Identification and Characterization of HLA Class I-Restricted MYD88 L265P-Derived Peptides As Tumor-Specific Targets for Immunotherapy

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2750-2750
Author(s):  
Annika Nelde ◽  
Juliane S Stickel ◽  
Daniel Johannes Kowalewski ◽  
Oliver Olaf Wolz ◽  
Lothar Kanz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Hla Class I ◽  
Class I ◽  
Specific Cell ◽  
Specific Lysis ◽  
Effector Cells

Abstract Non-Hodgkin lymphomas (NHL) are frequent malignancies with considerable mortality. A recurrent somatic and oncogenic driver mutation in the Toll-like receptor adaptor gene MYD88, Leu265Pro (L265P) has been identified in up to 90% of certain NHL subtypes. Genetic alterations affecting a protein-coding region have the potential to generate mutation-derived peptides that are presented by HLA class I proteins and might be recognized by cytotoxic T cells. Because MYD88L265P is a widely occurring and tumor-specific mutation, we investigated the potential of MYD88L265P -containing peptides for CD8+ T cell mediated immunotherapy as a new therapeutic approach for MYD88L265P+ NHL. Based on in silico prediction we identified potential HLA ligands encompassing the MYD88L265P mutation for several HLA class I allotypes. Functional characterization of the candidate HLA class I MYD88L265P-derived HLA class I ligands with regard to induction of T cell responses identified a set of immunogenic peptides for HLA-B*07 and -B*15. In one MYD88L265P-mutated NHL patient, memory T cell responses targeting three different MYD88L265P-derived HLA class I ligands were detected by IFN-γ ELISPOT. Efficient T cell priming was demonstrated in vitro using naïve T cells of healthy volunteers (HVs). In detail, three HLA-B*07 peptides (P1-3B*07) and one HLA-B*15-restricted peptide (P4B*15) were analyzed using artificial antigen-presenting cell-based (aAPC) in vitro priming experiments in three to six HVs, respectively. For all tested peptides proliferation of peptide-specific CD8+ T cells could be detected after in vitro priming. For the HLA-B*07-restricted ligands, peptide-specific CD8+ T cells could be induced in 6/6 (P1B*15), 1/3 (P2B*07) and 3/4 (P3B*07) HVs, respectively, with a maximum frequency of 14.1% peptide-specific CD8+ T cells. For the HLA-B*15-restricted ligand (P4B*15), peptide-specific CD8+ T cells could be induced in 2/3 HVs with a maximum frequency of 9.5% tetramer-positive CD8+ T cells. The functionality and specificity of peptide-specific CD8+ T cells after aAPC-based in vitro priming was validated by intracellular cytokine staining for IFN-γ and TNF-α as well as for the expression of the degranulation marker CD107a. In 3/3 HVs primed with P1B*07 (RPIPIKYKAM) as well as in 1/2 HVs primed with P4B*15 (HQKRPIPIKY), we detected specific and functional CD8+ T cell populations after stimulation with the mutated peptides, but not after stimulation with the corresponding wild type peptides (P1WT: RLIPIKYKAM, P4WT: HQKRLIPIKY). Furthermore, the peptide-specific cytotoxic activity of specific CD8+ T cells was demonstrated in a VITAL assay. The polyclonal P1B*07- and P4B*15-specific CD8+ T cells (0.12% and 0.76% peptide-specific T cells, respectively) lysed autologous peripheral blood mononuclear cells loaded with the mutated peptides, but not cells presenting the wild type peptides. P4B*15-specific CD8+ T cells showed 17.9% (±1.2%) MYD88L265P-peptide-specific cell killing at an E/T ratio of 1:1 compared to 2.6% (±1.2%) of non-specific cell lysis of unspecific effector cells against the same targets in three independent replicates, respectively. The specific lysis showed an E/T ratio-dependent manner as the specific lysis decreases with reducing E/T ratios. P1B*07-specific CD8+ T cells specifically killed 11.4% (±1.7%) of MYD88L265P loaded targets at an E/T ratio of 0.7:1 in comparison to 2.1% unspecific lysis of unspecific effector cells. In this study, we identified and characterized MYD88L265P mutation-derived HLA class I ligands for T cell mediated immunotherapy. The strong immunogenicity of the HLA-B*07 and HLA-B*15-restricted mutation-derived peptides as well as the functionality and specificity of peptide-specific CD8+ T cells, demonstrated by cytotoxicity assays, underline the potential of the MYD88L265P mutation as tumor-specific target. These data highlight the potential of MYD88L265P mutation-specific immunotherapy as a novel broadly applicable and tumor-specific treatment approach for patients with MYD88L265P+ NHL. Disclosures Langerak: InVivoScribe: Patents & Royalties: Licensing of IP and Patent on BIOMED-2-based methods for PCR-based Clonality Diagnostics.; DAKO: Patents & Royalties: Licensing of IP and Patent on Split-Signal FISH. Royalties for Dept. of Immunology, Erasmus MC, Rotterdam, NL; Roche: Other: Lab services in the field of MRD diagnostics provided by Dept of Immunology, Erasmus MC (Rotterdam).

scholarly journals A Novel Strategy for Off-the-Shelf T Cell Therapy Which Evades Allogeneic T Cell and NK Cell Rejection

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1711-1711
Author(s):  
Yong Zhang ◽  
Surbhi Goel ◽  
Aaron Prodeus ◽  
Utsav Jetley ◽  
Yiyang Tan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Hla Class I ◽  
Class Ii ◽  
Class I

Abstract Introduction. Despite the success of autologous chimeric antigen receptor (CAR)-T cells, barriers to a more widespread use of this potentially curative therapy include manufacturing failures and the high cost of individualized production. There is a strong desire for an immediately available cell therapy option; however, development of "off-the-shelf" T cells is challenging. Alloreactive T cells from unrelated donors can cause graft versus host disease (GvHD) for which researchers have successfully used nucleases to reduce expression of the endogenous T cell receptor (TCR) in the allogeneic product. The recognition of allogeneic cells by the host is a complex issue that has not been fully solved to date. Some approaches utilize prolonged immune suppression to avoid immune rejection and increase persistence. Although showing responses in the clinic, this approach carries the risk of infections and the durability of the adoptive T cells is uncertain. Other strategies include deletion of the B2M gene to remove HLA class I molecules and avoid recognition by host CD8 T cells. However, loss of HLA class I sends a "missing-self" signal to natural killer (NK) cells, which readily eliminate B2Mnull T cells. To overcome this, researchers are exploring insertion of the non-polymorphic HLA-E gene, which can provide partial but not full protection from NK cell-mediated lysis. Because activated T cells upregulate HLA class II, rejection by alloreactive CD4 T cells should also be addressed. Methods. Here, we developed an immunologically stealth "off-the-shelf" T cell strategy by leveraging our CRISPR/Cas9 platform and proprietary sequential editing process. To solve the issue of rejection by alloreactive CD4 and CD8 T cells, we knocked out (KO) select HLA class I and class II expression with a sequential editing process. Additionally, we utilize potent TCR-α and -β constant chain (TRAC, TRBC) gRNAs that achieve >99% KO of the endogenous TCR, addressing the risk of GvHD. An AAV-mediated insertion of a CAR or TCR into the TRAC locus is used in parallel with the TRAC KO step to redirect the T cells to tumor targets of interest. Alloreactivity by CD4 and CD8 T cells, NK killing, GvHD induction and T cell function was assessed in vitro and/or in vivo. Results. By knocking out select HLA class I and class II proteins, we were able to avoid host CD4- and CD8-T cell-mediated recognition. Edited T cells were protected from host NK cells, both in vitro and in an in vivo model engrafted with functional human NK cells. TRAC edited donor T cells did not induce GvHD in an immune compromised mouse model over the 90-day evaluation period. Using our proprietary T cell engineering process, we successfully generated allogeneic T cells with sequential KOs and insertion of a tumor-specific TCR or CAR with high yield. Importantly, these allogeneic T cells had comparable functional activity to their autologous T cell counterparts in in vitro assays (tumor cell killing and cytokine release) as well as in vivo tumor models. With a relatively small bank of donors, we can provide an "off-the-shelf" CAR or TCR-T cell solution for a large proportion of the population. Conclusions. We have successfully developed a differentiated "off-the-shelf" approach, which is expected to be safe and cost-effective. It is designed to provide long-term persistence without the need for an immune suppressive regimen. This promising strategy is being applied to our T cell immuno-oncology and autoimmune research candidates. Disclosures Zhang: Intellia Therapeutics: Current Employment. Goel: Intellia Therapeutics: Current Employment. Prodeus: Intellia Therapeutics: Current Employment. Jetley: Intellia Therapeutics: Current Employment. Tan: Intellia Therapeutics: Current Employment. Averill: Intellia Therapeutics: Current Employment. Ranade: Intellia Therapeutics: Current Employment. Balwani: Intellia Therapeutics: Current Employment. Dutta: Intellia Therapeutics: Current Employment. Sharma: Intellia Therapeutics: Current Employment. Venkatesan: Intellia Therapeutics: Current Employment. Liu: Intellia Therapeutics: Current Employment. Roy: Intellia Therapeutics: Current Employment. O′Connell: Intellia Therapeutics: Current Employment. Arredouani: Intellia Therapeutics: Current Employment. Keenan: Intellia Therapeutics: Current Employment. Lescarbeau: Intellia Therapeutics: Current Employment. Schultes: Intellia Therapeutics: Current Employment.

scholarly journals A new in vitro model of polymyositis reveals CD8+ T cell invasion into muscle cells and its cytotoxic role

Rheumatology ◽  
2019 ◽  
Vol 59 (1) ◽  
pp. 224-232
Author(s):  
Mari Kamiya ◽  
Fumitaka Mizoguchi ◽  
Akito Takamura ◽  
Naoki Kimura ◽  
Kimito Kawahata ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Muscle Injury ◽  
In Vitro Model ◽  
Muscle Cells ◽  
Cd8 T Cell ◽  
Class I ◽  
Vitro Model

Abstract Objectives The hallmark histopathology of PM is the presence of CD8+ T cells in the non-necrotic muscle cells. The aim of this study was to clarify the pathological significance of CD8+ T cells in muscle cells. Methods C2C12 cells were transduced retrovirally with the genes encoding MHC class I (H2Kb) and SIINFEKL peptide derived from ovalbumin (OVA), and then differentiated to myotubes (H2KbOVA-myotubes). H2KbOVA-myotubes were co-cultured with OT-I CD8+ T cells derived from OVA-specific class I restricted T cell receptor transgenic mice as an in vitro model of PM to examine whether the CD8+ T cells invade into the myotubes and if the myotubes with the invasion are more prone to die than those without. Muscle biopsy samples from patients with PM were examined for the presence of CD8+ T cells in muscle cells. The clinical profiles were compared between the patients with and without CD8+ T cells in muscle cells. Results Analysis of the in vitro model of PM with confocal microscopy demonstrated the invasion of OT-I CD8+ T cells into H2KbOVA-myotubes. Transmission electron microscopic analysis revealed an electron-lucent area between the invaded CD8+ T cell and the cytoplasm of H2KbOVA-myotubes. The myotubes invaded with OT-I CD8+ T cells died earlier than the uninvaded myotubes. The level of serum creatinine kinase was higher in patients with CD8+ T cells in muscle cells than those without these cells. Conclusion CD8+ T cells invade into muscle cells and contribute to muscle injury in PM. Our in vitro model of PM is useful to examine the mechanisms underlying muscle injury induced by CD8+ T cells.

Analysis of Memory T Lymphocytes Activity Following Stimulation with HLA-A24, A1 and Cw4 Restricted 9- and 10-mer Cytomegalovirus pp65 Overlapping Peptides.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2876-2876
Author(s):  
Monica Ghei ◽  
David F. Stroncek ◽  
Maurizio Provenzano
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Immune Therapy ◽  
Hla Class I ◽  
Class I ◽  
Specific Ctls ◽  
Over Time

Abstract In healthy subjects, primary infection with Cytomegalovirus (CMV) is usually mild or asymptomatic and is effectively controlled by the cell-mediated immune response. However, in immune compromised individuals, such as those with AIDS or after bone marrow transplantation, CMV reactivation is associated with significant morbidity until the individual’s immune system is completely reconstituted. One means of preventing post-transplant CMV infection is adoptive immunotherapy using CMV-specific cytotoxic T cells (CTLs) from the transplant donor. Several 9- and 10-mer HLA class I restricted peptides derived from the immune dominant CMV 65 kd matrix phosphoprotein (pp65) have been shown to produce CMV-specific CTLs. Two overlapping HLA-A24 restricted peptides have been specifically described: pp65 341–349 and pp65 341–350. These are 9- and 10-mer peptides that overlap except for the last amino acid phenylalanine (F) at the C-terminus [QYDPVAALF(F)]. Despite their similarity, the ability of these peptides to induce a T cell response has been reported to differ. Although it has been generally accepted that a unique CMV peptide is bound and presented by each separate HLA class I molecule, recent studies suggest that certain peptides are more promiscuous and may be presented by more than one HLA Class I antigen. For example, the 9-mer pp65 341–349 has been shown to stimulate CTLs from both HLA-A24 and Cw4 donors, while the 10-mer pp65 341–350 has been shown to be reactive with both HLA-A24 and A1 donors. The current investigation sought to compare the potency of these two peptides and determine the optimum peptide size for effective CMV adoptive immune therapy. Both peptides were tested for their ability to stimulate CMV-specific CTLs in HLA-A24, HLA-A1, and HLA-Cw4 restriction. In addition, a pp65 16-mer that included the 9- and 10-mers was tested for its ability to reactivate either CD8+ or CD4+ memory T cells. IFN-γ mRNA transcript as well as protein production were measured by in vitro cell culture assays. Peptide stimulations were performed on isolated CD8 and CD4 T lymphocytes by inducing the cells for 3 hours after a 2-week in vitro sensitization. The goal of the investigation was to determine whether both the 9- and the 10-mer peptides maintained high levels of CTL stimulation over time for all HLA restrictions studied. Moreover, it was important to investigate whether stimulation with the 16-mer, followed by restimulation by the two smaller peptides embedded within the larger sequence, led to effective T cell memory immune response. The 9- and 10-mer peptides effectively stimulated CTLs from HLA-A24, HLA-A1, and HLA-Cw4 CMV seropositive donors. Although both 9- and 10-mer were able to maintain high levels of stimulation over time for all restrictions, the 9-mer induced highest responses in cells expressing HLA-A24 (S.I. 4.07–528) or HLA-Cw4 (S.I. 4.15–483) while the 10-mer induced highest responses in cells expressing HLA-A24 (S.I. 3.5–528) or HLA-A1 (S.I. 8.25–615). The 16-mer peptide was also able to stimulate T cells from all HLA-A24, A1 and Cw4 donors (S.I. 6.95, 4.96, 5.02) at levels that are well maintained over time. This data confirmed that both the 9- and the 10-mer peptides are promiscuous and not restricted to a single HLA antigen. These peptides that have the ability to produce CMV-specific CTLs in patients with several different HLA types present a practical advantage over peptides that are restricted only to a single HLA type, and thus are optimal for CMV adoptive immune therapy.

Expansion of Inhibitory NK Receptor (CD94/NKG2A)-Expressing Cytolytic CD8 T Cells and CD4+CD25+ Regulatory T Cells from the Same Cord Blood.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1739-1739
Author(s):  
Junji Tanaka ◽  
Junichi Sugita ◽  
Naoko Kato ◽  
Tomomi Toubai ◽  
Jun Ibata ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cord Blood ◽  
Cd8 T Cells ◽  
Hla Class I ◽  
Treg Cells ◽  
Class I ◽  
Target Cells ◽  
Foxp3 Mrna ◽  
Effector Cells

Abstract It has recently been shown that inhibitory natural killer cell receptors (NKRs) on not only NK cells but also on T cells negatively regulate NK cell and T cell functions through their binding to MHC class I molecules. The C-type lectin superfamily inhibitory NKR CD94/NKG2A heterodimer recognizes an HLA-E that preferably bound to a peptide derived from the signal sequences of most HLA class I. Therefore, CD94-expressing cells can monitor the global status of HLA class I on the tumor and leukemic cells and induce cytolytic attack without inhibitory signal against HLA class I decreased target cells resulting induction of graft-versus-leukemia (GVL) effect but does not attack normal cells with HLA class I expression resulting no enhancement of graft-versus-host disease (GVHD). On the other hand, CD4+ CD25+ regulatory T cells (Treg) contribute to suppress allogeneic immune responses and prevent transplant rejection and GVHD. In this study, we tried to expand CD94-expressing T cells and Treg cells from the same cord blood cells and then investigated their cytolytic characteristics and immunoregulatory function in order to develop a potential strategy of cell therapy for hematological malignancy. After CD4 enrichment by negative selection using magnetic cell sorting (MACS) (Miltenyi Biotec)(CD4-enriched fraction) from cord blood, CD4+ CD25+ cells were isolated by positive selection with anti-CD25 magnetic microbeads. We could get more than 1,000 fold expansion of CD94-expressing CD8 T cells from CD4-depleted fraction after 8 days culture with immobilized anti-CD3 monoclonal antibody (mAb) (1 μg/mL) and IL-15 (5 ng/mL). Isolated CD4+ CD25+ cells were cultured with anti-CD3/CD28 mAb-coated dynabeads and IL-15 (5 ng/mL) and we could get about 50 fold expansion of Treg cells for 8 days. These expanded Treg cells could suppress allogeneic mixed lymphocyte culture more than 80% (effector cells: Treg cells= 2:1) and expressed FoxP3 mRNA about 100 fold compared with isolated CD25-negative cells. Cytolytic activities of purified CD94-expressing cells (CD94 > 90%) detected by 4 hours 51Cr release assay against K562 were 68.8 ± 16.8 % (n=5). Coculture of CD94-expressing cells with expanded Treg cells (CD94-expressing cell: Treg cells= 1:1, preincubation 4 hours) did not have any effect on cytolytic activities of purified CD94-expressing cells against K562 cells (66.1 ± 19.8 %, n=5). CD94-expressing CD8 T cells with cytolytic activity could be expanded from CD4-deplted fractions and Treg cells with immunosuppressive activity and increased expression level of FoxP3 mRNA could be expanded from CD4-enriched fractions of the same cord blood. Expanded these cytolytic CD94-expressing CD8 cells might be able to induce GVL effect without enhancing GVHD and Treg cells might be able to suppress allogeneic response including GVHD and graft rejection. Therefore, this strategy may be useful to differentiate lymphocytes in cord blood to two different kinds of effector cells exhibiting cytolytic or immunoreguratoly characters.

Suppression of CTL Responses against AAV-Capsid Epitopes by Peptide-Induced Regulatory T Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 377-377 ◽  
Author(s):  
Daniel J Hui ◽  
Gary C Pien ◽  
Etiena Basner-Tschakarjan ◽  
Federico Mingozzi ◽  
Jonathan D Finn ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cd8 T Cells ◽  
Transgene Expression ◽  
T Cell Responses ◽  
Effector Cells ◽  
Cell Responses ◽  
Ctl Activity

Abstract Abstract 377 Hemophilia B represents a promising model for the development of adeno-associated viral (AAV) vectors-based gene therapeutics. In the first clinical trial for AAV serotype 2 mediated gene transfer of Factor IX (F.IX) to the liver of severe hemophilia B subjects, transgene expression was short-lived with a gradual decline of F.IX levels. The loss of transgene expression was accompanied by a transient transaminitis, which we hypothesized to be the result of the reactivation of a pool of capsid-specific memory CD8+ T cells originated from a previous exposure to wild-type AAV. These results were unanticipated since previous work in small and large animal models showed that AAV administration is uneventful, allowing prolonged expression of F.IX transgene at therapeutic levels. We developed an in vitro cytotoxicity assay using a human hepatocyte cell line expressing HLA-B*0702, a common MHC class I allele for which the AAV capsid immunodominant epitope VPQYGYLTL was identified. Using this model, we demonstrated that HLA-matched AAV-specific effector CD8+ T cells were able to lyse target hepatocytes transduced with AAV-2. We now use this in vitro model of CTL killing of AAV-transduced hepatocytes to demonstrate the efficacy of a novel strategy to circumvent undesirable immune response through the engagement of regulatory T cells. A recently characterized MHC Class II-restricted T cell epitope (Tregitope) in the Fc fragment of IgG has been shown to induce regulatory T cells in vitro and in vivo (Blood, 2008; 112: 3303-3311). AAV-specific HLA-B*0702 effector cells expanded in the presence of a human Tregitope peptide resulted in 79% to 89% inhibition of cytotoxic activity against peptide-pulsed and AAV-transduced target cells, respectively. These results were confirmed using PBMCs from 5 different donors. A similar degree of inhibition of CTL activity was observed for the HLA allele A*0101, which binds to the AAV-derived epitope SADNNNSEY; co-culture of effector cells with the Tregitope inhibited CTL-mediated killing by 60%. Interestingly, the same Tregitope efficiently mediated suppression of CTL activity in subjects carrying different HLA alleles, indicating a high level of promiscuity of Tregitope binding. Staining for the regulatory T cell markers CD4, CD25, and FoxP3 supported the hypothesis that Tregitopes suppress T cell responses by expanding regulatory T cells; 62.2% of the CD4+ population stained positive for CD25 and FoxP3 in PBMCs expanded against AAV epitopes in the presence of Tregitope, compared with PBMCs expanded against an AAV epitope alone (3.63%), or against an AAV epitope and an irrelevant control peptide (1.94%). Polyfunctional analysis for markers for T cell activation showed that CD8+ T cells incubated in the presence of Tregitope had an approximately 5-fold decrease in production of IL-2 and IFN-γand a 2-fold reduction in TNF-α production, indicating levels of activation close to naïve CD8+ T cells. We further characterized the mechanism of action of Tregitopes by showing that Tregitopes are required at the time of CD8+ T cell priming, as CTL activity of AAV-expanded CD8+ T cells against transduced hepatocytes was not inhibited by the CD4+ T cell fraction of PBMC expanded separately in vitro with Tregitopes only. We conclude that the use of Tregitopes represents a promising strategy for antigen-specific, Treg-mediated modulation of capsid-specific T cell responses. Disclosures: Martin: EpiVax: Employment. De Groot:EpiVax, Inc.: Employment, Equity Ownership.

Sialoadhesin-Positive Host Macrophages Play an Essential Role in Graft-Versus-Leukemia Reactivity in Mice

Blood ◽  
1999 ◽  
Vol 93 (12) ◽  
pp. 4375-4386 ◽  
Author(s):  
Susanne Müerköster ◽  
Marian Rocha ◽  
Paul R. Crocker ◽  
Volker Schirrmacher ◽  
Victor Umansky
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Cd8 T Cells ◽  
Class I ◽  
Peptide Epitope ◽  
Peptide Epitopes ◽  
Graft Versus Leukemia

We recently established an effective immune T-cell–mediated graft-versus-leukemia (GVL) murine model system in which complete tumor remissions were achievable even in advanced metastasized cancer. We now describe that this T-cell–mediated therapy is dependent on host macrophages expressing the lymphocyte adhesion molecule sialoadhesin (Sn). Depletion of Kupffer cells in tumor-bearing mice during adoptive immunotherapy (ADI) or the treatment of these animals with anti-Sn monoclonal antibodies led to complete or partial inhibition of the immune T-cell–mediated therapeutic effect. Furthermore, Sn+ host macrophages in livers formed clusters during ADI with donor CD8 T cells. To test for a possible antigen presentation function of these macrophages, we used as an in vitro model the antigen β-galactosidase for which a dominant major histocompatibility complex (MHC) class I Ld-restricted peptide epitope is known to be recognized by specific CD8 cytotoxic T lymphocytes (CTL). We demonstrate that purified Sn+ macrophages can process exogenous β-galactosidase and stimulate MHC class I peptide-restricted CTL responses. Thus, Sn+ macrophages, which are significantly increased in the liver after ADI, may process tumor-derived proteins via the MHC class I pathway as well as via the MHC class II pathway, as shown previously, and present respective peptide epitopes to CD8 as well as to CD4 immune T cells, respectively. The synergistic interactions observed before between immune CD4 and CD8 T cells during ADI could thus occur in the observed clusters with Sn+ host macrophages.

Tumor-specific recognition of human myeloma cells by idiotype-induced CD8+ T cells

Blood ◽  
2000 ◽  
Vol 96 (8) ◽  
pp. 2828-2833 ◽  
Author(s):  
Yiwen Li ◽  
Maurizio Bendandi ◽  
Yuping Deng ◽  
Cynthia Dunbar ◽  
Nikhil Munshi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Class I ◽  
Specific Lysis ◽  
Myeloma Cells ◽  
Id Protein ◽  
Human Myeloma Cells

Immunoglobulin secreted by myeloma cells contains a unique antigenic determinant (idiotype [Id]) that may serve as a tumor-specific antigen. Although Id-protein–specific T-cell responses have been reported in patients with myeloma, it is not known whether primary myeloma tumor cells can present naturally processed Id peptides on their surface as a target. We immunized 2 healthy human stem-cell donors with Id proteins from their recipients. T cells from the immunized donors released high levels of T-helper 1–type cytokines in response to stimulation with myeloma cells from their recipients. The T-cell–mediated cytokine response to tumor cells was blocked by a major histocompatibility complex (MHC) class I monoclonal antibody, whereas the response to soluble Id protein was dependent on MHC class II. To investigate whether Id-specific CD8+ T cells can recognize and kill autologous myeloma cells, we generated T cells from peripheral blood mononuclear cells from a third patient with myeloma by means of in vitro stimulation with autologous dendritic cells pulsed with Id protein. Tumor-specific lysis of myeloma cells was demonstrated by the lack of killing of autologous nonmalignant B cells or natural killer–sensitive K562 cells. Lysis of autologous myeloma targets was restricted by MHC class I molecules. These data represent the first report of class I–restricted T-cell recognition of fresh autologous myeloma targets and formally demonstrate that human myeloma cells can serve as targets of an Id-specific T-cell response.

scholarly journals HLA Class I-T Cell Epitopes from trans-Sialidase Proteins Reveal Functionally Distinct Subsets of CD8+ T Cells in Chronic Chagas Disease

2008 ◽  
Vol 2 (9) ◽  
pp. e288 ◽  
Author(s):  
María G. Alvarez ◽  
Miriam Postan ◽  
D. Brent Weatherly ◽  
María C. Albareda ◽  
John Sidney ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chagas Disease ◽  
Cd8 T Cells ◽  
Hla Class I ◽  
Class I ◽  
T Cell Epitopes ◽  
Chronic Chagas Disease

scholarly journals Allelic variation in Class I HLA determines pre-existing memory responses to SARS-CoV-2 that shape the CD8+ T cell repertoire upon viral exposure

2021 ◽  
Author(s):  
Joshua M. Francis ◽  
Del Leistritz-Edwards ◽  
Augustine Dunn ◽  
Christina Tarr ◽  
Jesse Lehman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Cell Response ◽  
Hla Class I ◽  
T Cell Response ◽  
Class I ◽  
Epitope Specificity ◽  
Hla Genotype

AbstractEffective presentation of antigens by HLA class I molecules to CD8+ T cells is required for viral elimination and generation of long-term immunological memory. In this study, we applied a single-cell, multi-omic technology to generate the first unified ex vivo characterization of the CD8+ T cell response to SARS-CoV-2 across 4 major HLA class I alleles. We found that HLA genotype conditions key features of epitope specificity, TCR α/β sequence diversity, and the utilization of pre-existing SARS-CoV-2 reactive memory T cell pools. Single-cell transcriptomics revealed functionally diverse T cell phenotypes of SARS-CoV-2-reactive T cells, associated with both disease stage and epitope specificity. Our results show that HLA variations influence pre-existing immunity to SARS-CoV-2 and shape the immune repertoire upon subsequent viral exposure.One-Sentence SummaryWe perform a unified, multi-omic characterization of the CD8+ T cell response to SARS-CoV-2, revealing pre-existing immunity conditioned by HLA genotype.

scholarly journals CD73 Ectonucleotidase Restrains CD8+ T Cell Metabolic Fitness and Anti-tumoral Activity

2021 ◽  
Vol 9 ◽  
Author(s):  
Pedro Briceño ◽  
Elizabeth Rivas-Yañez ◽  
Mariana V. Rosemblatt ◽  
Brian Parra-Tello ◽  
Paula Farías ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
Cd8 T Cell ◽  
Tumor Burden ◽  
Effector Cells ◽  
Cd73 Expression ◽  
Metabolic Fitness

CD39 and CD73 are ectoenzymes that dephosphorylate ATP into its metabolites; ADP, AMP, and adenosine, and thus are considered instrumental in the development of immunosuppressive microenvironments. We have previously shown that within the CD8+ T cell population, naïve and memory cells express the CD73 ectonucleotidase, while terminally differentiated effector cells are devoid of this enzyme. This evidence suggests that adenosine might exert an autocrine effect on CD8+ T cells during T cell differentiation. To study the possible role of CD73 and adenosine during this process, we compared the expression of the adenosinergic signaling components, the phenotype, and the functional properties between CD73-deficient and WT CD8+ T cells. Upon activation, we observed an upregulation of CD73 expression in CD8+ T cells along with an upregulation of the adenosine A2A receptor. Interestingly, when we differentiated CD8+ T cells to Tc1 cells in vitro, we observed that these cells produce adenosine and that CD73-deficient cells present a higher cytotoxic potential evidenced by an increase in IFN-γ, TNF-α, and granzyme B production. Moreover, CD73-deficient cells presented a increased glucose uptake and higher mitochondrial respiration, indicating that this ectonucleotidase restrict the mitochondrial capacity in CD8+ T cells. In agreement, when adoptively transferred, antigen-specific CD73-deficient CD8+ T cells were more effective in reducing the tumor burden in B16.OVA melanoma-bearing mice and presented lower levels of exhaustion markers than wild type cells. All these data suggest an autocrine effect of CD73-mediated adenosine production, limiting differentiation and cytotoxic T cells’ metabolic fitness.

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