Expansion of natural killer cell receptor (CD94/NKG2A)-expressing cytolytic CD8 T cells and CD4+CD25+ regulatory T cells from the same cord blood unit.
OBJECTIVE
Cord blood contains a significant number of precursor cells that differentiate to cytotoxic effector cells and immunoregulatory cells. We tried to expand inhibitory natural killer cell receptor CD94-expressing CD8 T cells with cytolytic activity and CD4(+)CD25(+) regulatory T cells from the same cord cell unit.


METHODS
Cytotoxic CD94-expressing CD8 T cells were expanded from CD4-depleted cord blood using an immobilized anti-CD3 monoclonal antibody and a cytokine and also CD4(+)CD25(+) regulatory T cells were expanded from a CD4-enriched fraction derived from the same cord blood unit using anti-CD3/CD28 monoclonal antibody-coated Dynabeads and cytokines.


RESULTS
We were able to obtain a more than 1000-fold expansion of CD94-expressing CD8 T cells and a more than 50-fold expansion of CD4(+)CD25(+) cells from the same cord blood unit. These expanded CD4(+)CD25(+) cells expressed FoxP3 mRNA at a level about 100-fold higher than that in isolated CD25(-) cells and could suppress allogeneic mixed lymphocyte culture by >80% (effector cells: CD4(+)CD25(+) cells = 2:1). Cytolytic activities of purified CD94-expressing cells detected by a 4-hour (51)Cr release assay against K562 were >60%. Coculture of CD94-expressing cells with expanded CD4(+)CD25(+) cells did not have any effect on cytolytic activities of purified CD94-expressing cells against K562 cells.


CONCLUSIONS
These expanded cytolytic CD94-expressing CD8 cells might be able to induce a graft-vs-leukemia effect without enhancing graft-vs-host disease, and CD4(+)CD25(+) cells might be able to suppress allogeneic responses, including graft-vs-host disease and graft rejection after cord blood transplantation.
Department of Hematology and Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan. jutanaka@med.hokudai.ac.jp
Junji
J
Tanaka
Junichi
J
Sugita
Naoko
N
Kato
Tomomi
T
Toubai
Makoto
M
Ibata
Yusuke
Y
Shono
Shuichi
S
Ota
Takeshi
T
Kondo
Takahiko
T
Kobayashi
Masanobu
M
Kobayashi
Masahiro
M
Asaka
Masahiro
M
Imamura
D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D036101:Cord Blood Stem Cell Transplantation; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000276:immunology; D006086:Graft vs Host Disease / Q000276:immunology / Q000517:prevention & control; D020544:Graft vs Leukemia Effect / Q000276:immunology; D006801:Humans; D020014:K562 Cells; D008212:Lymphocyte Depletion; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D / Q000096:biosynthesis* / Q000276:immunology; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000276:immunology; D055607:Receptors, Natural Killer Cell; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D014184:Transplantation, Homologous
C527054:KLRC1 protein, human; C497869:KLRD1 protein, human; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell