[Study on the Effect and Mechanism of Tetrandrine on Bone Marrow Mesenchymal Stem Cell-Mediated Drug Resistance in Leukemia].

OBJECTIVE: To explore the role of bone marrow mesenchymal stem cells (BMSC)，an essential element of the bone marrow microenvironment, in multidrug resistance(MDR) of K562 cells, as well as the reversal effect of tetrandrine (TET) on BMSC-mediated MDR and its potential mechanism. METHODS: A mixed co-culture system and a transwell co-culture system for BMSC and K562 cells were established, and the cells were divided into different groups and treated with daunorubicin (DNR) alone or combined with TET and DNR. The CCK-8 assay was used to detect the proliferation of K562 cells in each group, and the cell inhibition rate was calculated. Cytometric bead array (CBA) was used to detect the expression levels of IFN, IL-2, IL-6 and IL-10 in the supernatant of different groups. RT-qPCR and Western blot were used to detected the expression of STAT3 at mRNA and protein levels, respectively. RESULTS: Compared with K562+DNR group, the inhibition rate of DNR on K562 cell proliferation in K562+BMSC+DNR group was significantly decreased (P < 0.05), while the levels of IL-6 in the culture supernatant and phosphorylated STAT3 in K562 cells were significantly increased (P < 0.05). Compared with K562+BMSC+DNR group, the inhibition rate of DNR on K562 cell proliferation in K562+BMSC+DNR+TET group was significantly increased (P < 0.05), while the level of IL-6 and phosphorylated STAT3 was significantly decreased (P < 0.05). CONCLUSION: BMSC can promote the drug resistance of leukemia cells, and TET may reverse the BMSC-mediated drug resistance via inhibiting IL-6/STAT3 signaling pathway.

[Basic Research on Therapy of Leukemia with Nanoparticles Drug Delivery System Modified by Transferrin Receptor Monoclonal Antibody].

OBJECTIVE: To investigate the therapeutic effect of targeted drug-loaded nanoparticles modified by transferrin receptor monoclonal antibody (TfR mAb) on acute leukemia and its potential anti-tumor mechanism. METHODS: Nanoparticles drug delivery system, which was composed of poly (lactic-co-glycolic acid), poly-l-lysine, polyethylene glycol, TfR mAb (TfR mAb-PLGA-PLL-PEG)-daunorubicin (DNR), was first synthesized. After drug intervention, the intracellular accumulation in leukemia HL60 cells was observed under a fluorescent microscope and concentration of DNR was determined by flow cytometry (FCM). Meanwhile, cell apoptosis rate was measured by FCM and the expression levels of apoptosis related protein Cleaved-caspase 3 was determined by Western blot. RESULTS: Under an inverted fluorescent microscope, intracellular accumulation of DNR autofluorescence in HL60 cells was observed in both TfR mAb-PLGA-PLL-PEG-DNR group and DNR group. FCM analysis showed that the intracellular concentration of DNR in TfR mAb-PLGA-PLL-PEG-DNR group was higher than that in DNR group（P<0.05）. The apoptotic rate of HL60 cells in TfR mAb-PLGA-PLL-PEG-DNR group was higher than that of DNR group（P<0.05）. Moreover, the expression levels of apoptosis-related protein Cleaved-caspase 3 in TfR mAb-PLGA-PLL-PEG-DNR group was significantly higher than that in DNR group（P<0.05）. CONCLUSION: TfR mAb-PLGA-PLL-PEG nanoparticle drug delivery system can target chemotherapy drugs to leukemia cells and enhance anticancer ability through apoptotic pathway.

The CSN5/HSF/SPI1/PU.1 Axis Regulates Cell Proliferation in Hypocellular Myelodysplastic Syndrome Patients.

OBJECTIVE: This study explored the relationship between the activation of the jak/stat3 signaling pathway and the CSN5 gene transcript and protein expression levels in the hematopoietic stem cells of patients with myelodysplastic syndromes (MDSs). This study also aimed to investigate the correlation between the expression level of CSN5 and the deubiquitination of HSF1, as well as the transcript level of the spi1/pu.1 genes to explore the pathogenesis of MDS. MATERIALS AND METHODS: We isolated cells from normal individuals and MDS patients, and the mRNA and protein expression levels of spi1/pu.1 in cd34+ cells (hematopoietic stem cells) were measured by PCR and western blotting, respectively. A ChIP assay was used to detect the binding of HSF1 to the spi1/pu.1 promoter in cd34+ cells. The ubiquitination of HSF1 in cd34+ cells was detected by CO-IP. The binding of HSF1 and Fbxw7α was detected in in cd34+ cells by CO-IP. The binding of HSF1 and CSN5 was evaluated. A luciferase reporter assay was used to detect the effect of STAT3 on CSN5 promoter activation in cd34+ cells. Western blotting was used to detect the phosphorylation of STAT3 in cd34+ cells of MDS patients. The binding of STAT3 and C/EBP beta in cd34+ cells was detected by CO-IP. RESULTS: Inhibition of SPI1/PU.1 expression was observed in MDS samples with low proliferation ability. Further experiments proved that phosphorylation of STAT3 affected CSN5 function and mediated the ubiquitination of HSF, the upstream regulator of SPI1/PU.1 transcription, which led to the inhibition of SPI1/PU.1 expression. Restoration of CSN5 rescued the inhibition of HSF1 ubiquitination, causing SPI1/PU.1 transcription to resume and increasing SPI1/PU.1 expression, promoting the recovery of cell proliferation in hypocellular MDS. CONCLUSIONS: Our research revealed the regulatory role of the CSN5/HSF/SPI1/PU.1 axis in hypocellular MDS, providing a probable target for clinical intervention.

[Clinical Characteristics and Prognosis of Patients with Hematological Malignancies Superimposed with Solid Tumors].

OBJECTIVE: To investigate the clinical characteristics and prognosis of hematological malignancies superimposed patients with solid tumors. METHODS: The clinical data of 30 patients with more than two kinds of malignancy (the second is hematological malignancy) from October 2011 to October 2020 in Department of Hematology, Jiangning Hospital Affiliated to Nanjing Medical University were collected and analyzed retrospectively. The overall survival time was used as the prognostic evaluation standard, and the survival of patients were analyzed by KaplanMeier method. Logrank test and Cox regression model were used to carry out univariate and multivariate retrospective analysis on clinical and laboratory parameters of 30 patients. RESULTS: Among 30 cases, 20 were male, 10 were female, the median age of onset of the second tumor was 70 years old. The common types of the secondary hematological malignancies to solid tumors are myelodysplastic syndrome, acute myeloid leukemia, multiple myeloma. Univariate analysis showed that patients' gender, age, type of solid tumors, the onset of interval between two kinds of tumor, chromosome karyotype were not related to do with the patients' overall survival time. Type of hematologic disease, ECOG score were associated with patients' overall survival time, and the multivariate analysis showed that the type of hematologic disease and ECOG score were independent risk factors for patients with poor prognosis. CONCLUSION: Patients superimposed with solid tumors complicated with myelodysplastic syndrome or acute leukemia and ECOG score ≥3 have poor prognosis and shorter overall survival time, which are independent risk factors influencing the prognosis. Bone marrow injury, immune dysfunction and genetic susceptibility after chemoradiotherapy may be the main causes of these diseases.

[Clinical and Cytogenetical Characteristics in Acute Myeloid Leukemia with Myelodysplasia-Related Changes].

OBJECTIVE: To explore the clinical and cytogenetic characteristics of acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) based on morphology define. METHODS: A total of 180 newly diagnosed acute myeloid leukemia (AML) patients were enrolled and retrospectively analyzed, and marrow cell morphology of 126 patients were re-evaluated. The clinical and cytogenetic characteristics, including ages, sex, WBC count, HGB level, PLT count, blasts percentage, abnormal karyotype detection rate of the patients in AML with multilineage dysplasia (AML-MRC-1), secondary AML from myelodysplastic/ myeloproliferative neoplasms (MDS/MPN) (AML-MRC-2), and AML not otherwise specified (AML-NOS) groups were investigated. RESULTS: There was no significant differences between the patients in three groups in terms of sex, age and platelet count (P=0.898, P=0.365, P=0.853), but AML-MRC-2 group (73.2%) was higher than AML-MRC-1 (60.0%) and AML-NOS (56.4%) in the percentages of patients over 60 years old (P=0.228); there were statistically significant differences on WBC count, HGB level, and blasts percentage (P=0.000, P=0.022, P=0.000, AML-MRC-2

[Prevalence of Human T-Cell Lymphotropic Virus Type 1 and 2 among Blood Donors in Jiangsu from 2016 to 2019].

OBJECTIVE: To investigate the prevalence of human T-cell lymphotropic virus (HTLV) type-I/II infection among voluntary blood donors in Jiangsu (Nanjing, Suzhou, Xuzhou). METHODS: From 2016 to 2019, 408 262 samples of voluntary blood donors from four blood stations in Jiangsu Province (Jiangsu Province Blood Center, Nanjing Red Cross Blood Center, Suzhou Central Blood Station, and Xuzhou Central Blood Station) were screened for HTLV-I/II antibody by ELISA. The positive samples were sent to National Center for Clinical Laboratories for confirmation by RT-PCR and Western blot. RESULTS: The positive rate of HTLV-I/II screened by ELISA was 0.20‰ (82/408 262), and three HTLV-I positive samples were confirmed. The prevalence of HTLV-1 infection was 0.74 per 100 000 (3/408 262). All three donors were female repeated blood donors of childbearing ages. CONCLUSION: Jiangsu is a low prevalence area of HTLV, and a reasonable blood screening strategy for HTLV can further reduce the risk of transfusion-transmitted virus infection.

[Analysis of Relevant Factors of Refractory and Relapse DLBCL Treated by Rituximab Combined with CHOP/EPOCH Regimen].

OBJECTIVE: To analyze the efficacy of rituximab combined with CHOP/EPOCH regimen for treatment of diffuse large B-cell lymphoma（DLBCL） patients, and to explore the high risk factors of refractory and relapsed patients. METHODS: The clinical data of 72 patients with de novo DLBCL from December 2012 to December 2018 in the Department of Hematology, Zhongda Hospital Affiliated to Southeast University were retrospectively analyzed. The remission rate of DLBCL patients treated by rituximab combined with CHOP/EPOCH was analyzed, and survival analysis was conducted to explore the risk factors influencing refractory recurrence. RESULTS: 45 cases among 72 patients achieved complete remission (CR), 11 cases achieved partial remission (PR), the total remission rate was 77.78%. 25 cases (34.2%) refractory and relapsed. Single factor analysis showed that the B symptoms, low Hb, high NLR, low MLR, high ß2-MG, high ESR, high hs-CRP, high LDH, low ALB, low HDL were high risk factors of refractory and relapsed DLBCL. Multivariate Logistic analysis showed B symptoms, low Hb, high ß2-MG, high ESR, and high hs-CRP were significantly related with refractory relapse. Survival analysis showed that OS of refractory and relapsed group was significantly worse than that in remission group. In addition, OS of patients with B symptoms, anemia, low LMR, high ß2-MG, high hs-CRP, high LDH, low ALB and low HDL was significantly worse than that of control group. CONCLUSION: The remission rate of DLBCL patients treated by rituximab combined with CHOP/EPOCH regimen is high, but about one third of the patients still show refractory and relapsed. B Symptoms, anemia, high ß2-MG, ESR and hs-CRP are the independent prognostic factors.

[Analysis of Non-genetic Factors Influencing the Overall Survival of Multiple Myeloma Patients].

OBJECTIVE: To explore the non-genetic factors of overall survival in patients with multiple myeloma (MM). METHODS: Kaplan-Meier survival curve, Log-rank test and Cox regression model were used to carry out univariate and multivariate retrospective analysis on clinical and laboratory parameters of 51 patients who were newly diagnosed with MM and had complete follow-up data in the Department of Hematology, the Affiliated Jiangning Hospital of Nanjing Medical University from November 2011 to October 2019. RESULTS: Fifty-one patients included 29 males and 22 females. Followed up to December 2019, 21 cases died and 30 cases survived. The univariate analysis showed that the overall survival time of the patients was influenced by age, disease stage, standard treatment, new drugs, maintenance treatment, hypercalcemia, globulin, albumin, and hemoglobin. The overall survival time of patients with age <65 years old, ISS stage I and II, standardized treatment, new drugs, normal or below normal blood calcium, normal or below normal globulin, albumin ≥35 g/L or hemoglobin ≥100 g/L was prolonged significantly (P<0.05). The multivariate analysis showed that maintenance treatment, hypercalcemia (≥2.6 mmol/L), and hemoglobin (<100 g/L) were independent risk factors influencing the prognosis of MM patients. CONCLUSION: Patients with blood calcium ≥2.6 mmol/L, hemoglobin <100 g/L, and who do not undergo regular maintenance therapy show a poor prognosis.

[Clinical Analysis of Autologous Peripheral Blood Hematopoietic Stem Cell Mobilization Regimen in Patients with Malignant Hematological Diseases].

OBJECTIVE: To analyze the factors influencing the mobilization and collection of peripheral blood hematopoietic stem cells (HSC) in the patients with malignant hematological diseases. METHODS: The peripheral blood stem cells in 50 patients with hematological malignancies had been mobilized in the Hematology Department Zhongda Hospital. The factors, such as age, sex, mobilization regimen, disease status, cell separator were analyzed, and the effect of above-mentioned factors on stem cell mobilization was evaluated. And the correlation between WBC, Hb, Plt counts and CD34+ cell collection was anzlyzed. RESULTS: There was significant effect at mobilization regimen on the success rate and collection counts of CD34+ cells, while sex, age, interval between diagnosis and mobilization, previous chemotherapy regimen and bone marrow involvement showed no significant effect on stem cell collection. There was positively correlation of the WBC count, hemoglobin level of peripheral blood before apheresis with the collection of CD34+ cells . The WBC and MNC counts in peripheral blood before apheresis closely related with the success rate of mobilization. CONCLUSION: Chemotherapy plus combined with G-CSF mobilization regimens is superior to mobilization regimen of cytokine alone for collection of HSC. The WBC and MNC count in peripheral blood before apheresis can predict the optimal time for the PBSC collection and increase the success rate of mobilization and collection.

[Advance of Research on the Immunotherapy Targeting B Cell Maration Antigen for Multiple Myeloma--Review].

Abstract　　B cell maturation antigen (BCMA) is an ideal target for precise treatment due to its highly selective expression on malignant myeloma cells. This review summarizes briefly the advances in the latest research progress on biological activity of BCMA, its significance as a biomarker and immunotherapy direcited against BCMA, such as bispecific antibodies, antibody drug conjugates, chimeric antigen receptor T cell therapy against mature B cell antigens.

A New Conditioning Regimen Can Significantly Promote Post-Transplant Immune Reconstitution and Improve the Outcome of Umbilical Cord Blood Transplantation for Patients.

This study included data from 81 consecutively enrolled patients with hematological diseases who had been treated with unrelated umbilical cord blood transplantation (UCBT) between September 2014 and April 2019. All patients received intense conditioning regimens with combined fludarabine and high-dose cyclophosphamide (FC) before undergoing UCBT. Sixty-seven patients received a single UCBT, and 14 patients received a double UCBT. Fifty patients were pretreated with the fludarabine, busulfan, and cyclophosphamide (FBC) protocol, while 31 patients were treated with FC before transplantation. Graft-versus-host disease (GVHD) was prevented with cyclosporine A and mycophenolate mofetil administration. According to low-resolution, human leukocyte antigen (HLA) donor-recipient matching at six sites, 53 patients had 5-6 matches, while 28 patients had 4 matches. Seventy-eight patients (96.3%) achieved complete engraftment in this study. Thirty-six patients developed acute GVHD (aGVHD). The cumulative incidence of grade I-II aGVHD at day 100 posthematopoietic stem cell transplantation was 29.6%, and the cumulative incidence of grade III-IV aGVHD was 14.8%. At the end of the follow-up, 12 patients died due to treatment-related complications, and 4 died of disease relapse after transplantation. The transplant-related deaths were due to transplant-related infection (8 of 81), GVHD (2 of 81), and organ toxicity (2 of 81). The probability of overall survival (OS) was 80.2%. A higher dose of cyclophosphamide combined with fludarabine conditioning in UCBT was an effective curative method for treatment of hematologic disorders and could enhance the engraftment of umbilical cord blood stem cells, promote post-transplant immune reconstitution, and improve OS.

A ZEB1/p53 signaling axis in stromal fibroblasts promotes mammary epithelial tumours.

Accumulating evidence indicates that the zinc-finger transcription factor ZEB1 is predominantly expressed in the stroma of several tumours. However, the role of stromal ZEB1 in tumour progression remains unexplored. In this study, while interrogating human databases, we uncover a remarkable decrease in relapse-free survival of breast cancer patients expressing high ZEB1 levels in the stroma. Using a mouse model of breast cancer, we show that ZEB1 inactivation in stromal fibroblasts suppresses tumour initiation, progression and metastasis. We associate this with reduced extracellular matrix remodeling, immune cell infiltration and decreased angiogenesis. ZEB1 deletion in stromal fibroblasts increases acetylation, expression and recruitment of p53 to FGF2/7, VEGF and IL6 promoters, thereby reducing their production and secretion into the surrounding stroma. Importantly, p53 ablation in ZEB1 stroma-deleted mammary tumours sufficiently recovers the impaired cancer growth and progression. Our findings identify the ZEB1/p53 axis as a stroma-specific signaling pathway that promotes mammary epithelial tumours.

[Characteristics and Clinical Significance of RAG1 Expression in Adult B-Cell Acute Lymphoblastic Leukemia].

OBJECTIVE: RAG1 plays important roles in lymphopoiesis and immune system, its dysfunction may result in the malignancies of hemopoietic system. The aim of this study was to investigate the characteristics of RAG1 expression in adult B-cell acute lymphoblastic leukemia (B-ALL), and to analyze the clinical significances. METHODS: Quantitative PCR (q-PCR) was performed to evaluate the expression of RAG1 in 104 newly diagnosed, 22 relapsed adult B-ALL patients and 30 normal controls, the clinical significances of RAG1 expression were analyzed. RESULTS: Compared with normal controls, newly diagnosed and relapsed adult B-ALL patients showed higher RAG1 expression level (3.94 vs 1.23) (P＜0.01), (5.86 vs 1.23) (P＜0.01). The analysis of paired simples from 6 cases of newly diagnosed and relapsed B-ALL showed that the expression level of RAG1 at relapse was significantly higher than that at new diagnosis (13.65 vs 2.31) (P＜0.01). The RAG1 expression level in IK6 positive patients was higher than that in IK6 negative patients (5.30 vs 2.11) (P＜0.05). The ratio of patients with LDH＞1 000 U/L in RAG1 high expression group was higher than that in RAG1 low expression group (42.2% vs 20.5%) (P＜0.05). CONCLUSION: RAG1 up-regulation may play an important role in the development of adult B-ALL especially when relapsed, which may also take part in the formation of Ik6. Monitoring RAG1 expression may provide a new method to evaluate the prognosis of adult B-ALL patients.

Shaping of CD56bri Natural Killer Cells in Patients With Steroid-Refractory/Resistant Acute Graft-vs.-Host Disease via Extracorporeal Photopheresis.

CD56bri natural killer (NK) cells play an important role in the pathogenesis of graft-vs. -host disease (GVHD) and immune defense in the early period after allogeneic hematopoietic stem cell transplantation. Extracorporeal photopheresis (ECP) as an immunomodulating therapy has been widely used for GVHD treatment. However, the mechanism of action of ECP still remains to be elucidated, particularly the influence of ECP on NK cells. Thirty-four patients with steroid-refractory/resistant acute GVHD (aGVHD) ≥ °II and moderate to severe chronic GVHD (cGVHD) received ECP therapy. Patient samples obtained during intensive and long-term treatment were analyzed. Immunomonitoring with respect to cell phenotype and function was performed on rested peripheral blood mononuclear cells (PBMCs) using multiparametric flow cytometry. NK activity in terms of cytokine release was analyzed by intracellular cytokine staining after co-culture with K562 cells. Moreover, the proliferative capacity of NK cells, CD4+, and CD8+ T cells was determined by carboxyfluorescein succinimidyl ester (CFSE) staining. Clinically, 75% of aGVHD and 78% of cGVHD patients responded to ECP therapy. Moreover, our data show that aGVHD, cGVHD patients and healthy donors (HDs) present distinct NK patterns: aGVHD patients have a higher frequency of CD56bri NK subsets with stronger NKG2D and CD62L expression, while CD56-CD16+ NK cells with higher expression of CD57 and CD11b stand out as a signature population for cGVHD. ECP therapy could significantly decrease CD56briCD16- NK cells with shifting the quality from a cytotoxic to a regulatory pattern and additionally mature CD56dim NK cells via upregulation of CD57 in complete responding aGVHD patients. Moreover, ECP could keep the anti-viral and anti-leukemic effects intact via maintaining specialized anti-viral/leukemic CD57+NKG2C+CD56dim NK cells as well as remaining the quality and quantity of cytokine release by NK cells. The proliferative capacity of effector cells remained constant over ECP therapy. In conclusion, ECP represents an attractive option to treat GVHD without compromising anti-viral/leukemic effects. Shaping of CD56bri NK cell compartment by downregulating the cytotoxic subset while upregulating the regulatory subset contributes to the mechanisms of ECP therapy in aGVHD.

[Efficacy Analysis of Unrelated Umbilical Cord Blood Transplantation for the Treatment of Wiskott-Aldrich Syndrome].

OBJECTIVE: To explore the clinical efficacy and safety of unrelated umbilical cord blood transplantation (UCBT) for the treatment of Wiskott-Aldrich syndrome(WAS). METHODS: Five pediatric patients with WAS received single UCBT were retrospectively analyzed. The median age of these male patients was 268 days (range, 3 days -695 days). Among them, 2 patients were transplanted with a 6/6 matched cord blood graft，the other 3 patients received a 5/6 matched cord blood graft. Myeloablative conditioning regimen was applied, and all patients received a combination of cyclosporine and mycophenolate mofetil for the prophylaxis of graft versus host disease (GVHD). The recovery time of neutrophils and platelets as well as chimerism after transplantation were taken as the evidence of hematopoietic reconstruction. RESULTS: All the five pediatric patients had hematopoietic recovery. A median time of neutrophil cells after transplantation was at 15.8 days (range,11 days -25 days), and platelet recovery was at a median of 20.4 days(range,12 days-30 days). Chimerism data were available for 5 patients at 30 days after UCBT, 4 out of the 5 patients had full donor chimerism and only one patient had mixed chimerism. There were 2 cases with pre-engraftment syndrome, 3 cases with acute GVHD gradeⅠ-Ⅲ, 4 cases with pulmonary infection and cytomegalovirus infection, but chronic GVHD was not observed in 5 cases. Four patients were alive with a median follow-up of 12.3 months (range, 5 months-17 months), and one patient had died at 22 days after UCBT. CONCLUSION: Unrelated umbilical cord blood transplantation is a safe and effective treatment method for Wiskott-Aldrich syndrome.

Anticancer activity and underlying mechanism of neogambogic acid.

Garcinia, a kind of dry resin secreted by Garcinia hanburyi Hook. F. G., is a traditional Chinese medicine with various biological functions such as detoxification, anti-inflammatory, and anthelmintic activities. Recent studies suggest that garcinia has potential anticancer activity. Increasing evidences indicate that the main active monomer gambogic acid isolated from garcinia can inhibit the growth of various cancer cells. Neogambogic acid is an isolated compound with a similar chemical structure as gambogic acid. Preliminary studies show that the neogambogic acid can selectively inhibit the growth of various cancer cells, and has a broader antitumor activity and lower toxicity than gambogic acid. In this review, we summarize the advances made in the investigation of the anti-tumor effect of neogambogic acid in recent years.

Gambogic acid induces cell apoptosis through endoplasmic reticulum stress triggered inhibition of Akt signaling pathways in extranodal NK/T-cell lymphoma cells.

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma (ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid (GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time- and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress (ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.

Modulation of B Cells and Homing Marker on NK Cells Through Extracorporeal Photopheresis in Patients With Steroid-Refractory/Resistant Graft-Vs.-Host Disease Without Hampering Anti-viral/Anti-leukemic Effects.

Graft-vs.-host disease (GvHD), a severe complication of allogeneic hematopoietic stem cell transplantation, significantly affects the post-transplant morbidity and mortality. Systemic steroids remain the gold standard for the initial management of GvHD. However, up to 60% of patients will not sufficiently respond to steroids. Extracorporeal photopheresis (ECP), a cell-based immunotherapy, has shown good clinical results in such steroid-refractory/resistant GvHD patients. Given its immunomodulatory, but not global immunosuppressive and steroid-sparing capacity, ECP constitutes an attractive option. In the case of GvHD, the balance of immune cells is destroyed: effector cells are not any longer efficiently controlled by regulatory cells. ECP therapy may restore this balance. However, the precise mechanism and the impact of ECP on anti-viral/anti-leukemic function remain unclear. In this study, 839 ECP treatments were performed on patients with acute GvHD (aGvHD) and chronic GvHD (cGvHD). A comprehensive analysis of effector and regulatory cells in patients under ECP therapy included multi-parametric flow cytometry and tetramer staining, LuminexTM-based cytokine, interferon-γ enzyme-linked immunospot, and chromium-51 release assays. Gene profiling of myeloid-derived suppressor cells (MDSCs) was performed by microarray analysis. Immunologically, modulations of effector and regulatory cells as well as proinflammatory cytokines were observed under ECP treatment: (1) GvHD-relevant cell subsets like CD62L+ NK cells and newly defined CD19hiCD20hi B cells were modulated, but (2) quantity and quality of anti-viral/anti-leukemic effector cells were preserved. (3) The development of MDSCs was promoted and switched from an inactivated subset (CD33-CD11b+) to an activated subset (CD33+CD11b+). (4) The frequency of Foxp3+CD4+ regulatory T cells (Tregs) and CD24+CD38hi regulatory B cells was considerably increased in aGvHD patients, and Foxp3+CD8+ Tregs in cGvHD patients. (5) Proinflammatory cytokines like IL-1ß, IL-6, IL-8, and TNF-α were significantly reduced. In summary, ECP constitutes an effective immunomodulatory therapy for patients with steroid-refractory/resistant GvHD without impairment of anti-viral/leukemia effects.