[Effect and mechanism of RetroNectin on the proliferation and cytotoxic activity of acute leukemia natural killer cells].

OBJECTIVE: To explore the effects of precoated RetroNectin on the proliferation and cytotoxicity of natural killer cells (NK) from acute leukemia (AL). METHODS: Mononuclear cells (MNCs) were isolated from peripheral blood of complete remission AL patients. The MNCs were cultured in vitro precoated with 50 µg/ml RetroNectin (group I), 25 µg/ml RetroNectin (group II) and by the traditional method (control group) to generate NK. The changes of growth rate, phenotypic characterization, secretion of cytokines of NK, cell cycle, apoptosis and cytotoxicity of NK were determined. RESULTS: The amplification of NK in group I ((51 ± 9)×10(6)) and II ((79 ± 16) ×10(6)) were higher than that in control group ((37 ± 11)×10(6)) (both P < 0.05), and the amplification of NK in groupII was higher than that in group I (P < 0.05). There were no differences among three groups with regards to the phenotypic characterization of CD3(-)CD56(+). The secretions of interleukin 2, interleukin 12, tumor necrosis factor alpha and interferon gamma in group I and II were higher than that in control group (all P < 0.05). The expression of CD25 positive cells in groups I (38.2% ± 4.1%) and II (37.5% ± 5.1%) were higher than that in control group (24.2% ± 5.8%) (both P < 0.05). The expression of NKG2D positive cells in groups I (81.6% ± 17.9%) and II (85.7% ± 20.1%) were higher than that in control group (63.6% ± 21.9%) (both P < 0.05). The percentages of G(1) stage cells in groups I (50% ± 10%) and II (49% ± 11%) were lower than that in control group (71% ± 15%) while the percentages of S stage cells in groups I (36% ± 14%) and II (37% ± 8%) were higher than that in control group (19% ± 10%) (all P < 0.05). But no difference existed between two groups (all P > 0.05). The expression of cell cycle regulatory genes p21 and p27 were reduced in groups I and II. The percentages of apoptotic cells in groups I (10.7% ± 2.1%) and II (9.4% ± 3.1%) were lower than that in control group (29.6% ± 10.3%) (both P < 0.05). The cytotoxicity to AL cells in groups I (82% ± 21%) and II (80% ± 18%) were higher than that in control group (61% ± 14%) (both P < 0.05) at the E/T scope 20:1. But no difference existed between two groups (all P > 0.05). CONCLUSION: The proliferation and cytotoxicity of NK cells may be boosted by precoated RetroNectin.

Generation and characterization of mouse parthenogenetic embryonic stem cells containing genomes from non-growing and fully grown oocytes.

It is known that oocytes can be activated without male contribution in vitro and develop to blastocysts which are used to isolate parthenogenetic embryonic stem cells. Unfortunately, differentiation capacity of the parthenogenetic embryonic stem cells was rather lower than fertilized embryos derived ES cells, which might be the result of the absence of male genome. It had been found that some maternally expressed genes were repressed and some paternally expressed genes were expressed in the non-growing oocytes. Therefore, maternal genome from non-growing oocytes can partially act as "sperm genome". In the present study, parthenogenetic blastocysts containing genome from non-growing and fully grown oocytes (named as NF-pBlastocysts) were produced by germinal vesicle transfer, and three newly established parthenogenetic embryonic stem (named as NF-pES) cell lines were derived from the resulting parthenogenetic blastocysts. All three NF-pES cell lines were positive for ES cell markers, such as alkaline phosphatase (AKP), stage-specific embryonic antigen 1 (SSEA-1) and octamer-binding transcription factor (Oct-4). They have a normal chromosome karyotype (40) and can be maintained in an undifferentiated state for extended periods of time. When NF-pES cells were injected into severe combined immunodeficient mice, teratomas with all three embryonic germ layers were obtained. The in vitro differentiation potential of NF-pES cells was analyzed by embryonic bodies (EB) formation. The expression of germ layer markers, such as nestin (ectoderm), desmin (mesoderm), and alpha-fetoprotein (endoderm) demonstrated that the NF-pES cells can differentiate into all three germ layers.