scholarly journals The Impact of Hypomethylating Agents and BCL-2 Inhibitor on HLA Expression on THP-1 Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3990-3990
Author(s):  
Benjamin Peton ◽  
Melissa Valerio ◽  
Michiko Taniguchi ◽  
Ivan Rodriguez ◽  
Ebtsesam Nafie ◽  
...  
Keyword(s):  
Immune Escape ◽  
Hla Class I ◽  
Surface Expression ◽  
Class Ii ◽  
Hla Class Ii ◽  
Class I ◽  
Hypomethylating Agents ◽  
Hla Dr ◽  
Hla Dq ◽  
Ifn Γ

Abstract Note: BP, MV and LG, KG contributed equally Background Relapsed acute myeloid leukemia (AML) remains the most common reason for allogeneic hematopoietic cell transplant (HCT) failure. Thus, understanding AML immune escape mechanism is important for improving the odds of curing HCT patients with AML. Downregulation of HLA Class I and II expression by AML is one of the potential immune escape mechanisms. Therefore, treatment to restore HLA surface expression is crucial to prevent and treat relapse. Endogenous cytokines, such as IFN-γ, have been shown to stimulate HLA expression but are poorly tolerated by patients. However, two hypomethylating agents (HMA), decitabine (Dec) and azacitadine (Aza), that are routinely used in AML treatment are known to augment HLA expression. For AML, HMAs are often combined with venetoclax (Ven), a drug that blocks the anti-apoptotic B-cell lymphoma-2 (Bcl-2) protein. Thus, while HMAs have been reported to increase HLA expression, what is unknown is whether these agents impact individual HLA loci differently and whether Ven has any impact on HLA expression. To address these questions, we treated the THP-1 cell line with Dec, Aza or Ven and measured changes in cell-surface expression of HLA proteins by flow cytometry using locus-specific HLA mAbs. Methods THP-1 cells were incubated with IFN-γ (500 U/mL), Aza (2µM), Dec (5µM), or Ven (30nM) for 48 hours (drug concentrations were determined by earlier titration experiments). THP-1 cells are a monocytic cell line, derived from the peripheral blood of a childhood case of acute monocytic leukemia (M5 subtype), that express HLA Class I and HLA-DR but not HLA-DQ or -DP under basal conditions, although they are inducible by IFN-γ. Thus, the induction of HLA Class II expression by IFN-γ serves as a positive control. Isotype controls were included to measure background. Data is presented as the difference in MFI (delta MFI) between cells treated with a drug and those treated with diluent only. Results Treatment of THP-1 cells with either IFN-γ or Dec led to increases in Class I HLA-A, -B & -C (Figure 1) compared to untreated cells (a mean fold increase of 1.4 and 1.2, respectively). Notably, Aza did not stimulate additional HLA-C expression and induced less of an increase in HLA-A & -B expression (an increase of 1.1-fold) than IFN-γ or Dec. Treatment of THP-1 cells by Ven did not induce a change in HLA Class I expression. For Class II, IFN-γ or Dec increased HLA-DR, -DQ and -DP expression in comparison to untreated cells (Figure 1). IFN-γ induced greater HLA-DR expression compared to Dec (an increase of 2.3-fold and 1.5-fold, respectively), and both stimulated similar increases in HLA-DQ (increases of 1.5-fold and 1.4-fold, respectively) & -DP (increases of 1.9-fold and 1.5-fold, respectively). However, treatment of cells with either Aza or Ven did not lead to changes in HLA Class II expression. Discussion Previous studies have illustrated the ability of IFN-γ to induce HLA Class II expression in THP-1 cells, however, data for Dec to induce HLA Class II expression was unconfirmed. We report differences in the degree to which IFN-γ and Dec are capable of stimulating HLA-DR with IFN-γ being more potent. The inability of Aza to induce HLA Class II expression in THP-1 cells may be related to the differing drug activating pathways of the two HMAs. Indeed, there are conflicting reports as to whether Aza can stimulate HLA Class II expression. Though Ven treatment of THP-1 cells did not impact HLA expression, because it is given with HMAs, it remains to be seen what effect these drugs may have on HLA expression when administered together. Additional studies to confirm these observations in patient-derived AML blasts are ongoing. Conclusion We report that HMAs increased expression of HLA-A, -B, & -C loci and Dec but not Aza stimulated HLA-DR, -DQ, and -DP expression in THP-1 cells. Given these data, Dec may be superior in increasing HLA Class II expression post-HCT. Figure 1 Figure 1. Disclosures Marcucci: Abbvie: Other: Speaker and advisory scientific board meetings; Agios: Other: Speaker and advisory scientific board meetings; Novartis: Other: Speaker and advisory scientific board meetings. Al Malki: Neximmune: Consultancy; CareDx: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; Rigel Pharma: Consultancy; Hansa Biopharma: Consultancy.

scholarly journals Class II HLA Epitope Level Mismatch Can Predict Chronic Graft-Versus-Host Disease and Survival Following Haploidentical Transplant Using Post-Transplant Cyclophosphamide

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 311-311
Author(s):  
Scott R Solomon ◽  
Michael T Aubrey ◽  
Cheri Anobile ◽  
Xu Zhang ◽  
Brian M Freed ◽  
...  
Keyword(s):  
Graft Versus Host Disease ◽  
Chronic Gvhd ◽  
Hla Class I ◽  
Class Ii ◽  
Class I ◽  
Transplant Outcome ◽  
Graft Versus Host ◽  
Hla Dr ◽  
Hla Dq ◽  
The Impact

Abstract Post-transplant cyclophosphamide (PTCy) has improved the outcomes and expanded the use of haploidentical hematopoietic cell transplantation (haplo-HCT). Unlike many other allogeneic HCT settings, the impact of HLA disparity on graft-versus-host disease (GVHD) and transplant outcome in this setting remains unclear. HLAMatchmaker is a computer algorithm that assesses HLA compatibility at the structural level by determining what and how many functional epitopes (eplets), defined as patches of polymorphic residues within a radius of 3.0-3.5 Ångstroms, are shared between donor and recipient. It has been useful in the identification of acceptable mismatches (mm) for alloimmunized kidney transplant candidates. In order to determine the effects of HLA class I (HLA-A, B, C) and II (HLA-DR, DQ, DP) epitope mm on transplant outcome, we retrospectively analyzed 208 consecutive donor-recipient pairs receiving haplo-HCT with PTCy for hematologic malignancy. The impact of epitope mm (GVH direction) on GVHD and survival endpoints was evaluated by Cox multivariate analysis (MVA), controlling for other significant patient, donor and transplant-related factors. Median (range) recipient and donor age was 52 (19-75) and 38 (15-73) years respectively. Patients were transplanted for AML (34%), MDS/MPS/CML (20%), ALL (17%), NHL/HD/CLL (25%). PBSC was used as the stem cell source in 66% of patients, and conditioning intensity was myeloablative in 41%. The donor was a child, sibling, or parent in 47%, 38%, and 14% respectively. Median (range) follow-up for surviving patients was 33 (7-130) months. HLA class I epitope mm had no effect on GVHD or survival. In contrast, increased HLA class II epitope mm (>16) was significantly correlated to an increased frequency of chronic GVHD (figure 1). In MVA, higher degree of class II epitope mm was associated with chronic GVHD, total (HR 1.91, p=0.012) and moderate-to-severe (HR 2.37, p=0.006). The positive effect of increased class II epitope mm on chronic GVHD was driven mostly by HLA-DQ epitope mm (HR 1.7 for >7 vs. ≤7, p=0.047) with a non-significant contribution from HLA-DP (HR 1.36 for >2 vs. ≤2, p=0.24). In contrast, increased HLA-DR epitope mm had a protective effect on chronic GVHD (HR 0.52 for >7 vs. ≤7, p=0.021). Epitope mm was not significantly associated with acute GVHD, grade 2-4 or 3-4. There was also no effect of allele-level mm at any HLA loci on acute or chronic GVHD. We next tested the impact of class I and II epitope mm on survival, including the individual impact of HLA-DR, -DQ and -DP epitope mm. Although class I epitope mm had no impact in univariate analysis, a higher number of class II epitope mm (>16) was correlated with better overall survival and the effect was primarily driven by HLA-DQ epitope mm (figure 2). To better assess the impact of class II epitope mm on survival, we analyzed this variable in the context of a previously published MVA (Solomon et al. Biol Blood Marrow Transplant. 2018;24:789-798). Controlling for other significant variables (age, race, CMV status, donor relationship, HLA-DR mm, nonpermissive HLA-DP mm, KIR receptor-ligand mm and KIR haplotype), only increased HLA-DQ epitope mm (>7) was independently associated with decreased non-relapse (HR 0.34, p=0.021) and overall mortality (HR 0.60, p=0.039). These results indicate a significant effect of class II epitope mm on chronic GVHD and survival following haplo-HCT with PTCy. Higher level of class II epitope mm and HLA-DQ epitope mm is associated with increased chronic GVHD incidence, whereas HLA-DR epitope mm is protective. Higher HLA-DQ epitope mm is independently associated with better survival, when controlling for the presence of HLA-DR allele-level mm or a nonpermissive HLA-DP mm, which have been shown previously to improve survival. Class II HLA epitope level matching provides important prognostic information in the setting of haplo-HCT and PTCy, which is not reflected by conventional allele-level matching. Disclosures Solh: Amgen: Speakers Bureau; Celgene: Speakers Bureau; ADC Therapeutics: Research Funding.

scholarly journals Characterization of cells emerging at the time of graft failure after bone marrow transplantation from an unrelated marrow donor

Blood ◽  
1993 ◽  
Vol 82 (3) ◽  
pp. 1023-1029 ◽  
Author(s):  
J Donohue ◽  
M Homge ◽  
NA Kernan
Keyword(s):  
T Cell ◽  
Mononuclear Cells ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Class Ii ◽  
Class I ◽  
Unrelated Donor ◽  
Peripheral Blood Mononuclear ◽  
Hla Dr

Abstract To help elucidate the mechanism responsible for graft failure (GF) following a T-cell depleted bone marrow transplant (BMT) from an unrelated donor, five patients (2 chronic myelogenous leukemia, 1 acute undifferentiated leukemia, 2 myelodysplastic syndrome) who experienced this complication were studied. All patients were HLA class I identical with their donors as determined by serology and one-dimensional isoelectric focusing (IEF); two were serologically matched with their donors for HLA class II antigens, whereas three donor-recipient pairs were serologically mismatched for one HLA-DR antigen. All patients received total body irradiation (fractionated, 1,500 rads), VP-16 (750 mg/m2), and cyclophosphamide (120 mg/kg) pre-BMT and antithymocyte globulin (15 mg/kg every other day) and methylprednisolone (2 mg/kg) post-BMT. Three patients experienced primary nonengraftment and two experienced secondary GF. Peripheral blood mononuclear cells obtained from the patients at the time of GF were studied to examine their functional and phenotypic characteristics. Emerging cells were of host origin and were found to be specifically cytotoxic to donor target cells and suppressive to the in vitro growth of donor BM, especially in the cases of primary nonengraftment. Peripheral blood mononuclear cells from these patients were expanded to form T-cell lines (TcLs). The cytotoxic activities of TcLs were tested in the presence of blocking MoAbs directed against various HLA determinants in an attempt to determine if HLA antigens expressed on donor cells were the target for cytotoxicity. The observed cytotoxic activity was blocked by antibodies to HLA-B, -C (1 patient), HLA-DR (1 patient), and HLA-DQ (1 patient). In two cases, antidonor cytotoxicity could not be blocked by MoAb directed against HLA-A, -B, -C, or -DR. Phenotypic characterization of four successfully maintained TcLs showed 100% CD3+ cells with 100% CD4+ (3 patients) or 50% CD4+/50% CD8+ (1 patient). In two of the three patients with 100% CD4+ cells, antidonor cytotoxicity was blocked by an anti-HLA class II MoAb. In contrast to our previous findings in cases of GF following T-cell-depleted HLA nonidentical family member BMT in which host T cells were CD8+ and cytotoxicity was directed against HLA class I antigens, our present study indicates host T cells emerging at the time of GF following BMT from an HLA class I IEF-identical unrelated donor can be of the CD4+ subset and seem to be capable of recognizing antigenic disparities in the HLA class II region.

P012 An HLA Typing for every JIA?

Rheumatology ◽  
2021 ◽  
Vol 60 (Supplement_5) ◽  
Author(s):  
N Boutrid ◽  
H Rahmoune ◽  
H Boutrid ◽  
B Bioud ◽  
M Madani ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Regulatory Region ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Typing ◽  
Class I ◽  
Coding Region ◽  
Hla Dr ◽  
Hla Dq ◽  
Wide Range

Abstract Background Among the genetic susceptibility factors of Juvenile Idiopathic Arthritis (JIA), the HLA class I and II genes are the most frequently involved. These HLA genes are extensively investigated, highlighting the role of self/non-self-balance in auto-immune and auto-inflammatory diseases. Methods We carried out a retrospective study of HLA class I and/or class II genes (HLA B and HLA DR genes) of 12 children. Genotyping was performed through microlymphocytotoxicity for class I (HLA B5 and B27) and through indirect immunofluorescence and PCR for class II (HLA DR4) Results The summarized results depict:     4 patients have the HLA B27 +     3 patients have the HLA B5+     1 patient had the HLA DR JIA comprises a broad spectrum influenced by both genetic and environmental factors. The International League of Rheumatology Associations (ILAR) has defined seven categories of JIA consisting of a myriad of pediatric auto-immune and auto-inflammatory diseases. The HLA genomic region is also associated with a wide range of auto-immune diseases, encoding the HLA-DR, HLA-DQ, and HLA-DP proteins involved in the peptide’s presentations to HLA -class II-restricted CD4 + helper T cells. These mechanisms are involved in the pathogenesis of various diseases such as rheumatoid arthritis. Juvenile arthritis has also been associated with a single nucleotide polymorphism in the regulatory region of the interleukin-6 gene, close to the HLA coding region. Conclusion Genetic exploration of the HLA system in JIA, more accessible and less expensive than other targeted genetic typing, can be a helpful tool. Its usage ought to be encouraged and expanded in clinical practice.

Myeloid Leukemic Blasts Use the Endogenous HLA Class I Antigen Processing Machinery for Peptide Loading Onto HLA Class II Molecules: Implications for Immunotherapy.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3114-3114
Author(s):  
Marvin M. van Luijn ◽  
Martine E.D. Chamuleau ◽  
Maaike E. Ressing ◽  
Emmanuel J.H.J. Wiertz ◽  
Suzanne Ostrand-Rosenberg ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Antigen Processing ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Class Ii ◽  
Class I ◽  
Antigen Processing Machinery ◽  
Hla Class I Antigen ◽  
Hla Dr ◽  
Hla Class Ii Molecules

Abstract Abstract 3114 Poster Board III-51 Besides professional antigen-presenting cells, certain tumor cells also have an intracellular machinery to process antigenic peptides for presentation via HLA class II molecules to CD4+ T cells. During the classical HLA class II presentation pathway, the Invariant Chain (Ii) stabilizes HLA class II molecules in the endoplasmic reticulum (ER) and mediates their transport to specialized lysosomal antigen-loading compartments termed MIICs. In HLA class II-transfected tumor cells however, it has been showed that HLA class II-peptide complexes can also be presented on the plasma membrane in the absence of Ii. The current study explores this alternative presentation pathway in physiologically HLA class II-expressing leukemic blasts and focuses on the role of endogenous antigen processing. We transduced the human KG-1 myeloid leukemic cell line with specific retroviral Ii siRNAs to evaluate the dependency of HLA-DR processing on the function of Ii. Western blot and flow cytometric analyses demonstrated that total and plasma membrane HLA-DR expression levels remained unaffected after Ii silencing in KG-1 blasts. Since HLA-DR expression does require peptide binding, Ii-independency in these blasts might be achieved by endogenous peptide loading in the ER. To test this hypothesis, we studied whether components of the endogenous HLA class I antigen processing machinery, including the proteasome and transporter associated with antigen processing (TAP), were involved in HLA-DR processing and presentation. Cytoplasmic degradation of endogenous antigens into peptides was suppressed by using the proteasome inhibitors bortezomib and MG-132. Additionally, retroviral transductions were performed with viral UL49.5 and BNLF2a proteins that interfere with the function of TAP in order to block the supply of proteasome-generated endogenous peptides into the ER. In both experimental setups, not only strong reductions in HLA class I, but also in HLA-DR expression levels were observed at the KG-1 plasma membrane, as determined by flow cytometry. Moreover, HLA-DR expression was completely abolished after dual suppression of TAP and Ii, which indicates that HLA-DR processing and presentation in leukemic blasts is dependent on either of these two molecules. Indeed, Ii silencing in blasts of the TAP-deficient human Kasumi-1 myeloid leukemic cell line resulted in a total loss of HLA-DR expression. Treatment of TAP-deficient Kasumi-1 blasts with proteasome inhibitors did not influence HLA-DR expression levels, confirming that the involvement of endogenous antigens in HLA-DR processing and presentation is related to the function of TAP. In conclusion, our data showing that KG-1 blasts are able to process antigens via the proteasome- and TAP-dependent pathway for HLA class II-restricted presentation and their known capacity to express endogenous peptides makes it likely that these tumor cells present tumor-associated peptides on both HLA class I and II molecules. Thus, the use of strategies that specifically target the HLA class I antigen processing machinery may represent an attractive immunomodulatory approach to simultaneously optimize HLA class I- and II-restricted presentation of relevant leukemia-associated peptides on either proteasome- or TAP-deficient leukemic blasts, thereby generating more effective whole-cell vaccines for the treatment of AML. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characterization of cells emerging at the time of graft failure after bone marrow transplantation from an unrelated marrow donor

Blood ◽  
1993 ◽  
Vol 82 (3) ◽  
pp. 1023-1029 ◽  
Author(s):  
J Donohue ◽  
M Homge ◽  
NA Kernan
Keyword(s):  
T Cell ◽  
Mononuclear Cells ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Class Ii ◽  
Class I ◽  
Unrelated Donor ◽  
Peripheral Blood Mononuclear ◽  
Hla Dr

To help elucidate the mechanism responsible for graft failure (GF) following a T-cell depleted bone marrow transplant (BMT) from an unrelated donor, five patients (2 chronic myelogenous leukemia, 1 acute undifferentiated leukemia, 2 myelodysplastic syndrome) who experienced this complication were studied. All patients were HLA class I identical with their donors as determined by serology and one-dimensional isoelectric focusing (IEF); two were serologically matched with their donors for HLA class II antigens, whereas three donor-recipient pairs were serologically mismatched for one HLA-DR antigen. All patients received total body irradiation (fractionated, 1,500 rads), VP-16 (750 mg/m2), and cyclophosphamide (120 mg/kg) pre-BMT and antithymocyte globulin (15 mg/kg every other day) and methylprednisolone (2 mg/kg) post-BMT. Three patients experienced primary nonengraftment and two experienced secondary GF. Peripheral blood mononuclear cells obtained from the patients at the time of GF were studied to examine their functional and phenotypic characteristics. Emerging cells were of host origin and were found to be specifically cytotoxic to donor target cells and suppressive to the in vitro growth of donor BM, especially in the cases of primary nonengraftment. Peripheral blood mononuclear cells from these patients were expanded to form T-cell lines (TcLs). The cytotoxic activities of TcLs were tested in the presence of blocking MoAbs directed against various HLA determinants in an attempt to determine if HLA antigens expressed on donor cells were the target for cytotoxicity. The observed cytotoxic activity was blocked by antibodies to HLA-B, -C (1 patient), HLA-DR (1 patient), and HLA-DQ (1 patient). In two cases, antidonor cytotoxicity could not be blocked by MoAb directed against HLA-A, -B, -C, or -DR. Phenotypic characterization of four successfully maintained TcLs showed 100% CD3+ cells with 100% CD4+ (3 patients) or 50% CD4+/50% CD8+ (1 patient). In two of the three patients with 100% CD4+ cells, antidonor cytotoxicity was blocked by an anti-HLA class II MoAb. In contrast to our previous findings in cases of GF following T-cell-depleted HLA nonidentical family member BMT in which host T cells were CD8+ and cytotoxicity was directed against HLA class I antigens, our present study indicates host T cells emerging at the time of GF following BMT from an HLA class I IEF-identical unrelated donor can be of the CD4+ subset and seem to be capable of recognizing antigenic disparities in the HLA class II region.

Impact of HLA High-Resolution Matching on Outcomes of Myeloablative Unrelated Donor Hematopoietic Stem Cell Transplantation in Chinese Population

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4361-4361
Author(s):  
He Huang ◽  
Yi Luo ◽  
Jimin Shi ◽  
Yamin Tan ◽  
Xiaoyan Han ◽  
...  
Keyword(s):  
Stem Cell ◽  
High Resolution ◽  
Chinese Population ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Class Ii ◽  
Class I ◽  
Unrelated Donor ◽  
Hematopoietic Stem ◽  
The Impact

Abstract Unrelated donor hematopoietic stem cell transplantation (URD-HSCT) is more frequently associated with severe graft-versus-host disease (GVHD) or graft rejection, and the success of URD-HSCT is influenced by the degree of HLA compatibility between the donor and patient. However, HLA mismatched unrelated donors should to be considerable for patients awaiting allogeneic HSCT who lack a suitable related donor or matched unrelated donor. The purpose of the study was to observed the impact of HLA-A, -B, -DRB1/B3 high-resolution matching on outcomes of URD-HSCT in Chinese population. Patients and methods: 182 patients with hematological malignancies received URD-HSCT (bone marrow, n=130; peripheral blood stem cell, n=52) in our center between Nov. 1998 and May. 2008, and donors were from Chinese Marrow Donor Program (Chinese Mainland) and Tzu Chi Stem Cells Center (Chinese Taiwan), and the median age of all patients was 26 years (range 8–52 years). The selection of unrelated donor relied on donor-recipient HLA-A, -B, -DRB1/B3 matching by high-resolution molecular typing by PCR-SSP or PCR-SSO, with 121 cases of HLA 6/6 alleles matched, 51 cases of 1/6 allele mismatched and 10 cases of 2/6 alleles mismatched. The distribution of single HLA class I or class II mismatching was as follows: 37 HLA class I mismatching with 21 HLA-A and 16 HLA-B, and 14 HLA class II mismatching with 12 HLA-DRB1 and 2 HLA-DRB3. All of the patients were received Bu/Cy or Bu/Cy modified myeloablative conditionging regimen. MMF combined with CsA and short course MTX were performed as aGVHD prophylaxis, while other 18 patients received additional anti-CD25 monoclonal antibody to prevent severe aGVHD. Results: After a median follow-up of 14.9 months, 170 patients achieved sustained engraftment with the engraft failure of 6.6%, early treatment-related mortality (TRM) of all patients was 14.4% at 100 days after transplant, and clinical relapse was observed in 8 patients (16.5%). aGVHD developed in 106 (58.2%) patients of all with grade I–II 82 (45.1%) and grade III–IV 24 (13.1%). By Kaplan-Meier method, the accumulative probability of 5-year overall survival (OS) and disease free survival (DFS) of all patients was 51.65±4.15% and 47.38±4.05%, respectively. The incidences of aGVHD was a little higher in HLA 1–2 alleles mismatched group (n=61) compared to HLA matched group (n=121) (67.2% vs 53.7%, p>0.05), and the incidences of grades I–II and III–IV aGVHD in HLA mismatched transplants were 45.9% and 21.3% respectively, while those in HLA matched transplants were 44.6% and 9.1% respectively. Comparing the outcomes between HLA 1–2 alleles mismatched and HLA matched transplants, the engraft failure were 9.8% and 5.0% (P>0.05), and early TRM were 18.0% and 12.4% (P>0.05), respectively. The Kaplan-Meier probability OS at 5 years were 44.31±6.86% and 55.66±5.11% in HLA mismatched and matched group (P>0.05) respectively. In HLA 2 alleles mismatched URD-HSCT, the incidence of engraft failure and aGVHD were 30.0% and 80.0%, and the outcomes were really inferior to HLA matched transplants. The impact of single HLA class I (n=37) or HLA class II mismatched (n=14) on the results of URD-HSCT had been also studied, and incidences of aGVHD in HLA class I or class II mismatched transplants was not significantly different compared with HLA matched transplants. In HLA class I and class II mismatched URD-HSCT, the engraft failure were 5.4% and 7.1% (p>0.05), and early TRM were 13.5% and 35.7% (p>0.05), respectively. The probability OS at 5 years in single HLA class II mismatched transplants was significantly lower compared with HLA matched transplants (23.81±12.94% vs 55.66±5.11%, p<0.01). Conclusion: URD-HSCT could be optimized by comprehensive and precise donor-recipient alleles matching, however, HLA mismatching was associated with the risk of URD-HSCT. Moreover, HLA 2 alleles mismatches of donor-recipient HLA-A, B, DRB high-resolution matching was correlated with an inferior clinical outcome. For patients with high-risk diseases without a suitable matched unrelated donor, alternative methods to URD-HSCT with a single HLA mismatch may permit early treatment before disease progression. In our study, it also demonstrated that HLA class I mismatching was correlated with a high incidence of aGVHD, and HLA class II mismatching was associated with an inferior overall survival in Chinese population, however, larger studies would have to dissect out the magnitude of the risk incurred with specific mismatches more clearly owing to small patient numbers in each group.

Characterization Of The HLA Class II Ligandome In Acute Myeloid Leukemia (AML) Reveals Novel Candidates For Peptide-Based Immunotherapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5012-5012 ◽  
Author(s):  
Juliane S. Stickel ◽  
Claudia Berlin ◽  
Daniel J. Kowalewski ◽  
Lothar Kanz ◽  
Helmut R. Salih ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Hla Class I ◽  
Class Ii ◽  
Hla Class Ii ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
Class I ◽  
Tumor Associated Antigens ◽  
Healthy Donors

Abstract CD4+ T cells are crucial for the induction and maintenance of cytotoxic T cell responses, but can also mediate direct tumor rejection. The therapeutic efficacy of peptide-based cancer vaccines may thus be improved by including HLA class II epitopes to stimulate T helper cells. In contrast to HLA class I ligands, only a small number of class II ligands of TAA has been described so far. We recently reported on the overexpression of HLA class II in AML cells as compared to autologous monocytes and granulocytes as well as on the first HLA class I leukemia associated antigens identified directly on the cell surface of primary AML cells (Stickel et. al. abstract in Blood 2012). In this study we characterized the HLA class II ligandome in AML to identify additional ligands for a peptide-based immunotherapy approach. HLA class II ligands from primary AML cells as well as bone marrow and peripheral blood mononuclear cell (BMNCs/PBMCs) of healthy donors were analyzed using the approach of direct isolation and identification of naturally presented HLA peptides by affinity chromatography and mass spectrometry (LC-MS/MS). LC-MS/MS peptide analysis provided qualitative and semi-quantitative information regarding the composition of the respective ligandomes. Comparative analysis of malignant and benign samples served to identify ligandome-derived tumor associated antigens (LiTAAs) and to select peptide vaccine candidates. Most abundantly detected peptides were functionally characterized with regard to their ability to induce a specific CD4+ T-cell response in healthy donors and in tumor patients using ELISpot. Samples from 10 AML patients (5 FLT3-ITD mutated) and 18 healthy donors were analyzed. We identified more than 2,100 AML-derived HLA class II ligands representing >1,000 different source proteins, of which 315 were exclusively represented in AML, but not in healthy PBMC/BMNC. Data mining for broadly represented LiTAAs pinpointed 26 HLA class II ligands from 8 source proteins that were presented exclusively on more than 40% of all analyzed AML samples as most promising targets. Amongst them were already described TAAs (e.g., RAB5A) as well as several so far understated proteins (e.g. calsyntenin 1, glycophorin A, mannose-binding lectin 2). Subset analysis revealed 58 LiTAAs presented exclusively on FLT3-ITD mutated AML cells. Additional screening for HLA class II ligands from described leukemia associated antigens showed positive results for NPM1 (1 peptide sequence) and MPO (13 peptide sequences). Peptides from calsyntenin 1 and RAB5A were able to elicit CD4+-T-cell response in 25% of tested AML patients (n=16). Thus, our study identified, for the first time, HLA class II tumor associated antigens directly obtained from the HLA ligandomes of AML patients and thereby represents a further step to our goal of developing a multipeptide vaccine for immunotherapy of AML. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Edmonston Measles Virus Prevents Increased Cell Surface Expression of Peptide-Loaded Major Histocompatibility Complex Class II Proteins in Human Peripheral Monocytes

2003 ◽  
Vol 77 (17) ◽  
pp. 9412-9421 ◽  
Author(s):  
Mamadi Yilla ◽  
Carole Hickman ◽  
Marcia McGrew ◽  
Elizabeth Meade ◽  
William J. Bellini
Keyword(s):  
Major Histocompatibility Complex ◽  
Protein Expression ◽  
Mhc Class Ii ◽  
Measles Virus ◽  
Surface Expression ◽  
Class Ii ◽  
Class I ◽  
Cell Surface Expression ◽  
Histocompatibility Complex ◽  
Ifn Γ

ABSTRACT Gamma interferon (IFN-γ) induces expression of the gene products of the major histocompatibility complex (MHC), whereas IFN-α/β can interfere with or suppress class II protein expression. In separate studies, measles virus (MV) was reported to induce IFN-α/β and to up-regulate MHC class II proteins. In an attempt to resolve this paradox, we examined the surface expression of MHC class I and class II proteins in MV-infected peripheral monocytes in the presence and absence of IFN-α/β. Infection of purified monocytes with Edmonston B MV resulted in an apparent increase in cell surface expression of HLA-A, -B, and -C class I proteins, but it had no effect on the expression of HLA-DR class II proteins. MV-infected purified monocytes expressed IFN-α/β, but no measurable IFN-γ expression was detected in supernatant fluids. Class II protein expression could be enhanced by coculture of purified monocytes with uninfected peripheral blood mononuclear cell (PBMC) supernatant. MV infection of PBMCs also did not affect expression of class II proteins, but the expression of HLA-A, -B, and -C class I proteins was increased two- to threefold in most donor cells. A direct role for IFN-α/β suppression of MHC class II protein expression was not evident in monocytes since MV suppressed class II protein expression in the absence of IFN-α/β. Taken together, these data suggest that MV interferes with the expression of peptide-loaded class II complexes, an effect that may potentially alter CD4+-T-cell proliferation and the cell-mediated immune responses that they help to regulate.

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