Diverse Patterns of T Cell Reactivity Directed against Multiple Y Chromosome-Derived, HLA a*0201 Restricted, Peptides in Patients with chronic Gvhd

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 464-464
Author(s):  
Yishay Ofran ◽  
Vladimir Brusic ◽  
H. T Kim ◽  
Robert J. Soiffer ◽  
J. H Antin ◽  
...  
Keyword(s):  
T Cell ◽  
Y Chromosome ◽  
Chronic Gvhd ◽  
T Cell Responses ◽  
Class I ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Healthy Donors ◽  
Male Patients ◽  
T Cell Reactivity

Abstract Minor histocompatibility antigens (mHA) are targets of graft versus host disease (GVHD) and graft versus leukemia (GVL) responses. In male patients with female donors, Y chromosome-encoded mHA are known to be highly immunogenic but few MHC class I presented epitopes have been identified and T cell responses to HY mHA have not been examined in large cohorts of patients. We recently developed a novel method for rapid identification of putative mHA based on in-silico prediction of potential MHC class I restricted peptides. Criteria for HY mHA prediction included the following: Y chromosome encoded gene sequence; high affinity binding to HLA A*0201 (≤100nM); lack of identical sequence in homologous X gene; validated protein expression not restricted to male-specific tissues; and amino acid disparities between Y and X chromosome homologues predicted to be immunogenic. In this study, 43 peptide epitopes (9–10 amino acids) representing 5 Y-encoded proteins (DBY, SMCY, UTY, PCDH11Y, USP9Y) were identified. The only previously known Y-encoded (SMCY) HLA A*0201 restricted mHA (FIDSYICQV) ranked first in the list of predicted epitopes. Two peptides failed synthesis and 41 HY peptides were tested for T cell reactivity in post-transplant samples from 21 male patients with female donors (M-F), 9 male patients with male donors (M-M) and 19 healthy donors (7 males; 12 females). All patients and donors were HLA A*0201+ and all patients had chronic GVHD. T cell reactivity was determined by ELISPOT. Peripheral blood mononuclear cells were stimulated with individual peptides for 7 days. IFN-g secreting T cells were enumerated after 18 hour restimulation with HLA A*0201 T2 cells pulsed with the same peptide. Known HLA A*0201 restricted peptides from EBV, CMV, HIV and HCV were used as positive and negative controls. T cell responses to individual peptides could be blocked by anti human HLA class I antibodies but not by anti HLA class II antibodies. Using the recursive partitioning method, a minimum of 20 spots/2×105 PBMC above background level was identified as an optimal cut-off point to classify positive responses for the majority of peptides. T cell responses to some HY peptides were also detected in M-M patients and healthy donors, but responses were most frequent and of greater magnitude in M-F patients. The median number of positive peptide responses per patient was 8 in the M-F patient group, 1 in M-M patients and 2 in healthy donors (p=0.002 for M-F vs M-M, p=0.02 for M-F vs healthy donors). All M-F patients responded to at least 1 HY peptide whereas 3/9 (33%) M-M patients and 7/19 (37%) healthy donors did not respond to any peptides. 18/21 (86%) M-F patients responded to 3 or more peptides but this level of reactivity was only detected in 2/9 (22%) M-M patients and 7/19 (37%) healthy donors. High frequency responses (>50 spots/2×105 PBMC) were detected in 19/21 (91%) M-F patients but only in 2/9 (22%) M-M patients, 1/7 (14%) healthy males and 4/12 (33%) healthy females. T cell responses were detected in at least 1 M-F patient for 36 of 41 peptides and responses were detected against all 5 Y-encoded proteins. However, a subset of 20 peptides appeared to be highly immunogenic with T cells responses detected in >25% of M-F patients. No single HY peptide elicited responses in all M-F patients including the previously known HY mHa, which was only positive in 40% of M-F patients. In fact 9 other peptides derived from DBY (1), SMCY (3), UTY (3), PCDH11Y (1) and USP9Y (1) elicited responses in 40–71% of M-F patients. Each of these 10 peptides elicited high frequency responses (>50 spots/2×105 PBMC) in at least 3 M-F patients but not in any M-M patients or healthy males. Within the M-F patients, the frequency of response was not associated with severity of cGVHD, underlying hematologic disease, age, stem cell source, transplant conditioning regimen or donor type. There was a correlation between time post transplant and the number of HY peptide responses (r=0.53, p=0.002 for all F-M and M-M patients combined). The functional application of bioinformatic models represents a new approach for identifying large numbers of novel HY peptides and assessing T cell responses after transplantation. These studies demonstrate a highly diverse T cell response despite identical mismatch and HLA type. Extending this method to other HLA alleles and to autosomal genetic disparities will improve our understanding of the role of mHA in GVL and GVHD after allogeneic transplantation.

scholarly journals Broad Cross-Clade T-Cell Responses to Gag in Individuals Infected with Human Immunodeficiency Virus Type 1 Non-B Clades (A to G): Importance of HLA Anchor Residue Conservation

2005 ◽  
Vol 79 (17) ◽  
pp. 11247-11258 ◽  
Author(s):  
Mark J. Geels ◽  
Sheri A. Dubey ◽  
Kiersten Anderson ◽  
Elly Baan ◽  
Margreet Bakker ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
T Cell Reactivity ◽  
Hiv 1

ABSTRACT We aimed to identify cross-clade human immunodeficiency virus type 1 (HIV-1) specific T-cell responses among 10 HLA-typed individuals who were infected with non-B HIV-1 strains (A, AG, C, D, G, or F) and to correlate these responses with genetic variation in documented T-cell epitopes. T-cell reactivity was tested against peptide pools spanning clade B Gag, Pol, Nef, Rev, and Tat consensus, with Gag and Nef providing the highest responses. Nine individuals who responded to clade B Gag demonstrated cross-reactive T-cell responses against clade A and C Gag pools, while six of seven responders to Nef-B reacted to clade A and C Nef pools. An inverse correlation between the height of the T-cell responses and the sequence divergence of the HLA class I-restricted epitopes was identified when we compared autologous Gag and Nef sequences with the reactive consensus pools. This could be explained for the Gag sequences through observed variations in the HLA anchor residues. Through mapping of 30 amino acid cross-clade-reactive regions using Gag-B pools, we were able to link 58% (14/24) of the T-cell responses to regions containing previously described HLA class I-restricted epitopes. Forty-two percent (10/24) of the responses were directed to regions containing new epitopes, for which predicted HLA class I motifs could be recognized in 70% (7/10) of individuals. We demonstrate here that cross-clade T-cell responses are frequently induced in individuals infected with distinct HIV-1 clades, suggesting that interclade variation outside of HLA anchor residues may have less impact on vaccine-induced T-cell reactivity than previously thought.

scholarly journals Negligible impact of SARS-CoV-2 variants on CD4+ and CD8+ T cell reactivity in COVID-19 exposed donors and vaccinees.

2021 ◽  
Author(s):  
Alison Tarke ◽  
John Sidney ◽  
Nils Methot ◽  
Yun Zhang ◽  
Jennifer M Dan ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Comprehensive Analysis ◽  
T Cell Epitopes ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Adaptive Immune ◽  
T Cell Reactivity

The emergence of SARS-CoV-2 variants highlighted the need to better understand adaptive immune responses to this virus. It is important to address whether also CD4+ and CD8+ T cell responses are affected, because of the role they play in disease resolution and modulation of COVID-19 disease severity. Here we performed a comprehensive analysis of SARS-CoV-2-specific CD4+ and CD8+ T cell responses from COVID-19 convalescent subjects recognizing the ancestral strain, compared to variant lineages B.1.1.7, B.1.351, P.1, and CAL.20C as well as recipients of the Moderna (mRNA-1273) or Pfizer/BioNTech (BNT162b2) COVID-19 vaccines. Similarly, we demonstrate that the sequences of the vast majority of SARS-CoV-2 T cell epitopes are not affected by the mutations found in the variants analyzed. Overall, the results demonstrate that CD4+ and CD8+ T cell responses in convalescent COVID-19 subjects or COVID-19 mRNA vaccinees are not substantially affected by mutations found in the SARS-CoV-2 variants.

Frequency and Intensity of Antibody Responses to Antigens Encoded by KDM5D (SMCY) and Other H-Y Genes After Allogeneic Hematopoietic Cell Transplantation,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4028-4028
Author(s):  
Takakazu Kawase ◽  
Nathan D. Ord ◽  
Andrea Towlerton ◽  
Shoko Satoh ◽  
Tara Bumgarner ◽  
...  
Keyword(s):  
T Cell ◽  
Y Chromosome ◽  
X Chromosome ◽  
Chronic Gvhd ◽  
T Cell Responses ◽  
Antibody Responses ◽  
Protein Fragments ◽  
Allogeneic Hct ◽  
Cell Responses ◽  
Reactive Antibody

Abstract Abstract 4028 Male recipients of female hematopoietic cell grafts (F->M HCT), when compared with other donor/recipient gender combinations, face an increased risk for both acute and chronic graft-versus-host disease (GVHD), but also have a significantly decreased risk of posttransplant relapse. F->M HCT is characterized at the cellular level by female donor T cell responses against male-specific minor histocompatibility (H-Y) antigens, which can contribute to both GVHD and graft-versus-leukemia (GVL) activity. Data from both murine models and clinical studies of allogeneic HCT demonstrate that the protein product of the Y chromosome gene KDM5D (previously known as SMCY) is one of the major targets of H-Y-specific T cell responses. CD8+ T cell responses against KDM5D peptides have been associated with GVHD and GVL in male recipients of female grafts, and with rejection of male grafts by female recipients. A subset of Y chromosome-encoded proteins, including several that are targets for CD8+ and CD4+ T cell responses after F->M HCT, are also the targets of antibody responses in this setting (Miklos et al., Blood 2005; 105:2973). Antibody responses to the protein products of DDX3Y and UTY, in particular, have been detected in up to 50% of F->M HCT recipients. Moreover, antibody responses to these Y chromosome gene products have been associated with the development of chronic GVHD as well as the maintenance of remission. T cell responses to KDM5D in F->M HCT recipients have been extensively studied, but KDM5D-reactive antibody responses have not been thoroughly evaluated. We hypothesized that KDM5D -reactive antibodies would also develop in a significant fraction of F->M HCT recipients, and undertook an exploratory study to define the frequency and intensity of antibody responses to KDM5D in both allogeneic HCT patients and healthy adult male and female control subjects. Plasma samples were obtained from 39 male HCT patients with female donors, 16 HCT patients with other donor/recipient gender combinations, 12 healthy female controls, and 9 healthy male controls, and assessed for IgG responses against an array of 84 different protein targets by ELISA. The target panel included partial (SMCY and UTY) or whole (DDX3Y, ZFY RPS4Y, and E1F1AY) recombinant H-Y proteins and their X chromosome-encoded homologues that had been expressed in and purified from E. coli, as well as synthetic overlapping peptides of length 15–21 residues derived from the KDM5D and DDX3Y protein sequences or from their X chromosome-encoded homologues KDM5C (SMCX) and DDX3X. Of the 55 samples acquired from HCT recipients, 49 came from recipients who had previously been diagnosed with cGVHD and were receiving immunosuppressive therapy. Reactivity with KDM5D-derived peptides or recombinant KDM5D protein fragments was observed in HCT recipients of all four donor-recipient gender combinations and also in some healthy control males and females. Amongst male patients with female donors, 7 of 39 (18%) samples were reactive with more than 3 KDM5D peptides, and 2 of 16 (13%) samples from patients with other donor/recipient gender combinations were reactive with 3 or more KDM5D peptides. Significant differences in the frequency of reactivity with individual peptides were observed, with a high frequency of responses to peptides corresponding to sequences within the interval KDM5D281–375, a region of the protein where there is significant nonidentity with the sequence of its X chromosome-encoded homologue KDM5C. This region also contains the sequence FIDSYICQV, which comprises the epitope recognized by CD8+ HLA-A*0201-restricted T cell clones that have frequently been isolated from HLA-A*0201+ F->M HCT recipients and have been associated with both GVHD and GVL. Antibody reactivity to KDM5D was correlated with reactivity to several DDX3Y-derived peptides previously shown to be the targets of antibody responses in F->M HCT recipients, but weakly associated with responses to UTY protein fragments, which were observed in 11 of 39 (28%) F->M patients and 1 of 16 (6%) patients with other donor/recipient gender combinations. These results suggest that KDM5D is a frequent target of posttransplant antibody responses in allogeneic HCT recipients. Current studies are evaluating in a larger cohort of patients the relationship of KDM5D-reactive antibody responses to H-Y-specific T cell responses and to the development of acute and chronic GVHD. Disclosures: No relevant conflicts of interest to declare.

HLA Class I Ligandome Analysis In Acute Myeloid Leukemia – Novel T-Cell Epitopes For Peptide-Based Immunotherapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5431-5431
Author(s):  
Stickel S. Juliane ◽  
Claudia Berlin ◽  
Daniel J. Kowalewski ◽  
Heiko Schuster ◽  
Lothar Kanz ◽  
...  
Keyword(s):  
T Cell ◽  
Conflicts Of Interest ◽  
Peptide Vaccine ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Isolation And Identification ◽  
Cell Responses ◽  
Healthy Donors ◽  
Hla Ligands

Abstract Data regarding the graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (SCT) and donor lymphocyte infusion strongly suggest that T lymphocytes play a major role in the rejection of leukemic cells. Immunotherapy directed against leukemia- associated antigens might elicit specific immune responses that may serve to eliminate minimal residual disease after chemotherapy, or enhance the GVL effect after SCT. To achieve this goal there is need to identify appropriate leukemia associated HLA ligands, which are able to induce specific T cell responses. We here aimed to characterize the HLA class I ligandome in AML patients to provide novel tumor associated antigens (TAA) for peptide-based immunotherapy employing our recently implemented approach of direct isolation and identification of naturally presented HLA ligands by affinity chromatography and mass spectrometry (LC-MS/MS) in AML (Stickel et.al., abstract in Blood 2012). Absolute HLA surface expression on AML cells and autologous monocytes and granulocytes was quantified by flow cytometry. HLA class I ligands were isolated from AML cells as well as bone marrow and peripheral blood mononuclear cell (BMNCs/PBMCs) of healthy donors. 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 TAA (LiTAA) and to select peptide vaccine candidates. The most abundantly detected peptide candidates were checked for immunogenicity by ELISpot and confirmed by intracellular interferon-g staining of CD8+ T-cells. Meanwhile 15 AML patients (8 FLT3-ITD mutant) and 35 healthy donors were analyzed. We observed overexpression of HLA class I and II on AML cells as compared to autologous monocytes and granulocytes, with the level of significance reached for HLA class II (p=0,04). A total of more than 12,000 AML derived HLA ligands representing >6,000 different source proteins were identified; of which 2,220 were exclusively represented in AML, but not in healthy PBMC/BMNC. Data mining for broadly represented LiTAA pinpointed 98 TAA as most promising targets. HLA ligands derived from these TAA were presented exclusively on more than 33% of all analyzed AML samples, amongst them already described TAA (e.g. JUP, FAF1) as well as several new leukemia-associated proteins (e.g. MTCH2, METTL7A). Subset analysis of the FLT3-ITD positive AML cohort revealed 21 LiTAA presented exclusively on more than 50% of FLT3-ITD positive AML cases. Additional screening for HLA ligands derived from described leukemia associated antigens revealed overrepresentation for e.g. FLT3, NUSAP, RHAMM and RGS5. Specific CD8+ T cell responses were detected against two A*03 epitope pools (pool 1: APLP2, DKGZ, FAF1, MTCH2; pool 2: KLF2, METTL7A, VCIP1, WIPI1) in AML patients. Notably, the chosen A*03 epitope pools did not elicit specific responses of CTL from healthy donors. Taken together, our HLA class I ligandome analysis in AML for the first time identified naturally presented HLA ligands from patients including a vast array of new leukemia associated antigens representing promising targets for a multipeptide-based immunotherapy approach in AML. Disclosures: No relevant conflicts of interest to declare.

Dissection of anti-CTLA4-induced cytotoxic T-cell responses in melanoma.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 9078-9078
Author(s):  
John B. A. G. Haanen ◽  
Pia Kvistborg ◽  
Daisy Philips ◽  
Sander Kelderman ◽  
Bianca Heemskerk ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Cytotoxic T Cell ◽  
Clinical Activity ◽  
Immune Reactivity ◽  
Cell Detection ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Cytotoxic T Cell Responses ◽  
T Cell Reactivity

9078 Background: There is strong evidence that melanoma-reactive T cells induced by immunotherapeutic interventions such as anti-CTLA4 therapy can exert clinically effects. However, there is very little information on how these therapies influence tumor-specific T cell responses. Furthermore, as the number of potential melanoma-associated antigens to which these responses can be directed is very high, classical strategies to map cytotoxic T cell reactivity do not suffice. Knowledge of such reactivities would be useful to design targeted strategies, selectively aiming to induce immune reactivity against these antigens. Methods: We have addressed these issues by designing MHC class I molecules occupied with UV-sensitive ‘conditional’ ligands, thereby allowing the production of very large collections of pMHC complexes for T cell detection. Secondly, we have developed a ‘combinatorial coding’ strategy that allows parallel detection of dozens of different T cell populations within a single sample. The combined use of MHC ligand exchange and combinatorial coding allows the high-throughput dissection of disease- and therapy-induced CTL immunity. We have used this platform to monitor immune reactivity against a panel of 145 melanoma-associated epitopes in patients receiving Ipilimumab treatment. Results: Comparison of PBMC samples from 32 melanoma patients pre- and post-therapy indicated a significant increase in the number of detectable melanoma-associated T cell responses (p=0.004). Furthermore, kinetic data on T cell responses during therapy suggests that this broadening generally occurs within weeks after start of therapy. The magnitude of melanoma-specific T cell responses that was detectable prior to start of therapy was not significantly altered (p=0.8). Conclusions: These results establish the pattern of melanoma-specific T-cell reactivity induced by anti-CTLA4 treatment and form a benchmark for evaluation of other immunotherapeutic interventions, like anti-PD1 treatment, that are currently undergoing clinical evaluation. Furthermore, our data suggests that the clinical activity of Ipilimumab may be mostly due to epitope spreading, rather than through enhancement of pre-existing immune activity.

scholarly journals Profound CD8 T cell responses towards the SARS-CoV-2 ORF1ab in COVID-19 patients

2020 ◽  
Author(s):  
Anastasia Gangaev ◽  
Steven L. C. Ketelaars ◽  
Sanne Patiwael ◽  
Anna Dopler ◽  
Olga I. Isaeva ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Clinical Activity ◽  
Cell Reactivity ◽  
T Cell Recognition ◽  
Cell Responses ◽  
T Cell Reactivity ◽  
Very High

Abstract A large global effort is currently ongoing to develop vaccines against SARS-CoV-2, the causative agent of COVID-19. While there is accumulating evidence on the antibody response against SARS-CoV-2, little is known about the SARS-CoV-2 antigens that are targeted by CD8 T cells. To address this issue, we have analyzed samples from 20 COVID-19 patients for T cell recognition of 500 predicted MHC class I epitopes. CD8 T cell reactivity against SARS-CoV- 2 was common. Remarkably, a substantial fraction of the observed CD8 T cell responses were directed towards the ORF1ab polyprotein 1ab, and these CD8 T cell responses were frequently of a very high magnitude. The fact that a major part of the SARS-CoV-2 specific CD8 T cell response is directed against a part of the viral genome that is not included in the majority of vaccine candidates currently in development may potentially influence their clinical activity and toxicity profile.

scholarly journals T cell reactivity to the SARS-CoV-2 Omicron variant is preserved in most but not all prior infected and vaccinated individuals

2022 ◽  
Author(s):  
Vivek Naranbhai ◽  
Anusha Nathan ◽  
Clarety Kaseke ◽  
Cristhian Berrios ◽  
Ashok Khatri ◽  
...  
Keyword(s):  
T Cell ◽  
Booster Vaccination ◽  
T Cell Responses ◽  
Cell Compartment ◽  
Cell Reactivity ◽  
T Cell Recognition ◽  
Cell Responses ◽  
T Cell Reactivity ◽  
Prior Infection ◽  
Spike Proteins

The SARS-CoV-2 Omicron variant (B.1.1.529) contains mutations that mediate escape from infection and vaccine-induced antibody responses, although the extent to which these substitutions in spike and non-spike proteins affect T cell recognition is unknown. Here we show that T cell responses in individuals with prior infection, vaccination, both prior infection and vaccination, and boosted vaccination are largely preserved to Omicron spike and non-spike proteins. However, we also identify a subset of individuals (~21%) with a >50% reduction in T cell reactivity to the Omicron spike. Evaluation of functional CD4+ and CD8+ memory T cell responses confirmed these findings and reveal that reduced recognition to Omicron spike is primarily observed within the CD8+ T cell compartment. Booster vaccination substantially enhanced T cell responses to Omicron spike. In contrast to neutralizing immunity, these findings suggest preservation of T cell responses to the Omicron variant, although with reduced reactivity in some individuals.

scholarly journals Mapping T Cell Responses to Native and Neo-Islet Antigen Epitopes in at Risk and Type 1 Diabetes Subjects

2021 ◽  
Vol 12 ◽  
Author(s):  
Sefina Arif ◽  
Irma Pujol-Autonell ◽  
Yogesh Kamra ◽  
Evangeline Williams ◽  
Norkhairin Yusuf ◽  
...  
Keyword(s):  
At Risk ◽  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell ◽  
Single Cell ◽  
T Cell Responses ◽  
Cell Reactivity ◽  
Cell Responses ◽  
T Cell Reactivity

AimsRecent studies highlight the potentially important role of neoepitopes in breaking immune tolerance in type 1 diabetes. T cell reactivity to these neoepitopes has been reported, but how this response compares quantitatively and phenotypically with previous reports on native epitopes is not known. Thus, an understanding of the relationship between native and neoepitopes and their role as tolerance breakers or disease drivers in type 1 diabetes is required. We set out to compare T cell reactivity and phenotype against a panel of neo- and native islet autoantigenic epitopes to examine how this relates to stages of type 1 diabetes development.MethodsFifty-four subjects comprising patients with T1D, and autoantibody-positive unaffected family members were tested against a panel of neo- and native epitopes by ELISPOT (IFN-γ, IL-10, and IL-17). A further subset of two patients was analyzed by Single Cell Immune Profiling (RNAseq and TCR α/β) after stimulation with pools of native and neoepitope peptides.ResultsT cell responses to native and neoepitopes were present in patients with type 1 diabetes and at-risk subjects, and overall, there were no significant differences in the frequency, magnitude, or phenotype between the two sets of peptide stimuli. Single cell RNAseq on responder T cells revealed a similar profile in T1D patients stimulated with either neo- or native epitopes. A pro-inflammatory gene expression profile (TNF-α, IFN-γ) was dominant in both native and neoepitope stimulated T cells. TCRs with identical clonotypes were found in T cell responding to both native and neoepitopes.Conclusion/InterpretationThese data suggest that in peripheral blood, T cell responses to both native and neoepitopes are similar in terms of frequency and phenotype in patients with type 1 diabetes and high-risk unaffected family members. Furthermore, using a combination of transcriptomic and clonotypic analyses, albeit using a limited panel of peptides, we show that neoepitopes are comparable to native epitopes currently in use for immune-monitoring studies.

scholarly journals Mapping of novel peptides of WT-1 and presenting HLA alleles that induce epitope-specific HLA-restricted T cells with cytotoxic activity against WT-1+ leukemias

Blood ◽  
2012 ◽  
Vol 120 (8) ◽  
pp. 1633-1646 ◽  
Author(s):  
Ekaterina Doubrovina ◽  
Taissia Carpenter ◽  
Dmitry Pankov ◽  
Annamalai Selvakumar ◽  
Aisha Hasan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Wilms Tumor ◽  
T Cell Responses ◽  
Class Ii ◽  
Class I ◽  
Hla Alleles ◽  
Cell Responses ◽  
Healthy Donors

Abstract The Wilms tumor protein (WT-1) is widely recognized as a tumor antigen that is expressed differentially by several malignancies. However, WT-1 peptides known to induce tumoricidal T cells are few. In the present study, we evaluated T-cell responses of 56 healthy donors to in vitro sensitization with autologous APCs loaded with a pool of overlapping 15-mer peptides spanning the sequence of WT-1. Thereafter, we mapped the WT-1 peptides eliciting responses in each individual, defined the immunogenic peptides, and identified their presenting HLA alleles. We report 41 previously unreported epitopes of WT-1: 5 presented by class II and 36 by class I alleles, including 10 that could be presented by more than 1 class I allele. IFNγ+ T cells responding to 98% of the class I and 60% of the class II epitopes exhibited HLA-restricted cytotoxicity against peptide-loaded targets. T cells specific for 36 WT-1 peptides were evaluable for leukemocidal activity, of which 27 (75%) lysed WT-1+ leukemic targets sharing their restricting HLA allele. Each epitope identified induced T-cell responses in most donors sharing the epitopes' presenting allele; these responses often exceeded responses to flanking peptides predicted to be more immunogenic. This series of immunogenic epitopes of WT-1 should prove useful for immunotherapies targeting WT-1+ malignancies.

scholarly journals Broad T Cell Targeting of Structural Proteins After SARS-CoV-2 Infection: High Throughput Assessment of T Cell Reactivity Using an Automated Interferon Gamma Release Assay

2021 ◽  
Vol 12 ◽  
Author(s):  
Isabel Brand ◽  
Leonard Gilberg ◽  
Jan Bruger ◽  
Mercè Garí ◽  
Andreas Wieser ◽  
...  
Keyword(s):  
T Cell ◽  
Interferon Gamma ◽  
High Throughput ◽  
T Cell Responses ◽  
Structural Proteins ◽  
Interferon Gamma Release Assay ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Release Assay ◽  
T Cell Reactivity

BackgroundAdaptive immune responses to structural proteins of the virion play a crucial role in protection against coronavirus disease 2019 (COVID-19). We therefore studied T cell responses against multiple SARS-CoV-2 structural proteins in a large cohort using a simple, fast, and high-throughput approach.MethodsAn automated interferon gamma release assay (IGRA) for the Nucleocapsid (NC)-, Membrane (M)-, Spike-C-terminus (SCT)-, and N-terminus-protein (SNT)-specific T cell responses was performed using fresh whole blood from study subjects with convalescent, confirmed COVID-19 (n = 177, more than 200 days post infection), exposed household members (n = 145), and unexposed controls (n = 85). SARS-CoV-2-specific antibodies were assessed using Elecsys® Anti-SARS-CoV-2 (Ro-N-Ig) and Anti-SARS-CoV-2-ELISA (IgG) (EI-S1-IgG).Results156 of 177 (88%) previously PCR confirmed cases were still positive by Ro-N-Ig more than 200 days after infection. In T cells, most frequently the M-protein was targeted by 88% seropositive, PCR confirmed cases, followed by SCT (85%), NC (82%), and SNT (73%), whereas each of these antigens was recognized by less than 14% of non-exposed control subjects. Broad targeting of these structural virion proteins was characteristic of convalescent SARS-CoV-2 infection; 68% of all seropositive individuals targeted all four tested antigens. Indeed, anti-NC antibody titer correlated loosely, but significantly with the magnitude and breadth of the SARS-CoV-2-specific T cell response. Age, sex, and body mass index were comparable between the different groups.ConclusionSARS-CoV-2 seropositivity correlates with broad T cell reactivity of the structural virus proteins at 200 days after infection and beyond. The SARS-CoV-2-IGRA can facilitate large scale determination of SARS-CoV-2-specific T cell responses with high accuracy against multiple targets.

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