Establishment of Mouse Model of H-2 Haploidentical Hematopoietic Stem Cell Transplantation from Double Donors / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To establish a new mouse model of H-2 haploidentical stem cell transplantation from double donors (DHSCT) and compare with conventional haploidentical hematopoietic stem cell transplantation (HSCT) so as to alleviate transplant-related complications.</p><p><b>METHODS</b>The recipients CB6F1 of conventional HSCT group were pretreated by 8 Gy total body irradiation(TBI), and received 3×10donor (male C57) spleen mononuclear cells (spMNC) mobilized by G-CSF within 2 hours after TBI. Recipients CB6F1 of D-HSCT groups accepted 2 Gy TBI, and received total 12×10spMNC mobilized by G-CSF from 2 donors within 2 hours after TBI, each donor donated 6×10cells. According to the different strains and sex of donors, DHSCT were divided into 3 groups: in group A, the stem cells were from male C57 and female BALB/c; in group B, stem cells were from male C57 and male BALB/c, while the stem cells in group C were from male C57 and male C3H. Hematopoietic reconstruction, engraftment, GVHD and survival were observed among these 4 groups.</p><p><b>RESULTS</b>The nadir of white blood cell count after conventional HSCT were lower than 1×10/L and lasted for 3 to 5 days, while not less than 3×10/L after D-HSCT among either group A, B or C. The complete chimerism (CC) in conventional HSCT group was achieved quickly within only 1 week in peripheral blood. Mixed chimerism (MC) in peripheral blood was found within the first week after DHSCT among either group A, B or C, and transformed into stable CC within the second week eventually. Both GVHD morbidity and mortality of conventional HSCT were 100% at 34th day after transplantation.Among DHSCT groups,the overall GVHD morbidity and mortality at 34th day after transplant were 49.6% and 50%(P<0.01,P<0.05), respectively,and 60.4% and 81.2% at 50th day after transplant. Overall survival of 50 days was 50.9% that indicated a long survival in such mice DHSCT. The differences of hematopoietic reconstruction, donor cell engraftment, GVHD incidence, GVHD mortality and OS were not statistically significant among group A, B and C(P>0.05).</p><p><b>CONCLUSION</b>A new mouse model of H-2 haploidentical peripheral blood stem cell transplantation from double donors (DHSCT) has been successfully established by reducing conditioning intensity and increasing graft cell numbers from double haploidentical donors without GVHD prophylaxis. DHSCT successfully achieved stable complete chimerism, less GVHD morbidity and mortality and longer OS without hematopoietic suppression. This study provides experimental evidence for clinical application of HLA haploidentical peripheral blood stem cell transplantation from double donors.</p>

Biological Characteristics of Microvesicles Secreted by Human Peripheral Blood Hematopoietic Stem Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of microvesicles(MV) isolated from human peripheral blood hematopoietic stem cells(PB-HSC) on immune regulation and hematopoiesis.</p><p><b>METHODS</b>PB-HSCs were separated by density-gradient centrifugation and cultrued. The supernatants of PB-HSC at 48 h were harvested for isolation and purification of MV by using ultracentrifugation. The electron microscopy was used to observe the morphology of MV. The protein level in MV was quantified through bicinchoninic acid(BCA) protein assay. Flow cytometry was used to detect the immunophenotype of MV. Human peripheral blood mononuclear cells(PB-MNC) were isolated from healthy donor and treated with isolated MV. After being co-cultured for 12 h, confocal microscopy was used to observe the action mode of MV on PB-MNC. After being co-cultured for 48 h, the levels of IL-2, IL-6, IL-8, IL-10, IFN-γ and TNF-α were detected by ELISA. Flow cytometry was used to detect the changes of T cell subsets and the activation of T cell subsets as well as intracellular cytokine staining after co-culture for 48 h. The methylcellulose was used to assess the hematopoiesis-supportive function of MV as well as co-cultured supernatants.</p><p><b>RESULTS</b>The eletron microscopy revealed that MV were elliptical membrane vesicles. The protein amount in MV ranges from 29 to 110 µg. Flow cytometry showed that MV expressed mix markers on the surface, especially highly expressed MV specific marker CD63(85.86%) and hematopoietic stem cell marker CD34(33.52%). After being co-cultured for 12 h, confocal microscopy showed that MV were merged with PB-MNC. After being co-cultured for 48 h, ELISA showed that the secretion of cytokines IL-6,IL-8, IL-10 as well as TNF-α was increased while the level of IL-2 and IFN-γ was not changed much. The results of flow cytometry showed that there was no significant change in T cell subsets and T cell activation. Staining of intracellular factor showed that IL-8 was increased significantly in CD11ccells. The colony-forming experiments revealed that MV and the co-cultured supernatants could facilitate the colony formation.</p><p><b>CONCLUSION</b>MV isolated from PB-HSC have immune-regulatery function and can prornote hematopoiesis.</p>

Effect of Infusion of Recipient Spleen Cells at Different Time after Murine Haploidentical Hematopoietic Stem Cell Transplantation on Graft Versus Host Disease / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of infusing G-CSF mobilized recipient spleen cells at different time after haploidentical stem cell transplantation(HSCT) on graft-versus-host disease (GVHD) in mice and its possible mechanism.</p><p><b>METHODS</b>Forty mice after HSCT were randomly divided into 4 groups (n=10): GVHD positive control group (control group), 1st d recipient cell infusion group after transplantation (+1 d group), 4th d recipient cell infusion group after transplantation(+4 d group), 7th d recipient cell infusion group after transplantation(+7 d group). The mice in control group were injected the normal saline of same equivalent with experimental group which were given the same amount of G-CSF-mobilized recipient spleen cells. The general manifestation and pathological change of GVHD were observed. The expression changes of CD3CD4, CD3CD8cell subsets and FasL in peripheral blood were detected by flow cytometry.</p><p><b>RESULTS</b>The incidence of GVHD was significantly decreased in +4 d group and the median survival time was longer than 60 days, which was significantly higher than that of control group (24 d), +1 d group (21 d), +7 d group (28 d). (P<0.01, P<0.01, P<0.01). The Fasl expression of peripheral blood T lymphocytes in +4 d group were significantly lower than that in the other 3 groups(P<0.05).</p><p><b>CONCLUSION</b>The +4 d infusion of G-CSF mobilized recipient spleen cells on 4th day after haploidentical HSC transplantation can inhibit the expression of FasL in donor T lymphocytes, and significantly reduce the incidence of GVHD.</p>

Biological characteristics of Microvesicles Derived from Bone Marrow Mesenchymal Stem Cells and Their Capacities Supporting ex vivo Expansion of Hematopoietic Stem Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the biological characteristics of microvesicles(MV) derived from bone marrow mesenchymal stem cells (BM-MSC) and their capability supporting ex vivo expansion of hematopoietic stem cells(HSC).</p><p><b>METHODS</b>The MV from cultured BM-MSC supernatant were isolated by multi-step differential velocity contrifugation; the morphological characteristics of MV were observed by electron microscopy with negative staining of samples; the protein level in MV was detected by using Micro-BCA method; the surface markers on MV were analyzed by flow cytometry. The peripheral blood HSC(PB-HSC) were isolated after culture and mobilization; the experiment was diveded into 2 group: in MV group, the 10 mg/L MV was given, while in control group, the same volume of PBS was given; the change of PB-HSC count was observed by cell counting; the change of surface markers on PB-HSC was detected dynamically by flow cytometry; the cell colony culture was used to determin the function change of PB-HSC after co-culture with MV.</p><p><b>RESULTS</b>MSC-MVs are 20-100 nm circular vesicles under electron microscope. About 10 µg protein could be extracted from every 1×10MSC. The flow cytometry showed that CD63 and CD44 were positive with a rate of 96.0% and 50.2%, while the HLA-DR, CD34, CD29 and CD73 etc were negative. When being co-cultured with GPBMNC for 2 days, the cell number of MV groups was 1.49±0.15 times of the control group (P>0.05). When being co-cultured for 4 days, the cell number of MV groups was 2.20±0.24 times of the control group(P<0.05). The CD34cell number of MV groups was 1.76±0.30 times the control group after culture for 2 day and 1.95±0.20 times after culture for 4 day.</p><p><b>CONCLUSION</b>The MV has been successfully extracted from MSC culture supernatant by multi-step differential velocity centrifugation. MSC-MV can promote HSC expansion in vitro.</p>

Features of Immunophenotypes and Characteristics of Molecular Biology and Cellular Genetics of AML Patients with CD4 and CD7 Expression / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the features of immunophenotypes and the characteristics of molecular biology and cellular genetics of AML patients with CD7 and CD4 expression.</p><p><b>METHODS</b>The immunophenotypical markers of AML cells were detected by multiple parameter flow cytometry; the expression of WT1, MDK, ETO, PML-RaRa and BCR-ABL were detected by RT-PCR; and cellular features were analyzed by R-band in 304 patients. The patients were divided into three groups according to their immunophenotypes: AML with CD7 expression (CD7 group), AML with CD4 expression(CD4 group) and AML without CD7 and CD4 expression (common AML group).</p><p><b>RESULTS</b>The expression rate and level of HLA-DR in CD7 group were higher than those in the common AML group, and the expression rate of CD33 and CD34 was higher than that in the other two groups. The expression rate and level of CD15, CD64 in the CD4 group were higher than those in the other 2 groups, and the expression rate and level of CD33 were higher than those in the common AML group. WT1 expression in the CD7 group was lower than that in the common AML group. PML-RaRa was not detected in the CD7 group. AML with co-expression of CD4 or CD7 showed more normal karyotype. (15;17) was not found in AML with CD7 expression.</p><p><b>CONCLUSION</b>AML cells with CD7 expression originate from precursor cells and are blocked in the early phase of hematological development; AML cells with CD4 expression originate from more mature stage of hematological devevelopment and with CD33, CD64 and CD15 high expression; AML cells with CD7 and CD4 expression are characterized by no-specific change of cellular genetics. According to the expression level and intesity of CD4 and CD7, and together with other specific lineage markers, the MRD in AML patients can be quantitatively detected.</p>

Efficacy of Nonmyeloablative Allogeneic Hematopoietic Stem Cells for 14 Case of Severe Acquired Aplastic Anemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic efficacy of nonmyeloablative allogeneic hematopoietic stem cells transplantation for severe acquired aplastic anemia (SAA).</p><p><b>METHODS</b>Fourteen patients with severe acquired aplastic anemia received nonmyeloablative allogeneic hematopoietic stem cells transplantation from HLA matched sibling donors, among them 8 cases were dagnosed as SAA-I, 6 cases were diagnosed as SAA-II. The conditioning regimen consisted of fludarabine (FIUD), cyclophosphamide (CTX) and anti-thymocyte globulin (ATG/ALG). The prophylaxis for graft-versus-host disease (GVHD) was performed with cyclosporine (CsA) combined with mycophenolate mofetil (MMF) or tacrolimus (FK506).</p><p><b>RESULTS</b>All the patients gained a quick successfully engraftment of donor hametopoietic cells. The mean recovery time for neutrophil and platelet was 9 d and 13 d respectively. All the patients have acquired a full donor chimerism before 14 d. There were only 2 cases of GVHD: one out of them was acute skin GVHD (grade I) at day 70 after transplantation and the other was chronic liver GVHD (grade I) in 1 years after transplantation, the GVHD more than degree II did not coccur in all patients, 9 patients with bacterial and fungal mixed infection and (or) virus infection were observed, and improved after anti-infection therapy. The median follow-up time were 54.5 months (ranged between 5-144 months), and 12 patients remain disease-free survival currently, only 2 patients died of fungal infectin.</p><p><b>CONCLUSION</b>Transplantation of nonmyeloablative allogeneic hematopoietic stem cell is safe and effective for the treatment of severe acquired aplastic, but the prevention, treatment and monitoring of infection need to be enhance.</p>

Clinical Analysis of 4 AML Patients Aged Over 80 Years Treated with Chemotherapy Combined with Haploidentical Hematopoietic Stem Cell Infusion / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the efficacy and safety of MA (mitoxantrone and cytarabine) regimen chemotherapy combined with granulocyte-colony stimulating factor (G-CSF)-mobilized family related HLA-haploidentical donor peripheral blood hematopoietic stem cell (G-PBHSC) infusion for the treatment of acute myeloid leukemia (AML) patients aged over 80 years.</p><p><b>METHODS</b>Four elderly patients with AML were treated in Chinese Second Artillery General Hospital from August 2008 to September 2013. The proportion of male to female was 1 : 3 and the median age 83 (80-85) years. All patients received programmed infusions of G-PBHSC after MA regimen chemotherapy without graft-versus-host disease (GVHD) prophylaxis. After complete remission (CR), patients only received G-PBHSC infusion without chemotherapy.</p><p><b>RESULTS</b>Three cases achieved CR and their disease free survival (DFS) time was 18, 8, 6 months, respectively. 1 case did not reach remission after 2 cycles chemotherapy. The median overall survival (OS) time was 10 (3-20) months. No GVHD was observed in any of the patients during treatment. Concludsion: The combination of chemotherapy and programmed haploidentical G-PBHSC infusion is an alternative approach for AML patients aged over 80 years.</p>

Establishment and identification of a H-2 completely mismatched microtransplantation model of leukemia mouse / 中国实验血液学杂志

This study was purposed to establish and identify a H-2 completely mismatched microtransplantation model of leukemia mouse. The recipients were female BALB/c mice, while donors were male C57BL/6J mice. Recipients were inoculated intravenously with 1×10(6) of WEHI-3 cells, a cell line of myelomonocytic leukemia. Donors received 100 µg/kg G-CSF mobilization through hypodermic injection, every 12 hours, and it last 5 days. Chemotherapy regimens was MA (mitoxantrone+cytarabine), and it last 4 days. Recipients were given chemotherapy conditioning without GVHD prophylaxis after inoculation of leukemic cells for 2 days, and within 8 hours after last chemotherapy received donor mobilized spleen mononuclear cells (sMNC). The number of sMNC was (3, 6, 12) ×10(7), respectively. The early death rate, recovery level of WBC in peripheral blood and leukemia load were compared between chemotherapy and microtransplantation groups. The donor chimerism was detected by RT-PCR. From the clinical manifestation and pathological features, the GVHD in recipients was evaluated. The results showed that the early mortality in chemotherapy group was 25%, meanwhile those in the (3, 6, 12)×10(7) groups were 16.67%, 8.33%, 8.33%, respectively. The(3, 6)×10(7) groups has a stronger hematopoietic recovery capability than that in chemotherapy and 12×10(7) groups (P < 0.05) . There were more leukemic cells in chemotherapy mice than that in microtransplantation mice (P < 0.01) , and (12, 6)×10(7) groups had lower leukemia load than that in 3×10(7) group (P < 0.05) . No signs of GVHD were observed in microtransplantation mice. The donor microchimerism could be discovered at eraly 2 weeks after donor cell transfusion. It is concluded that a H-2 completely mismatched microtransplantation model of leukemia mouse has been successfully established, and it will provide a experimental base for studying microtransplantation in clinic.

Clinical analysis of lymphoblastic lymphoma/leukemia treated with Hyper-CVAD/MA regimen chemotherapy combined with haploidentical hematopoietic stem cell infusion / 中国实验血液学杂志

This study was aimed to investigate the efficacy of Hyper-CVAD/MA regimen chemotherapy combined with haploidentical hematopoietic stem cell infusion for the treatment of lymphoblastic lymphoma/leukemia (LBL/ALL). Seven patients with LBL/ALL were treated in Second Artillery General Hospital from August 2009 to September 2012. All patients received programmed infusions of granulocyte-colony stimulating factor (G-CSF)-mobilized family related HLA-haploidentical donor peripheral blood hematopoietic stem cell (G-PBHSC) after each of cycle of Hyper-CVAD/MA regimen chemotherapy without graft-versus-host disease (GVHD) prophylaxis. A total of four cycles of therapy were planned. The interval between each cycle of treatment was 8 to 12 weeks. By April 2014, the median follow-up time was 41 (20-57) months. The results showed that the 7 patients totally received 30 cycles of treatment, and all patients achieved complete remission (CR). The patients were generally well-tolerated to therapy, and the most significant toxicities of grade 3 to 4 neutropenia and thrombocytopenia developed in nearly all of the patients after each course of the Hyper-CVAD/MA regimen. No GVHD was observed in any of the patients during treatment. Up to now, 5 patients were still alive, 2 patients were died of relapse. It is concluded that the combination of chemotherapy and programmed haploidentical G-PBHSC infusion is a promising approach to the treatment of LBL/ALL.

Prophylactic G-CSF mobilized donor lymphocytes infusion after non-myeloablative stem cell transplantation prevents relapse in patients with high-risk leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the anti-leukemia effects of prophylactic G-CSF mobilized donor lymphocytes infusion (pG-DLI) and its relationship with the incidence of graft-versus-host disease (GVHD) in high-risk leukemia patients with non-myeloablative stem cell transplantation (NST).</p><p><b>METHODS</b>12 patients with high-risk leukemia were analyzed, including Ph⁺ acute lymphocytic leukemia (n=1), acute leukemia (AL) with persistent non-complete remission (n=2), acute myeloid leukemia (AML) with central nervous system (CNS) relapse (n=3), hybrid AL (n=1), secondary AML evolving from myelodysplastic syndrome (MDS/AML) (n=2), chronic myeloid leukemia in accelerated phase (CML-AP) (n=1), CML in blastic phase (CML-BP) (n=2). All patients received non-myeloablative conditioning and pG-DLIs were administered 30-40 days post transplantation if no signs of GVHD were present. The percentage of donor cell chimera was analyzed by short tandem repeat-polymerase chain reaction (STR-PCR) just before and after pG-DLI. The incidence of leukemia relapse and GVHD were observed.</p><p><b>RESULTS</b>12 high-risk leukemia patients with a median age of 38 (range: 29-52) years received G-DLI at a median interval of 35 (32-40) days. The median numbers of infused mononuclear cells (MNCs), CD34⁺, and CD3⁺ cells/kg recipient body weight was 2.3×10⁸/kg, 1.7×10⁶/kg, and 0.6×10⁸/kg, respectively. 10 of 12 patients had full donor chimera before pG-DLIs and conversion from mixed to full donor chimera occurred in the other 2 patients shortly after pG-DLI. Grade II acute GVHD (aGVHD) was observed in only 2 patients and chronic GVHD (cGVHD) developed in 6 patients, including involvement of skin (n=3), skin and intestine (n=2), liver (n=1). 1 patient died of cGVHD. With a median follow-up of 40 (24-64) months, 7 patients are alive in remission, with 3-year actuarial overall survival (OS) and disease-free survival (DFS) rates of the same 58.3%.</p><p><b>CONCLUSION</b>Our findings indicate that pG-DLI after NST does not increase the risk of aGVHD, but could enhance the capacity graft-vs-leukemia and prevent relapse in high-risk leukemia patients.</p>

In vitro skin transplantation and TUNEL assay in evaluation of cellular immunity caused by infusion of rhesus mesenchymal stem cells / 第二军医大学学报

Objective: To transfuse rhesus bone marrow derived mesenchymal stem cells (MSCs) to rhesus leucocytes antigen (RhLA) mismatched recipients, in attempt to study the immunological reaction between recipients' T lymphocytes and the skin of donor or a third party. Methods: Bone marrow aspirates were collected from femurs of donor rhesus, and the mononuclear cells were isolated and resuspended in low glucose Dulbecco's Modified Eagles Medium (DMEM) containing 2% fetal bovine serum. Phenotype of MSCs was analyzed by flow cytometry and the differentiated cells were identified by relevant specific staining. Allogeneic MSCs were given to recipients (single infusion) without preconditioning. Peripheral blood lymphocytes from recipients were co-cultured in vitro with the donor's skin or a third rhesus for 72 h before and 20 days, 40 days, and 60 days after infusion. The pathological lesions were evaluated and the keratinocyte apoptosis of the skin sections was determined by TUNEL assay. Results: Twenty days after infusion, the pathological lesion in in vitro skin explants from MSCs donor was less and the apoptosis rate was declined to (12.2±1.9)% from a pre-infusion level of (23.0±4.9)%. The apoptosis of cells in skin explants from the third party also declined to (11.8±1.4)% from a pre-infusion level of (22.0±2.0)% (P<0.05). Intensive immunological reaction was observed between recipient and donor/the third party on day 40 and day 60 after transplantation, with the apoptosis rate being (22.0±3.2)%, (22.0±2.5)% (donor) and (23.2±2.4)%, (24.0±2.6)% (the third party). Conclusion: Allogenic MSCs transfusion can decrease the immunological reaction between donors and recipients in rhesus, but this decreased reaction is temporary and reversible.

Kinetic study of various cytokine mRNA expressions in rhesus treated with haploidentical peripheral blood stem cell transplantation / 中国实验血液学杂志

This study was aimed to analyze the mRNA expression of cytokines (TGF-beta, IL-2, IL-6, IL-10, IFN-gamma, TNF-alpha, FAS-L) in five rhesus treated with haploidentical peripheral blood stem cell transplantation after nonmyeloablative preparative regimens and to explore the role of these cytokines in the development and pathology of acute graft-versus-host-disease (aGVHD). Five rhesus monkeys received nonmyeloablative haploidentical peripheral blood stem cells transplantation. Semi-quantitative reversed transcription polymerase chain reaction (RT-PCR) was used to analyze the kinetics of cytokine mRNA expression in the transplantation and aGVHD. The results showed that five rhesus monkeys acquired hematopoietic reconstitution successfully. The graft was rejected in one monkey which survived without disease, the other four achieved mixed chimerism and full donor chimerism. Chimerism of low centigrade in one monkey achieved high centigrade at 35 days after donor stem cell infusion. Intestinal aGVHD grade III developed in one monkey. Cytokines of Th1 and Th2 changed after transplantation. In period of aGVHD, expression of TGF-beta decreased but all others increased in various levels. When donor chimerism decreased, the cytokines decreased accordingly. It is concluded that the decrease of TGF-beta mRNA may be an indicator to predict aGVHD, and can be used as a differential diagnostic indicator for intestinal GVHD.

Study on biological characteristics of cultured rhesus mesenchymal stem cells / 中国实验血液学杂志

This study was aimed to isolate and culture rhesus mesenchymal stem cells (MSC), and to analyze its phenotype and biological characteristics. Bone marrow was aspirated from femur of rhesus, mononuclear cells were extracted, the nonadherent cells were removed after 24 hours, adherent cells were subcultured when they grew 80% confluence. After the fifth passage, the cells were used for examination. The phenotypes of MSC were analyzed by flow cytometry, differentiated cells were identified by relevant specific staining. Cytokines' mRNA expressed by MSC were detected by RT-PCR. The results showed that rhesus MSC gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast-like morphology. During the log phase of growth, MSC proliferated to a two-fold population at 31 - 40 hours. MSC could be ex vivo expanded by successive cycles of trypsinization, seeding, and culture. The phenotypes expressed on rhesus MSC were Flk-1, CD29, CD105, CD166 positive and CD34, CD45, CD33 nearly negative. In various induction differentiation conditions, rhesus MSC could differentiate into the osteoblast and lipocyte. IL-6, TGF-beta were highly expressed, TNF-alpha was lowly expressed and IL-2, Fas-L, IFN-gamma were not detected on rhesus MSC using RT-PCR method. It is concluded that rhesus MSC can be successfully isolated and culture-expanded and the biological characteristics of rhesus MSC are similar to those of human MSC.

Establishment of rhesus model for haploidentical hematopoietic stem cell transplantation with nonmyeloablative conditioning / 中国实验血液学杂志

To study if rhesus haploidentical hematopoietic stem cell transplantation model can be established by non-myeloablative conditioning, parent monkeys were used as donors, offspring monkeys were used as recipients. The recipient monkeys received a nonmyeloablative conditioning consisting of fludarabine, cyclophosphamide, total body irradiation and rabbit anti-human thymocyte globulin. Cyclosporine, mycophenolate mofetil and anti CD25 antibody were used for GVHD prevention. Donor mobilized peripheral blood stem cells were transplantated on day 0. Hematopoietic recovery, chimerism level, GVHD were assessed regularly. The results indicated that hematopoietic recoveries in all 4 cases were observed within 8 days after transplantation. Donor hematopoietic chimerism could be induced in all cases, chimerism analysis showed full donor chimerism (FDC) in case 3 and 4, and II to III grade GVHD developed on day 12 and 14. In case 1, only low level donor chimerism was detected on day 7, and transplantation rejection happened eventually. Unfortunately, kidney failure happened in case 2 after conditioning and died several days later, chimerism analysis showed 50% donor rate on day 7. It is concluded that the rhesus transplantation model was successfully established by nonmyeloablative conditioning for striding over the MHC barrier. This rhesus monkey model would provide a basis for future research.

Establishment and application of a method for assessing hemopoietic chimerism in rhesus after allogeneic stem cell transplantation / 中国实验血液学杂志

Monitoring engraftment of donor cells after allogeneic transplantation is the key of assessing successful establishment of animal transplantation model. The purpose of this study was to establish a method for analysis of chimerism in rhesus transplantation model. Y-specific sequence in rhesus was amplified by the polymerase chain reaction (PCR), method for analysis of chimerism in rhesus after sex-mismatched transplantation was established; the feasibility and sensitivity of the approach were tested by using serial DNA mixtures of sex-mismatched individuals; the accuracy of results was confirmed by chromosome karyotype analysis simultaneously; Chimerisms of one rhesus received allogeneic stem cell transplantation and the other received mesenchymal stem cells (MSC) transfusion were detected by this method. The results showed that a 176 bp long sequence of PCR product was gained in male rhesus, while no product was gained in female rhesus. The sensitivity of this method was up to 0.05% (male/female DNA ratio). Male donor chimerism were found on day 7 and 14 after allogeneic stem cell transplantation by Y-specific sequence and chromosome karyotype analysis. Otherwise, male donor chimerism was found in peripheral blood at 1 hour and in bone marrow on day 30 after MSC transfusion by this method, but no male donor chimerism was found after MSC transfusion using chromosome karyotype analysis. In conclusion, this rapid, sensitive approach can used to assess chimerism in experiments of rhesus alloorgan transplantation and cell transfusion.

Establishment of a rhesus haploidentical hematopoietic stem cell and mesenchymal stem cell transplantation model by nonmyeloablative conditioning / 中华血液学杂志

<p><b>OBJECTIVE</b>To establish rhesus haploidentical hematopoietic stem cell transplantation model by nonmyeloablative conditioning, and examine the effects of mesenchymal stem cells (MSC) in haploidentical transplantation.</p><p><b>METHODS</b>The recipient haploidentical rhesus monkeys were conditioned with a nonmyeloablative regimen consisted of fludarabine, cyclophosphamide, 200 cGy total body irradiation, and rabbit anti-human thymocyte globulin. Cyclosporine A, mycophenolate mofetil and anti CD25 antibody were used for graft versus host disease (GVHD) prophylaxis. Rhesus monkeys in one group were given hematopoietic stem cell (HSC) only, while in the other group HSC combined with MSC. The differences in hematopoiesis recovery, chimerism level, and GVHD between the two groups were evaluated.</p><p><b>RESULTS</b>Stable chimerism could be achieved in recipient monkeys. Hematopoiesis recovery was mainly related with chimerism level. MSC seemed capable of facilitating HSC engraftment, as there were more mixed chimerism and less GVHD occurrence in the HSC combined with MSC recipient group.</p><p><b>CONCLUSION</b>A rhesus haploidentical hematopoietic stem cell transplantation model is successfully established by nonmyeloablative conditioning. MSC was of great benefit to haploidentical transplantation.</p>