Novel PD-L1- and collagen-expressing patient-derived cell line of undifferentiated pleomorphic sarcoma (JBT19) as a model for cancer immunotherapy.

Soft tissue sarcomas are aggressive mesenchymal-origin malignancies. Undifferentiated pleomorphic sarcoma (UPS) belongs to the aggressive, high-grade, and least characterized sarcoma subtype, affecting multiple tissues and metastasizing to many organs. The treatment of localized UPS includes surgery in combination with radiation therapy. Metastatic forms are treated with chemotherapy. Immunotherapy is a promising treatment modality for many cancers. However, the development of immunotherapy for UPS is limited due to its heterogeneity, antigenic landscape variation, lower infiltration with immune cells, and a limited number of established patient-derived UPS cell lines for preclinical research. In this study, we established and characterized a novel patient-derived UPS cell line, JBT19. The JBT19 cells express PD-L1 and collagen, a ligand of the immune checkpoint molecule LAIR-1. JBT19 cells can form spheroids in vitro and solid tumors in immunodeficient nude mice. We found JBT19 cells induce expansion of JBT19-reactive autologous and allogeneic NK, T, and NKT-like cells, and the reactivity of the expanded cells was associated with cytotoxic impact on JBT19 cells. The PD-1 and LAIR-1 ligand-expressing JBT19 cells show ex vivo immunogenicity and effective in vivo xenoengraftment properties that can offer a unique resource in the preclinical research developing novel immunotherapeutic interventions in the treatment of UPS.

The novel HLA-A*29:172 allele identified in a patient indicated for hematopoietic stem cell transplantation.

HLA-A*29:172 allele differs from HLA-A*29:01:01:01 by one missense single C/G nucleotide exchange in codon 77.

Non-Mutated Nucleophosmin 1 Is Recognized by the CD8+ T Lymphocytes of an AML Patient after the Transplantation of Hematopoietic Stem Cells from an HLA-Haploidentical Donor.

Nucleophosmin (NPM1, B23) is a multifunctional phosphoprotein expressed in all tissues. The protein is mainly localized in nucleoli. In hematological malignancies, NPM1 belongs to commonly altered genes. Its mutation, always heterozygous, leads to the re-localization of the NPM1 protein from the nucleolus to the cytoplasm (NPM1c+). NPM1c+ is found in 30% of acute myeloid leukemia (AML). Our study showed that an AML patient, whose leukemia cells carried the NPM1c+ mutation and who was the recipient of allogeneic HSCT from a haploidentical donor, raised a robust allorestricted CD8+ T cell response directed against the NPM1wt protein. Favourably, the response against NPM1wt was not accompanied by side effects such as GvHD. Moreover, the induction of a high NPM1wt-specific response coincided with the decrease in NPM1c+ transcripts detected, implying a beneficial graft versus leukemia effect. On the basis of these results, we suppose that TCRs from allorestricted NPM1wt-specific T cells are worth studying in other recipients of grafts from haploidentical donors as a possible tool for TCR gene therapy.

WT1 Gene Expression in Peripheral Blood Before and After Allogeneic Stem Cell Transplantation is a Clinically Relevant Prognostic Marker in AML - A Single-center 14-year Experience.

BACKGROUND: This work summarizes our experience with WT1 monitoring before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT). PATIENTS AND METHODS: The expression of WT1 gene was measured by real-time polymerase chain reaction in peripheral blood according to the European Leukemia Net recommendations. Between May 2005 and August 2019, we analyzed 147 consecutive patients with acute myeloid leukemia with high WT1 expression at diagnosis, transplanted in first (CR1) or second (CR2) complete remission. RESULTS: At the time of allo-HSCT, 107 patients had WT1-normal expression (WT1 ≤ 50 copies), and 40 patients had WT1-high expression. The median follow-up was 21 months. The estimated 5-year overall survival and event-free survival was significantly better in the WT1-normal cohort (65% and 57% vs. 37% and 25%; P = .0003 and P < .0001, respectively) and 5-year cumulative incidence of relapse was significantly lower in the WT1-normal group (19% vs. 53%; P < .0001). Five-year non-relapse mortality was not significantly different (20% and 23%). Multivariate analysis revealed WT1-high expression and acute graft-versus-host disease grade 3/4 as significantly negative prognostic factors for OS. Overall, 49 patients developed WT1 molecular relapse in the post-transplant period; in 14 cases, the therapeutic intervention was done. In all but 1 relapsed patient where WT1 minimal residual disease (MRD) was monitored (38 patients), we detected WT1-high levels (sensitivity of 97%). CONCLUSION: The results of the analysis confirmed our previous experience that WT1 status before allo-HSCT is a strong prognostic factor for both OS and relapse risk. In addition, we confirmed the usefulness of this marker for MRD monitoring after allo-HSCT. The main advantage is the possibility of frequent MRD monitoring in peripheral blood and early bone marrow examination based on WT1-high expression.

Hematopoietic Stem Cell Transplantation From Haploidentical Donors in Aplasia After Cladribine/Cytarabine Chemotherapy for Refractory Acute Myeloid Leukemia or Myelodysplastic Syndrome.

INTRODUCTION: Survival rate of patients with chemorefractory acute myeloid leukemia (AML) or myelodysplastic syndrome with excess blasts (MDS-EB) is poor. Allogeneic hematopoietic cell transplantation (HCT) is the only potentially curative therapy in these patients. PATIENTS AND METHODS: We report a retrospective analysis of outcomes of therapy of 24 patients with AML or MDS-EB refractory to high-dose salvage chemotherapy or who had failed previous HCT, who received T-cell-replete HLA haploidentical HCT in aplasia after cladribine/cytarabine-based chemotherapy followed by reduced intensity or myeloablative conditioning. All patients had active disease before commencement of the treatment. RESULTS: Of the patients, 91.7% achieved complete remission (CR), whereas 2 patients (8.2%) died in aplasia. One-year relapse rate was 49.3%. Cumulative incidence of nonrelapse mortality (NRM) was 25.6%. In a subgroup of patients with HCT-comorbidity index score ≤ 3, NRM was 15.4%. Two-year overall survival and relapse-free survival were 30.6% and 22.6%, respectively. Incidence of grade 3 and 4 acute graft versus host disease was 21.3% and 8.3, respectively. CONCLUSION: We found that sequential therapy with HCT in aplasia after cladribine/cytarabine chemotherapy is feasible, results in high CR rates, and has acceptable toxicity profile; however, posttransplant relapse is common in patients treated with active disease.

Association of HLA class I type with prevalence and outcome of patients with acute myeloid leukemia and mutated nucleophosmin.

Acute myeloid leukemia with mutated nucleophosmin (NPMc+ AML) forms a distinct AML subgroup with better prognosis which can potentially be associated with immune response against the mutated nucleophosmin (NPM). As the T-cell-mediated immunity involves antigen presentation on HLA class I molecules, we hypothesized that individuals with suitable HLA type could be less prone to develop NPMc+ AML. We compared HLA class I distribution in NPMc+ AML patient cohort (398 patients from 5 centers) with the HLA allele frequencies of the healthy population and found HLA-A*02, B*07, B*40 and C*07 underrepresented in the NPMc+ AML group. Presence of B*07 or C*07:01 antigen was associated with better survival in patients without concomitant FLT3 internal tandem duplication. Candidate NPM-derived immunopeptides were found for B*40 and B*07 using prediction software tools. Our findings suggest that a T-cell-mediated immune response could actually explain better prognosis of NPMc+ patients and provide a rationale for attempts to explore the importance of immunosuppressive mechanisms in this AML subgroup.

Distribution of HLA-DQB1 in Czech Patients with Central Hypersomnias.

The aim of our study was to analyze the distribution of HLA-DQB1 in Czech patients with central hypersomnias and differences between diagnostic groups of narcolepsy type 1 (NT1), type 2 (NT2), idiopathic hypersomnia (IH) and no central hypersomnia subjects (no-CH). Statistical analysis of DQB1 genotyping was performed on the cohort of 716 patients (375 men, 341 women) with reported excessive daytime sleepiness. DQB1*06:02 allele was present in 94% of the NT1 patients. The decrease of DQB1*06:03 allele was also confirmed. No other DQB1*06 allele nor any other DQB1 allele group was differently distributed in the NT1. In the cohort of NT2 patients DQB1*06:02 allele was present in 43%. Allele group DQB*05 was detected with a significantly higher frequency in this diagnostic unit. Any differences in presence of DQB1*05 alleles in NT2 patients were not reported so far. The cohort of patients with IH did not show any difference in allele distribution of DQB1 alleles/allele groups comparing to healthy controls. DQB1*06:02 allele was significantly increased in the no hypersomnia group. No other DQB1 allele/allele group had any difference in distribution in patients comparing to healthy controls. The different distribution of DQB1*06:02 and other DQB1 alleles/allele groups was detected in analyzed diagnostic groups. These results indicate that DQB1 contributes to the genetic predisposition to NT1, NT2, IH and no-CH in different manners.

Ovulation stimulation protocols utilizing GnRH-antagonist/hCG, promote cytotoxic cell populations, predominant in patients with embryo implantation complications.

OBJECTIVE: Gonadotropin-releasing hormone (GnRH) antagonist combined with the human chorionic gonadotropin hormone (hCG) is commonly used in assisted reproduction techniques (ARTs) to induce controlled ovarian hyperstimulation (COH) and to synchronize oocyte maturation. While hCG is known to have immunomodulatory properties, we aimed to assess its effect on immunological changes, with respect to HLA-G binding receptors and embryo implantation success. DESIGN: The study involved 103 subjects, including patients undergoing COH protocols (n=66), divided on the basis of the pair's fertility disorder (FD) causes (female FD, n=29; male FD, n=37), and age matched healthy women (n=37). The relative distribution of T cell (CD3+/CD4+, CD3+/CD8+) and NK cell (CD56bright/CD16-, CD56dim/CD16+) populations was evaluated together with HLA-G ligands KIR2DL4 and LILRB1 expression by flow cytometry in the peripheral blood of all subjects, as well as in patient follicular fluids. RESULTS: Both groups of patients exhibited a significant decrease of their CD4/CD8 index, a down-modulation of LILRB1-positive CD8 T cells, and increased KIR2DL4-positive NK cell distribution, when compared to the healthy donors. We attribute these changes to the COH protocol, since the only significant change between the patient groups was in the number of cytotoxic CD56dim NK cells (elevated in the female FD group). Patients with male FD causes, having an above-average CD4/CD8 index (≥3.17) and below-average KIR2DL4+/CD56bright NK cell levels(≤13.3%), exhibited higher embryo implantation rates. CONCLUSION: The GnRH antagonist/hCG protocol promotes CD3+/CD8+ and KIR2DL4+ NK cell levels, more abundant in subjects with lower implantation rates, and thus decreases the embryotransfer success in otherwise fertile women.

Prevalence of human leukocyte antigen HLA-B*57:01 in HIV-infected subjects in the Czech Republic.

The HLA-B*57:01 allele is associated with a hypersensitivity reaction to abacavir, and its prevalence varies in different populations. The aim of the study was to investigate HLA-B*57:01 prevalence in the Czech HIV-infected population. HLA-B*57:01 prevalence in our cohort was 5.33%, which is similar to the situation in other Central European countries.

Impact of HLA-DPB1 allelic and single amino acid mismatches on HSCT.

The interpretation of the role of HLA-DPB1 in unrelated haematopoietic stem cell transplantation (HSCT) is subject to discussion. We have investigated the role of HLA-DPB1 allele matching in HSCT outcomes in 161 recipients who were HLA-A, -B, -C, -DRB1 and -DQB1-matched with their unrelated donors at the allelic level (10/10). In addition, we analysed the association of polymorphic amino acid mismatches of DPB1 molecule with HSCT end-points, and a previously published permissiveness concept. HLA-DPB1 allele mismatches were significantly associated with an increased incidence of acute graft-versus-host disease (aGvHD) and worse overall survival (OS). The mismatch at amino acid position 69 significantly increased the risk for transplant-related mortality (TRM). Risk factors for aGvHD also included mismatches at positions 8, 9, 35, 76 and 84. This is to our knowledge, the first report of an in vivo effect of single amino acid mismatches on HSCT outcomes. In this study, grouping of allelic mismatches into permissive and non-permissive categories and their association with transplantation end-points was relevant for TRM but not for other clinical end-points.

Allogeneic stem cell transplantation in children with leukemia using human leukocyte antigen-mismatched unrelated donors.

Allogeneic HSCT is a curative treatment, when chemotherapy fails, for certain malignant diseases. In Europe, only 15% of the indicated children have an HLA-matched sibling available; in 65-70% of others, HLA allele-matched (9-10/10) UDs can be identified. For the rest, it is necessary to identify other alternative donors (HLA-mismatched family or unrelated cord blood). We present our data of HSCT using HLA partially allele-mismatched (7-8/10) UDs in 24 children with leukemia. Uniform GvHD prophylaxis was used (rATG, CsA and MTX). Acute GvHD grade II was diagnosed in 70.8% of the patients and grade III-IV in 12.5%. Overall incidence of chronic GvHD was 38.7% (extensive in 30%). The probability of EFS was 60.3% (95% CI 35.5-78.1) and OS was 74.9 (95% CI 49.1-88.9). No difference in survival between PBSC and BM recipients was observed. TRM at day + 100 was 4%, and overall was 12.5%. We conclude that used combination of drugs for GvHD prophylaxis is efficient even for patients transplanted with grafts from a HLA-mismatched UDs. It enables stable engraftment, good control of GvHD, full reconstitution of immunity, and is not connected with unacceptable transplant-related mortality.