Enhanced in vitro and in vivo cytotoxicity of umbilical cord blood cells against human breast cancer following activation with IL-15 and colony stimulating factors.
BACKGROUND
Cord blood mononuclear cells (MNC) are a rich source of precursor cytotoxic effector cells. Earlier we have shown that interleukin-2 (IL-2)-activated MNC from cord blood have significant cytotoxic activity against human leukemia and breast cancer cells in vitro and in vivo, compared to MNC from peripheral blood.


METHODS
In order to further improve the antitumor cytotoxic ability of cord blood MNC, IL-2 was combined with IL-15 and colony stimulating factors GMCSF, G-CSF and M-CSF for the activation. The activated cells were examined for their cytotoxic effects in vitro against human breast cancer cell lines MDA-231, MDA453 and SKB43 and in vivo against MDA-231 grown in SCID mice. Phenotypes of these activated cells were determined using flow cytometry. The expression of immune response related genes in activated cells was measured using RT-PCR techniques.


RESULTS
There was a significant increase in cytotoxicity of the effector cells activated with IL-2, IL-15 and some colony stimulating factors compared to cells activated with each of these cytokines alone or other combinations. Our results demonstrated the increase in cytotoxicity appears to be due to: 1) increase in CD56-positive cytotoxic cells; 2) cytokine/cytotoxic factors produced by the effector cells, such as Interferon-7 and Perforin; 3) stimulation by accessory cells, such as dendritic cells. In vivo administration of in vitro-activated cord blood cells into SCID mice bearing MDA-231 tumors reduced the number of metastases and increased survival compared to untreated tumor bearing controls.


CONCLUSIONS
The combination of IL-2 with IL-15 and CSF is better for the activation of cord blood effector cells than to IL-2 alone.
Lovgren
Todd R
TR
Departments of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska 68198-6395, USA.
Tarantolo
Stefano R
SR
Evans
Cody
C
Kuszynski
Charles A
CA
Joshi
Shantaram S
SS
D000818:Animals; D001943:Breast Neoplasms / Q000276:immunology* / Q000628:therapy; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D003602:Cytotoxicity, Immunologic; D004338:Drug Combinations; D053222:Fas Ligand Protein; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D019409:Interleukin-15 / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D003115:Colony-Stimulating Factors; D004338:Drug Combinations; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D019409:Interleukin-15; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D012333:RNA, Messenger; D054353:Perforin; D007371:Interferon-gamma