Putative IKDCs are functionally and developmentally similar to natural killer cells, but not to dendritic cells.
Interferon-producing killer dendritic cells (IKDCs) have been described as possessing the lytic potential of NK cells and the antigen-presenting capacity of dendritic cells (DCs). In this study, we examine the lytic function and antigen-presenting capacity of mouse spleen IKDCs, including those found in DC preparations. IKDCs efficiently killed NK cell targets, without requiring additional activation stimuli. However, in our hands, when exposed to protein antigen or to MHC class II peptide, IKDCs induced little or no T cell proliferation relative to conventional DCs or plasmacytoid DCs, either before or after activation with CpG, or in several disease models. Certain developmental features indicated that IKDCs resembled NK cells more than DCs. IKDCs, like NK cells, did not express the transcription factor PU.1 and were absent from recombinase activating gene-2-null, common gamma-chain-null (Rag2(-/-)Il2rg(-/-)) mice. When cultured with IL-15 and -18, IKDCs proliferated extensively, like NK cells. Under these conditions, a proportion of expanded IKDCs and NK cells expressed high levels of surface MHC class II. However, even such MHC class II(+) IKDCs and NK cells induced poor T cell proliferative responses compared with DCs. Thus, IKDCs resemble NK cells functionally, and neither cell type could be induced to be effective antigen-presenting cells.
Caminschi
Irina
I
Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, 3050, Australia. caminschi@wehi.edu.au
Ahmet
Fatma
F
Heger
Klaus
K
Brady
Jason
J
Nutt
Stephen L
SL
Vremec
David
D
Pietersz
Suzanne
S
Lahoud
Mireille H
MH
Schofield
Louis
L
Hansen
Diana S
DS
O'Keeffe
Meredith
M
Smyth
Mark J
MJ
Bedoui
Sammy
S
Davey
Gayle M
GM
Villadangos
Jose A
JA
Heath
William R
WR
Shortman
Ken
K
D000818:Animals; D003713:Dendritic Cells / Q000145:classification / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D016130:Immunophenotyping; D039421:Integrin alpha2 / Q000032:analysis / Q000276:immunology; D007372:Interferons / Q000096:biosynthesis* / Q000276:immunology; D007694:Killer Cells, Natural / Q000145:classification / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000032:analysis / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D000949:Histocompatibility Antigens Class II; D039421:Integrin alpha2; D007372:Interferons; D017493:Leukocyte Common Antigens