Minor Histocompatibility Antigen DBY Elicits a Coordinated B and T Cell Response after Allogeneic Stem Cell Transplantation

We examined the immune response to DBY, a model H-Y minor histocompatibility antigen (mHA) in a male patient with chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplant from a human histocompatibility leukocyte antigen (HLA)-identical female sibling. Patient peripheral blood mononuclear cells were screened for reactivity against a panel of 93 peptides representing the entire amino acid sequence of DBY. This epitope screen revealed a high frequency CD4(+) T cell response to a single DBY peptide that persisted from 8 to 21 mo after transplant. A CD4(+) T cell clone displaying the same reactivity was established from posttransplant patient cells and used to characterize the T cell epitope as a 19-mer peptide starting at position 30 in the DBY sequence and restricted by HLA-DRB1*1501. Remarkably, the corresponding X homologue peptide was also recognized by donor T cells. Moreover, the T cell clone responded equally to mature HLA-DRB1*1501 male and female dendritic cells, indicating that both DBY and DBX peptides were endogenously processed. After transplant, the patient also developed antibodies that were specific for recombinant DBY protein and did not react with DBX. This antibody response was mapped to two DBY peptides beginning at positions 118 and 536. Corresponding DBX peptides were not recognized. These studies provide the first demonstration of a coordinated B and T cell immune response to an H-Y antigen after allogeneic transplant. The specificity for recipient male cells was mediated by the B cell response and not by donor T cells. This dual DBX/DBY antigen is the first mHA to be identified in the context of chronic GVHD

The chicken gene nomenclature committee report

Comparative genomics is an essential component of the post-genomic era. The chicken genome is the first avian genome to be sequenced and it will serve as a model for other avian species. Moreover, due to its unique evolutionary niche, the chicken genome can be used to understand evolution of functional elements and gene regulation in mammalian species. However comparative biology both within avian species and within amniotes is hampered due to the difficulty of recognising functional orthologs. This problem is compounded as different databases and sequence repositories proliferate and the names they assign to functional elements proliferate along with them. Currently, genes can be published under more than one name and one name sometimes refers to unrelated genes. Standardized gene nomenclature is necessary to facilitate communication between scientists and genomic resources. Moreover, it is important that this nomenclature be based on existing nomenclature efforts where possible to truly facilitate studies between different species. We report here the formation of the Chicken Gene Nomenclature Committee (CGNC), an international and centralized effort to provide standardized nomenclature for chicken genes. The CGNC works in conjunction with public resources such as NCBI and Ensembl and in consultation with existing nomenclature committees for human and mouse. The CGNC will develop standardized nomenclature in consultation with the research community and relies on the support of the research community to ensure that the nomenclature facilitates comparative and genomic studies

Long-Term Follow-up of Reduced Intensity Allogeneic Stem Cell Transplantation for Chronic Lymphocytic Leukemia: Prognostic Model to Predict Outcome

CLL remains incurable with chemoimmunotherapy, and allogeneic hematopoietic stem cell transplantation (HSCT) offers potential for cure. We assessed the outcomes of 108 CLL patients undergoing first allogeneic HSCTs, 76 with reduced intensity (RIC) and 32 with myeloablative (MAC) conditioning between 1998 and 2009 at Dana-Farber Cancer Institute. With median follow-up 5.9 years in surviving patients, the 5 year OS for the entire cohort is 63% for RIC regimens and 49% for MAC regimens (p=0.18). The risk of death declined significantly starting in 2004 and we found that 5 year OS for HSCT between 2004–2009 was 83% for RIC regimens compared to 47% for MAC regimens (p=0.003). For RIC transplantation, we developed a prognostic model based on predictors of PFS, specifically remission status, LDH, comorbidity score and lymphocyte count, and found 5-year PFS 83% for score 0, 63% for score 1, 24% for score 2, and 6% for score >= 3 (p<0.0001). We conclude that RIC HSCT for CLL in the current era is associated with excellent long-term PFS and OS, and, as potentially curative therapy, should be considered early in the disease course of relapsed high-risk CLL patients

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: Report from the Committee on Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation

Relapse is a major cause of treatment failure after allogeneic hematopoietic stem cell transplantation (alloHSCT). Treatment options for relapse have been inadequate, and the majority of patients ultimately die of their disease. There is no standard approach to treating relapse after alloHSCT. Withdrawal of immune suppression and donor lymphocyte infusions are commonly used for all diseases; although these interventions are remarkably effective for relapsed chronic myelogenous leukemia, they have limited efficacy in other hematologic malignancies. Conventional and novel chemotherapy, monoclonal antibody therapy, targeted therapies, and second transplants have been utilized in a variety of relapsed diseases, but reports on these therapies are generally anecdotal and retrospective. As such, there is an immediate need for well-designed, disease-specific trials for treatment of relapse after alloHSCT. This report summarizes current treatment options under investigation for relapse after alloHSCT in a disease-specific manner. In addition, recommendations are provided for specific areas of research necessary in the treatment of relapse after alloHSCT

Combined CD4 T-Cell and Antibody Response to Human Minor Histocompatibility Antigen DBY After Allogeneic Stem-Cell Transplantation

Antibody responses to HY antigens in male recipients are frequent after transplantation of stem cells from female donors (Miklos et al., Blood 2005; 105: 2973; Miklos et al., Blood 2004; 103: 353). However, evidence that this B-cell immunity is accompanied by T-cell responses to the cognate antigens is scarce. Here, we examined T- and B-cell responses to DBY antigen in a male patient who received hematopoietic stem cells from a human leukocyte antigen-identical female sibling

Targeting PI3Kδ function for amelioration of murine chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) is a leading cause of morbidity and mortality following allotransplant. Activated donor effector T cells can differentiate into pathogenic T helper (Th)-17 cells and germinal center (GC)-promoting T follicular helper (Tfh) cells, resulting in cGVHD. Phosphoinositide-3-kinase-δ (PI3Kδ), a lipid kinase, is critical for activated T cell survival, proliferation, differentiation, and metabolism. We demonstrate PI3Kδ activity in donor T cells that become Tfh cells is required for cGVHD in a nonsclerodermatous multiorgan system disease model that includes bronchiolitis obliterans (BO), dependent upon GC B cells, Tfhs, and counterbalanced by T follicular regulatory cells, each requiring PI3Kδ signaling for function and survival. Although B cells rely on PI3Kδ pathway signaling and GC formation is disrupted resulting in a substantial decrease in Ig production, PI3Kδ kinase-dead mutant donor bone marrow-derived GC B cells still supported BO cGVHD generation. A PI3Kδ-specific inhibitor, compound GS-649443, that has superior potency to idelalisib while maintaining selectivity, reduced cGVHD in mice with active disease. In a Th1-dependent and Th17-associated scleroderma model, GS-649443 effectively treated mice with active cGVHD. These data provide a foundation for clinical trials of US Food and Drug Administration (FDA)-approved PI3Kδ inhibitors for cGVHD therapy in patients

HLA-Identical Sibling Allogeneic Transplants versus Chemotherapy in Acute Myelogenous Leukemia with t(8;21) in First Complete Remission: Collaborative Study between the German AML Intergroup and CIBMTR

AbstractWe studied the role of HLA-matched sibling hematopoietic cell transplantation (HCT) in treating t(8;21) acute myelogenous leukemia (AML) in first remission. Outcomes of 118 patients receiving HCT and reported to the Center for International Blood and Marrow Transplant Research were compared with 132 similar patients receiving chemotherapy selected from 8 German AML Intergroup multicenter trials. Characteristics of the cohorts were similar except that chemotherapy recipients were significantly older. To adjust for time to treatment bias, outcomes were compared using left-truncated Cox regression models. Transplants were associated with higher treatment-related mortality (TRM; relative risk [RR] 6.76, 95% confidence interval [CI] 2.95-15.45, P < .001), lower relapse (RR 0.47, 95% CI 0.25-0.85, P = .01), and similar relapse-free survival (P = .2). Loss of sex chromosomes (LOS) in addition to t(8;21) had a negative impact on overall survival (OS) in patients receiving chemotherapy. Patients without LOS experienced shorter survival after HCT comparing to chemotherapy (RR 3.05, P = .02), whereas patients with LOS had similar survival regardless of postremission therapy. In both cohorts, white blood cell count (WBC) at diagnosis >25 × 109/L was associated with a higher relapse risk (RR = 2.09, P = .03), lower relapse-free (RR = 1.9, P = .008), and OS (RR = 1.91, P = .01). In this cohort of patients with t(8;21) AML, HCT did not improve OS, because reduction of relapse was offset by high TRM. In the group without LOS, survival after chemotherapy was far superior to HCT. These results suggest that patients with t(8;21) AML without poor prognostic factors have higher rates of survival after chemotherapy as a post remission therapy compared to HCT

Tacrolimus versus Cyclosporine after Hematopoietic Cell Transplantation for Acquired Aplastic Anemia

AbstractCombinations of cyclosporine (CSP) with methotrexate (MTX) have been widely used for immunosuppression after allogeneic transplantation for acquired aplastic anemia. We compared outcomes with tacrolimus (TAC)+MTX versus CSP+MTX after transplantation from HLA-identical siblings (SIB) or unrelated donors (URD) in a retrospective cohort of 949 patients with severe aplastic anemia. Study endpoints included hematopoietic recovery, graft failure, acute graft-versus-host disease (GVHD), chronic GVHD, and mortality. TAC+MTX was used more frequently in older patients and, in recent years, in both SIB and URD groups. In multivariate analysis, TAC+MTX was associated with a lower risk of mortality in URD recipients and with slightly earlier absolute neutrophil count recovery in SIB recipients. Other outcomes did not differ statistically between the 2 regimens. No firm conclusions were reached regarding the relative merits of TAC+MTX versus CSP+MTX after hematopoietic cell transplantation for acquired aplastic anemia. Prospective studies would be needed to determine whether the use of TAC+MTX is associated with lower risk of mortality in URD recipients with acquired aplastic anemia

AFM-Detected Apoptotic Changes in Morphology and Biophysical Property Caused by Paclitaxel in Ishikawa and HeLa Cells

The apoptosis of cancer cells is associated with changes in the important cell properties including morphology, surface roughness and stiffness. Therefore, the changes in morphology and biophysical properties can be a good way of evaluating the anticancer activity of a drug. This study examined the effect of paclitaxel on the properties of Ishikawa and HeLa cells using atomic force microscopy (AFM), and the relationship between the changes in morphology and the biophysical properties and apoptosis was discussed. The viability and proliferation of the cells were analyzed using the methylthiazol tetrazolium (MTT) method and a TUNEL assay to confirm cellular apoptosis due to a paclitaxel treatment. AFM observations clearly showed the apoptotic morphological and biophysical changes in Ishikawa and HeLa cells. After the paclitaxel treatment, the cell membrane was torn and holed, the surface roughness was increased, and the stiffness was decreased. These changes were observed more apparently after a 24 h treatment and in Ishikawa cells compared to HeLa cells. The MTT and TUNEL assays results revealed the Ishikawa cells to be more sensitive to paclitaxel than HeLa cells and definite apoptosis occurred after a 24 h treatment. These results showed good agreement with the AFM results. Therefore, research on the morphological and biophysical changes by AFM in cancer cells will help to evaluate the anticancer activities of the drugs