scholarly journals Identification of Tyrosinase-related Protein 2 as a Tumor Rejection Antigen for the B16 Melanoma

1997 ◽  
Vol 185 (3) ◽  
pp. 453-460 ◽  
Author(s):  
Matthew B. Bloom ◽  
Donna Perry-Lalley ◽  
Paul F. Robbins ◽  
Yong Li ◽  
Mona El-Gamil ◽  
...  
Keyword(s):  
Normal Tissue ◽  
Tumor Antigens ◽  
Human Tumor ◽  
Human Melanoma ◽  
Tissue Differentiation ◽  
B16 Melanoma ◽  
Tumor Rejection ◽  
Site Directed Mutagenesis ◽  
Preclinical Model ◽  
Binding Motif

Recently, major advances have been made in the identification of antigens from human melanoma which are recognized by T cells. In spite of this, little is known about the optimal ways to use these antigens to treat patients with cancer. Progress in this area is likely to require accurate preclinical animal models, but the availability of such models has lagged behind developments in human tumor immunology. Whereas many of the identified human melanoma antigens are normal tissue differentiation proteins, analogous murine tumor antigens have not yet been identified. In this paper we identify a normal tissue differentiation antigen, tyrosinaserelated protein 2 (TRP-2), expressed by the murine B16 melanoma which was found by screening a cDNA library from B16 with tumor-reactive cytotoxic T lymphocytes (CTL). A peptide conforming to the predicted MHC class I H2-Kb binding motif, TRP-2181-188, was identified as the major reactive epitope within TRP-2 recognized by these anti-B16 CTLs. By site-directed mutagenesis, it was shown that alteration of this epitope eliminated recognition of TRP-2. It was further demonstrated that a CTL line raised from splenocytes by repeated stimulation in vitro with this peptide could recognize B16 tumor and was therapeutic against 3-d-old established pulmonary metastases. The use of TRP-2 in a preclinical model of tumor immunotherapy may be helpful in suggesting optimal vaccination strategies for cancer therapy in patients.

scholarly journals Therapeutic Cancer Vaccination with Immunopeptidomics-Discovered Antigens Confers Protective Antitumor Efficacy

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3408
Author(s):  
Karita Peltonen ◽  
Sara Feola ◽  
Husen M. Umer ◽  
Jacopo Chiaro ◽  
Georgios Mermelekas ◽  
...  
Keyword(s):  
Tumor Antigens ◽  
Endogenous Retrovirus ◽  
Peptide Ligands ◽  
Tumor Control ◽  
Preclinical Model ◽  
Vaccine Platform ◽  
Therapeutic Cancer Vaccine ◽  
Mhc I ◽  
Specific Tumor ◽  
Therapeutic Cancer Vaccines

Knowledge of clinically targetable tumor antigens is becoming vital for broader design and utility of therapeutic cancer vaccines. This information is obtained reliably by directly interrogating the MHC-I presented peptide ligands, the immunopeptidome, with state-of-the-art mass spectrometry. Our manuscript describes direct identification of novel tumor antigens for an aggressive triple-negative breast cancer model. Immunopeptidome profiling revealed 2481 unique antigens, among them a novel ERV antigen originating from an endogenous retrovirus element. The clinical benefit and tumor control potential of the identified tumor antigens and ERV antigen were studied in a preclinical model using two vaccine platforms and therapeutic settings. Prominent control of established tumors was achieved using an oncolytic adenovirus platform designed for flexible and specific tumor targeting, namely PeptiCRAd. Our study presents a pipeline integrating immunopeptidome analysis-driven antigen discovery with a therapeutic cancer vaccine platform for improved personalized oncolytic immunotherapy.

scholarly journals The Next-Generation of Combination Cancer Immunotherapy: Epigenetic Immunomodulators Transmogrify Immune Training to Enhance Immunotherapy

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3596
Author(s):  
Reza Bayat Mokhtari ◽  
Manpreet Sambi ◽  
Bessi Qorri ◽  
Narges Baluch ◽  
Neda Ashayeri ◽  
...  
Keyword(s):  
Immune System ◽  
Cancer Immunotherapy ◽  
Tumor Cells ◽  
Tumor Antigens ◽  
Response Rates ◽  
Viral Proteins ◽  
Tumor Rejection ◽  
Therapeutic Approaches ◽  
Patient Response ◽  
Specific Antigens

Cancer immunotherapy harnesses the immune system by targeting tumor cells that express antigens recognized by immune system cells, thus leading to tumor rejection. These tumor-associated antigens include tumor-specific shared antigens, differentiation antigens, protein products of mutated genes and rearrangements unique to tumor cells, overexpressed tissue-specific antigens, and exogenous viral proteins. However, the development of effective therapeutic approaches has proven difficult, mainly because these tumor antigens are shielded, and cells primarily express self-derived antigens. Despite innovative and notable advances in immunotherapy, challenges associated with variable patient response rates and efficacy on select tumors minimize the overall effectiveness of immunotherapy. Variations observed in response rates to immunotherapy are due to multiple factors, including adaptative resistance, competency, and a diversity of individual immune systems, including cancer stem cells in the tumor microenvironment, composition of the gut microbiota, and broad limitations of current immunotherapeutic approaches. New approaches are positioned to improve the immune response and increase the efficacy of immunotherapies, highlighting the challenges that the current global COVID-19 pandemic places on the present state of immunotherapy.

549 Characterizing double positive T cells in the tumor microenvironment: a tale of promiscuous cell fates

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A586-A586
Author(s):  
Sara Schad ◽  
Andrew Chow ◽  
Heng Pan ◽  
Levi Mangarin ◽  
Roberta Zappasodi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Cd8 T Cells ◽  
Human Melanoma ◽  
B16 Melanoma ◽  
T Cell Subsets ◽  
Double Positive ◽  
Cell Fates ◽  
Single Positive

BackgroundCD4 and CD8 T cells are genetically and functionally distinct cell subsets of the adaptive immune system that play pivotal roles in immune surveillance and disease control. During development in the thymus, transcription factors ThPOK and Runx3 regulate the differentiation and maturation of these two lineages into single positive T cells that enter the periphery with mutually exclusive expression of either the CD4 or CD8 co-receptor.1–2 Despite our expectation that these two cell fates are fixed, mature CD4+CD8+ double positive (DP) T cells have been described in the context of numerous immunological responses, including cancer, but their molecular and functional properties and therapeutic relevance remain controversial and largely unknown.3–5MethodsOur lab has identified and characterized a heterogenous DP T cell population in murine and human melanoma tumors comprised of CD4 and CD8 T cells re-expressing the opposite co-receptor and a parallel uptake in the opposite cell type’s phenotype and function. Using CD4 (Trp1) and CD8 (Pmel) transgenic TCR T cells specific to B16 melanoma antigens gp75 and gp100 respectively, we demonstrate the re-expression of the opposite co-receptor following adoptive T cell transfer in B16 melanoma tumor bearing mice.ResultsSpecifically, up to 50% of transferred CD4 Trp1 T cells will re-express CD8 to become a DP T cell in the tumor microenvironment. Further, these CD4 derived DP T cells upregulate CD8 lineage regulator Runx3 and cytolytic genes Gzmb, Gzmk, and Prf1 to become potent cytotoxic T cells. Alternatively, a subset of CD8 Pmel T cells differentiate into DP T cells characterized by the increased expression of CD4, ThPOK, and regulatory marker FoxP3 (figure 1). In addition, we utilized 10x single cell and ATAC sequencing to further characterize these divergent DP T cell populations among open repertoire T cells isolated from murine and human melanoma tumors.ConclusionsOur findings highlight the capability of single positive T cells to differentiate in response to antigen and local stimuli into novel T cell subsets with polyfunctional characteristics. The resulting cell subsets will potentially affect the tumor microenvironment in distinct ways. Our studies may inform therapeutic approaches to identify antigen specific T cells as well as innovative signaling pathways to target when genetically engineering T cells to optimize cytotoxic function in the setting of adoptive cell therapy.Ethics ApprovalThe human biospecimen analyses were approved by Memorial Sloan Kettering Cancer Center IRB #06-107ReferencesEllmeier W, Haust L & Tschismarov R. Transcriptional control of CD4 and CD8 coreceptor expression during T cell development. Cell Mol Life Sci 2013;70:4537–4553.Luckey MA, et al. The transcription factor ThPOK suppresses Runx3 and imposes CD4+ lineage fate by inducing the SOCS suppressors of cytokine signaling. Nature Immunology 2014; 15, 638–645.Bohner P, et al. Double positive CD4(+)CD8(+) T Cells are enriched in urological cancers and favor T Helper-2 polarization. Front Immunol 2019; 10, 622.Nascimbeni M, Shin E-C, Chiriboga L, Kleiner DE & Rehermann B. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions. Blood 2004;104:478–486.Nishida K, et al. Clinical importance of the expression of CD4+CD8+ T cells in renal cell carcinoma. Int Immunol 2020;32:347–357.

scholarly journals Structural and Functional Insights into Peptidoglycan Access for the Lytic Amidase LytA of Streptococcus pneumoniae

mBio ◽  
2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Peter Mellroth ◽  
Tatyana Sandalova ◽  
Alexey Kikhney ◽  
Francisco Vilaplana ◽  
Dusan Hesek ◽  
...  
Keyword(s):  
Cell Wall ◽  
Streptococcus Pneumoniae ◽  
Solution Structure ◽  
Substrate Binding ◽  
Substrate Recognition ◽  
Lytic Activity ◽  
Site Directed Mutagenesis ◽  
Binding Motif ◽  
Content Type ◽  
Peptidoglycan Synthesis

ABSTRACT The cytosolic N-acetylmuramoyl-l-alanine amidase LytA protein of Streptococcus pneumoniae, which is released by bacterial lysis, associates with the cell wall via its choline-binding motif. During exponential growth, LytA accesses its peptidoglycan substrate to cause lysis only when nascent peptidoglycan synthesis is stalled by nutrient starvation or β-lactam antibiotics. Here we present three-dimensional structures of LytA and establish the requirements for substrate binding and catalytic activity. The solution structure of the full-length LytA dimer reveals a peculiar fold, with the choline-binding domains forming a rigid V-shaped scaffold and the relatively more flexible amidase domains attached in a trans position. The 1.05-Å crystal structure of the amidase domain reveals a prominent Y-shaped binding crevice composed of three contiguous subregions, with a zinc-containing active site localized at the bottom of the branch point. Site-directed mutagenesis was employed to identify catalytic residues and to investigate the relative impact of potential substrate-interacting residues lining the binding crevice for the lytic activity of LytA. In vitro activity assays using defined muropeptide substrates reveal that LytA utilizes a large substrate recognition interface and requires large muropeptide substrates with several connected saccharides that interact with all subregions of the binding crevice for catalysis. We hypothesize that the substrate requirements restrict LytA to the sites on the cell wall where nascent peptidoglycan synthesis occurs. IMPORTANCE Streptococcus pneumoniae is a human respiratory tract pathogen responsible for millions of deaths annually. Its major pneumococcal autolysin, LytA, is required for autolysis and fratricidal lysis and functions as a virulence factor that facilitates the spread of toxins and factors involved in immune evasion. LytA is also activated by penicillin and vancomycin and is responsible for the lysis induced by these antibiotics. The factors that regulate the lytic activity of LytA are unclear, but it was recently demonstrated that control is at the level of substrate recognition and that LytA required access to the nascent peptidoglycan. The present study was undertaken to structurally and functionally investigate LytA and its substrate-interacting interface and to determine the requirements for substrate recognition and catalysis. Our results reveal that the amidase domain comprises a complex substrate-binding crevice and needs to interact with a large-motif epitope of peptidoglycan for catalysis.

scholarly journals WDFY4 is required for cross-presentation in response to viral and tumor antigens

Science ◽  
2018 ◽  
Vol 362 (6415) ◽  
pp. 694-699 ◽  
Author(s):  
Derek J. Theisen ◽  
Jesse T. Davidson ◽  
Carlos G. Briseño ◽  
Marco Gargaro ◽  
Elvin J. Lauron ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Tumor Antigens ◽  
Critical Role ◽  
Tumor Rejection ◽  
Interleukin 12 ◽  
Cross Presentation ◽  
Histocompatibility Complex ◽  
Crispr Screen

During the process of cross-presentation, viral or tumor-derived antigens are presented to CD8+ T cells by Batf3-dependent CD8α+/XCR1+ classical dendritic cells (cDC1s). We designed a functional CRISPR screen for previously unknown regulators of cross-presentation, and identified the BEACH domain–containing protein WDFY4 as essential for cross-presentation of cell-associated antigens by cDC1s in mice. However, WDFY4 was not required for major histocompatibility complex class II presentation, nor for cross-presentation by monocyte-derived dendritic cells. In contrast to Batf3–/– mice, Wdfy4–/– mice displayed normal lymphoid and nonlymphoid cDC1 populations that produce interleukin-12 and protect against Toxoplasma gondii infection. However, similar to Batf3–/– mice, Wdfy4–/– mice failed to prime virus-specific CD8+ T cells in vivo or induce tumor rejection, revealing a critical role for cross-presentation in antiviral and antitumor immunity.

Human tumor antigens recognized by antibodies (SEREX)

2003 ◽  
pp. 161-171
Author(s):  
Frank Neumann ◽  
Claudia Bormann ◽  
Carsten Zwick ◽  
Klaus-Dieter Preuss ◽  
Michael Pfreundschuh
Keyword(s):  
Tumor Antigens ◽  
Human Tumor

scholarly journals 912 Preferential recognition of neoantigens over non-canonical peptides in cancer patients

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A958-A958
Author(s):  
Maria Lozano-Rabella ◽  
Andrea Garcia-Garijo ◽  
Jara Palomero ◽  
Florian Erhard ◽  
Juan Martín-Liberal ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Cell ◽  
Somatic Mutations ◽  
Tumor Antigens ◽  
Tumor Rejection ◽  
Tumor Cell Lines ◽  
Coding Regions ◽  
Cell Responses ◽  
Whole Exome

BackgroundDespite recent advances in exome and RNA sequencing to identify tumor-rejection antigens including neoantigens, the existing techniques fail to identify the vast majority of antigens targeted by tumor-reactive cells. A growing number of studies suggest that HLA-I peptides derived from non-canonical (nonC) open reading frames or derived from allegedly non-coding regions can contribute to tumor immunogenicity. Here we use proteogenomics to identify personalized candidate canonical and non-canonical tumor-rejection antigens and to evaluate their contribution to cancer immune surveillance in patients.MethodsWhole exome sequencing was performed to identify the non-synonymous somatic mutations (NSM) and immunopeptidomics to identify the HLA-I presented peptides (pHLA) in 9 patient-derived tumor cell lines (TCL). Peptid-PRISM proteogenomics pipeline was used to identify both canonical and non-canonical pHLA, including those derived from NSM in coding regions. All peptides containing mutations and derived from either cancer-testis (CTA) or tumor-associated antigens (TAA) were selected as candidate tumor antigens. For nonC peptides, an immunopeptidomics healthy dataset containing several tissues and HLA-allotypes was used to eliminate those derived from normal ORFs and select nonC peptides preferentially expressed in tumor cells (nonC-TE). The selected candidate peptides were synthesized, pulsed onto autologous APCs and co-cultured with tumor-reactive ex vivo expanded lymphocytes to assess immune recognition (figure 1).ResultsNonC-TE peptides were identified in all TCL studied, ranging from 0.5% to 5.4% of the total HLA-I presented peptides (n= 506). As described previoulsy, 5’UTR were the main source. Of note, the tumor type did not have an impact on the frequency of presented nonC peptides, but rather the presence of HLA-A*11:01 and HLA-A*03:01 was a major determinant. T cell responses were detected against at least 13/33 putative neoantigens, 2/24 CTA and 2/61 TAA. On the contrary, none of the 471 nonC-TE candidate peptides tested thus far, including one containing a NSM were able to elicit a recall immune response. Nevertheless, T cells recognizing at least 3 of them were detected through in vitro sensitization of non-autologous PBMCs.Abstract 912 Figure 1Workflow diagramTumor biopsies and blood samples are obtained from cancer patients (left panel). Patient-derived tumor cell lines are generated in vitro, the peptides presented on HLA molecules are further isolated and analyzed in a mass-spectrometer (top panel). Whole exome sequencing (WES) from matched tumor and healthy tissue is performed to identify the non-synonymous somatic mutations (NSM) (middle panel). Peptide-PRISM proteogenomics pipeline combines the information from the immunopeptidomics data and WES to identify pHLA sequences from both canonical and non-canonical candidate tumor antigens (top right panel). Lymphocyte populations either TILs or sorted PBMCs are expanded and further screened for pre-existing T cell responses (bottom panel) against the candidate epitopes by co-culturing the T cells with peptide-pulsed autologous APC. The recognition is assessed by measuring IFNg release by elispot and the upregulation of activation surface markers by FACS (bottom right panel).ConclusionsOur results show that although HLA-I nonC peptides were frequently presented in all TCLs studied and they can be immunogenic, neoantigens derived from mutations in canonical coding regions were preferentially recognized by tumor-reactive lymphocytes, suggesting T cells targeting the latter are primed more efficiently. The identification of mutated nonC antigens using whole genome sequencing to identify mutations in non-coding regions warrants further examination. Still, the specificity of many tumor-reactive TILs remains unknown.Ethics Approval”This study was approved by the ”Comité de Ética de Investigación con Medicamentos del Hospital Universitario Vall d’Hebron” institution’s Ethics Board; approval number PR(AG)537/2019.”

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