Genetic ablation of adhesion ligands mitigates rejection of allogeneic cellular immunotherapies.

Allogeneic cellular immunotherapies hold promise for broad clinical implementation but face limitations due to potential rejection of donor cells by the host immune system. Silencing of beta-2 microglobulin (B2M) expression is commonly employed to evade T cell-mediated rejection by the host, although the absence of B2M is expected to trigger missing-self responses by host natural killer (NK) cells. Here, we demonstrate that genetic deletion of the adhesion ligands CD54 and CD58 in B2M-deficient chimeric antigen receptor (CAR) T cells and multi-edited induced pluripotent stem cell (iPSC)-derived CAR NK cells reduces their susceptibility to rejection by host NK cells in vitro and in vivo. The absence of adhesion ligands limits rejection in a unidirectional manner in B2M-deficient and B2M-sufficient settings without affecting the antitumor functionality of the engineered donor cells. Thus, these data suggest that genetic ablation of adhesion ligands effectively alleviates rejection by host immune cells, facilitating the implementation of universal immunotherapy.

Graft conditioning with fluticasone propionate reduces graft-versus-host disease upon allogeneic hematopoietic cell transplantation in mice.

Hematopoietic cell transplantation (HCT) treats many blood conditions but remains underused due to complications such as graft-versus-host disease (GvHD). In GvHD, donor immune cells attack the patient, requiring powerful immunosuppressive drugs like glucocorticoids (GCs) to prevent death. In this study, we tested the hypothesis that donor cell conditioning with the glucocorticoid fluticasone propionate (FLU) prior to transplantation could increase hematopoietic stem cell (HSC) engraftment and reduce GvHD. Murine HSCs treated with FLU had increased HSC engraftment and reduced severity and incidence of GvHD after transplantation into allogeneic hosts. While most T cells died upon FLU treatment, donor T cells repopulated in the hosts and appeared less inflammatory and alloreactive. Regulatory T cells (Tregs) are immunomodulatory and survived FLU treatment, resulting in an increased ratio of Tregs to conventional T cells. Our results implicate an important role for Tregs in maintaining allogeneic tolerance in FLU-treated grafts and suggest a therapeutic strategy of pre-treating donor cells (and not the patients directly) with GCs to simultaneously enhance engraftment and reduce GvHD upon allogeneic HCT.

Genetic ablation of adhesion ligands averts rejection of allogeneic immune cells.

Allogeneic cell therapies hold promise for broad clinical implementation, but face limitations due to potential rejection by the recipient immune system. Silencing of beta-2-microglobulin ( B2M ) expression is commonly employed to evade T cell-mediated rejection, although absence of B2M triggers missing-self responses by recipient natural killer (NK) cells. Here, we demonstrate that deletion of the adhesion ligands CD54 and CD58 on targets cells robustly dampens NK cell reactivity across all sub-populations. Genetic deletion of CD54 and CD58 in B2M -deficient allogeneic chimeric antigen receptor (CAR) T and multi-edited induced pluripotent stem cell (iPSC)-derived NK cells reduces their susceptibility to rejection by NK cells in vitro and in vivo without affecting their anti-tumor effector potential. Thus, these data suggest that genetic ablation of adhesion ligands effectively alleviates rejection of allogeneic immune cells for immunotherapy.

[Standard CHOP immuno-chemotherapy for primary mediastinal lymphomas]. / A primer mediastinalis lymphomák standard R-CHOP immun-kemoterápiás kezelése.

INTRODUCTION: Primary mediastinal lymphoma (PMBCL) is an aggressive diffuse large B-cell lymphoma entity. It is a rare disease with specific clinical symptoms. The tumor is predominantly localized in the mediastinum but grows rapidly and infiltrates the surrounding tissues and organs. Two thirds of the patients are young females. Previous studies showed that third generation treatments are more effective than former standard cyclophosphamide-doxorubicin-vincristine-prednisolone (CHOP) regimens. AIM: Authors' goal was to assess whether adding the anti-CD20 monoclonal antibody, rituximab to the standard CHOP regimen improves the efficacy of the treatment compared to their previous results with CHOP and third generation chemotherapy regimens. METHODS: Between October, 2002 and December, 2004 they have started the rituximab-CHOP (R-CHOP) treatment of 20 newly diagnosed, previously untreated PMBCL patients. Results were compared to the data of 24 patients receiving CHOP (n = 9) or procarbazin-prednisolone-doxorubicin-cyclophosphamide-etoposide-cytosin-arabinoside-bleomycin-vincristin-methotrexate (ProMACE-CytaBOM) (n = 15) treatment in the past. RESULTS: During an average follow-up of 64.6 months, the 5-year overall survival (OS) rate was significantly higher in the R-CHOP group compared to the CHOP treatment (79.4% vs. 33.3%; p = 0.026). However, due to the low number of cases, significant statistical difference could not be demonstrated in the 5-year event-free survival (EFS: 70.0% vs. 33.3%; p>0.05), disease-free survival (DFS: 70.0% vs. 33.3%; p>0.05) and relapse-free survival rate (RFS: 93.0% vs. 100%; p> 0.05), despite of the remarkable numeric difference. When comparing the 5-year survival rates of R-CHOP and ProMACE-CytaBOM treatments, the results were very similar without any significant statistical difference between the two types of treatment (OS: 79.4% vs. 80%; EFS: 70.0% vs. 60.0%; DFS: 70.0% vs. 60.0%; RFS: 93.0% vs. 82.0%; p> 0.05 in all cases). With adding rituximab to CHOP treatment, which was previously considered an insufficient treatment on its own, authors have obtained as good results in treating PMBCL as with third generation regimens. Patients have received the R-CHOP treatments without major side effects and mainly as out-patients. CONCLUSIONS: Standard R-CHOP treatment could therefore replace the more toxic third generation regimens in PMBCL as well. The data are comparable with those reported in the international literature.

Absence of CD11a Expression Identifies Embryonic Hematopoietic Stem Cell Precursors via Competitive Neonatal Transplantation Assay.

Hematopoietic stem cells (HSCs) are defined by their self-renewal, multipotency, and bone marrow (BM) engraftment abilities. How HSCs emerge during embryonic development remains unclear, but are thought to arise from hemogenic endothelium through an intermediate precursor called "pre-HSCs." Pre-HSCs have self-renewal and multipotent activity, but lack BM engraftability. They can be identified functionally by transplantation into neonatal recipients, or by in vitro co-culture with cytokines and stroma followed by transplantation into adult recipients. While pre-HSCs express markers such as Kit and CD144, a precise surface marker identity for pre-HSCs has remained elusive due to the fluctuating expression of common HSC markers during embryonic development. We have previously determined that the lack of CD11a expression distinguishes HSCs in adults as well as multipotent progenitors in the embryo. Here, we use a neonatal transplantation assay to identify pre-HSC populations in the mouse embryo. We establish CD11a as a critical marker for the identification and enrichment of pre-HSCs in day 10.5 and 11.5 mouse embryos. Our proposed pre-HSC population, termed "11a- eKLS" (CD11a- Ter119- CD43+ Kit+ Sca1+ CD144+), contains all in vivo long-term engrafting embryonic progenitors. This population also displays a cell-cycle status expected of embryonic HSC precursors. Furthermore, we identify the neonatal liver as the likely source of signals that can mature pre-HSCs into BM-engraftable HSCs.

[Results of immuno-chemotherapeutic treatment of patients with diffuse large B-cell lymphoma]. / Diffúz nagy B-sejtes lymphomák immunokemoterápiás kezelésével elért eredményeink.

Treatment with cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP) has been considered as the standard therapy for diffuse large B-cell lymphoma (DLBCL) for more than 20 years. CHOP treatment in combination with targeted immunotherapy, rituximab (R-CHOP), resulted in significant improvements in the treatment of this group of patients. In this study, efficacy of R-CHOP and R-CHOP-like treatments was analysed. Results were compared to the data of historical patients only receiving CHOP treatment or CHOP-like treatment. Between September 2002 and April 2005, 140 newly diagnosed, untreated DLBCL patients started to receive R-CHOP treatment in a single centre. The eligibility criteria included advanced stage (clinical stages III-IV), or large tumour size (>7 cm) and/or symptom B or extranodal manifestation in the case of clinical stages I-II. The results were compared to the data of 130 patients only receiving CHOP treatment in the past. In the patients receiving R-CHOP, the therapeutic outcomes were superior for all parameters. During an average follow-up period of 44 or 52 months, the overall remission rate was 73.6% in the R-CHOP group in comparison with 47.7% in the CHOP group. The 5-year overall survival was 68.6% vs. 41.0% (RR: 0.4293, CI: 0.2963-0.6221; p < 0.0001), the event-free survival was 59.8% vs. 33.5% (RR: 0.5038, CI: 0.3606-0.7038; p < 0.0001) and the progression-free survival was 64.4% vs. 37.6% (RR: 0.4915, CI: 0.3442-0.7019; p < 0.0001). Since prognostic parameters were more favourable in the R-CHOP group, patient groups were also compared using the International Prognostic Index score. Again, significant differences were revealed by the subgroup analyses. The 5-year overall survival was 74.4% vs. 47.9% (RR: 0.4475, CI: 0.2418-0.8285; p = 0.0084) and 52.0% vs. 28.8% (RR: 0.4989, CI: 0.3098-0.8035; p = 0.003) in the group with good prognosis and in the group with poor prognosis, respectively. In the group with very good prognosis, the statistical difference between the two groups in terms of the 5-year survival parameters remained undetectable as a result of the already very high therapeutic effect and low case number (OS and EFS: CHOP: 100% and 62.5% vs. R-CHOP: 90.9% and 87.0%; p = 0.3873 and p = 0.1702). Combining the standard CHOP treatment with rituximab resulted in a significant improvement of the therapeutic outcomes irrespective of the prognostic grouping. The data are comparable with those reported in the international literature.

[Prognostic value of FDG-PET in Hodgkin lymphoma for posttreatment evaluation. Long-term follow-up results]. / Az FDG-PET prognosztikai értéke Hodgkin-lymphomás betegek követésében - hosszú távú eredményeink.

UNLABELLED: In the past few decades Hodgkin lymphoma (HL) has become a highly curable malignant disease, as a result of using modern polychemotherapy and irradiation. Differentiation of active tumor from fibrosis or necrosis within residual radiographic masses represents a problem of interpretation. AIMS: The aim of this retrospective study is to assess the value of FDG-PET for prediction of remission or relapse in HL. PATIENTS AND METHODS: Data of 128 patients, who had residual masses on CT after completion of their planned treatment, have been analyzed. FDG-PET was performed between January 1995 and February 2005. RESULTS: The median duration of the follow-up from PET was 75.5 months (range: 20-180 months). 89 (70%) patients had negative and 39 (30%) patients had positive FDG-PET results. The numbers of true-positive, true-negative, false-positive and false-negative subjects were 29, 83, 10 and 6, respectively. Sensitivity of post-treatment FDG-PET was 83%, specificity 93%, positive predictive value 74%, negative predictive value 93%, and accuracy 88%. The difference between the event free survival of PET positive and negative cases is highly significant (p = 0.0000), according to the Mantel-Cox test. CONCLUSION: Our results, in accordance with literature, clearly indicate that patients with negative FDG-PET results are unlikely to progress or relapse during a long follow-up. However, false positive uptake is a problem. We have investigated the effect of age, histological subtype, clinical stage and the type of treatment on the accuracy, but on the basis of these facts we could not find any significant difference. However, the date of the investigation influenced the results: before 2000 the number of false results was significantly higher than after that time, which shows the importance of investigators' experience.

Microsatellite characterization and marker development for the fungus Penicillium digitatum, causal agent of green mold of citrus.

Penicillium digitatum is one of the most important postharvest pathogens of citrus on a global scale causing significant annual losses due to fruit rot. However, little is known about the diversity of P. digitatum populations. The genome of P. digitatum has been sequenced, providing an opportunity to determine the microsatellite distribution within P. digitatum to develop markers that could be valuable tools for studying the population biology of this pathogen. In the analyses, a total of 3,134 microsatellite loci were detected; 66.73%, 23.23%, 8.23%, 1.24%, 0.16%, and 0.77% were detected as mono-, di-, tri-, tetra-, penta-, and hexanucleotide repeats, respectively. As consistent with other ascomycete fungi, the genome size of P. digitatum does not seem to correlate with the density of microsatellite loci. However, significantly longer motifs of mono-, di-, and tetranucleotide repeats were identified in P. digitatum compared to 10 other published ascomycete species with repeats of over 800, 300, and 900 motifs found, respectively. One isolate from southern California and five additional isolates from other countries ("global isolates") were used to initially screen microsatellite markers developed in this study. Twelve additional isolates, referred to as the "local isolates," were also collected from citrus at the University of California Riverside agricultural experiment station and were subsequently used to screen the primers that sequenced well and were polymorphic based on the global isolates. Thirty-six primers were screened, and nine trinucleotide loci and one hexanucleotide locus were chosen as robust markers. These loci yielded two to seven alleles and will be useful to study population genetic structure of P. digitatum populations.

Induction of Mesoderm and Neural Crest-Derived Pericytes from Human Pluripotent Stem Cells to Study Blood-Brain Barrier Interactions.

In the CNS, perivascular cells ("pericytes") associate with endothelial cells to mediate the formation of tight junctions essential to the function of the blood-brain barrier (BBB). The BBB protects the CNS by regulating the flow of nutrients and toxins into and out of the brain. BBB dysfunction has been implicated in the progression of Alzheimer's disease (AD), but the role of pericytes in BBB dysfunction in AD is not well understood. In the developing embryo, CNS pericytes originate from two sources: mesoderm and neural crest. In this study, we report two protocols using mesoderm or neural crest intermediates, to generate brain-specific pericyte-like cells from induced pluripotent stem cell (iPSC) lines created from healthy and AD patients. iPSC-derived pericytes display stable expression of pericyte surface markers and brain-specific genes and are functionally capable of increasing vascular tube formation and endothelial barrier properties.

[Hodgkin's lymphoma in adolescents: where to treat it--in an adult or pediatric institution?]. / Hodgkin-lymphoma adolescens korban. Hol érdemes kezelni: felnôtt- vagy gyermekintézményben?

UNLABELLED: Adolescent patients with Hodgkin's lymphoma (HL) are treated either in pediatric, or in adult oncological wards. AIM: The aim of our work was to compare the treatment modalities and the survival rates in adolescents with HL treated in adult (A) or pediatric (P) institutes. METHODS: From January 1990 to December 2004, 138 patients (14-21 years) with HL were treated in two adult institutes (A) and 107 in the 10 centres of the Hungarian Pediatric Oncology Network (P). RESULTS: Male:female ratio was 1:1.15 (A) and 1:1.38 (P). The mean age was 18.6 (A) and 15.7 (P) years. There was no difference between the distribution of the stages in the two patient groups. The distribution of histological subtypes (A and P): nodular sclerosing 47% and 59%, mixed cellularity 45% and 25%, lymphocyte rich 1.5% and 10%, lymphocyte depleted 4% and 1%, nodular lymphocyte predominant 1.5% and 3% and unknown 1% and 2%. The majority of the patients were treated with ABVD (A) and OPPA/OEPA +/- COPP (P). One hundred and fifteen (A) and 97 (P) adolescents received irradiation therapy. 80% (A) and 91% (A) of the patients got radiotherapy. In group A 14%, in group P 13% of the patients had relapse. In group A 16 patients died and in group P 7. There was no significant difference in the overall survival (OS) rates at 5 and 10 years in the two patient groups. The event-free survival (EFS) was 76.5 +/- 4% and 72.5 +/- 4% at 5 and 10 years in group A, and 85.3 +/- 4% at both times in group P ( p = 0.0452). CONCLUSION: Survival rates in HL are quite high, 80-90% of the patients can be cured. Event-free survival was higher in pediatric than in adult institutes. In case of patients younger than 18 years, the survival rates were much better in pediatric institutes, so these patients should be treated in pediatric institutes or with protocols used by the pediatricians.