title: 4-1BB functions as a survival factor in dendritic cells.
abstract: 4-1BB (CD137) is expressed on dendritic cells (DCs) and its biological function has remained largely unresolved. By comparing 4-1BB-intact (4-1BB(+/+)) and 4-1BB-deficient (4-1BB(-/-)) DCs, we found that 4-1BB was strongly induced on DCs during the maturation and that DC maturation was normal in the absence of 4-1BB. However, DC survival rate was low in the absence of 4-1BB, which was due to the decreased Bcl-2 and Bcl-x(L) in 4-1BB(-/-) DCs compared with 4-1BB(+/+) DCs after DC maturation. Consistent with these results, 4-1BB(-/-) DCs showed an increased turnover rate in steady state and more severely decreased in spleen by injecting LPS compared with 4-1BB(+/+) DCs. When OVA-pulsed DCs were adoptively transferred to recipient mice along with OVA-specific CD4(+) T cells, 4-1BB(-/-) DCs did not properly migrate to the T cell zone in lymph nodes and poorly induced proliferation of CD4(+) T cells, although both DCs comparably expressed functional CCR7. Eventually, 4-1BB(-/-) DCs generated a reduced number of OVA-specific memory CD4(+) T cells compared with 4-1BB(+/+) DCs. To further assess the role of 4-1BB on DC longevity in vivo, 4-1BB(+/+) and 4-1BB(-/-) C57BL/6 were administrated with Propionibacterium acnes that develop liver granuloma by recruiting DCs. Number and size of granuloma were reduced in the absence of 4-1BB, but the inflammatory cytokine level was comparable between the mice, which implied that the granuloma might be reduced due to the decreased longevity of DCs. These results demonstrate that 4-1BB on DCs controls the duration, DC-T interaction, and, therefore, immunogenicity.
authors.affiliation: R&D Center for Cancer Therapeutics, National Cancer Center, Ilsan, Korea.
authors.forename: Beom K
authors.initials: BK
authors.lastname: Choi
authors.forename: Young H
authors.initials: YH
authors.lastname: Kim
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Kwon
authors.forename: Sang C
authors.initials: SC
authors.lastname: Lee
authors.forename: Sang W
authors.initials: SW
authors.lastname: Kang
authors.forename: Moon S
authors.initials: MS
authors.lastname: Kim
authors.forename: Myoung J
authors.initials: MJ
authors.lastname: Lee
authors.forename: Byoung S
authors.initials: BS
authors.lastname: Kwon
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002470:Cell Survival / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D005434:Flow Cytometry; D015870:Gene Expression; D019254:Genes, bcl-2; D016908:Gram-Positive Bacterial Infections / Q000276:immunology; D006099:Granuloma / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D008099:Liver / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D011425:Propionibacterium acnes; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9 / Q000276:immunology* / Q000378:metabolism*; D051020:bcl-X Protein / Q000096:biosynthesis / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D051020:bcl-X Protein