Functional evaluation of ex vivo expanded cord blood lymphocytes: possible use for adoptive cellular immunotherapy.
OBJECTIVE
To examine the possibility of adoptive cellular immunotherapy such as donor lymphocyte infusion using ex vivo expanded cord blood (CBL) lymphocytes, the potential expansion ability of CBL lymphocytes and the function of expanded CBL lymphocytes were evaluated.


METHODS
Mononuclear cell fractions derived from CBL or peripheral blood (PBL) were placed in anti-CD3 monoclonal antibody-coated flasks and cultured in the presence of recombinant human interleukin-2 for 4 days. Cells then were transferred to noncoated flasks and cultured for another 2 weeks. On day 14, polyclonality, cell surface markers, killer activity, and intracellular cytokine profiles were evaluated.


RESULTS
Cells were polyclonally expanded. The differences in cumulative fold expansion on day 14 between CBL [1174 +/- 637 (292-1939), n = 6] and PBL [1247 +/- 568 (517-2328), n = 9] were not significant (p = 0.95). Phenotypic patterns of both expanded CBL and PBL were similar. CD4/CD8 ratio of expanded CBL appeared to remain greater than 1 on day 8. In contrast, that of expanded PBL became less than 1. In both cases, approximately 20% of cells had the CD3(+)CD8(+)CD56(+) phenotype. At an effector to target ratio (E/T) of 40:1, the natural killer activity of expanded CBL (64.5% +/- 10.8%, n = 9) was significantly higher than that of expanded PBL (48.3% +/- 16.8%, n = 9) (p < 0.01, Mann-Whitney U-test). However, there was no significant difference in lymphokine-activated killer activity between expanded CBL (45.3% +/- 25.2%, n = 7) and expanded PBL (67.2% +/- 12.3%, n = 7). Interferon-gamma-producing cells were dominant in both cases.


CONCLUSIONS
It was feasible to achieve approximately 1000-fold expansion of CBL, and the phenotype and function of expanded CBLs were essentially equivalent to those of expanded PBL. This suggested that ex vivo expanded CBL may be applied to adoptive cellular immunotherapy such as donor lymphocyte infusion.
Azuma
Hiroshi
H
Hokkaido Red Cross Blood Center, Yamanote 2-2 Nishi-ku, Sapporo 063-0002, Japan. azuma@hokkaido.bc.jrc.or.jp
Yamada
Yoshiko
Y
Shibuya-Fujiwara
Nobuko
N
Yamaguchi
Miki
M
Murahashi
Hideaki
H
Fujihara
Mitsuhiro
M
Sato
Norihiro
N
Fukazawa
Keiko
K
Ikebuchi
Kenji
K
Ikeda
Hisami
H
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000032:analysis; D017252:CD3 Complex / Q000276:immunology; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive / Q000379:methods; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology; D008214:Lymphocytes / Q000166:cytology* / Q000276:immunology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D017252:CD3 Complex; D016207:Cytokines; D007376:Interleukin-2