Blockade of CCR5 and CXCR3 attenuates murine acute graft-versus-host disease through modulating donor-derived T cell distribution and function.

BACKGROUND: Lymphocyte trafficking via chemokine receptors such as CCR5 and CXCR3 plays a critical role in the pathogenesis of aGVHD. Our previous studies showed that addition of CCR5 or CXCR3 antagonist could only slightly alleviate the development of aGVHD. Given the specificity of T lymphocytes bearing CXCR3 and CCR5, we investigated whether combined CCR5 and CXCR3 blockade could further attenuate murine aGVHD. METHODS: A mouse model of aGVHD was established to assess the efficacy of CCR5 or/and CXCR3 blockade on the development of aGVHD. The distribution of lymphocytes was calculated by quantification of immunostaining cells. The immunomodulatory effect on T cells were assessed by evaluating T- cell proliferation, viability, and differentiation. RESULTS: Using murine allo-HSCT model, we demonstrated that blockade of both CCR5 and CXCR3 could efficiently alleviate the development of aGVHD. Further investigation on the immune mechanisms for this prophylactic effect showed that more T cells were detained into secondary lymphoid organs (SLOs), which may lead to reduced infiltration of T cells into GVHD target organs. Our study also showed that T cells detained into SLOs dampened the activation, suppressed the polarization toward Th1 and Tc1, and induced the production of Treg cells. CONCLUSION: These data suggest that concurrent blockade of CCR5 and CXCR3 attenuates murine aGVHD through modulating donor-derived T cell distribution and function, and this might be applicable for aGVHD prophylaxis in clinical settings.

Efficacy and safety of coadministration of venetoclax and anti-fungal agents under therapeutic drug monitor in unfit acute myeloid leukemia and high-risk myelodysplastic syndrome with neutropenia: a single-center retrospective study.

Unfit acute myeloid leukemia and high-risk myelodysplastic syndrome patients with prolonged neutropenia demand coadministration of venetoclax and azoles. However, venetoclax dosing under drug-drug interaction with azoles remains controversial. Therapeutic drug monitoring (TDM) is expected to guide drug dosage adjustments. We retrospectively enrolled 17 patients under this coadministration and TDM. Venetoclax dosages were interfered when inappropriate drug concentrations appeared. The primary endpoints were objective response and adverse events. Venetoclax concentration outliers were more frequently evaluated before than after dose adjustment (Cmax 60.87% vs. 0.00%, p < .0001). MRD negativity rate was higher in patients staying within reference range than those having outliers (90.91% vs. 33.33%, p = .028). Objective response rate was 100%. Hematologic adverse events included neutropenia (93.3%), febrile neutropenia (53.3%), and thrombocytopenia (81.3%). Median time to neutropenia and thrombocytopenia recovery was 20 (14-32) and 16.5 (6-34) days, respectively. No invasive fungal and other life-threatening infections were observed.

Retrospective cohort evaluation of non-HIV Castleman disease from a single academic center in Beijing, China.

The purpose is to ascertain the clinical impact of Castleman disease (CD) by reassessment of the real-world data from Peking University First Hospital (PKUFH). The results will contribute to the standardization of diagnosis and treatment on CDs. Based on the last 15-year retrospective real-world data from Peking University First Hospital (PKUFH), we reclassified and re-evaluated the clinical and pathological information of patients with pathologically suspected diagnosis of CD. A total of 203 patients were included in our study, in which the diagnosis of CD was confirmed in 189 cases, including 118 patients with unicentric CD (UCD, n = 118, 62.4%) and 71 patients with multicentric CD (MCD, n = 71, 37.6%). A total of 44.1% (n = 52) of UCDs in our cohort were complicated with paraneoplastic pemphigus (PNP). The treatment of UCD is primarily surgical, with a 5-year overall survival (OS) of 88.1%. Patients with PNP had a poorer prognosis than those without PNP (82.9% (95% CI 123-178) vs 92.8% (95% CI 168-196), log-rank p = 0.041). The rate of concurrent systemic symptoms was 74.6% (n = 53), and renal involvement occurred in 49.3% (n = 35) MCD patients. The MCD treatments were mainly chemotherapy regimens, with a 5-year OS of 77.6% (95% CI, 143-213). Patients with UCD demonstrate a better overall prognosis than patients with MCD. But the prognosis of those complicated with PNP was poor. The differential diagnosis of MCD is extensive. MCD treatment in China is heterogeneous. The inaccessibility of anti-IL-6-targeted drugs in China may contribute to the poor prognosis for patients with MCD.A preprint has previously been published (Guo et al. 34).

Clinical characteristics and prognostic factors analysis of core binding factor acute myeloid leukemia in real world.

BACKGROUND: Chromosomal translocations involving core binding factor (CBF) genes account for 15% of adult acute myeloid leukemia (AML) cases in China. Despite being classified as favorable-risk by European Leukemia Net (ELN), CBF-AML patients have a 40% relapse rate. This study aims to analyze clinical characteristics and prognosis of CBF-AML, compare its subtypes (inv(16) and t(8;21)), and validate prognostic factors. METHODS: Retrospective analysis of 149 AML patients (75 CBF-AML, 74 non-CBF) at Peking University First Hospital (March 2012-March 2022). RESULTS: CBF-AML patients have significantly lower disease-free survival (DFS) (p = 0.005) and higher non-relapse mortality (NRM) (p = 0.028) compared to non-CBF AML. inv (16) and t(8;21) show distinct co-occurring gene mutation patterns, with inv(16) being prone to central nervous system (CNS) leukemia. Multivariate analysis identifies age as a risk factor for overall survival (OS) and disease free survival (DFS), kinase mutation as a risk factor for DFS and Recurrence, while WT1 mutation as a risk factor for OS and non relapse mortality (NRM) risk in t(8;21) AML. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) improves prognosis in low-risk t(8;21). CONCLUSION: Prognosis of CBF-AML is poorer than ELN guidelines suggest. inv(16) and (8;21) are separate entities with relatively poor prognoses, requiring rational risk stratification strategies. Allo-HSCT may benefit low-risk t(8;21), but further research is needed for conclusive evidence.

Low-dose decitabine-intensified modified conditioning regimen alleviates aGVHD in AML/MDS patients treated with allogeneic hematopoietic stem cell transplantation.

Background: The widespread adoption of Allogeneic Hematopoietic Stem Cell Transplantation (Allo-HSCT) has significantly improved the survival rates of patients with hematological malignancies. However, Graft-Versus-Host Disease (GVHD) remains a formidable complication, threatening patient prognosis. Recent research has indicated that decitabine (DAC), known for its hypomethylating properties may also exhibit immune-regulatory capabilities and a potential for reducing GVHD incidence and enhancing survival. Methods: We retrospectively reviewed data from AML/MDS patients who underwent Allo-HSCT at our center from January 2010 to January 2023. From a total of 251 patients with complete data, we employed propensity score matching (PSM) to create 100 matched pairs (200 patients) for comprehensive trial analysis. Patients receiving low-dose DAC-containing regimen were matched with those who did not receive DAC. Results: Patients in the DAC group exhibited a significantly lower incidence of grade II-IV acute GVHD (aGVHD) compared to non-DAC group (21% vs. 38%, P=0.013). Univariable and multivariable logistic regression analysis demonstrated DAC intervention as a protective factor against grade II-IV aGVHD (P=0.017, OR=0.47, 95% CI 0.23-0.81; P=0.018, OR=0.46, 95% CI 0.24-0.87). Multivariate competing risk regression further supported administration of decitabine as a protective factor against grade II-IV aGVHD (P=0.038, SHR=0.53, 95%CI 0.29-0.97). There was no significant difference between both groups concerning chronic GVHD, infection, disease relapse, overall survival, disease-free survival and GVHD free, relapse free survival. In MRD negative or intermediate risk subgroup, the grade II-IV aGVHD ameliorating effect of DAC was confirmed as well. Conclusion: Low-dose DAC-intensified modified conditioning regimen could improve prognosis in AML/MDS Patients treated with allogeneic hematopoietic stem cell transplantation.

[Clinical Study of Blinatumomab in the Treatment of Adult Relapsed/Refractory Ph-Negative Acute B-Lymphoblastic Leukemia].

OBJECTIVE: To investigate the efficacy and safety of CD19/CD3 bisecific monoclonalantibody (Blinatumomab) in the treatment of adult patients with relapsed / refractory Ph-negative acute B-lymphoblastic leukemia (R/R-B-ALL). METHODS: Ten adult R/R B-ALL patients were all treated with Blinatumomab. Each treatment cycle was administered for 28 days and stopped for 14 days. The dose was 9 µg/day for the first 7 days of cycle 1, and 28 µg/day for days 8-28 if there were no adverse reactions. From the second cycle onwards, the daily dose was 28 µg. The remission, survival time (EFS and OS) and adverse reactions were observed after treatment. RESULTS: Nine patients with curative effect could be evaluated. Four patients achieved CR after one course, and one patient achieved CR after two courses, the overall remission rate was 55.6%(5/9). The median EFS was 4 months (1-12 months), and the median OS was 6 months (2-44 months). Nine of the 10 patients had fever of different degrees. Serum levels of cytokines such as IL-6, IL-10, IL-17 and IFN-γ increased. Two patients resumed medication after 1 week of treatment interruption due to neurotoxicity and CRS, respectively. One patient was discontinued due to grade 3 CRS and died of tropical candidiaemia. CONCLUSION: Blinatumomab has a good response rate in the treatment of relapsed/refractory B-ALL patients, but the duration of remission is shorter. Drug-related adverse reactions are mainly CRS and neurotoxicity. Inflammatory factors IL-6, IL-10, IL-17 and IFN-γ can be used as indicators to monitor CRS. The bisspecificity MAbs provide an opportunity for subsequent allogeneic hematopoietic stem cell transplantation in R/R-B-ALL patients.

Aponermin or placebo in combination with thalidomide and dexamethasone in the treatment of relapsed or refractory multiple myeloma (CPT-MM301): a randomised, double-blinded, placebo-controlled, phase 3 trial.

BACKGROUND: Aponermin, a circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, is a potential death receptor 4/5-targeted antitumour candidate. Previous phase 1/2 studies have demonstrated the efficacy of aponermin in patients with relapsed or refractory multiple myeloma (RRMM). To confirm the superiority of aponermin plus thalidomide and dexamethasone (aponermin group) over placebo plus thalidomide and dexamethasone (placebo group) in RRMM, a randomized, double-blinded, placebo controlled phase 3 trial was performed. METHODS: Four hundred seventeen patients with RRMM who had previously received at least two regimens were randomly assigned (2:1) to receive aponermin, thalidomide, and dexamethasone or placebo, thalidomide, and dexamethasone. The primary endpoint was progression-free survival (PFS). Key secondary endpoints included overall survival (OS) and overall response rate (ORR). RESULTS: A total of 415 patients received at least one dose of trial treatment (276 vs. 139). The median PFS was 5.5 months in the aponermin group and 3.1 months in the placebo group (hazard ratio, 0.62; 95% confidence interval [CI], 0.49-0.78; P < 0.001). The median OS was 22.4 months for the aponermin group and 16.4 months for the placebo group (hazard ratio, 0.70; 95% CI, 0.55-0.89; P = 0.003). Significantly higher rates of ORR (30.4% vs. 13.7%, P < 0.001) and very good partial response or better (14.1% vs. 2.2%, P < 0.0001) were achieved in the aponermin group than in the placebo group. Treatment with aponermin caused hepatotoxicity in some patients, as indicated by the elevated alanine transaminase, aspartate transaminase, or lactate dehydrogenase levels (52.2% vs. 24.5%, 51.1% vs. 19.4% and 44.9% vs. 21.6%, respectively), mostly grade 1/2, transient and reversible. The main grade 3/4 adverse events included neutropenia, pneumonia and hyperglycemia. The incidence of serious adverse events was similar between the two groups (40.6% vs. 37.4%). There was no evidence that aponermin leads to hematological toxicity, nephrotoxicity, cardiotoxicity, or secondary tumors. CONCLUSIONS: Aponermin plus thalidomide and dexamethasone significantly improved PFS, OS and ORR with manageable side effects in RRMM patients who had received at least two prior therapies. These results support the use of aponermin, thalidomide, and dexamethasone as a treatment option for RRMM patients. TRIAL REGISTRATION: The trial was registered at http://www.chictr.org.cn as ChiCTR-IPR-15006024, 17/11/2014.

Real-world outcomes and prognostic factors among patients with acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation.

Acute myeloid leukemia (AML) is a malignant lymphohematopoietic tumor that ranks among the most frequent indications for allogeneic hematopoietic stem cell transplantation (allo-HSCT). This article aims to provide a comprehensive analysis of the application of allo-HSCT for AML and identify prognostic factors to enhance future treatment effect. This retrospective study collected data from 323 patients diagnosed with AML at Peking University First Hospital who underwent allo-HSCT between September 2003 and July 2022. The annual number of transplantations has steadily increased. Our center has observed a rise in the proportion of cytogenetic high-risk and measurable residual disease (MRD) positive patients since 2013, as well as an increase in the number of haploidentical transplantations. The overall leukocyte engraftment time has decreased over the past 20 years. Furthermore, both overall survival (OS) and disease-free survival (DFS) have significantly improved, while non-relapse mortality (NRM) has significantly decreased since 2013. Multivariate analysis identified transplantation before 2013, patients in complete remission (CR) 2 or non-CR, and recipients older than 50 years as risk factors for NRM, while patients in non-CR and patients with positive MRD are risk factors for recurrence. These findings offer insights into AML treatment outcomes in China, highlighting changes in transplantation practices and the need to reduce post-transplant relapse. Effective interventions, such as MRD monitoring and risk stratification schemes, are crucial for further enhancing transplant outcomes.

Romiplostim in primary immune thrombocytopenia that is persistent or chronic: phase III multicenter, randomized, placebo-controlled clinical trial in China.

Background: Multiple trials have confirmed that romiplostim could increase platelet count in individuals with primary immune thrombocytopenia (ITP), but no related study has assessed Chinese patients. Objectives: To assess the effectiveness of romiplostim as a second-line treatment of persistent or chronic ITP in Chinese adults. Methods: This phase III multicenter, randomized, placebo-controlled, double-blind, then open-label clinical trial (NCT02868099, CTR20150395) was conducted at 28 investigational sites in China. The patients were randomly assigned (3:1) to romiplostim (starting and maximum doses of 1 and 10 µg/kg, respectively) or placebo for 9 weeks (double-blind period), followed by the open-label period (both groups administered romiplostim) to week 22. The primary endpoint was the time (in weeks) during which platelet counts were ≥50 × 109/L in the double-blind period. Results: In this study, 202 patients (romiplostim, n = 151; placebo, n = 51) started the treatment. The median (range) numbers of weeks with platelet response after 6 weeks of treatment were 2 (0-6) and 0 (0-2) in patients administered romiplostim and placebo, respectively (P < .001). During the double-blind period, the proportions of patients with treatment-emergent adverse events were comparable between the romiplostim and placebo groups (82.8% vs 82.4%). The treatment-emergent adverse event with ≥10% difference in incidence between these 2 groups was injection site bleeding (1.3% vs 11.8%). Conclusion: Romiplostim significantly increased the time with maintained platelet response in patients with persistent or chronic ITP in comparison with placebo. No new safety signal was observed. Trial registration: ClinicalTrials.gov, NCT02868099. www.chinadrugtrials.org.cn/clinicaltrials.searchlist.dhtml, CTR20150395.

[High-Throughput Sequencing Technology for Detection of Gene Mutations in Myeloid Malignancies and Its Clinical Prognostic Significance].

OBJECTIVE: To detect the gene mutations in patients with myeloid malignancies by high-throughput sequencing and explore the correlation between gene mutations and prognosis. METHODS: A retrospective analysis was performed on 56 patients with myeloid malignancies who were hospitalized in the department of hematology, Peking University International Hospital from January 2020 to May 2021. The genetic mutations of the patients were detected by next-generation sequencing technology, and the correlation between the genetic mutations and prognosis of myeloid malignancies was analyzed. RESULTS: In 56 patients, the number of mutated genes detected in a single patient is 0-9, with a median of 3. Sequencing results showed that the most common mutated genes were RUNX1(21.4%), TET2(17.9%), DNMT3A(17.9%), TP53(14.3%) and ASXL1(14.3%), among which the most common mutations occurred in the signaling pathway-related genes (23.3%) and the transcription factor genes (18.3%). 84% of the patients carried multiple mutated genes (≥2), and correlation analysis showed there were obvious co-occurring mutations between WT1 and FLT3, NPM1 and FLT3-ITD, and MYC and FLT3. TP53 mutation was more common in MDS patients.The overall survival time of patients with NRAS mutation was significantly shortened (P =0.049). The prognosis of patients with TP53 mutation was poor compared with those without TP53 mutation, but the difference wasn't statistically significant (P =0.08). CONCLUSION: The application of next-generation sequencing technology is of great significance in myeloid malignancies, which is helpful to better understand the pathogenesis of the disease, to judge the prognosis and to find possible therapeutic targets.

Combination of ST2 With Organ-Specific Biomarker is More Sensitive and Specific for the Diagnosis of Acute Graft-vs-Host Disease.

BACKGROUND: Diagnosis of acute graft-vs-host disease (aGVHD) based on clinical symptoms and biopsy of involved organ was not satisfactory; reliable plasma biomarkers or their panels would be of great value to increase the sensitivity and specificity for such a fatal complication. METHOD: One hundred two patients who received allogeneic hematopoietic stem cell transplantation in our center were included in this study. Systemic biomarkers of ST2, IP10, IL-2Rα, TNFR1, and organ-specific biomarkers of Elafin, REG-3α, and KRT-18F in plasma were tested by ELISA. The correlation of each biomarker or selected panel of some systemic and organ-specific biomarker with aGVHD was investigated. RESULTS: The level of each systemic biomarker in aGVHD patients was significantly higher than that in patients without aGVHD. Organ-specific biomarker of Elafin, REG-3α, and KRT-18F also had predictive value for aGVHD of skin, gastrointestinal tract, and liver, respectively. Combination of ST2 with one of the 3 organ-specific biomarkers could provide more accurate prediction for aGVHD with skin, gastrointestinal tract, and liver, respectively. CONCLUSIONS: All the biomarkers tested in our study correlated with the severity and clinical course of aGVHD. Combination of each systemic biomarker with organ-specific biomarker could increase the sensitivity and specificity for the diagnosis of aGVHD, whereas ST2 with organ-specific biomarker is more sensitive for the diagnosis of organ-specific aGVHD.

High-Dose immunoglobulin Intervention as an effective and simple strategy for donor specific Anti-HLA antibody desensitization in haploidentical transplant.

Donor-specific anti-HLA antibody (DSA) is a significant obstacle to successful haploidentical hematopoietic stem cell transplantation (haplo-HSCT) and is associated with poor engraftment rates. DSA strongly positive patients with a mean fluorescence intensity (MFI) over 5000 have a primary poor graft function (PGF) rate of over 60%. Currently, there is no consensus on the desensitization of DSA, and existing strategies are complex and have limited effectiveness. To address this issue, we conducted a retrospective study on 19 patients with strongly positive DSA (MFI over 5000) who underwent haplo-HSCT and were treated with intravenous immunoglobulin (IVIg)-based therapy. We also included 38 baseline-matched patients with DSA-negative as controls. Our findings revealed that the cumulative incidence of engraftment, PGF, graft-versus-host disease (GVHD), virus infection, overall survival (OS), disease-free survival (DFS), relapse, and non-relapse mortality (NRM) in the DSA strongly positive group after desensitization were comparable to those in the DSA negative group (P > 0.05). Our multivariable analysis showed that disease remission was a protective factor against PGF (P = 0.005, OR = 0.019, 95% CI 0.001-0.312). Subgroup analysis revealed that the desensitization efficacy was equal regardless of DSA type against HLA-I or II, and MFI value over 5000 or not. In conclusion, we propose a simple and effective DSA desensitization strategy based on immunoglobulin to ensure successful engraftment and improve patient prognosis.

Clinical characteristics and prognosis of a Chinese cohort with systemic light chain amyloidosis: a single-center study.

Light chain amyloidosis is a plasma cell dyscrasia characterized by deposition of misfolded amyloid fibrils in tissues, leading to multi-organ dysfunction. We retrospectively analyzed 335 patients (median age, 60 years) with systemic light chain amyloidosis in the First Hospital of Peking University from 2011 to 2021. Involved organs were the kidney (92.8%), heart (57.9%), liver (12.8%) and peripheral nervous system (6.3%). Chemotherapy was administered to 55.8% (187/335) of patients, among whom 94.7% received novel agent-based regimens. Hematologic response (≥ very good partial response) was achieved in 63.4% of patients who received chemotherapy. Only 18.2% of patients received autologous hematopoietic stem cell transplant (ASCT). Among transplant-eligible patients, the overall survival of ASCT recipients was better than those who received chemotherapy only. The median overall survival of the patients with light chain amyloidosis was 77.5 months. Estimated glomerular filtration rate and Mayo 2012 stage were independent prognostic factors for overall survival in multivariate analysis. Although the younger age and high ratio of renal involvement might contribute to the favorable prognosis of this cohort, the role of novel agents and ASCT is also discernible. This study will provide a comprehensive perspective on progress in treatment of light chain amyloidosis in China.

Tocilizumab, an IL6-receptor antibody, proved effective as adjuvant therapy for cytokine storm induced by severe infection in patients with hematologic malignancy.

Patients with hematological malignancies who experience severe infections are at risk of developing dangerous complications due to excessive inflammatory cytokines. To improve the prognosis, it is crucial to identify better ways to manage the systemic inflammatory storm after infection. In this study, we evaluated four patients with hematological malignancies who developed severe bloodstream infections during the agranulocytosis phase. Despite receiving antibiotics, all four patients presented elevated serum IL-6 levels as well as persistent hypotension or organ injury. Adjuvant therapy with tocilizumab, an IL-6-receptor antibody, was administered, and three of the four patients showed significant improvement. Unfortunately, the fourth patient died due to multiple organ failure caused by antibiotic resistance. Our preliminary experience suggests that tocilizumab, as an adjuvant therapy, may help alleviate systemic inflammation and reduce risk of organ injury in patients with elevated IL-6 levels and severe infection. Further randomized controlled trials are needed to confirm the effectiveness of this IL-6 targeting approach.

Intrathecal CAR-NK cells infusion for isolated CNS relapse after allogeneic stem cell transplantation: case report.

A 24-year-old man with central nervous system (CNS) involvement of T-cell lineage acute lymphoblastic leukemia received sibling allogeneic stem cell transplantation (allo-SCT). He developed isolated CNS relapse early post-SCT, while high-dose systemic chemotherapy, intrathecal (IT) triple infusion and IT donor lymphocytes infusion (DLI) all demonstrated effectiveness. We performed IT umbilical cord blood-derived CAR-NK (target CD7) cells infusion, which was not previously reported. After infusion, detection of cytokines revealed that interferon-γ, interleukin-6 and interleukin-8 increased in CSF. He developed high fever, headache, nausea, vomiting and a spinal cord transection with incontinence in a short time, whereas the ptosis and blurred vision improved completely. The bone marrow remained encouragingly complete remission and complete donor chimerism over 9 months after IT CAR-NK cells infusion. In conclusion, IT CAR-NK cells infusion is a potentially feasible and effective option for patients with CNS relapse, with limited neurological toxicity.

Autoimmune Hemolytic Anemia After Cord Blood Transplantation: A Retrospective Single-Center Experience.

Objective: To describe the incidence, possible risk factors, and treatment options of autoimmune hemolytic anemia (AIHA) occurring after cord blood transplantation (CBT). Methods: We retrospectively analyzed the patients who underwent CBT at Peking University First Hospital between January 2004 and July 2022. Results: We totally identified thirty-six patients who received CBT. Median age was 27.5 years (range, 1.6-52). With a median 6 (range 0.6-10.0) years survivor follow-up, six patients developed AIHA (2 Evans syndrome included) at a median of 168 (range, 122-264) days post-CBT for 8% cumulative incidence density 3 years. Its mortality was 50% and mainly associated with concomitant infections (CMV reactivation rate nearly 100%). The possible risk factors for developing AIHA are CMV reactivation, GvHD and HLA mismatch. Conclusion: AIHA is a clinically significant common complication in recipients post-CBT. Corticosteroids combined with intravenous immunoglobulin (IvIg) is recommended for the treatment of warm antibody AIHA after CBT.

Lymph Node Fibroblastic Reticular Cells Attenuate Immune Responses Through Induction of Tolerogenic Macrophages at Early Stage of Transplantation.

BACKGROUND: Fibroblastic reticular cells (FRCs) are a type of stromal cells located in the T zone in secondary lymphoid organs. Previous studies showed that FRCs possess the potential to promote myeloid differentiation. We aim to investigate whether FRCs in lymph nodes (LNs) could induce tolerogenic macrophage generation and further influence T-cell immunity at an early stage of allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: LNs were assayed to confirm the existence of proliferating macrophages after allo-HSCT. Ex vivo-expanded FRCs and bone marrow cells were cocultured to verify the generation of macrophages. Real-time quantitative PCR and ELISA assays were performed to observe the cytokines expressed by FRC. Transcriptome sequencing was performed to compare the difference between FRC-induced macrophages (FMs) and conventional macrophages. Mixed lymphocyte reaction and the utilization of FMs in acute graft-versus-host disease (aGVHD) mice were used to test the inhibitory function of FMs in T-cell immunity in vitro and in vivo. RESULTS: We found a large number of proliferating macrophages near FRCs in LNs with tolerogenic phenotype under allo-HSCT conditions. Neutralizing anti-macrophage colony-stimulating factor receptor antibody abolished FMs generation in vitro. Phenotypic analysis and transcriptome sequencing suggested FMs possessed immunoinhibitory function. Mixed lymphocyte reaction proved that FMs could inhibit T-cell activation and differentiation toward Th1/Tc1 cells. Injection of FMs in aGVHD mice effectively attenuated aGVHD severity and mortality. CONCLUSIONS: This study has revealed a novel mechanism of immune regulation through the generation of FRC-induced tolerogenic macrophages in LNs at an early stage of allo-HSCT.

Identification of CD8+ T-cell epitope from multiple myeloma-specific antigen AKAP4.

Multiple myeloma (MM) is a malignant plasma cell disorder affecting mainly the elderly population. Revolutionary progress in immunotherapy has been made recently, including monoclonal antibodies and chimeric antigen receptor T cell (CAR-T) therapies; however, the high relapse rate remains problematic. Therefore, combination therapies against different targets would be a reasonable strategy. In this study, we present a new X-chromosome encoded testis-cancer antigen (CTA) AKAP4 as a potential target for MM. AKAP4 is expressed in MM cell lines and MM primary malignant plasma cells. HLA-A*0201-restricted cytotoxic T lymphocytes (CTLs) induced by dendritic cells (DCs) transduced with an adenovirus vector encoding the full-length AKAP4 gene were demonstrated to lyse AKAP4+ myeloma cells. Seven of the 12 candidate epitopes predicated by the BIMAS and SYFPEITH algorithms were able to bind HLA-A*0201 in the T2 binding assay, of which only two peptides were able to induce CTL cytotoxicity in the co-culture of peptide-loaded human mature dendritic cells and the autologous peripheral blood mononuclear cells (PBMCs) from the same HLA-A*0201 donor. The AKAP4 630-638 VLMLIQKLL was identified as the strongest CTL epitope by the human IFN-γ ELISPOT assay. Finally, the VLMLIQKLL-specific CTLs can lyse the HLA-A*0201+AKAP4+ myeloma cell line U266 in vitro, and inhibit tumor growth in the mice bearing U266 tumors in vivo. These results suggest that the VLMLIQKLL epitope could be used to develop cancer vaccine or T-cell receptor transgenic T cells (TCR-T) to kill myeloma cells.

C-C chemokine receptor 5 and acute graft-versus-host disease.

BACKGROUND: The C-C chemokine receptor 5 (CCR5) is mainly expressed in a variety of immune cells. It interacts with multiple chemokine ligands that mediate the trafficking and recruitment of effector cells toward sites of inflammation. CCR5 not only plays a critical role in cell growth, activation, differentiation, adhesion, and migration but also participates in the development of acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation. METHODS: This is a literature review article. The research design method is an evidence-based rapid review. The present discourse aim is first to scrutinize and assess the available literature on CCR5 and acute GVHD. Standard literature and database searches were implemented, gathered relevant material, and extracted information was then assessed. RESULTS: CCR5 is a marker of GVHD effector cells, and CCR5 expression is elevated when acute GVHD occurs. CCR5 blockade with maraviroc in clinical trials results in a low incidence of acute GVHD. The immune mechanism includes that CCR5 blockade inhibits donor T cell migration and recruitment toward target organs, reduces the absolute numbers of donor T cells, is capable of slightly suppressing dendritic cell maturation, and reduces the percentage of Th1 and Th17 subsets. CCR5 blockade also inhibits internalization and activation of chemokines, inhibits proliferation and chemotaxis of T cells, and decreases the production of TNF-α and IFN-γ. In addition, there may be a form of crosstalk between CCR5 and CCR2. Inconsistently, infusion of CCR5-/- Tregs into lethally irradiated mice significantly increased the infiltration of CD4+ and CD8+ T cells into the liver, resulting in earlier and more severe GVHD. CONCLUSION: This review indicates that CCR5 plays an important role in pathogenesis and development of acute GVHD. Elucidating its role in different immune cells will aid the development of targeted therapeutic treatments.