Invented by Hans-Georg Rammensee, Juliane STICKEL, Daniel Johannes Kowalewski, Stefan Stevanovic, Simon Walz, Immatics Biotechnologies GmbH
The Immatics Biotechnologies GmbH invention works as followsThe present invention is a method of immunotherapy that uses peptides and proteins as well as nucleic acid and cells. The present invention is primarily concerned with the immunotherapy of cancers, and in particular, myeloma. The present invention also relates to tumor associated T-cell epitopes alone or in combination other tumor associated peptides. These can be used as active pharmaceutical components of vaccine compositions to stimulate anti-tumor immunity responses or to stimulate and transfer T cells into patients. “Peptides that are bound to the MHC molecules, or peptides themselves, can be targets for antibodies, soluble receptors of T cells, and other binding molecules.
Background for Cell Epitopes and Combination of Cell Epitopes for Use in Immunotherapy of Myeloma
Multiple myeloma is a low grade B cell lymphoma characterized by proliferation of malignant cells in the bone marrow. Despite recent advancements in treatment including high-dose chemotherapy, followed by autologous cell transplantation, new immunomodulatory drugs, and proteasome inhibitors, MM is still largely incurable. [15,16]. This is mainly due to the persistent minimal residual disease (MRD), leading to high relapse rate [17,18].
There is a pressing need to identify factors which can be used for the treatment of myeloma and cancer in general, given the serious side effects and high costs associated with cancer. It is important to identify biomarkers that can be used to diagnose cancer and to predict treatment outcomes.
Antigen-specific immune therapy has the potential to produce clinically effective anticancer T-cell reactions and could be used to guide and improve the specificity and effectiveness of cancer immunotherapy for future combination trials. To this end, the exact knowledge of tumor-associated/specific T-cell epitopes is crucial. After decades of research into overexpressed tumor antigens, more recently the focus has shifted to the patient-individualized identification of mutation-derived neoantigens [4, 5]. These new studies have shown encouraging results [6-8], which has led to the neoepitopes becoming the primary targets of anticancer immune responses.
The inventors recently demonstrated, however, that non-mutated antibodies are important targets for spontaneous anti-leukemia responses [12-13]. These studies used mass spectrometry to map the HLA ligandomes in hematological cell populations in health and in disease. This strategy was effective in identifying tumor-associated antigens.
The only immunotherapeutic option available for MM patients is allogenic stem cells transplantation. This is associated with a significant morbidity and mortality, and is only an option for a small fraction of patients. [19-21]” “Antigen-specific T cell based immunotherapy (22, 23)?especially when MRD is characterized by favorable target to effector ratios?might be an effective and low-side effect option .
The current classification for tumor-associated antigens (TAAs), includes the following major groups:
a) Cancer-testis antigens: The first TAAs ever identified that can be recognized by T cells belong to this class, which was originally called cancer-testis (CT) antigens because of the expression of its members in histologically different human tumors and, among normal tissues, only in spermatocytes/spermatogonia of testis and, occasionally, in placenta. These antigens are not recognized by T-cells in normal tissues because testis cells do not express class 1 and II HLA molecules. “Well-known CT antigens include the MAGE family and NY-ESO-1.
b) Difference antigens: TAAs that are found in both tumors and normal tissues from which tumors arose. The majority of differentiation antigens can be found in normal and malignant melanocytes. These melanocyte-lineage-related proteins, which are involved in the biosynthesis of melanin, are not tumor specific and therefore are used widely for cancer immunotherapy. “Examples include, but aren’t limited to, Melan-A/MART-1 and tyrosinase for melanoma, or PSA for prostate carcinoma.
c) Overexpressed TAAs. Genes that encode TAAs with high expression have been found in a variety of histologically distinct tumors, as well as many normal tissues. These genes are usually expressed at lower levels. It’s possible that the T-cell threshold for recognition of many epitopes is below normal tissue levels, but their overexpression by tumor cells can trigger a response against cancer by breaking established tolerance. This class of TAAs is characterized by Her-2/neu or survivin. Telomerase and WT1 are also prominent examples.
d) Tumor specific antigens (TAAs): These TAAs are unique and arise from mutations in normal genes, such as?-catenin or CDK4. These molecular modifications are sometimes associated with the neoplastic progression or transformation. In general, tumor-specific antigens can induce strong immune reactions without causing autoimmune reactions to normal tissues. These TAAs, however, are only relevant for the specific tumor that they were found in and are not usually shared by many tumors. “Tumor-specificity or -association” of a protein can also occur if a peptide is derived from an exon that’s associated with tumors in the case of proteins that have tumor-specific (associated) variants.
TAAs that result from abnormal post-translational modification: These TAAs can arise from proteins that are not tumor specific or overexpressed, but which nevertheless become tumor related by posttranslational mechanisms primarily active in tumours. This class includes altered glycosylation patterns that lead to novel epitopes, such as MUC1, or events like protein degradation during splicing which may or not be tumor-specific.
f) Oncoviral Proteins: These TAAs, which are viral proteins, may play a crucial role in oncogenic processes. They can also elicit a T-cell reaction because they are not of human origin. These proteins include the human papilloma virus type 16 proteins E6 and E7 that are expressed in cervical cancer.
T-cell-based immunotherapy targets epitopes of peptides derived form tumor-associated proteins or tumor-specific protein molecules. These epitopes are presented by molecules in the major histocompatibility complicated (MHC). The tumor-specific T lymphocytes recognize antigens. These epitopes can be molecules from all protein classes such as enzymes and transcription factors. These antigens are usually expressed in tumor cells and up-regulated when compared to cells unaltered of the same origin.
There are two types of MHC-molecules: MHC class I or MHC class 2. MHC class I molecules are composed of an alpha heavy chain and beta-2-microglobulin, MHC class II molecules of an alpha and a beta chain. The binding groove is formed by their three-dimensional conformation, which allows for non-covalent interaction of peptides.
Most nucleated cells contain MHC class I molecules. They contain peptides derived from the proteolytic cleavages of endogenous proteins and defective ribosomal product (DRIP) as well as larger peptides. Nevertheless, peptides from exogenous or endosomal sources can also be found on MHC class 1 molecules. In the literature, this non-classical method of class I display is called cross-presentation (Brossart & Bevan, 1997, Rock et. al., 1990). MHC class II molecules are found mainly on professional antigen-presenting cells (APCs) and they primarily present transmembrane or exogenous proteins which APCs take up e.g. The endocytosis occurs and the peptides are then processed. Complexes of peptide and MHC class I are recognized by CD8-positive T cells bearing the appropriate T-cell receptor (TCR), whereas complexes of peptide and MHC class II molecules are recognized by CD4-positive-helper-T cells bearing the appropriate TCR. The TCR, peptides and MHC molecules are present in a 1:1:1 stoichiometric ratio.
CD4-positive helper cells are crucial in inducing and maintaining effective responses by CD8+ cytotoxic T cell cells. It is crucial to identify CD4-positive T cell epitopes from tumor-associated antigens (TAA), in order to develop pharmaceutical products that can trigger anti-tumor immune reactions (Gnjatic and al., 2003). T helper cells are present at the tumor site and support a cytotoxic-T cell-friendly cytokine milieu. (Mortara, et al. 2006) They also attract effector cells such as. CTLs, natural killing (NK) cells and macrophages are all present at the tumor site (Hwang et. al., 2007).
In the absence of inflammation the expression of MHC class 2 molecules is restricted to immune cells. This includes monocytes, monocyte derived cells, macrophages and dendritic cell. Cells of tumors have been observed to express MHC Class II molecules in cancer patients (Dengjel, et. al., 2006.)
The invention can be used as MHC class 2 active epitopes.
MHC class II epitopes activate T-helper cells and play an important role in the orchestration of CTLs’ anti-tumor immunity effector function. The T-helper cells that activate a T-helper response of the type TH1 support effector functions for CD8-positive killer cells. These functions include cytotoxic functions directed at tumor cells with tumor-associated protein/MHC complexes. This allows tumor-associated Thelper cell peptide epitopes to be used as active pharmaceutical ingredients in vaccine compositions that stimulate antitumor immune responses.
It was demonstrated in mammalian animal models (e.g. mice) that CD4-positive cells can inhibit the manifestation of tumors via inhibition o giogenesis by secretion interferon-gamma. Mumberg et. al. 1999; Beatty and Paterson 2001. Evidence supports the direct anti-tumor effects of CD4 T cells (Braumuller and Paterson, 2013; Tran and al. 2014).
HLA class II constitutive expression is typically limited to immune cells so the possibility of isolating class 2 peptides directly in primary tumors was not previously considered. However, Dengjel et al. Dengjel et al.
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