PCR—小卫生DNA指纹图在异基因造血干细胞移植植活指标监测…

为了解异基因骨髓移植治疗某些遗传及恶性血液性疾病的植活监测指标，用聚合酶式反应（ＰＣＲ）扩增具有高度多态性的小卫生ＤＮＡ３３．１、３３．６位点，联合地高辛标记的位点特异性寡核苷酸探针杂交的方法，以小卫星ＤＮＡ指纹图为特异性遗传标志，对６例基因骨髓移植，１例脐血移植进行植活指标监测，６例获供者源性细胞植活证据。结果显示：小卫星ＤＮＡ指纹图个体特异性强，可作为监测异基因造血干细胞移植植活的可靠指标，尤     

可变串联重复序列的高度多态性用于骨髓移植植入验证

采用聚合酶链式反应（ＰＣＲ）扩增可变串联重复序列（ｖａｒｉｂａｌｅｎｕｍｂｅｒｔａｎｄｅｍｒｅｐｅａｔ，ＶＮＴＲ）的３３．６位点，加地高辛标记的位点特异性寡核苷酸探针杂交的方法，制作出ＰＣＲ－ＤＮＡ片段长度图像，它具有良好的个体特异性，遗传稳定性和同一性，灵敏度达０．５％。运用该方法成功地对１例慢性粒细胞性白血病患者进行了骨髓移植后的植入验证。     

人类疱疹病毒7型DNA断裂包装位点序列分析

目的测定分析人类疱疹病毒７型（ＨＨＶ７）ＤＮＡ末端、断裂位点及包装信号的基因序列。方法ＨＨＶ７感染Ｓｕｐ－Ｔ１细胞后提取ＤＮＡ，ＰＣＲ扩增待测ＤＮＡ片断，与质粒载体连接后筛选目的基因克隆，双脱氧末端终止法测定目的基因序列。结果经测序后得到了ＨＨＶ７ＤＮＡ末端及其断裂位点和包装信号的基因序列。分析比较后发现在靠近ＨＨＶ７ＤＮＡ末端的基因序列中存在与人类端粒重复序列相同的基元序列ＧＧＧＴＴＡ。ＨＨＶ７断裂位点具有ｐａｃ２·Ｘ·ｐａｃｌ的排列，ＨＨＶ７的断裂位点位于包装信号ｐａｃ１及ｐａｃ２之间，只有当三者同时存在时才能构成一个完整的断裂包装位点。并且只有当复制型ＨＨＶ７ＤＮＡ环化时才能形成完整的断裂包装位点。结论ＨＨＶ７ｐａｃ１的基因序列与ＨＨＶ６ｐａｃ１的基因序列具有较高同源性。ＨＨＶ７与ＨＨＶ６具有相似的ＤＮＡ末端基因结构。     

用PCR扩增分析中国汉族人D1S80位点的遗传多态性

用扩增片段长度多态性技术分析人类的Ｄ１Ｓ８０位点的ＤＮＡ多态性，检测了１０９名无关中国汉族人，发现了１８个等位基因，５０种基因型，杂合性为０．７７，个人鉴别力为０．９６．观察的基因型频率的分布符合Ｈａｒｄｙ－Ｗｅｉｎｂｅｒｇ遗传平衡。检测的二例二代３口之家的基因型结果说明该位点属孟德尔式遗传。该位点个人鉴别力高，ＰＣＲ方法简便、灵敏，可在个人识别和亲子鉴定中发挥重要作用。     

HLAⅡ类基因PCR-SSP分型技术在骨髓移植配型中的应用

建立快速、准确的ＨＬＡ基因分型方法,满足临床移植配型的需要。方法通过序列特异性引物聚合酶链反应,对拟行骨髓移植的１０例血液病患者及１２名相关供者的ＨＬＡ－Ⅱ类基因ＤＲＢ１,ＤＱＢ１位点扩增,琼脂糖凝胶电泳分析ＰＣＲ产物并确定其基因型。结论该方法具有快速准确,特异性高,简便省时的特点。     

小环DNA

在细胞中广泛存在长度在０．１～２μ的多分散共价闭环ＤＮＡ分子，称为小环ＤＮＡ或ｐｌａｓｍｉｄ－ｌｉｋｅ ＤＮＡ，可能是核ＤＮＡ或线粒体ＤＮＡ的产物，它可以通过膜系统进行基因漂移，在细胞各部之间信息交流，特别是在核遗传系统与线粒体遗传系统的相互调解、细胞突变、衰老和其它分子病过程中可能起到非常重要的作用。     

应用MS32单位点小卫星DNA探针检测小儿急性淋巴细胞性白血病PCR－DNA指纹

利用单位点ＰＣＲ－ＤＮＡ指纹，检测小儿急性淋巴细胞性白血病患者外周血淋巴细胞（混有白血病细胞）和粒细胞基因组ＤＮＡ中ＤＩＳ８小卫星位点上ＶＮＴＲ，并将两者进行比较，发现混有白血病细胞的淋巴细胞ＰＣＲ－ＤＮＡ指纹图中存在带型的增多和带强度的变化，表明在此位点白血病细胞的ＶＮＴＲ发生了改变。     

用PCR扩增分析中国汉族人DIS80位点的遗传多态性

和扩增片段长度多态性技术分析人类的ＤＩＳ８０位点的ＤＮＡ多态性。检测了１０９名无关中国汉族人，发现了１８个等位基因，５０种基因型，杂合性为０．７７，个人鉴别力为０．９６。观察的基因型频率的分布符合Ｈａｒｄｙ－Ｗｅｉｎｂｅｒｇ遗传平衡。检测的二例二代３口之家的基因型结果说明该位点属孟德尔式遗传。该位点个人鉴别力高，ＰＣＲ方法简便，灵敏，可在个人识别和亲子鉴定中发挥重要作用。     

HLA类基因PCR-SSP分型技术在骨髓移植配型中的应用

目的建立快速、准确的 HL A基因分型方法 ,满足临床移植配型的需要。方法通过序列特异性引物聚合酶链反应 (PCR- SSP) ,对拟行骨髓移植的 10例血液病患者及 12名相关供者的 HL A- 类基因 DRB1,DQB1位点扩增 ,琼脂糖凝胶电泳分析 PCR产物并确定其基因型。结果发现 2例患者与其相关供者 HL A- DRB1,DQB1基因全相同 ,其中 1例成功进行了骨髓移植。结论该方法具有快速准确、特异性高、简便省时的特点。     

3‘HVR的结构多态性及其PCR指纹分析

设计了一对与３＇ＨＶＲ中重复单位ａ以及旁侧单拷贝序列互补的寡核苷酸引物，建立了直接反映重复单位位变异体排序多态性的ＰＣＲ技术，即小卫星变异重复单位ＰＣＲ。对１０名无血缘关系正常个体外周血白细胞ＤＮＡ样本以及１例死蜡块组织ＤＮＡ进行了分析。     

Photochemical treatment of donor lymphocytes inhibited their ability to facilitate donor engraftment or increase donor chimerism after nonmyeloablative conditioning or establishment of mixed chimerism.

Donor T-cells can provide a graft-versus-leukemia effect and help to promote donor engraftment after allogeneic BMT; however, these benefits can be outweighed by the ability of the cells to induce life-threatening GVHD. Photochemical treatment (PCT) of T-cells with S-59 psoralen and long-wavelength UV-A light can inhibit their proliferative capacity and significantly decrease their ability to induce acute GVHD after allogeneic BMT. PCT donor T-cells have been shown to facilitate donor engraftment in a myeloablative BMT model. In this study, we examined whether donor T-cells subjected to PCT ex vivo could retain the ability to facilitate engraftment or increase donor chimerism after nonmyeloablative BMT or after establishment of mixed hematopoietic chimerism. In a transplantation model in which mice were conditioned for BMT with sublethal (600 cGy) TBI, an infusion of PCT donor T-cells was unable to facilitate engraftment of donor BM. A BMT model was used in which a mixture of allogeneic and syngeneic marrow cells was infused into lethally irradiated recipients for establishment of mixed hematopoietic chimerism. The goal was to determine whether PCT donor splenocytes could increase levels of donor chimerism. Recipients of splenocytes treated with UV-A light only (no S-59 psoralen) and given at the time of BMT or in a donor lymphocyte infusion (DLI) had significantly higher levels of donor chimerism than did recipients of BM only. Although PCT donor splenocytes given at the time of BMT modestly increased donor chimerism, PCT donor splenocytes given in a DLI did not increase donor chimerism. A nonmyeloablative BMT model was employed for determining whether DLI given relatively late after BMT could increase donor chimerism. Recipient mice were conditioned for BMT with a combination of low-dose TBI (50 or 100 cGy) and anti-CD154 (anti-CD40L) monoclonal antibody for achievement of low levels of mixed chimerism. When control mixed chimeras were given a DLI 71 days after BMT, donor chimerism was significantly increased. In contrast, PCT of the donor cells eliminated the ability of the cells to increase donor chimerism after infusion. Together results from these 3 distinct BMT models indicate that PCT of donor T-cells significantly inhibited the ability of the cells to facilitate donor engraftment after nonmyeloablative BMT or to increase donor chimerism in mixed hematopoietic chimeras when the cells were administered in a DLI.     

Comparison of molecular and cytogenetic methods in the evaluation of engraftment following allogeneic bone marrow transplantation.

Cytogenetic evaluation of patients after bone marrow transplantation (BMT) has provided a standard method of documentation of hematopoietic engraftment. More recently, recombinant DNA technology has also been applied to determine engraftment status. In order to establish the relative utility of these methods in clinical practice we have directly compared the data from cytogenetic and recombinant DNA methods, evaluating engraftment status in 68 BMT recipients. Patients were evaluated pre-transplant, 30, 60, 90, and 180 days after BMT, and yearly thereafter for 1) the presence or absence of the Y chromosome in sex-mismatched allogeneic transplant recipients, 2) the presence or absence of the Philadelphia chromosome [t(9;22)] in patients transplanted for chronic myelogenous leukemia (CML), 3) restriction fragment length polymorphism (RFLP) profiles, and/or 4) clonal rearrangement of the bcr gene. Cytogenetic examination of unstimulated bone marrow and recombinant DNA tests of nucleated peripheral blood or bone marrow cells produce qualitatively similar data in the identification of patient and donor cells and/or normal and tumor cells. Differences in the results obtained by the two analytic methods were most often due to the restricted cell populations evaluable by cytogenetic studies of PHA-stimulated peripheral blood specimens. DNA analyses could frequently be applied at earlier intervals after transplantation and, in cases of graft rejection, when cell counts were low. Although recombinant DNA methods required fewer cells and demonstrated greater sensitivity in detection of minor cell populations in the majority of instances, the cytogenetic evaluation may complement the DNA studies and allow detection of additional chromosomal anomalies.     

Transplantation of X-linked severe combined immunodeficient dogs with CD34+ bone marrow cells.

X-linked severe combined immunodeficiency (X-SCID) is the most common form of human SCID and is caused by mutations in the common gamma chain (gammac), a shared component of the interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15, and IL-21 receptors. BMT for human X-SCID results in engraftment of donor T-cells and reconstitution of normal T-cell function but engraftment of few, if any, donor B-cells and poor reconstitution of humoral immune function. Canine X-SCID is also caused by mutations in the yc and has an immunological phenotype identical to that of human X-SCID. We have previously reported that transplantation of nonconditioned X-SCID dogs with unfractionated histocompatible bone marrow results in engraftment of both donor B- and T-cells and reconstitution of normal T-cell and humoral immune function. In this study, we assessed the ability of purified canine CD34+ bone marrow cells to reconstitute lymphoid populations after histocompatible BMT in 6 nonablated X-SCID dogs. All dogs showed engraftment of donor T-cells, with T-cell regeneration occurring through a thymic-dependent pathway, and had reconstituted normal T-cell function. In contrast to our previous studies, only 3 dogs had engraftment of donor B-cells and reconstituted normal antigen-specific B-cell function post-BMT. The variable donor B-cell engraftment and reconstitution of normal humoral immune function observed in this study are similar to the outcomes observed in the majority of human X-SCID patients following BMT. This study demonstrates that canine CD34+ cells contain progenitors capable of immune reconstitution and is the first study to document the ability of CD34+ bone marrow cells to reconstitute normal B- and T-cell function in a nonablated large-animal model of BMT. This study also demonstrates that the quality of immune reconstitution following CD34+ BMT may be dosage dependent Thus canine X-SCID provides a large-animal preclinical model that can be used not only to determine the optimal conditions for both donor B- and T-cell engraftment following CD34 BMT, but also to develop and evaluate strategies for gene therapy protocols that target CD34 cells.     

Allergy development after bone marrow transplantation from a non-atopic donor

BACKGROUND: Transfer of allergy from atopic bone marrow donors to recipients is known to occur. Development of allergy in a non-atopic patient transplanted from a non-atopic donor is an unfamiliar phenomenon in clinical practice. OBJECTIVES: To clarify the course of events causing a bone marrow recipient to acquire an allergic disease in such non-conducive circumstances. METHODS: Full medical history, prick and intradermal skin tests, and serum IgE levels were obtained from both donor and recipient patients. DNA and red blood cell phenotype analyses were used to detect the degree of chimerism. RESULTS: Only the recipient patient showed positive specific IgE antibodies and skin tests to house dust mite. The recipient patient displayed 100% donor chimera, based on all engraftment markers sought. CONCLUSION: Full engraftment after allogeneic bone marrow transplantation may be associated with modulation of T and B cell function, which in turn could cause the onset of allergic disease after bone marrow transplantation.     

Lack of correlation between an assay used to determine early marrow allograft rejection and long-term chimerism after murine allogeneic bone marrow transplantation: effects of marrow dose.

The acute rejection of bone marrow (BM) allografts by host effectors can occur within a short period after BM transplantation (BMT) in lethally irradiated mice. Common assays used to ascertain engraftment/resistance involve measuring the growth of granulocyte/monocyte progenitors (colony-forming unit-granulocyte-macrophage) in vitro or splenocyte proliferation assessed by radioisotope incorporation in vivo 5 to 8 days after BMT. However, the correlation of the long-term outcome of BMT with the kinetics of recovery by using the dose of allogeneic BM cells (BMCs) that leads to early rejection as determined by the in vitro assessment has not been extensively studied. Thus, to investigate whether the early rejection of donor BMCs is an indication of a long-term engraftment failure, C57BL/6 (H2b) mice were lethally irradiated and transplanted with various doses of BALB/c (H2d) BMCs. The short-term engraftment of donor precursors (colony-forming unit-granulocyte-macrophage), the kinetics of hematopoietic cell recovery, the extent of donor chimerism, and the proportion of the recipients with long-term survival were determined. The results show that the kinetics and extent of hematopoietic cell recovery were significantly delayed in mice receiving limiting doses of BMCs that were rejected or severely resisted at day 8 after BMT. However, a proportion of these mice survived up to 98 days after BMT with mixed chimerism or donor chimerism. This study demonstrates that early rejection of BM precursors, as assessed by measurement of myeloid progenitors in the spleen after BMT, does not always correlate with the long-term outcome of the marrow allograft and that significant variability is inherent in the extent of chimerism when threshold amounts of BMCs are used.     

Variants of autophagy-related gene 5 are associated with neuromyelitis optica in the Southern Han Chinese population

Using animal models for autoimmune diseases, we have previously shown that allogeneic bone marrow transplantation (allo BMT) can be used to treat autoimmune diseases. Using cynomolgus monkeys, we have recently developed new BMT methods for the treatment of autoimmune diseases. The methods include the perfusion method (PM) for the collection of bone marrow cells (BMCs), and intra-bone marrow (IBM)-BMT for the direct injection of collected whole BMCs into the bone marrow cavity. The PM, in comparison with the conventional aspiration method, can minimize the contamination of BMCs with T cells from the peripheral blood. Therefore, without removing T cells, no graft-versus-host disease (GvHD) develops in the case of the PM. Since BMCs collected by the PM contain not only hemopoietic stem cells (HSCs) but also mesenchymal stem cells (MSCs), the injection of both cells directly into the bone marrow cavity (IBM–BMT) facilitates the engraftment of donor hemopoietic cells. In organ allografts with IBM–BMT, no graft failure occurs even if the radiation dose is reduced. In addition, IBM–BMT is applicable to regeneration therapy and various age-associated diseases such as osteoporosis, since it can efficiently recruit donor-derived normal MSCs.

We have also found that IBM–BMT in conjunction with donor lymphocyte infusion can prevent GvHD, but suppress tumor growth. We believe that this strategy heralds a revolution in the field of transplantation (BMT and organ allografts) and regeneration therapy.     

Endonuclease analyses of DNA of human herpesvirus-6 isolated from blood before and after bone marrow transplantation.

Three strains of human herpesvirus-6 (HHV-6) were isolated from peripheral blood mononuclear cells of a leukemic child with the antibody of HHV-6 before and after bone marrow transplantation (BMT); two strains were obtained before BMT and one after BMT. The DNA extracted from the three isolates was analyzed by six different restriction endonucleases. The cleavage profiles of two strains obtained before BMT were different, but the third strain isolated after BMT was identical with one of the two, which suggest reactivation of HHV-6 from the recipient's own body after BMT and possible mutation or super-infection of the virus in an immunocompromised patient.     

Evaluation of an automated technique for assessment of marrow engraftment after allogeneic bone marrow transplantation using a commercially available kit

Several methods have been used to evaluate engraftment after allogeneic bone marrow transplantation (BMT). We assessed the usefulness of a multiple short tandem repeat (STR) amplification kit combined with a capillary electrophoresis unit for DNA identity analysis in the evaluation of engraftment after BMT. For 17 of 18 patients, at least 1 locus showed unique alleles for the donor and the recipient. In all cases, at least 1 locus was informative for the presence of small amounts of recipient DNA. The results from STR analysis were the same as Southern blot analysis in 14 of 17 cases. Differences included mixed chimerism detected only with STR analysis, informative loci present only with STR analysis, and informative loci present only with Southern blot analysis (1 case each). By using mock mixed chimeras, minor populations of 5% were detected routinely in all loci using the kit manufacturer's default protocol. By increasing the amount of amplified DNA, minor populations of 1% were detected in all cases but not in all loci. This single reaction technique provides for faster results, reduced workforce needs, and greater sensitivity than traditional Southern blot.     

A prospective study of diagnosis of Toxoplasma gondii infection after bone marrow transplantation

Active infection with Toxoplasma gondii in immunocompromised transplant recipients can lead to toxoplasmosis, which may have a rapid disease course and in some cases be fatal. It is of paramount importance to diagnose toxoplasmosis at an early stage, and to initiate specific treatment to improve the outcome. Polymerase chain reaction (PCR) is today the primary diagnostic tool to diagnose toxoplasmosis in immunocompromised patients. Timely diagnosis may, however, be difficult if toxoplasmosis is at first asymptomatic. To investigate the magnitude of toxoplasmosis after bone marrow transplantation (BMT), we conducted a screening study by PCR where 21 autologous and 12 allogeneic BMT recipients were included. Peripheral blood samples were taken one week prior to BMT; thereafter, blood samples were drawn weekly for the first 6 months, and monthly up to one year after BMT. The samples were analyzed by conventional PCR and real-time PCR. T. gondii DNA was detected in peripheral blood from one patient 5 days post allogeneic BMT. There were no clinical signs of toxoplasmosis. Medical records were reviewed and showed a previously undiagnosed eye infection in another allogeneic BMT recipient. These two patients were seropositive for T. gondii. We concluded that monitoring for T. gondii DNA in peripheral blood samples using PCR might be a valuable method for identifying toxoplasma-seropositive stem cell transplant recipients.