Comparison of the Tumor-forming Rate between the SCID and NOD/SCID Mice used to Set up Acute Myeloid Leukemia Model / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To compare the tumor-forming rate between the SCID and NOD/SCID mice to set up acute myeloid leukemia (AML) mouse model.</p><p><b>METHODS</b>The SCID and NOD/SCID mice were injected with HL-60 cells in to the abdominal cavity in order to contruct the AML mouse model. The gereral status of mice was observed, the positive rate of CD33 in bone marrow cells was detected by flow cytometry, the mouse model was identified by pathologic examination.</p><p><b>RESULTS</b>The tumor-forming rate in constructed model using SCID mouse was 30%, while the tumor-forming rate in constructed model using NOD/SCID mouse was 100%.</p><p><b>CONCLUSION</b>Compared with SCID mice, the tumor-forming rate in NOD/SCID mice injected with HL-60 cells is high, the incidence of AML is stable, suggesting that the NOD/SCID mouse model is more suitable to explore the pathogenesis of leukemia.</p>

MUC1-2VNTR DNA Vaccine Induces Immune Responses in Mouse Model with Multiple Myeloma / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the humoral and cellular immune responses induced by MUC1-2VNTR DNA vaccine in multiple myeloma (MM) tumor-bearing mice.</p><p><b>METHODS</b>In vitro, multiple myeloma cells were transfected by plasmid pcDNA3.1-2VNTR/myc-hisB with Lipofectamine2000. The above-mentioned mouse myeloma cells were inoculated subcutaneously into female BALB/c mice for establishing tumor-bearing animal models. These female BALB/c mice were immunized with pcDNA-2VNTR/myc-hisB or pcDNA/myc-hisB. The cytotoxic T lymphocyte (CTL) activity was detected by the LDH method and the spleen lymphocyte proliferation activity was detected by CCK-8 method.</p><p><b>RESULTS</b>After immunization of BALB/c tumor-bearing mice with recombinant plasmid for 25 days, the tumor mass (0.5605 ± 0.2065 g) was significantly lighter than that in the empty plasmid control group (1.521 ± 0.6985 g) (P < 0.01) and the control group (1.5315 ± 0.5425 g) (P < 0.01). The difference of tumor mass was not statislically significant between empty plasmid control group (1.521 ± 0.6985 g) and the control group (1.5315 ± 0.5425 g) (P > 0.05). The CTL and NK cell activity was significantly higher in the group of intramuscular injection with recombinant plasmid than that in control group. The spleen lymphocyte proliferation was statistically significantly increased after being immunized with recombinant plasmid pcDNA3.1-2VNTR/myc-hisB, compared with empty vector (P < 0.01). The results showed that MUC1-2VNTR gene immunization could induce anti-tumor effect in MM tumor-bearing mice.</p><p><b>CONCLUSION</b>MUC1-2VNTR DNA immunization can elicit both humoral and cellular tumor specific immune response to multiple myeloma in MM tumor-bearing mice. It suggested that the MUC1-2VNTR DNA vaccine may be a potential treatment measure for patients with MM.</p>

A novel diagnostic measure of platelet-specific antibody in immune thrombocytopenia / 中华血液学杂志

<p><b>OBJECTIVE</b>To detect the platelet glycoprotein-specific antibodies in serum of thrombocytopenia patients and evaluate its diagnostic value for immune thrombocytopenia.</p><p><b>METHOD</b>Anti-GPIIb/IIIa, GPIb/IX and GPIa/IIa antibodies were assayed by ELISA kit (PAKUTO) in patients with thrombocytopenia.</p><p><b>RESULTS</b>The sensitivity and specificity of PAKAUTO in immune thrombocytopenia were 44.0% and 95.7%, respectively. The values of positive and negative predictions were 98.0% and 26.2%, respectively. Among those PAKAUTO positive patients, positive rates of GPIIb/IIIa, GPIa/IIa and GPIb/IX were 87%, 35% and 10%, respectively. The positive rate of patients not received immune suppressive agents (58.5%) was significantly higher than those received immune suppressive agents (26.9%) (P < 0.01). The positive rate of patients with platelet count ≤ 20 × 10(9)/L (51.6%) was significantly higher than those with platelet count > 20 × 10(9)/L (27.8%) (P < 0.01). The positive rate of patients with secondary immune thrombocytopenia (66.7%) was significantly higher than those with primary immune thrombocytopenia (41.7%) (P < 0.05).</p><p><b>CONCLUSION</b>The highly specific method (PAKAUTO) could effectively differentiate immune or non-immune thrombocytopenia and be applied to diagnosis of immune thrombocytopenia.</p>

Efficacy and safety of two different low-dose rituximab regimens for Chinese adult patients with immune thrombocytopenia / 中华血液学杂志

<p><b>OBJECTIVE</b>To compare the efficacy of two different regimens of low doses rituximab for the treatment of adult patients with immune thrombocytopenia (ITP).</p><p><b>METHODS</b>Fifty-one patients were enrolled in this study and was non-randomly assigned to receive 100 mg rituximab weekly for 4 weeks (group A, 31 cases) or a single dose of 375 mg/m2 rituximab (group B, 20 cases).</p><p><b>RESULTS</b>For group A: Overall and complete response (OR and CR) rates were 58% and 29% , respectively. In responders, the median time to response was 42 (10 -101) days, with a median follow-up time of 15 (10 - 16) months, 3 of 18 responders (17%) relapsed. For group B: OR and CR rates were 50% and 35% , respectively. In responders, the median time to response was 35 (18 - 108) days, with a median follow-up time of 13 (6 -17) months, 1 of 9 responders (11%) relapsed. No significant difference in the OR, CR, the relapse rate and relapse free survival was observed in patients between the two groups.</p><p><b>CONCLUSION</b>The low dose rituximab regimen (100 mg weekly for 4 weeks or a single close of 375 mg/m2) may be a useful alternative therapy in patients with ITP.</p>

The role of Th17 cells in immune thrombocytopenia mice models / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the role of Th17 cells in immune thrombocytopenia (ITP) mice model.</p><p><b>METHOD</b>ITP was induced by daily intraperitoneal injection of anti-platelet membrane CD41 antibody (MWReg30) into BALB/c mice, the mRNA expressions of Th17 cell associated transcription factors and cytokines in peripheral blood and spleen mononuclear cells were measured by real-time PCR, and the proportion of Th17 cells by FCM analysis.</p><p><b>RESULTS</b>The percentage of Th17 cell was significantly elevated in ITP mice both in splenocyte and peripheral blood as compared with that in normal controls (P<0.01). ITP mice had elevated mRNA expressions of IL-17F, IL-17A and IL-6 in splenocyte (P<0.05), and of IL-21 in peripheral blood (P<0.05). There was a positive correlation between IL-17A and IL-17F (r = 0.934, P = 0.000), and between IL-17A/IL-17F and IL-6 (r = 0.598, P = 0.001; r = 0. 619, P = 0.000).</p><p><b>CONCLUSIONS</b>Th17 cell might play an important role in the pathogenesis of ITP, at least involving in the clearance of platelets.</p>

Immune tolerance induction in a severe hemophilia A patient with inhibitor / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the immune tolerance induction (ITI) in a severe hemophilia A patient with inhibitor, and to improve the therapeutic efficacy for patient.</p><p><b>METHODS</b>The FVIII:C was assayed by one-stage method and FVIII antibody by Bethesda method. Mutation screening of FVIII gene intron 22 inversion was performed using LD-PCR.</p><p><b>RESULTS</b>FVIII gene intron 22 inversion was detected in this patient. Clinical tolerance to FVIII was successfully induced after administration of the ITI regimen combined with immunosuppression. A fall of inhibitor titer from 8 BU to 0 BU after treatment for 3 months, and in vivo FVIII recovery (> 66%) was normalized. The patient had no bleeding episode in the following 6 months.</p><p><b>CONCLUSION</b>This is the first case report on successful immune tolerance induction therapy in Chinese hemophilia A patient. ITI is the most effective therapy for hemophilia A with inhibitor.</p>

Expression of human factor IX in retrovirus-transfected human umbilical cord tissue derived mesenchymal stem cells / 中国实验血液学杂志

The purpose of this study was to investigate the expression of human Factor IX (hFIX) in retrovirus-transfected human umbilical cord tissue derived mesenchymal stem cells (hUCT-MSCs). The pLEGFP-N1-hFIX vector was generated by cloning a 3.0 kb Bgl II-BamH I fragment from the pIRES2-EGFP-hFIX plasmid containing the hFIX cDNA and part of intron 1 of hFIX in pLEGFP-N1 vector. The retroviral supernatants were produced from the Phoenix packaging cell line and then infected the hUCT-MSCs. After selection with G418 for 10 day, the expression of FIX was detected by ELISA and Western blot. The biological activity of FIX was determined by the clotting assay employing human Factor IX-deficient plasma. The results showed that compared with the activity of pooled human normal plasma (100%), transduced cells produced biologically active hFIX with 100-130% activity in two-day culture supernatant and expressed hFIX at levels of 2.68 +/- 0.36 microg/10(6) cells/24 hours after G418 selection for 10 days. The secretion of hFIX into culture supernatant was also confirmed by Western blot analysis. It is concluded that genetically modified hUCT-MSCs can express biologically active hFIX and thus serve as an efficient drug delivery vehicle carrying hFIX used as a way of somatic gene therapy for hemophilia B.

Effect of silencing bmi-1 by RNA interference on function of K562 cell line / 中国实验血液学杂志

Bmi-1 is a transcriptional repressor, which belongs to the polycomb group family. It has been demon- started that over-expression of Bmi-1 occurs in a variety of cancers, including several types of leukemia. Bmi-1 gene plays a key role in regulation of self-renewal in normal and leukemic stem cells. Acute myeloid leukemic cells lacking Bmi-1 undergo proliferation arrest and show signs of differentiation and apoptosis, which leads to the proposal of Bmi-1 as a potential target for therapeutic intervention in leukemia. The purpose of this study was to investigate the effect of short hairpin RNA (shRNA) targeting Bmi-1 on functions of K562 cell line. The shRNA eukaryotic expression vector targeting Bmi-1 was constructed and transfected into K562 cells through lipofectamine 2000. The mRNA and protein levels of Bmi-1 were detected by PCR and Western blot respectively. The proliferation of K562 after Bmi-1 silencing was measured by using MTT assay and clone formation assay. The cell cycle was detected by flow cytometry. The results indicated that among the four shRNA designed, there was a shRNA which efficiently interfered with the expression of Bmi-1. The results of PCR and Western blot validated that the Bmi-1 gene of K562 cells transfected with such a Bmi-1 shRNA was suppressed successfully. Although levels of Bmi-1 mRNA and protein were significantly reduced, delivery of this siRNAs had no effect on cell viability or growth. Flow cytometry analysis suggested that Bmi-1 inhibition did not affect the cell cycle. It is concluded that the suppression of Bmi-1 expression is not able to reduce proliferation of K562 cells, suggesting existence of some other parallel signaling pathways, which are fundamental for leukemic transformation and are independent of Bmi-1 over-expression. Bmi-1 over-expression may play a secondary role in chronic myeloid leukemia transformation.

Mesenchymal stem cells derived from human umbilical cord tissue modulate the secretion of antiplatelet antibody from splenocytes of ITP patients in vitro / 中国实验血液学杂志

The study was aimed to investigate the potential immunotherapeutical values of umbilical cord tissue-derived mesenchymal stem cells (UC-MSC) on patients with chronic idiopathic thrombocytopenic purpura (ITP). UC-MSC was cocultured in vitro with splenocytes isolated from ITP patients who experienced splenectomy. The level of IgG antiplatelet antibody (PAIgG) was determined by a competitive micro-enzyme-linked immunosorbent assay (ELISA) method. The proliferation of platelet-reactive CD4+ T lymphocytes was also measured in the presence of UC-MSCs. The results showed that UC-MSCs could stimulate the spontaneous secretion of PAIgG in supernatants; In the platelet-inducing condition, UC-MSC inhibited the production of PAIgG at a low ratio of 1 UC-MSC to 100 splenocytes, but promoted at a high proportion of 1 UC-MSC to 10 splenocytes. Moreover, UC-MSC exerted a suppressive effect on proliferation of platelet-reactive T helper cells in a dose-dependent manner. It is concluded that the UC-MSCs can regulate secretion of antiplatelet antibodies in vitro. Its concrete regulation mechanism and potential immunotherapeutical value are need to further study.

Myelodysplastic syndromes associated with acquired hemoglobin H disease / 中华血液学杂志

<p><b>OBJECTIVE</b>To report 7 cases of acquired hemoglobin H in myelodysplastic syndromes.</p><p><b>CASE DATA AND DISCUSSION</b>Clinical materials of the 7 cases were retrospectively presented. Clinical features of the similar cases in literatures were reviewed. The criteria for diagnosis of this entity by Steensma and its pathogenesis were discussed.</p><p><b>CONCLUSION</b>This entity is a new subtype of MDS with unique clinical features and pathogenesis, and might be a proper model in the study of MDS transformation.</p>