[Efficacy and safety of ruxolitinib in the salvage treatment of chronic graft versus-host disease].

Objective: To investigate the efficacy and safety of low-dose Ruxolitinib in the treatment of patients with chronic graft-versus-host disease (cGVHD) and refractory to the first-line and/or second-line drugs after allogeneic hematopoietic stem cell transplantation. Methods: The clinical data was retrospectively analyzed of patients diagnosed with cGVHD in Anhui Provincial Hospital from July 9, 2018 to May 23, 2019. They were refractory to first-line and second-line drugs and were given a low-dose of Ruxolitinib (a dose of 5 mg twice daily if body weight ≥ 25 kg and 2.5 mg twice daily if body weight<25 kg). There was 2.5 mg reduction per week or every two weeks if the condition improved until withdrawal. The efficacy and safety of Ruxolitinib were retrospectively analyzed weekly or biweekly. If the condition improved, the dosage would be reduced by 2.5 mg weekly or biweekly until discontinuance. Results: A total of 47 patients were included in the study,and the median time of taking Ruxolitinib was 55 (21-154) days. The median time of taking effect was 14(7-28) days. The overall response rate was 87.2% (41/47). The complete response rate was 63.8% (30/47) and the partial response rate was 23.4%(11/47). Among them, 13 cases were mild and the overall response rate was 100%(13/13). Twenty one cases were moderate and the overall response rate was 90.5%(19/21). Thirteen cases were severe and the overall response rate was 69.2%(9/13). The highest overall response rate of all organs the was 100% in the gastrointestinal tract (7/7), and it was 95.8%(23/24) for the skin, 83.3%(5/6) for the liver and 76.9%(10/13) for the lung. The highest rate of complete organ response was 95.8% for skin. Eight patients (17%) developed cytopenia, of which 2(4.2%) were with a decrease of 3-4 degree hemoglobin. Recrudescence of cytomegalovirus occurred in 3 patients (6.4%). After withdrawal of Ruxolitinib, 6 patients (12.7%) had recurrence of cGVHD. The median time to relapse was 35.5(7-90) days. All of their conditions were improved after addition of Ruxolitinib. The median time of response was 7(5-14) days. The median follow-up was 208(33-412) days. Three patients(6.4%) died, and all of them died of severe pulmonary infection. Three patients (6.4%) had relapse of primary disease. The 6-month overall survival rate was 95.7%. Conclusion: Low-dose Ruxolitinib has good efficacy and safety in the treatment of cGVHD.

[Comparison of intensified myeloablative conditioning regime without antithymocytic globulin (ATG) with myeloablative conditioning regime for single-unit unrelated umbilical cord blood transplantation in hematological malignancies].

OBJECTIVE: To campare the effect and tolerance beween intensified myeloablative conditioning regime (IMCR) without antithymocyte globulin (ATG) and myeloablative conditioning regime (MCR) for single-unit unrelated umbilical cord blood transplantation (sUCBT) in hematological malignancies. METHODS: The clinical data of 190 patients with hematological malignancies undergoing sUCBT between April 2000 and December 2013 at Department of Hematology, Anhui Provincial Hospital were retrospectively analyzed, of whom 156 received IMCR without ATG (IMCR group), including 79 patient receiving total body irradiation (TBI)/cytosine arabinoside (Ara-C)/cyclophosphamide (CY) regime, 47 receiving fludarabine (Flu)/busulfan (Bu)/CY regime, and 30 receiving Ara-C/Bu/CY regime, and all of the 156 received a combination of cyclosporine A (CsA) and mycophelonate mofetil (MMF) for the prophylaxis of graft-versus-host disease (GVHD); the remaining 34 patients received MCR (MCR group), 30 patients receiving Bu/CY regime, and 4 receiving TBI/CY regime, all using CsA/MMF±ATG or methotrexate (MTX) for the prophylaxis of GVHD. The two groups were compared in disease status at the time of transplantation, characteristics of graft, transplantation effect, and transplantation-related complications. RESULTS: There were no statistically significant differences between the two groups in gender, disease type, human leukocyte antigen match, ABO blood type match, and disease status at the time of transplantation (all P>0.05). The median age and body weight at transplantation in the IMCR group were significantly higher than those in the MCR group (13 years vs 9 years, P=0.003; 44 kg vs 26 kg, P=0.000). The median doses of infused total nucleated cells (×10(7)/kg) and CD34(+) cells (×10(5)/kg) in the IMCR group were significantly lower than in the MCR group (3.87 vs 4.99, P=0.002; 2.00 vs 3.17, P=0.000). The cumulative incidence of myeloid engraftment on the 42th day and platelet engraftment on the 120th day in the IMCR group were remarkably higher than in the MCR group [96.33%(95%CI: 96.27%-96.39%)vs 82.30%(95%CI: 80.67%-83.93%), P=0.000; 86.44%(95%CI: 86.28%-86.60%)vs 51.17%(95%CI: 49.02%-53.32%), P=0.002]. There were no statistically significant differences in the incidences of grade Ⅱ to Ⅳ acute GVHD, grade Ⅲ to Ⅳ acute GVHD, and 2-year chronic GVHD(P=0.482, 0.928, 0.579). The incidence of pre-engraftment syndrome in the IMCR group was higher than in the MCR group(82.70% vs 47.06%, P=0.000). And 180-day transplantation-related mortality (TRM) in the IMCR group was lower than that in the MCR group [20.50%(95%CI: 20.28%-20.71%)vs 42.20% (95%CI: 41.32%-45.09%), P=0.004]. Up to October 2015, with a median follow-up of 44.2(22.7-188.9)months, the estimated 3-year overall survival and disease-free survival in the IMCR group were both significantly higher than those in the MCR group (62.90% vs 34.10%, P=0.000; 58.60% vs 34.10%, P=0.001). CONCLUSION: IMCR without ATG may improve the engraftment without increasing complications, reduce early transplantation-related mortality, and improve survival.

[Single non-blood-related umbilical cord blood transplantation using a reduced-intensity conditioning regimen for the treatment of severe aplastic anemia].

Objective: To evaluated the clinical efficacy of a reduced-intensity preconditioning regimen for single non-blood-related umbilical cord blood transplantation (sUCBT) in the treatment of severe aplastic anemia (SAA) . Methods: The clinical data of 63 patients with SAA who underwent sUCBT from January 2021 to July 2023 at the Department of Hematology of the First Affiliated Hospital of USTC were retrospectively analyzed. Fifty-two patients received total body irradiation/total bone marrow irradiation (TMI) combined with fludarabine or a cyclophosphamide- conditioning regimen (non-rATG group) , while 11 patients received rabbit anti-human thymocyte immunoglobulin (rATG) combined with TMI, fludarabine, or the cyclophosphamide-conditioning regimen (rATG group) . All patients received cyclosporine A and mycophenolate mofetil for graft-versus-host disease (GVHD) prophylaxis. Complications post-transplantation and long-term survival were compared between the two groups. Results: The baseline parameters were balanced between the two groups (P>0.05) . In the rATG group, all patients achieved stem cell engraftment, and in the non-rATG group, five patients had primary graft failure. There was no significant difference in the cumulative incidence of neutrophil engraftment at 42 days after transplantation or platelet engraftment at 60 days between the two groups. The incidence of grade Ⅱ-Ⅳ acute GVHD in the rATG group was significantly lower than in the non-rATG group (10.0% vs. 46.2% , P=0.032) , and the differences in the cumulative incidences of grade Ⅲ/Ⅳ acute GVHD and 1-year chronic GVHD were not statistically significant (P=0.367 and P=0.053, respectively) . There were no significant differences in the incidences of pre-engraftment syndrome, bacterial bloodstream infections, cytomegalovirus viremia, or hemorrhagic cystitis between the two groups (P>0.05 for all) . The median follow-up time for surviving patients was 536 (61-993) days, and the 1-year transplantation related mortality (TRM) of all patients after transplantation was 13.0% (95% CI 6.7% -24.3% ) . Among the patients in the non-rATG and rATG groups, 15.5% (95% CI 8.1% -28.6% ) and 0% (P=0.189) , respectively, had mutations. The 1-year overall survival (OS) rate of all patients after transplantation was 87.0% (95% CI 75.7% -93.3% ) . The 1-year OS rates in the rATG group and non-rATG group after transplantation were 100% and 84.5% , respectively (95% CI 71.4% -91.9% ) (P=0.198) . Conclusion: The preliminary results of sUCBT with a low-dose irradiation-based reduced-intensity conditioning regimen with fludarabine/cyclophosphamide for the treatment of patients with SAA showed good efficacy. Early application of low-dose rATG can reduce the incidence of acute GVHD after transplantation without increasing the risk of implantation failure or infection.

[Unrelated cord blood stem cell transplantation for high-risk/refractory childhood acute myeloid leukemia: a clinical analysis of 160 cases].

Objective: To retrospectively analyze the clinical outcomes of single unrelated cord blood transplantation (UCBT) in children with high risk and refractory acute myeloid leukemia (AML) . Methods: Between June 2008 and December 2018, a total of 160 consecutive pediatric patients with AML received single UCBT (excluding acute promyelocytic leukemia) . Myeloablative conditioning (MAC) regimen were applied. All patients received a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) for the prophylaxis of graft -versus- host disease (GVHD) . Results: The cumulative incidence of neutrophil cells engraftment at day +42 and platelet recovery at day +120 was 95.0% (95% CI 90.0%-97.5%) at a median of 16 days after transplantation (range, 11-38 days) and 85.5% (95%CI 83.3%-93.4%) with a median time to recovery of 35 days (range, 13-158) , respectively. Incidence of grades Ⅱ-Ⅳ and Ⅲ-Ⅳ acute GVHD and chronic GVHD were 37.3% (95%CI 29.3%-45.2%) , 27.3% (95%CI 20.0%-35.0%) and 22.4% (95%CI 15.5%-28.7%) , respectively. The transplant-related mortality (TRM) at 360 day was 13.1% (95%CI 8.4%-18.9%) . The 5-year cumulative incidence of relapse was 13.8% (95%CI 8.5%-20.3%) . The 5-year disease-free survival (DFS) and overall survival (OS) were 71.7% (95%CI 62.7%-77.8%) and 72.2% (95%CI 64.1%-78.7%) , respectively. The 5-year GVHD and relapse free survival (GRFS) was 56.1% (95%CI 46.1%-64.9%) . The 5-year cumulative recurrence rates of CR1, CR2, and NR groups were 5.3%, 19.9%, and 30.9% (P=0.001) , and the 5-year OS rates were 79.9% (95%CI 70.3%-86.7%) , 71.1% (95%CI 50.4%-84.4%) and 52.9% (95%CI 33.0%-69.3%) (χ(2)=7.552, P=0.020) , respectively. Conclusions: For pediatric patients with high risk and refractory AML, UCBT is a safe and effective treatment option, and it is favorable to improve the survival rate in CR1 stage.

[Effect of KIR/HLA receptor-ligand mode on prognosis of single unrelated cord blood transplantation in patients with hematological malignancies].

Objective: To explore the impact of the natural killer cell immunoglobulin-like receptor/human leukocyte antigen (KIR/HLA) receptor-ligand model in single unrelated cord blood transplantation (sUCBT) . Methods: Between July 2012 and June 2018, 270 patients with malignant hematologic diseases receiving single-unit UCBT were divided into two groups. Group 1 (n=174) patients lacked a C-ligand for inhibitory KIR on UCB NK cells (patients homozygous C1/C1 or C2/C2) . Group 2 (n=96) patients expressed both C ligands for inhibitory KIR in the receptor (patients heterozygous C1/C2) . Results: A total of 270 patients (146 males, 124 females) with a median age of 13 years (1-62) were included in this retrospective study. All patients received a myeloablative conditioning regimen (without ATG) . The ratio of neutrophil engraftment for group 1 and 2 were both 98.9%, the median time of neutrophil engraftment for group 1 and 2 was 16 (10-41) days vs 17 (11-33) days (P=0.705) . The ratio of platelet engraftment was 88.5% for group 1 and 87.5% for group 2, the median time of platelet engraftment was 35 (11-113) days vs 38.5 (13-96) days (P=0.317) . The cumulative incidence of Ⅱ-Ⅳ acute GVHD in 100 days was 38.7% (95%CI 31.4%-45.9%) for group 1 and 50.0% (95%CI 39.6%-59.6%) for group 2 (P=0.075) , but multivariate analysis showed that HLA-C ligand absence was an independent protective factor for Ⅱ-Ⅳ acute GVHD after transplantation (P=0.036) . Patients in absence of a C-ligand for inhibitory KIRs (Group 1) showed a lower relapse rate than patients with both C-ligands (group 2) : 17.7% (95%CI 11.7%-24.9%) vs 22.7% (95%CI 4.4%-32.2%) after 3 years (P=0.288) . The median follow-up time was 742 (335-2 512) days. The 3-year OS was 72.1% for group 1 and 60.5% for group 2 (P=0.079) . There was no statistically significant difference between the two groups in 3-year disease-free survival [64.9% (95%CI 56.2%-72.3%) vs 55.4% (95%CI 44.4%-65.0%) (χ(2)=3.027, P=0.082) ]. Non-relapse mortality for group 1 was 12.1% (95%CI 7.7%-17.4%) and for group 2 was 16.7% (95%CI 10.0%-24.8%) (P=0.328) . Conclusion: Patients lacking a KIR-ligand of HLA group C1 or C2 had a lower incidence of grades Ⅱ-Ⅳ acute GVHD after sUCBT.

Molecular cloning, characterization, subcellular localization and dynamics of p23, the mammalian KDEL receptor.

We have isolated a cDNA clone (mERD2) for the mammalian (bovine) homologue of the yeast ERD2 gene, which codes for the yeast HDEL receptor. The deduced amino acid sequence bears extensive homology to its yeast counterpart and is almost identical to a previously described human sequence. The sequence predicts a very hydrophobic protein with multiple membrane spanning domains, as confirmed by analysis of the in vitro translation product. The protein encoded by mERD2 (p23) has widespread occurrence, being present in all the cell types examined. p23 was localized to the cis-side of the Golgi apparatus and to a spotty intermediate compartment which mediates ER to Golgi transport. A majority of the intracellular staining could be accumulated in the intermediate compartment by a low temperature (15 degrees C) or brefeldin A. During recovery from these treatments, the spotty intermediate compartment staining of p23 was shifted to the perinuclear staining of the Golgi apparatus and tubular structures marked by p23 were observed. These tubular structures may serve to mediate transport between the intermediate compartment and the Golgi apparatus.

Selective inhibition of protein targeting to the apical domain of MDCK cells by brefeldin A.

Dipeptidyl peptidase IV (DPPIV) is mainly vectorially targeted to the apical surface in MDCK cells. BFA was found to abolish the apical targeting of DPPIV. This BFA effect could be achieved under conditions where the ER to Golgi transport and the total surface expression of DPPIV were essentially unaffected. BFA executed its effect during the transport from the trans-Golgi network (TGN) to the surface. The inhibition of apical targeting resulted in enhanced mis-targeting to the basolateral surface. The mistargeted DPPIV was transcytosed back to the apical domain only after BFA withdrawal. In contrast, the basolateral targeting of uvomorulin was unaffected by BFA. These results established that the apical targeting of DPPIV was selectively abolished by BFA.

The mammalian protein (rbet1) homologous to yeast Bet1p is primarily associated with the pre-Golgi intermediate compartment and is involved in vesicular transport from the endoplasmic reticulum to the Golgi apparatus.

Yeast Bet1p participates in vesicular transport from the endoplasmic reticulum to the Golgi apparatus and functions as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) associated with ER-derived vesicles. A mammalian protein (rbet1) homologous to Bet1p was recently identified, and it was concluded that rbet1 is associated with the Golgi apparatus based on the subcellular localization of transiently expressed epitope-tagged rbet1. In the present study using rabbit antibodies raised against the cytoplasmic domain of rbet1, we found that the majority of rbet1 is not associated with the Golgi apparatus as marked by the Golgi mannosidase II in normal rat kidney cells. Rather, rbet1 is predominantly associated with vesicular spotty structures that concentrate in the peri-Golgi region but are also present throughout the cytoplasm. These structures colocalize with the KDEL receptor and ERGIC-53, which are known to be enriched in the intermediate compartment. When the Golgi apparatus is fragmented by nocodazole treatment, a significant portion of rbet1 is not colocalized with structures marked by Golgi mannosidase II or the KDEL receptor. Association of rbet1 in cytoplasmic spotty structures is apparently not altered by preincubation of cells at 15 degrees C. However, upon warming up from 15 to 37 degrees C, rbet1 concentrates into the peri-Golgi region. Furthermore, rbet1 colocalizes with vesicular stomatitis virus G-protein en route from the ER to the Golgi. Antibodies against rbet1 inhibit in vitro transport of G-protein from the ER to the Golgi apparatus in a dose-dependent manner. This inhibition can be neutralized by preincubation of antibodies with recombinant rbet1. EGTA is known to inhibit ER-Golgi transport at a stage after vesicle docking but before the actual fusion event. Antibodies against rbet1 inhibit ER-Golgi transport only when they are added before the EGTA-sensitive stage. These results suggest that rbet1 may be involved in the docking process of ER-derived vesicles with the cis-Golgi membrane.

Localization of the Lys, Asp, Glu, Leu tetrapeptide receptor to the Golgi complex and the intermediate compartment in mammalian cells.

The carboxyl-terminal Lys-Asp-Glu-Leu (KDEL), or a closely-related sequence, is important for ER localization of both lumenal as well as type II membrane proteins. This sequence functions as a retrieval signal at post-ER compartment(s), but the exact compartment(s) where the retrieval occurs remains unresolved. With an affinity-purified antibody against the carboxyl-terminal sequence of the mammalian KDEL receptor, we have investigated its subcellular localization using immunogold labeling on thawed cryosections of different tissues, such as mouse spermatids and rat pancreas, as well as HeLa, Vero, NRK, and mouse L cells. We show that rab1 is an excellent marker of the intermediate compartment, and we use this marker, as well as budding profiles of the mouse hepatitis virus (MHV) in cells infected with this virus, to identify this compartment. Our results demonstrate that the KDEL receptor is concentrated in the intermediate compartment, as well as in the Golgi stack. Lower but significant labeling was detected in the rough ER. In general, only small amounts of the receptor were detected on the trans side of the Golgi stack, including the trans-Golgi network (TGN) of normal cells and tissues. However, some stress conditions, such as infection with vaccinia virus or vesicular stomatitis virus, as well as 20 degrees C or 43 degrees C treatment, resulted in a significant shift of the distribution towards the trans-TGN side of the Golgi stack. This shift could be quantified in HeLa cells stably expressing a TGN marker. No significant labeling was detected in structures distal to the TGN under all conditions tested. After GTP gamma S treatment of permeabilized cells, the receptor was detected in the beta-COP-containing buds/vesicles that accumulate after this treatment, suggesting that these vesicles may transport the receptor between compartments. We propose that retrieval of KDEL-containing proteins occurs at multiple post-ER compartments up to the TGN along the exocytotic pathway, and that within this pathway, the amounts of the receptor in different compartments varies according to physiological conditions.

[Comparison of umbilical cord blood transplantation and hematopoietic stem cell transplantation from HLA-matched sibling donors in the treatment of myelodysplastic syndrome-EB or acute myeloid leukemia with myelodysplasia-related changes].

Objective: To compare the clinical efficacy of umbilical cord blood transplantation (UCBT) and hematopoietic stem cell transplantation from HLA-matched sibling donors (MSD-HSCT) in the treatment of myelodysplastic syndrome-EB (MDS-EB) or acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) . Methods: A cohort of 64 patients (including 38 cases of MDS-EB and 26 cases of AML-MRC) who received UCBT/MSD-HSCT from February 2011 to December 2017 were retrospectively analyzed. Results: ①Compared with MSD-HSCT group, UCBT group had a higher proportion of AML-MRC patients [52.8% (19/36) vs 25.0% (7/28) , P=0.025], and a lower median age [13 (1.5-52) years vs 32 (10-57) years, P=0.001]. ②The engraftment of neutrophils both in UCBT and MSD-HSCT groups on +42 d was 100%, and the median engraftment time was 17.5 (11-31) d and 11.5 (10-20) d, respectively. The engraftment of platelet at +100 d in UCBT group was 91.4%, the median engraftment time was 40 (15-96) d; The engraftment of platelet at +100 d in MSD-HSCT group was 100%, and the median engraftment time was 15 (11-43) d. ③There were no statistically significant differences in terms of the cumulative incidence of Ⅱ-Ⅳ and Ⅲ/Ⅳ aGVHD of 100 d and transplant related mortality (TRM) of 180 d, relapse rate, overall survival (OS) , disease-free survival (DFS) between UCBT and MSD-HSCT groups (P>0.05) . ④The 3-year cumulative incidence of chronic GVHD (cGVHD) and severe chronic GVHD in UCBT group were lower than of MSD-HSCT group [28.3% (95%CI 13.4%-45.3%) vs 67.9% (95%CI 46.1%-82.4%) , P=0.002; 10.3% (95%CI 2.5%-24.8%) vs 50.0% (95%CI 30.0%-67.1%) , respectively, P<0.001]. The cumulative 3-year incidence of GVHD-free and relapse-free survival (GRFS) of UCBT group was significantly higher than of MSD-HSCT group [55.0% (95%CI 36.0%-70.6%) vs 28.6% (95%CI 13.5%-45.6%) , P=0.038]. Conclusion: UCBT could obtain better quality of life after transplantation than MSD-HSCT in treatment of MDS-EB/AML-MRC.

[Efficacy analysis of unrelated cord blood transplantation in the treatment of refractory and relapsed adult acute leukemia].

Objective: To explore the clinical efficacy and safety of unrelated umbilical cord blood transplantation (UCBT) in the treatment of refractory and relapsed acute leukemia (AL) patients. Methods: The clinical data of 22 refractory and relapsed AL patients who were treated with UCBT as salvage therapy from November 2009 to May 2017 were retrospectively analyzed. All patients received a myeloablative conditioning regimen for prevention of graft-versus-host disease (GVHD) with cyclosporine A (CSA)/short course of mycophenolate mofetil (MMF). Results: ①Of 22 patients, 9 cases were male and 13 female. The median age was 23 (15-44) years and median weight of 52.5 (43-82) kg. All patients were transplanted with a median umbilical cord blood nucleated cells of 3.07 (1.71-5.30)×107/kg (by weight), the median CD34+ cells was 1.60 (0.63-3.04)×105/kg (by weight). ②The myeloid cumulative implantation rate was 95.5% (95%CI 45.2-99.7%) after transplantation of 42 d, with the median implantation time of 19 (13-27) d. The platelet cumulative implantation rate after transplantation of 120 d was 81.8% (95%CI 54.2-93.6%), the median implantation time of 42 (20-164) d. ③The incidence of Ⅱ-Ⅳ, Ⅲ-Ⅳ aGVHD and the 2 year cumulative incidence of cGVHD were 36.4%, 13.6% and 40.3% respectively. ④ The transplant related mortality (TRM) after transplantation of 180d was 22.7%, 2 year cumulative rate of relapse was 18.7% (95%CI 3.6-42.5%), 2 year disease-free survival rate (DFS) and overall survival rate (OS) were 53.7% and 58.1%, respectively. Conclusion: The preliminary results show that the use of UCBT is safe and effective for refractory and relapsed AL patients who fail to respond to conventional chemotherapy.

Transmembrane topology of the mammalian KDEL receptor.

The mammalian KDEL receptor is an integral membrane protein with seven hydrophobic regions. Fusion proteins comprising a 37-kDa N-glycosylation reporter fused downstream of amino-terminal fragments of the KDEL receptor with varying numbers of hydrophobic regions were synthesized in an in vitro translation system containing canine pancreatic microsomes. The luminal or cytosolic orientation of the reporter, and hence of the hydrophilic region to which it is fused, was inferred from the presence or absence of glycosylation, which occurs only in the lumen of the microsomes. The cytosolic orientation of the N and C termini was also confirmed immunocytochemically. Our results suggest that the KDEL receptor is inserted into the membrane with only six transmembrane domains and that both the amino and carboxy termini are located in the cytoplasm.

The mammalian homolog of yeast Sec13p is enriched in the intermediate compartment and is essential for protein transport from the endoplasmic reticulum to the Golgi apparatus.

The role of COPII components in endoplasmic reticulum (ER)-Golgi transport, first identified in the yeast Saccharomyces cerevisiae, has yet to be fully characterized in higher eukaryotes. A human cDNA whose predicted amino acid sequence showed 70% similarity to the yeast Sec13p has previously been cloned. Antibodies raised against the human SEC13 protein (mSEC13) recognized a cellular protein of 35 kDa in both the soluble and membrane fractions. Like the yeast Sec13p, mSEC13 exist in the cytosol in both monomeric and higher-molecular-weight forms. Immunofluorescence microscopy localized mSEC13 to the characteristic spotty ER-Golgi intermediate compartment (ERGIC) in cells of all species examined, where it colocalized well with the KDEL receptor, an ERGIC marker, at 15 degrees C. Immunoelectron microscopy also localized mSEC13 to membrane structures close to the Golgi apparatus. mSEC13 is essential for ER-to-Golgi transport, since both the His6-tagged mSEC13 recombinant protein and the affinity-purified mSEC13 antibody inhibited the transport of restrictive temperature-arrested vesicular stomatitis virus G protein from the ER to the Golgi apparatus in a semi-intact cell assay. Moreover, cytosol immunodepleted of mSEC13 could no longer support ER-Golgi transport. Transport could be restored in a dose-dependent manner by a cytosol fraction enriched in the high-molecular-weight mSEC13 complex but not by a fraction enriched in either monomeric mSEC13 or recombinant mSEC13. As a putative component of the mammalian COPII complex, mSEC13 showed partially overlapping but mostly different properties in terms of localization, membrane recruitment, and dynamics compared to that of beta-COP, a component of the COPI complex.

Morphological and functional association of Sec22b/ERS-24 with the pre-Golgi intermediate compartment.

Yeast Sec22p participates in both anterograde and retrograde vesicular transport between the endoplasmic reticulum (ER) and the Golgi apparatus by functioning as a v-SNARE (soluble N-ethylmaleimide-sensitive factor [NSF] attachment protein receptor) of transport vesicles. Three mammalian proteins homologous to Sec22p have been identified and are referred to as Sec22a, Sec22b/ERS-24, and Sec22c, respectively. The existence of three homologous proteins in mammalian cells calls for detailed cell biological and functional examinations of each individual protein. The epitope-tagged forms of all three proteins have been shown to be primarily associated with the ER, although functional examination has not been carefully performed for any one of them. In this study, using antibodies specific for Sec22b/ERS-24, it is revealed that endogenous Sec22b/ERS-24 is associated with vesicular structures in both the perinuclear Golgi and peripheral regions. Colabeling experiments for Sec22b/ERS-24 with Golgi mannosidase II, the KDEL receptor, and the envelope glycoprotein G (VSVG) of vesicular stomatitis virus (VSV) en route from the ER to the Golgi under normal, brefeldin A, or nocodazole-treated cells suggest that Sec22b/ERS-24 is enriched in the pre-Golgi intermediate compartment (IC). In a well-established semi-intact cell system that reconstitutes transport from the ER to the Golgi, transport of VSVG is inhibited by antibodies against Sec22b/ERS-24. EGTA is known to inhibit ER-Golgi transport at a stage after vesicle/transport intermediate docking but before the actual fusion event. Antibodies against Sec22b/ERS-24 inhibit ER-Golgi transport only when they are added before the EGTA-sensitive stage. Transport of VSVG accumulated in pre-Golgi IC by incubation at 15 degreesC is also inhibited by Sec22b/ERS-24 antibodies. Morphologically, VSVG is transported from the ER to the Golgi apparatus via vesicular intermediates that scatter in the peripheral as well as the Golgi regions. In the presence of antibodies against Sec22b/ERS-24, VSVG is seen to accumulate in these intermediates, suggesting that Sec22b/ERS-24 functions at the level of the IC in ER-Golgi transport.

Localization and recycling of gp27 (hp24gamma3): complex formation with other p24 family members.

We report here the characterization of gp27 (hp24gamma3), a glycoprotein of the p24 family of small and abundant transmembrane proteins of the secretory pathway. Immunoelectron and confocal scanning microscopy show that at steady state, gp27 localizes to the cis side of the Golgi apparatus. In addition, some gp27 was detected in COPI- and COPII-coated structures throughout the cytoplasm. This indicated cycling that was confirmed in three ways. First, 15 degrees C temperature treatment resulted in accumulation of gp27 in pre-Golgi structures colocalizing with anterograde cargo. Second, treatment with brefeldin A caused gp27 to relocate into peripheral structures positive for both KDEL receptor and COPII. Third, microinjection of a dominant negative mutant of Sar1p trapped gp27 in the endoplasmic reticulum (ER) by blocking ER export. Together, this shows that gp27 cycles extensively in the early secretory pathway. Immunoprecipitation and coexpression studies further revealed that a significant fraction of gp27 existed in a hetero-oligomeric complex. Three members of the p24 family, GMP25 (hp24alpha2), p24 (hp24beta1), and p23 (hp24delta1), coprecipitated in what appeared to be stochiometric amounts. This heterocomplex was specific. Immunoprecipitation of p26 (hp24gamma4) failed to coprecipitate GMP25, p24, or p23. Also, very little p26 was found coprecipitating with gp27. A functional requirement for complex formation was suggested at the level of ER export. Transiently expressed gp27 failed to leave the ER unless other p24 family proteins were coexpressed. Comparison of attached oligosaccharides showed that gp27 and GMP25 recycled differentially. Only a very minor portion of GMP25 displayed complex oligosaccharides. In contrast, all of gp27 showed modifications by medial and trans enzymes at steady state. We conclude from these data that a portion of gp27 exists as hetero-oligomeric complexes with GMP25, p24, and p23 and that these complexes are in dynamic equilibrium with individual p24 proteins to allow for differential recycling and distributions.

A novel synaptobrevin/VAMP homologous protein (VAMP5) is increased during in vitro myogenesis and present in the plasma membrane.

cDNA clones encoding a novel protein (VAMP5) homologous to synaptobrevins/VAMPs are detected during database searches. The predicted 102-amino acid VAMP5 harbors a 23-residue hydrophobic region near the carboxyl terminus and exhibits an overall amino acid identity of 33% with synaptobrevin/VAMP1 and 2 and cellubrevin. Northern blot analysis reveals that the mRNA for VAMP5 is preferentially expressed in the skeletal muscle and heart, whereas significantly lower levels are detected in several other tissues but not in the brain. During in vitro differentiation (myogenesis) of C2C12 myoblasts into myotubes, the mRNA level for VAMP5 is increased approximately 8- to 10-fold. Immunoblot analysis using antibodies specific for VAMP5 shows that the protein levels are also elevated approximately 6-fold during in vitro myogenesis of C2C12 cells. Indirect immunofluorescence microscopy and immunoelectron microscopy reveal that VAMP5 is associated with the plasma membrane as well as intracellular perinuclear and peripheral vesicular structures of myotubes. Epitope-tagged versions of VAMP5 are similarly targeted to the plasma membrane.

[Comparison of unrelated cord blood transplantation and HLA-identical sibling peripheral blood stem cell transplantation for the treatment of adult hematological malignancies].

Objective: To compare the efficacy of unrelated cord blood transplantation (UCBT) and HLA-identical sibling peripheral blood stem cell transplantation (PBSCT) for the treatment of adult hematological malignancies. Methods: From April 2011 to December 2015, a total of 81 patients receiving single-unit UCBT and 57 patients receiving HLA-identical sibling PBSCT were enrolled in this study. All of the patients received myelablative conditioning. Cyclosporine combined with mycophenolate mofetil was adopted for GVHD prophylaxis. Results: The cumulative incidence of neutropil engraftment at day-42 was 95.0% and 100% in UCBT and sibling PBSCT groups, respectively (P=0.863) . Platelet engraftment at day 100 was 87.3% (95%CI 76.8%-93.1%) in UCBT group, which was significantly lower than that of sibling PBSCT group[98.2% (95%CI 87.3%-99.7%) ] (P=0.005) . There were no significant differences in terms of Ⅱ-Ⅳ acute GVHD or Ⅲ-Ⅳ acute GVHD in two groups (P=0.142, 0.521) . The 3-year chronic GVHD and extensive chronic GVHD were 14.9% (95%CI 5.2%-23.5%) and 11.2% (95%CI 2.9%-18.7%) , respectively in UCBT group, which was significantly lower than that of sibling PBSCT group[35.2% (95%CI 19.4%-47.8%) , 31.4% (95%CI 16.2%-43.9%) ] (P=0.008, 0.009) . The 3-year transplant-related mortality (TRM) was similar between two groups (30.1% vs 23.2%, P=0.464) . The relapse rate at 3-year in UCBT group[12.9% (95%CI 6.6%-21.5%) ]was significantly lower than that in sibling PBSCT group[24.3% (95%CI 13.5%-36.8%) ] (P=0.039) . There were no significant differences in terms of overall survival (OS) and disease-free survival (DFS) between two groups (58.6% vs 54.8%, P=0.634; 57.0% vs 52.4%, P=0.563) . But GVHD-free and relapse-free survival (GRFS) in UCBT group [55.7% (95%CI 44.1%-65.8%) ]was significantly higher than that of sibling PBSCT group[42.9% (95%CI 29.8%-55.3%) ] (P=0.047) . Conclusions: For adult hematological malignancies, the incidences of acute GVHD and TRM were similar between UCBT and sibling PBSCT recipients, and the incidences of chronic GVHD and relapse were lower in UCBT recipients. UCBT recipients had higher GRFS rate although OS and DFS were similar between two groups, which may reflect the real recovery and better quality of life following UCBT.

Clinical separation of cGvHD and GvL and better GvHD-free/relapse-free survival (GRFS) after unrelated cord blood transplantation for AML.

Few studies have presented a comparison of myeloablative cord blood transplantation (CBT) and HLA-identical sibling hematopoietic cell transplantation (HCT) for AML in a disease-specific analysis, and the evaluation of GvHD-free and relapse-free survival (GRFS) in AML patients after unrelated CBT has not been reported. A total of 162 consecutive AML patients receiving intensified myeloablative unrelated CBT (n=107) or allogeneic PBSC transplantation (allo-PBSCT) or bone marrow transplantation (BMT) from an HLA-identical sibling donor (n=55) were investigated. Neutrophil or platelet engraftment was slower in the CBT cohort compared with that in the allo-PBSCT/BMT cohort. The incidence of grade II-IV or grade III-IV acute GvHD (aGvHD) and transplant-related mortality (TRM) were not significantly different in the two cohorts. Compared with the allo-PBSCT/BMT cohort, the CBT cohort had a significantly lower rate of chronic GvHD (cGvHD) (13.7% vs 28.3%; P=0.047) or extensive cGvHD (9.9% vs 24.1%; hazard ratio (HR)=2.06, P=0.039). The incidence of relapse at 5 years in the CBT cohort was significantly lower than that in the allo-PBSCT/BMT cohort (15.3% vs 36.1%; HR=4.62, P=0.009). The probabilities of overall survival and leukemia-free survival were similar between the two cohorts. The adjusted 5-year probability of GRFS was higher after CBT than that after allo-PBSCT/BMT (55.4% vs 39.2%; HR=1.63, P=0.042). The present study suggests that, for AML patients, intensified myeloablative unrelated CBT is associated with less cGvHD and a lower risk of relapse. In addition, these patients do not experience excessive TRM or severe aGvHD that translates into better GRFS compared with those patients who undergo HLA-identical sibling allo-PBSCT/BMT; this observation may reflect the clinical separation between cGvHD and GvL within our CBT protocol.

[Pathogens and clinical characteristics of bacterial infection in hematology department between 2010 and 2014].

OBJECTIVE: To analyze the characteristics of distribution and drug resistance of bacterial infection in several different parts of hematology department inpatients of Anhui Provincial Hospital from January 2010 to December 2014, including patients who had received hematopoietic stem cell transplantation (HSCT). METHODS: Anti-microbial susceptibility test was done by Kirby-Bauer method and automated systems and the data were analysed by WHONET 5.6 software. RESULTS: A total of 3 312 copies of inspection samples were analyzed, including 2 716 (82%) blood samples and other 596 specimens (18%). 634 bacterial strains were isolated from 3 312 samples (19.14%) including 488 samples (76.97%) from blood culture. 427 (67.35%) bacterial strains were gram-negative, and the other 207 (32.65%) were gram-positive. Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were most common gram-negative bacterial and the resistant rates to imipenem were 0.8%, 11.8% and 3.3%, respectively. Detection rates of Extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae were 83.9% and 75.0%, respectively. At the same time, Coagulase negative Staphylococcus, Streptococcus and Enterococcus were most common kinds of gram-positive bacteria. Methicillin-resistant coagulase negative staphylococcus accounted for 65.9% antibiotic resistance. No vancomycin and/or linezolid and/or tigecycline resistant strains of Staphylococcus spp. and Enterococcus spp. were found in those patients. CONCLUSION: Patients with hematology diseases had a higher risk of bacterial infections, mainly caused by Gram-negative bacteria. There are different distributions of bacterial in different wards.