scholarly journals Molecular basis for universal HLA-A*0201–restricted CD8+ T-cell immunity against influenza viruses

2016 ◽  
Vol 113 (16) ◽  
pp. 4440-4445 ◽  
Author(s):  
Sophie A. Valkenburg ◽  
Tracy M. Josephs ◽  
E. Bridie Clemens ◽  
Emma J. Grant ◽  
Thi H. O. Nguyen ◽  
...  

Memory CD8+ T lymphocytes (CTLs) specific for antigenic peptides derived from internal viral proteins confer broad protection against distinct strains of influenza A virus (IAV). However, immune efficacy can be undermined by the emergence of escape mutants. To determine how T-cell receptor (TCR) composition relates to IAV epitope variability, we used ex vivo peptide–HLA tetramer enrichment and single-cell multiplex analysis to compare TCRs targeted to the largely conserved HLA-A*0201-M158 and the hypervariable HLA-B*3501-NP418 antigens. The TCRαβs for HLA-B*3501-NP418+ CTLs varied among individuals and across IAV strains, indicating that a range of mutated peptides will prime different NP418-specific CTL sets. Conversely, a dominant public TRAV27/TRBV19+ TCRαβ was selected in HLA-A*0201+ donors responding to M158. This public TCR cross-recognized naturally occurring M158 variants complexed with HLA-A*0201. Ternary structures showed that induced-fit molecular mimicry underpins TRAV27/TRBV19+ TCR specificity for the WT and mutant M158 peptides, suggesting the possibility of universal CTL immunity in HLA-A*0201+ individuals. Combined with the high population frequency of HLA-A*0201, these data potentially explain the relative conservation of M158. Moreover, our results suggest that vaccination strategies aimed at generating broad protection should incorporate variant peptides to elicit cross-reactive responses against other specificities, especially those that may be relatively infrequent among IAV-primed memory CTLs.

1992 ◽  
Vol 176 (5) ◽  
pp. 1335-1341 ◽  
Author(s):  
Y S Hahn ◽  
C S Hahn ◽  
V L Braciale ◽  
T J Braciale ◽  
C M Rice

Cytotoxic T lymphocytes (CTL) recognize short antigenic peptides associated with cell surface class I major histocompatibility complex (MHC) molecules. This association presumably occurs between newly synthesized class I MHC molecules and peptide fragments in a pre-Golgi compartment. Little is known about the factors that regulate the formation of these antigenic peptide fragments within the cell. To examine the role of residues within a core epitope and in the flanking sequences for the generation and presentation of the newly synthesized peptide fragment recognized by CD8+ CTL, we have mutagenized the coding sequence for the CTL epitope spanning residues 202-221 in the influenza A/Japan/57 hemagglutinin (HA). In this study over 60 substitution mutations in the epitope were tested for their effects on target cell sensitization using a cytoplasmic viral expression system. The HA202-221 site contains two overlapping subsites defined by CTL clones 11-1 and 40-2. Mutations in HA residues 204-213 or residues 210-219 often abolished target cell lysis by CTL clones 11-1 and 40-2, respectively. Although residues outside the core epitope did not usually affect the ability to be lysed by CTL clones, substitution of a Gly residue for Val-214 abolished lysis by clone 11-1. These data suggest that residues within a site that affect MHC binding and T cell receptor recognition appear to play the predominant role in dictating the formation of the antigenic complex recognized by CD8+ CTL, and therefore the antigenicity of the protein antigen presented to CD8+ T cells. Most alterations in residues flanking the endogenously expressed epitope do not appreciably affect the generation and recognition of the site.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Vuorela ◽  
T. L. Freitag ◽  
K. Leskinen ◽  
H. Pessa ◽  
T. Härkönen ◽  
...  

AbstractNarcolepsy type 1 (NT1) is a chronic neurological disorder having a strong association with HLA-DQB1*0602, thereby suggesting an immunological origin. Increased risk of NT1 has been reported among children or adolescents vaccinated with AS03 adjuvant-supplemented pandemic H1N1 influenza A vaccine, Pandemrix. Here we show that pediatric Pandemrix-associated NT1 patients have enhanced T-cell immunity against the viral epitopes, neuraminidase 175–189 (NA175–189) and nucleoprotein 214–228 (NP214–228), but also respond to a NA175–189-mimic, brain self-epitope, protein-O-mannosyltransferase 1 (POMT1675–689). A pathogenic role of influenza virus-specific T-cells and T-cell cross-reactivity in NT1 are supported by the up-regulation of IFN-γ, perforin 1 and granzyme B, and by the converging selection of T-cell receptor TRAV10/TRAJ17 and TRAV10/TRAJ24 clonotypes, in response to stimulation either with peptide NA175–189 or POMT1675–689. Moreover, anti-POMT1 serum autoantibodies are increased in Pandemrix-vaccinated children or adolescents. These results thus identify POMT1 as a potential autoantigen recognized by T- and B-cells in NT1.


2016 ◽  
Vol 90 (15) ◽  
pp. 6936-6947 ◽  
Author(s):  
Sergio M. Quiñones-Parra ◽  
E. Bridie Clemens ◽  
Zhongfang Wang ◽  
Hayley A. Croom ◽  
Lukasz Kedzierski ◽  
...  

ABSTRACTNovel influenza viruses often cause differential infection patterns across different age groups, an effect that is defined as heterogeneous demographic susceptibility. This occurred during the A/H2N2 pandemic, when children experienced higher influenza attack rates than adults. Since the recognition of conserved epitopes across influenza subtypes by CD8+cytotoxic T lymphocytes (CTLs) limit influenza disease, we hypothesized that conservation of CTL antigenic peptides (Ag-p) in viruses circulating before the pH2N2-1957 may have resulted in differential CTL immunity. We compared viruses isolated in the years preceding the pandemic (1941 to 1957) to which children and adults were exposed to viruses circulating decades earlier (1918 to 1940), which could infect adults only. Consistent with phylogenetic models, influenza viruses circulating from 1941 to 1957, which infected children, shared with pH2N2 the majority (∼89%) of the CTL peptides within the most immunogenic nucleoprotein, matrix 1, and polymerase basic 1, thus providing evidence for minimal pH2N2 CTL escape in children. Our study, however, identified potential CTL immune evasion from pH2N2 irrespective of age, within HLA-A*03:01+individuals for PB1471-L473V/N476I variants and HLA-B*15:01+population for NP404–414-V408I mutant. Further experiments using the murine model of B-cell-deficient mice showed that multiple influenza infections resulted in superior protection from influenza-induced morbidity, coinciding with accumulation of tissue-resident memory CD8+T cells in the lung. Our study suggests that protection against H2N2-1957 pandemic influenza was most likely linked to the number of influenza virus infections prior to the pandemic challenge rather than differential preexisting CTL immunity. Thus, the regimen of a CTL-based vaccine/vaccine-component may benefit from periodic boosting to achieve fully protective, asymptomatic influenza infection.IMPORTANCEDue to a lack of cross-reactive neutralizing antibodies, children are particularly susceptible to influenza infections caused by novel viral strains. Preexisting T cell immunity directed at conserved viral regions, however, can provide protection against influenza viruses, promote rapid recovery and better clinical outcomes. When we asked whether high susceptibility of children (compared to adults) to the pandemic H2N2 influenza strain was associated with immune evasion from T-cell immunity, we found high conservation within T-cell antigenic regions in pandemic H2N2. However, the number of influenza infections prior to the challenge was linked to protective, asymptomatic infections and establishment of tissue-resident memory T cells. Our study supports development of vaccines that prime and boost T cells to elicit cross-strain protective T cells, especially tissue-resident memory T cells, for lifelong immunity against distinct influenza viruses.


2018 ◽  
Author(s):  
Guo Luo ◽  
Aditya Ambati ◽  
Ling Lin ◽  
Mélodie Bonvalet ◽  
Markku Partinen ◽  
...  

AbstractType 1 narcolepsy (T1N) is caused by hypocretin (HCRT) neuronal loss. Association with the Human Leukocyte Antigen (HLA)-DQB1*06:02/DQA1*01:02 (98% vs 25%) heterodimer (DQ0602), T cell receptor (TCR) and other immune loci suggest autoimmunity but autoantigen(s) are unknown. Onset is seasonal and associated with influenza A, notably pandemic 2009 H1N1 (pH1N1). An extensive unbiased DQ0602 binding peptide screen was performed encompassing peptides derived from Pandemrix® X-179-A pH1N1 influenza-A vaccine, a known T1N trigger, other H1N1 strains, and potential human autoantigens HCRT and RFX4, identifying 109 binders. The presence of cognate tetramer-peptide specific CD4+ T cells was studied in 35 narcolepsy cases and 22 DQ0602 controls after expansion of antigen-specific cells in Peripheral Blood Monocytes Cell (PBMC) cultures. Higher reactivity to influenza epitopes pHA273-287 (pH1N1 specific) and PR8 (H1N1 pre 2009)-specific NP17-31 were observed in T1N. Extensive reactivity to C-amidated but not native version of HCRT54-66 and HCRT86-97, which are two highly homologous peptides (HCRTNH2) was observed with higher frequencies of specific T cells in T1N. TCRα/β CDR3 sequences found in pHA273-287, NP17-31 and HCRTNH2 tetramer positive CD4+ cells were also retrieved in single INFγ-secreting CD4+ sorted cells stimulated with Pandemrix®, confirming immunodominance and functional significance in DQ0602-mediated responses and molecular mimicry. TCRα/β CDR3 motifs of HCRT54-66 and HCRT86-97 tetramers were extensively shared. Particularly notable was sharing across subjects of an CDR3α, CAVETDSWGKLQF (in association with various CDR3β that used TRAJ24, a chain modulated by Single Nucleotide Polymorphism (SNPs) rs1154155 and rs1483979 associated with T1N. Sharing of CDR3β CASSQETQGRNYGYTF (in association with various CDR3α was also observed with HCRTNH2 and pHA273-287-tetramers across subjects. This segment uses TRBV4-2, a segment modulated by narcolepsy-associated SNP rs1008599. Higher HCRTNH2 positive CD4+ T cell numbers in T1N together with sharing of J24 CAVETDSWGKLQF in HCRTNH2 autoimmune responses, indicates causal DQ0602-mediated CD4+ autoreactivity to HCRT in T1N. Our results provide evidence for autoimmunity and molecular mimicry with flu antigens modulated by genetic components in the pathophysiology of T1N.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Koen Debackere ◽  
Lukas Marcelis ◽  
Sofie Demeyer ◽  
Marlies Vanden Bempt ◽  
Nicole Mentens ◽  
...  

AbstractPeripheral T-cell lymphoma (PTCL) is a heterogeneous group of non-Hodgkin lymphomas with poor prognosis. Up to 30% of PTCL lack distinctive features and are classified as PTCL, not otherwise specified (PTCL-NOS). To further improve our understanding of the genetic landscape and biology of PTCL-NOS, we perform RNA-sequencing of 18 cases and validate results in an independent cohort of 37 PTCL cases. We identify FYN-TRAF3IP2, KHDRBS1-LCK and SIN3A-FOXO1 as new in-frame fusion transcripts, with FYN-TRAF3IP2 as a recurrent fusion detected in 8 of 55 cases. Using ex vivo and in vivo experiments, we demonstrate that FYN-TRAF3IP2 and KHDRBS1-LCK activate signaling pathways downstream of the T cell receptor (TCR) complex and confer therapeutic vulnerability to clinically available drugs.


1996 ◽  
Vol 184 (6) ◽  
pp. 2261-2270 ◽  
Author(s):  
Kristen M. Hege ◽  
Keegan S. Cooke ◽  
Mitchell H. Finer ◽  
Krisztina M. Zsebo ◽  
Margo R. Roberts

Gene modification of hematopoietic stem cells (HSC) with antigen-specific, chimeric, or “universal” immune receptors (URs) is a novel but untested form of targeted immunotherapy. A human immunodeficiency virus (HIV) envelope–specific UR consisting of the extracellular domain of human CD4 linked to the ζ chain of the T cell receptor (CD4ζ) was introduced ex vivo into murine HSC by retroviral transduction. After transplantation into immunodeficient SCID mice, sustained high level expression of CD4ζ was observed in circulating myeloid and natural killer cells. CD4ζ-transplanted mice were protected from challenge with a lethal dose of a disseminated human leukemia expressing HIV envelope. These results demonstrate the ability of chimeric receptors bearing ζ-signaling domains to activate non–T cell effector populations in vivo and thereby mediate systemic immunity.


2016 ◽  
Vol 113 (5) ◽  
pp. 1333-1338 ◽  
Author(s):  
Kylie M. Quinn ◽  
Sophie G. Zaloumis ◽  
Tania Cukalac ◽  
Wan-Ting Kan ◽  
Xavier Y. X. Sng ◽  
...  

In advanced age, decreased CD8+ cytotoxic T-lymphocyte (CTL) responses to novel pathogens and cancer is paralleled by a decline in the number and function of naïve CTL precursors (CTLp). Although the age-related fall in CD8+ T-cell numbers is well established, neither the underlying mechanisms nor the extent of variation for different epitope specificities have been defined. Furthermore, naïve CD8+ T cells expressing high levels of CD44 accumulate with age, but it is unknown whether this accumulation reflects their preferential survival or an age-dependent driver of CD8+ T-cell proliferation. Here, we track the number and phenotype of four influenza A virus (IAV)-specific CTLp populations in naïve C57BL/6 (B6) mice during aging, and compare T-cell receptor (TCR) clonal diversity for the CD44hi and CD44lo subsets of one such population. We show differential onset of decline for several IAV-specific CD8+ T-cell populations with advanced age that parallel age-associated changes in the B6 immunodominance hierarchy, suggestive of distinct impacts of aging on different epitope-specific populations. Despite finding no evidence of clonal expansions in an aged, epitope-specific TCR repertoire, nonrandom alterations in TCR usage were observed, along with elevated CD5 and CD8 coreceptor expression. Collectively, these data demonstrate that naïve CD8+ T cells expressing markers of heightened self-recognition are selectively retained, but not clonally expanded, during aging.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4225-4225
Author(s):  
Hussein Hamad ◽  
Wingchi K Leung ◽  
Spyridoula Vasileiou ◽  
Shivani Mukhi ◽  
Quillan Huang ◽  
...  

Myelodysplastic syndromes (MDS) are a heterogeneous group of disorders characterized by bone marrow failure and a propensity to progress to acute myeloid leukemia (AML). A core component of the underlying pathogenesis in MDS is deregulation of inflammatory cytokines, such as tumor growth factor-β (TGFβ), which impact the function of immune cells and hence their capacity to mount anti-infective or anti-tumor responses. However, little is known about antigen-specific T cell function in patients with MDS. We hypothesized that virus-specific T cell (VST) function might be preserved in patients with MDS, and that the functional capacity of T cells reactive against tumor-associated antigens aberrantly overexpressed by clonal MDS cells such as Cyclin A1 (CCNA1) and Proteinase (PR3) might also be preserved and exploited for immunotherapeutic purposes. Following informed consent, we collected peripheral blood samples from 10 patients (pts) with MDS and 17 healthy donors. Most pts (9 out of 10) were transfusion dependent and 3 subsequently underwent an allogeneic HSCT. Table 1 summarizes the other clinical characteristics, karyotypic and mutational profile at the time of blood collection. Compared with T cells isolated from healthy donors, MDS patient-derived T cells had a similar CD4 to CD8 ratio (1.5-2.5:1 for healthy donors and 3:1 for MDS pts), but displayed a more exhausted profile at baseline (CD3+TIM3+: 1% in healthy donors and 5% in MDS pts) and produced higher levels of inflammatory cytokines [IFNγ (18±3pg/ml vs 36±16pg/ml, healthy donor vs MDS; p=0.12), and IL-8 (56±32 vs 704±446 pg/ml, p=0.01)]. Next, to assess the capacity of MDS pts to mount ex vivo functional virus-directed responses, we stimulated patient-derived PBMCs (n=5) with overlapping peptide libraries (pepmixes) spanning immunogenic AdV, CMV, EBV, BK and HHV-6 antigens. Similar to healthy donor-derived T cell lines (n=5, 3 specific for 4 viruses and 2 for 5 viruses), all 5 MDS patient-derived lines demonstrated specificity for one or more of the target viruses (1 for 5 viruses, 1 for 4, 2 for 3 and 1 for 1 virus) as observed by IFNγ ELISpot assay with comparable magnitude (range Adv: 43-730 vs 384-941 in healthy donors, CMV: 0-1599 vs 0-3002, EBV: 0-1486 vs 0-541, BK: 0-839 vs 38-275 and HHV6: 0-794 vs 5-407 SFU/2x105 cells, respectively). We next examined the feasibility of expanding autologous MDS-antigen directed T cell products (n=10) to determine whether an adoptive immunotherapeutic approach might be applicable for MDS treatment. Thus, we exposed patient-derived PBMCs to autologous dendritic cells (DC) loaded with pepmixes spanning 6 MDS-associated antigens (CCNA1, survivin, WT1, PRAME, PR3 and NYESO1). After 3 rounds of stimulation, the products obtained were predominantly CD3+ T cells (mean 88±1.3%) that were polyclonal (CD4: 46±5% and CD8: 41±4%) containing predominantly memory T cells (TEM: 36±6% TCM: 37±5% and Tnaïve =13±3%). Six lines (60%) showed specific recognition to at least one of the target antigens: 4 lines specific for PRAME, 1 for CCNA1, 1 for WT1 and 1 for NYESO1 (range 0-40, 0-184, 0-1386 and 0-179 SFU/2x105 cells, respectively by IFNγ ELIspot). T cell lines were capable of specifically secreting multiple effector cytokines in response to targets (TNFα: 12% and IFNγ: 16% in response to PRAME in a representative patient-derived T cell line). Furthermore, this line was capable of killing PRAME+ targets in a 4hr 51Cr release assay [60% specific lysis, E:T 20:1]. In conclusion, functional virus-directed T cell immunity in patients with MDS is preserved, potentially explaining the lower rates of viral reactivation seen in these patients compared with other infections. Moreover, T cells specific for MDS-expressed tumor antigens can also be successfully expanded ex vivo from patients. Taken together this raises the possibility of applying an adoptive immunotherapeutic approach for the treatment of MDS. Disclosures Ramos: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Research Funding. Leen:Allovir: Consultancy, Other: Cofounder, Ownership Interest; Marker Therapeutics: Consultancy, Other: Cofounder, Ownership Interest.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2344 ◽  
Author(s):  
Preeti Sharma ◽  
David M. Kranz

Adoptive T-cell therapies have shown exceptional promise in the treatment of cancer, especially B-cell malignancies. Two distinct strategies have been used to redirect the activity of ex vivo engineered T cells. In one case, the well-known ability of the T-cell receptor (TCR) to recognize a specific peptide bound to a major histocompatibility complex molecule has been exploited by introducing a TCR against a cancer-associated peptide/human leukocyte antigen complex. In the other strategy, synthetic constructs called chimeric antigen receptors (CARs) that contain antibody variable domains (single-chain fragments variable) and signaling domains have been introduced into T cells. Whereas many reviews have described these two approaches, this review focuses on a few recent advances of significant interest. The early success of CARs has been followed by questions about optimal configurations of these synthetic constructs, especially for efficacy against solid tumors. Among the many features that are important, the dimensions and stoichiometries of CAR/antigen complexes at the synapse have recently begun to be appreciated. In TCR-mediated approaches, recent evidence that mutated peptides (neoantigens) serve as targets for endogenous T-cell responses suggests that these neoantigens may also provide new opportunities for adoptive T-cell therapies with TCRs.


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