Effects of human umbilical cord blood mononuclear cells on ovalbumin-induced asthma in mice

BACKGROUND: Umbilical cord blood mononuclear cells (UCMNCs) show broad immune-modulation effects, which may be helpful for treating asthma. Effects of UCMNCs on asthma were investigated with mouse model in present study. METHODS: Asthma was induced in BALB/c mice by ovalbumin (OVA) immunization and challenge. Asthmatic mice were then treated on days 7 and 20 with intravenous injections of UCMNCs in doses of 4×10(5), 2×10(6), and 10(7) cells per mouse for the low-dose UCMNC (UCMNC(L)), medium-dose UCMNC (UCMNC(M)), and high-dose UCMNC (UCMNC(H)) groups, respectively. Fetal mouse blood mononuclear cells (FMMNCs) were administered to FMMNC group at a dose of 2×10(6) cells per mouse as approximate allograft control. Airway hyperresponsiveness (AHR), airway inflammation indexes, and CD4/CD8 T cell subsets were measured at day 25. RESULTS: Compared with the model group, AHR in the UCMNC(L) group, inflammation score of lung tissue in the UCMNC(M) group, interleukin (IL)-5 in bronchoalveolar lavage fluid (BALF) in UCMNC(L) group, IL-5 and IL-13 in BALF in UCMNC(M) group, and IL-17 in serum in UCMNC(H) group were significantly inhibited. Compared with the model group, CD4(+)CD8(+) T cells were reduced in the UCMNC(L) group, while decrease of CD4(−)CD8(−) T cells and increase of CD4(+)CD8(−) T cells were further strengthened in UCMNC(M) group. FMMNC treatment significantly reduced the IL-13 and IL-17 in serum, decreased CD4(−)CD8(−) and CD4(+)CD8(−) T cells, and increased the CD4(+)CD8(+) and CD4(−)CD8(+) T cells in BALF. CONCLUSIONS: UCMNCs can modulate AHR, T-helper (Th)2 inflammation, and airway injury in experimental asthma at appropriate dose.