals; D017951:Antigen Presentation; D001853:Bone Marrow / Q000276:immunology / Q000382:microbiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D004274:DNA, Recombinant / Q000235:genetics / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000382:microbiology; D004527:Egg Proteins / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000235:genetics* / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics*; D005260:Female; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics; D007700:Kinetics; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D012486:Salmonella typhimurium / Q000235:genetics*
D004274:DNA, Recombinant; D004527:Egg Proteins; D018984:Epitopes, T-Lymphocyte; D049452:Green Fluorescent Proteins