• Food Science of Animal Resources
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• v.23 no.3
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• pp.269-277
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• 2003

This study was carried out to evaluate the safety of Korean human milk. The microorganisms were identified from human milk of 149 healthy mothers by two collection methods, hand and pump expression. The means of total bacterial counts were 2.33x10$^4$ cfu/mL on the samples collected by the pump expression and 7.83xl0$^3$ cfu/mL on those collected by the hand expression. Therefore, the total bacterial counts of pump expression samples was 9.80xl0$^2$∼3.06x10$^4$ cfu/mL more than that of hand expression samples. The coliform counts of pump expression was 9.36xl0$^3$∼8.57xl0$^4$ cfu/mL more than that of hand expression. However, there was any significant differences of the lactic acid bacterial counts between the two samples collected by each methods. 100 strains of 5 patterns of total bacterial counts were isolated based on the morphology of colony in the standard plate count agar. 13 species were identified among the isolated strains. The dominant species in Korean human milk were Staphylococcus which 7 subspecies identified(81% in the rate of total bacteria, 1.07x10$^4$ cfu/mL). Other species identified were Micrococcus, Bacillus, Providencia, Pseudomonas, Yersinia and Acinetobacter. 36 strains of 6 patterns of lactic acid bacterial counts were isolated based on morphology of colony in the BCP agar. 7 species were identified among the isolated strains. The dominant species of lactic acid bacteria in Korean human milk were Lactobacillus brevis(50.9% in the rate of lactic acid bacteria, 4.72xl0$^4$ cfu/mL). Others species identified(49.1% lactic acid bacteria) were Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus acidophilus, Leuconostic lactis and Streptococcus salivarius subsp. thermophilus.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.287-294
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• 2003

Background: In kidney transplantation, donor specific transfusion may induce tolerance as a result of some immune regulatory cells against the graft. In organ transplantation, the immune state arises from a relationship between the immunocompromised graft and the immunocompetent host. However, a reverse immunological situation exists between the graft and the host in hematopoietic stem cell transplantation (HSCT). In addition, early IL-2 injections after an allogeneic murine HSCT have been shown to prevent lethal graft versus host disease (GVHD) due to CD4+ cells. We investigated the induction of the regulatory CD4+CD25+ cells after a transfusion of irradiated recipient cells with IL-2 into a donor. Methods: The splenocytes (SP) were obtained from 6 week-old BALB/c mice ($H-2^d$) and irradiated as a single cell suspension. The donor mice (C3H/He, $H-2^k$) received $5{\times}10^6$ irradiated SP, and 5,000 IU IL-2 injected intraperitoneally on the day prior to HSCT. The CD4+CD25+ cell populations in SP treated C3H/He were analyzed. In order to determine the in vivo effect of CD4+CD25+ cells, the lethally irradiated BALB/c were transplanted with $1{\times}10^7$ donor BM and $5{\times}10^6$ CD4+CD25+ cells. The other recipient mice received either $1{\times}10^7$ donor BM with $5{\times}10^6$ CD4+ CD25- cells or the untreated SP. The survival and GVHD was assessed daily by a clinical scoring system. Results: In the MLR assay, BALB/c SP was used as a stimulator with C3H/He SP, as a responder, with or without treatment. The inhibition of proliferation was $30.0{\pm}13%$ compared to the control. In addition, the MLR with either the CD4+CD25+ or CD4+CD25- cells, which were isolated by MidiMacs, from the C3H/He SP treated with the recipient SP and IL-2 was evaluated. The donor SP treated with the recipient cells and IL-2 contained more CD4+CD25+ cells ($5.4{\pm}1.5%$) than the untreated mice SP ($1.4{\pm}0.3%$)(P<0.01). There was a profound inhibition in the CD4+CD25+ cells ($61.1{\pm}6.1%$), but a marked proliferation in the CD4+CD25- cells ($129.8{\pm}65.2%$). Mice in the CD4+CD25+ group showed low GVHD scores and a slow progression from the post-HSCT day 4 to day 9, but those in the control and CD4+CD25- groups had a high score and rapid progression (P<0.001). The probability of survival was 83.3% in the CD4+CD25+ group until post-HSC day 35 and all mice in the control and CD4+CD25- groups died on post-HSCT day 8 or 9 (P=0.0105). Conclusion: Donor graft engineering with irradiated recipient SP and IL-2 (recipient specific transfusion) can induce abundant regulatory CD4+CD25+ cells to prevent GVHD.