Claudin-6-specific immunoreceptors and T cell epitopes
12559531 · 2026-02-24
Assignee
- BioNTech Cell & Gene Therapies GmbH (Mainz, DE)
- TRON-TRANSLATIONALE ONKOLOGIE AN UNIVERSITATSMEDIZIN DER JOHANNES GUTENBERG-UNIVERSITAT MAINZ GE (Mainz, DE)
- Astellas Pharma Inc. (Tokyo, JP)
Inventors
- Ugur Sahin (Mainz, DE)
- Özlem Türeci (Mainz, DE)
- Petra Simon (Mainz, DE)
- Tana Omokoko (Mainz, DE)
- Holger HOFF (Mainz, DE)
- Ralf-Holger VOSS (Ingelheim, DE)
- Andrea BREITKREUZ (Worms, DE)
- Kathleen HOBOHM (Kelkheim i. Ts, DE)
- Karolina Anna MROZ (Wiesbaden, DE)
Cpc classification
A61K40/428
HUMAN NECESSITIES
A61K40/11
HUMAN NECESSITIES
C07K2319/30
CHEMISTRY; METALLURGY
A61K40/4202
HUMAN NECESSITIES
C07K14/4748
CHEMISTRY; METALLURGY
C07K16/28
CHEMISTRY; METALLURGY
A61K2239/59
HUMAN NECESSITIES
A61K2239/38
HUMAN NECESSITIES
A61P35/00
HUMAN NECESSITIES
International classification
A61K40/11
HUMAN NECESSITIES
C07K14/705
CHEMISTRY; METALLURGY
C07K16/28
CHEMISTRY; METALLURGY
G01N33/50
PHYSICS
Abstract
The present invention provides Claudin-6-specific immunoreceptors (T cell receptors and artificial T cell receptors (chimeric antigen receptors; CARs)) and T cell epitopes which are useful for immunotherapy.
Claims
1. An artificial T cell receptor comprising: a binding domain for claudin-6 (CLDN6) comprising the amino acid sequence of SEQ ID NO: 40; a costimulatory domain selected from the group consisting of: CD28, CD137 (4-1BB), CD134 (OX40), and CD278 (COS); and a T cell signaling domain that activates cytotoxic lymphocytes upon binding to CLDN6.
2. The artificial T cell receptor of claim 1, wherein the costimulatory domain is CD137 (4-1BB).
3. The artificial T cell receptor of claim 1, further comprising a transmembrane domain.
4. The artificial T cell receptor of claim 3, further comprising a spacer region which links the binding domain for CLDN6 to the transmembrane domain.
5. The artificial T cell receptor of claim 1, wherein the T cell signaling domain comprises the endodomain of CD3-zeta or a functional fragment thereof.
6. The artificial T cell receptor of claim 1 which comprises a signal peptide which directs the nascent protein into the endoplasmic reticulum.
7. The artificial T cell receptor of claim 6, which comprises the structure: NH2-signal peptide-binding domain for CLDN6-spacer region-transmembrane domain-T cell signaling domain-COOH.
Description
FIGURES
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
EXAMPLES
(23) The techniques and methods used herein are described herein or carried out in a manner known per se and as described, for example, in Sambrook et al., Molecular Cloning: A Laboratory Manual, 2.sup.nd Edition (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. All methods including the use of kits and reagents are carried out according to the manufacturers' information unless specifically indicated.
Example 1: Materials and Methods
(24) Cell Lines and Reagents
(25) The human chronic myeloid leukemia cell line K562 (Lozzio, C. B. & Lozzio, B. B (1975), Blood 45, 321-334) was cultured under standard conditions. K562 cells stably transfected with HLA-A*0201 (Britten, C. M. et al. (2002), J. Immunol. Methods 259, 95-110) (referred to e.g. as K562-A*0201) were used for validation assays. The primary human newborn foreskin fibroblast cell line CCD-1079Sk (ATCC No. CRL-2097) was cultured according to the manufacturers' instructions.
(26) The human CLDN6 expressing ovarian carcinoma cell line OV-90-SC12 was used for in vivo validation of the CLDN6-CAR.
(27) The culture medium for PA-1-SC12_A0201 luc_gfp_F7 is composed of 86% RPMI 1640+ Glutamax (Co. Gibco, Cat-No. 61870), 10% FCS (Co. Biochrome, Cat-No. S0615), 1% Sodium Pyruvate (100 mM) (Co. Gibco, Cat-No. 11360), 1% MEM Non-Essential Amino Acids Solution (100) (Co. Gibco, Cat-No. 11140), 2% Sodium Bicarbonate 7.5% solution (Co. Gibco, Cat-No. 25080).
(28) The culture medium for OV-90-SC12 is composed of 41.5% MCDB 105 (Co. Sigma Aldrich, Cat-No. M6395-1L), 41.5% Medium 199 (Co. Sigma Aldrich, Cat-No. M2154-500 mL), 15% FCS (Co. Biochrome, Cat-No. S0615), 2% Sodium Bicarbonate 7.5% solution (Co. Gibco, Cat-No. 25080).
(29) The culture medium for SK-MEL-37 is composed of 90% DMEM+ Glutamax (Co. Gibco, Cat-No. 31966), 10% FCS (Co. Biochrome, Cat-No. 50615). The culture medium for MDA-MB-231_luc_tom is composed of 88% RPMI 1640+ Glutamax (Co. Gibco, Cat-No. 61870), 10% FCS (Co. Biochrome, Cat-No. S0615), 1% Sodium Pyruvate (100 mM) (Co. Gibco, Cat-No. 11360), 1% MEM Non-Essential Amino Acids Solution (100) (Co. Gibco, Cat-No. 11140). Feeding and/or splitting of the cell lines was done every 2 to 3 days.
(30) Peripheral Blood Mononuclear Cells (PBMCs), Monocytes and Dendritic Cells (DCs)
(31) PBMCs were isolated by Ficoll-Hypaque (Amersham Biosciences, Uppsala, Sweden) density gradient centrifugation from buffy coats. HLA allelotypes were determined by PCR standard methods. Monocytes were enriched with anti-CD14 microbeads (Miltenyi Biotech, Bergisch-Gladbach, Germany). Immature DCs (iDCs) were obtained by differentiating monocytes for 5 days in cytokine-supplemented culture medium as described in Kreiter et al. (2007), Cancer Immunol. Immunother., CII, 56, 1577-87.
(32) Peptides and Peptide Pulsing of Stimulator Cells
(33) Pools of N- and C-terminally free 15-mer peptides with 11 amino acid overlaps corresponding to sequences of Claudin-6 or HIV-gag (referred to as antigen peptide pool) were synthesized by standard solid phase chemistry (JPT GmbH, Berlin, Germany) and dissolved in DMSO to a final concentration of 0.5 mg/ml. Nonamer peptides were reconstituted in PBS 10% DMSO. For pulsing stimulator cells were incubated for 1 h at 37 C. in culture medium using different peptide concentrations.
(34) Vectors for In Vitro Transcription (IVT) of RNA
(35) All constructs are variants of the previously described pST1-sec-insert-2gUTR-A(120)-Sap1 plasmid (Holtkamp, S. et al. (2006), Blood 108, 4009-4017). To obtain plasmids encoding human TCR chains, cDNA coding for TCR- or TCR-.sub.1 and TCR-.sub.2 constant regions were amplified from human CD8+ T cells and cloned into this backbone. For generation of plasmids encoding murine TCR chains, cDNAs coding for TCR-, -.sub.1 and -.sub.2 constant regions were ordered from a commercial provider and cloned analogously (GenBank accession numbers M14506, M64239 and X67127, respectively). Specific V(D)J PCR products were introduced into such cassettes to yield full-length TCR chains (referred to as pST1-human/murineTCR-2gUTR-A(120)).
(36) Analogously, individual HLA class I and II alleles cloned from PBMCs of donors and beta-2-microglobulin (B2M) cDNA from human DCs were inserted into this backbone (referred to as pST1-HLA class I/II-2gUTR-A(120) and pST1-B2M-2gUTR-A(120)).
(37) Plasmids coding for pp65 antigen of CMV (pST1-sec-pp65-MITD-2gUTR-A(120)) and NY-ESO-I (pST1-sec-NY-ESO-1-MITD-2gUTR-A(120)) linked to a secretion signal (sec) and the MHC class I trafficking signal (MITD) were described previously (Kreiter, S. et al. (2008), J. Immunol. 180, 309-318). PLAC1 encoding plasmid pST1-sec-PLAC1-MITD-2gUTR-A(120) was generated by cloning a cDNA obtained from a commercial provider (GenBank accession number NM_021796) into the Kreiter et al. backbone. TPTE encoding plasmids pST1-gUTR-TPTE-2gUTR-A(120) and pST1-gUTR-TPTE-MITD-2gUTR-A(120) were generated by cloning a cDNA obtained from a commercial provider (GenBank accession number AF007118) into a variant of the Holtkamp et al. vector featuring an additional alpha-globin 5-untranslated region.
(38) Primers were purchased from Operon Biotechnologies, Cologne, Germany.
(39) Generation of In Vitro Transcribed (IVT) RNA and Transfer into Cells
(40) Generation of IVT RNA was performed as described previously (Holtkamp, S. et al. (2006), Blood 108, 4009-4017) and added to cells suspended in X-VIVO 15 medium (Lonza, Basel, Switzerland) in a pre-cooled 4-mm gap sterile electroporation cuvette (Bio-Rad Laboratories GmbH, Munich, Germany) Electroporation was performed with a Gene-Pulser-II apparatus (Bio-Rad Laboratories GmbH, Munich, Germany) (T cells: 450 V/250 F; IVSB T cells: 350 V/200 F; SupT1 (ATCC No. CRL-1942): 300 V/200 F; human DC: 300 V/150 F; K562: 200 V/300 F).
(41) In Vivo Priming of T Cells by Intranodal Immunization of HLA A2.1/DR1 Mice with IVT RNA
(42) T cells of A2/DR1 mice (Pajot A. et al. (2004), Eur. J. Immunol. 34, 3060-69) were primed in vivo against the antigen of interest by repetitive intranodal immunization using antigen-encoding IVT RNA (Kreiter S. et al. (2010), Cancer Research 70, 9031-40). For intranodal immunizations, mice were anesthetized with xylazine/ketamine The inguinal lymph node was surgically exposed, 10 L RNA (20 g) diluted in Ringer's solution and Rnase-free water were injected slowly using a single-use 0.3-ml syringe with an ultrafine needle (31G, BD Biosciences), and the wound was closed. After six immunization cycles the mice were sacrificed and spleen cells were isolated.
(43) Harvest of Spleen Cells
(44) Following their dissection under sterile conditions, the spleens were transferred to PBS containing falcon tubes. The spleens were mechanically disrupted with forceps and the cell suspensions were obtained with a cell strainer (40 m). The splenocytes were washed with PBS centrifuged and resuspended in a hypotonic buffer for lysis of the erythrocytes. After 5 min incubation at RT, the reaction was stopped by adding 20-30 ml medium or PBS. The spleen cells were centrifuged and washed twice with PBS.
(45) Single-Cell Sorting of Antigen-Specific CD8+ T Cells after CD137 Staining
(46) For antigen-specific restimulation 2.510{circumflex over ()}6/well spleen cells from immunized A2/DR1 mice were seeded in a 24-well plate and pulsed with a pool of overlapping peptides encoding the antigen of interest or a control antigen. After 24 h incubation cells were harvested, stained with a FITC-conjugated anti-CD3 antibody, a PE-conjugated anti-CD4 antibody, a PerCP-Cy5.5-conjugated anti-CD8 antibody and a Dylight-649-conjugated anti-CD137 antibody. Sorting was conducted on a BD FACS Aria flow cytometer (BD Biosciences). Cells positive for CD137, CD3 and CD8 were sorted, one cell per well was harvested in a 96-well V-bottom-plate (Greiner Bio-One) containing human CCD-1079Sk cells as feeder cells, centrifuged at 4 C. and stored immediately at 80 C.
(47) RNA Extraction, SMART-Based cDNA Synthesis and Unspecific Amplification from Sorted Cells
(48) RNA from sorted T cells was extracted with the RNeasy Micro Kit (Qiagen, Hilden, Germany) according to the instructions of the supplier. A modified BD SMART protocol was used for cDNA synthesis: BD PowerScript Reverse Transcriptase (BD Clontech, Mountain View, CA) was combined with oligo(dT)-T-primer long for priming of the first-strand synthesis reaction and TS-short (Eurogentec S. A., Seraing, Belgium) introducing an oligo(riboG) sequence to allow for creation of an extended template by the terminal transferase activity of the reverse transcriptase and for template switch (Matz, M. et al. (1999) Nucleic Acids Res. 27, 1558-1560). First strand cDNA synthesized according to the manufacturer's instructions was subjected to 21 cycles of amplification with 5 U PfuUltra Hotstart High-Fidelity DNA Polymerase (Stratagene, La Jolla, CA) and 0.48 M primer TS-PCR primer in the presence of 200 M dNTP (cycling conditions: 2 min at 95 C. for, 30 s at 94 C., 30 s at 65 C., 1 min at 72 C. for, final extension of 6 min at 72 C.). Successful amplification of TCR genes was controlled with either human or murine TCR- constant region specific primers and consecutive clonotype-specific human or murine V-/V-PCRs were only performed if strong bands were detected.
(49) First strand cDNA for the amplification of HLA class I or II sequences was synthesized with SuperScriptII Reverse Transcriptase (Invitrogen) and Oligo(dT) primer with 1-5 g RNA extracted from patient-derived PBMCs.
(50) Design of PCR Primers for TCR and HLA Amplification
(51) For design of human TCR consensus primers, all 67 TCR-V and 54 TCR-V genes (open reading frames and pseudogenes) as listed in the ImMunoGeneTics (IMGT) database (http://www.imgt.org) together with their corresponding leader sequences were aligned with the BioEdit Sequence Alignment Editor (e.g. http://www.bio-soft.net). Forward primers of 24 to 27 bp length with a maximum of 3 degenerated bases, a GC-content between 40-60% and a G or C at the 3end were designed to anneal to as many leader sequences as possible and equipped with a 15 bp 5extension featuring a rare restriction enzyme site and Kozak sequence. Reverse primers were designed to anneal to the first exons of the constant region genes, with primer TRACex1_as binding to sequences corresponding to amino acids 7 to 16 of C and TRBCex1_as to amino acids (aa) 8 to 16 in C1 and C2. Both oligonucleotides were synthesized with a 5 phosphate. Primers were bundled in pools of 2-5 forward oligos with identical annealing temperature.
(52) This strategy was replicated for the design of murine TCR consensus primers, aligning 129 listed TCR-V and 35 listed TCR-V genes. Reverse primers mTRACex1_as and mTRBCex1_as are homologous to sequences corresponding to aa 24 to 31 and 8 to 15, respectively.
(53) HLA consensus primers were designed by aligning all HLA class I and II sequences listed on the Anthony Nolan Research Institute website (www.anthonynolan.com) with the BioEdit Sequence Alignment Editor. Forward primers of 23 to 27 bp length with a maximum of 3 degenerated but code-preserving bases annealing to as many as possible HLA sequences of one locus were equipped with a 5-phosphate and Kozak sequence extension. Reverse primers were designed analogously but without introduction of wobble bases and equipped with a 14 bp 5-extension encoding an AsiSI restriction enzyme site.
(54) PCR Amplification and Cloning of V(D)J Sequences
(55) 3-6 l of preamplified cDNA from isolated T cells was subjected to 40 cycles of PCR in the presence of 0.6 M V-/V-specific oligo pool, 0.6 M C- or C-oligo, 200 M dNTP and 5 U Pfu polymerase (cycling conditions: 2 min at 95 C., 30 s at 94 C., 30 s annealing temperature, 1 min at 72 C., final extension time of 6 min at 72 C.). PCR products were analyzed using Qiagen's capillary electrophoresis system. Samples with bands at 400-500 bp were size fractioned on agarose gels, the bands excised and purified using a Gel Extraction Kit (Qiagen, Hilden, Germany). Sequence analysis was performed to reveal the sequence of both the V(D)J domain and constant region, as TRBCex1_as and mTRBCex1_as primer, respectively, match to both TCR constant region genes 1 and 2 in human and mouse, respectively. DNA was digested and cloned into the IVT vectors containing the appropriate backbone for a complete TCR-/ chain.
(56) Flow Cytometric Analyses
(57) Cell surface expression of transfected TCR genes was analyzed by flow cytometry using PE-conjugated anti-TCR antibody against the appropriate variable region family or the constant region of the TCR chain (Beckman Coulter Inc., Fullerton, USA) and FITC-/APC-labeled anti-CD8/-CD4 antibodies (BD Biosciences). Cell surface expression of transfected CARs was analyzed using a Dylight-650-conjugated idiotype-specific antibody (Ganymed Pharmaceuticals) recognizing the scFv fragment contained in all CLDN6-CAR constructs. HLA antigens were detected by staining with FITC-labeled HLA class II-specific (Beckman Coulter Inc., Fullerton, USA) and PE-labeled HLA class I-specific antibodies (BD Biosciences). CLDN6 surface expression on target cells was analyzed by staining with an Alexa-Fluor647-conjugated CLDN6-specific antibody (Ganymed Pharmaceuticals). Flow cytometric analysis was performed on a FACS CANTO II flow cytometer using the FACS Diva software (BD Biosciences).
(58) Luciferase Cytotoxicity Assay
(59) For assessment of cell-mediated cytotoxicity a bioluminescence-based assay was established as an alternative and optimization to .sup.51Cr release. In contrast to the standard chromium release assay, this assay measures lytic activity of effector cells by calculating the number of viable luciferase expressing target cells following coincubation. The target cells were stably or transiently transfected with the luciferase gene coding for the firefly luciferase from firefly Photinus pyralis (EC 1.13.12.7). Luciferase is an enzyme catalyzing the oxidation of luciferin. The reaction is ATP-dependent and takes place in two steps:
luciferin+ATP.fwdarw.luciferyl adenylate+PP.sub.i
luciferyl adenylate+O.sub.2.fwdarw.oxyluciferin+AMP+light
(60) Target cells were plated at a concentration of 10.sup.4 cells per well in white 96-well plates (Nunc, Wiesbaden, Germany) and were cocultivated with varying numbers of TCR-transfected T cells in a final volume of 100 l. 3 h later 50 l of a D-Luciferin (BD Biosciences) containing reaction mix (Luciferin (1 g/l), HEPES-buffer (50 mM, pH), Adenosine 5-triphosphatase (ATPase, 0.4 mU/l, Sigma-Aldrich, St. Louis, USA) was added to the cells. By addition of ATPase to the reaction mix luminescence resulting from luciferase released from dead cells was diminished.
(61) After a total incubation time of 4 h bioluminescence emitted by viable cells was measured using the Tecan Infinite 200 reader (Tecan, Crailsheim, Germany) Cell-killing activity was calculated in regard to luminescence values obtained after complete cell lysis induced by the addition of 2% Triton-X 100 and in relationship to luminescence emitted by target cells alone. Data output was in counts per second (CPS) and percent specific lysis was calculated as follows:
(1(CPS.sub.expCPS.sub.min)/(CPS.sub.maxCPS.sub.min)))*100.
(62) Maximum luminescence (maximum counts per second, CPSmax) was assessed after incubating target cells without effectors and minimal luminescences (CPSmin) was assessed after treatment of targets with detergent Triton-X-100 for complete lysis.
(63) ELISPOT (Enzyme-Linked ImmunoSPOT Assay)
(64) Microtiter plates (Millipore, Bedford, MA, USA) were coated overnight at room temperature with an anti-IFN antibody 1-D1k (Mabtech, Stockholm, Sweden) and blocked with 2% human albumin (CSL Behring, Marburg, Germany) 2-510.sup.4/well antigen presenting stimulator cells were plated in triplicates together with 0.3-310.sup.5/well TCR-transfected CD4+ or CD8+ effector cells 24 h after electroporation. The plates were incubated overnight (37 C., 5% CO.sub.2), washed with PBS 0.05% Tween 20, and incubated for 2 hours with the anti-IFN biotinylated mAB 7-B6-1 (Mabtech) at a final concentration of 1 g/ml at 37 C. Avidin-bound horseradish peroxidase H (Vectastain Elite Kit; Vector Laboratories, Burlingame, USA) was added to the wells, incubated for 1 hour at room temperature and developed with 3-amino-9-ethyl carbazole (Sigma, Deisenhofen, Germany)
(65) CFSE (Carboxyfluorescein Succinimidyl Ester) Proliferation Assay
(66) CD8+ T cells were transfected with TCR or CAR RNA and labeled with 2.5 M CFSE. Labeled T cells were washed and cocultured with RNA-transfected autologous monocytes or iDCs (E:T (effector cells: target(tumor) cells)=10:1). After 4 days of coculture cells were harvested and proliferation was analyzed by flow cytometry based on the progressive halving of CFSE fluorescence within daughter cells following cell divisions.
(67) Retroviral Construct for Stable CAR Expression
(68) For stable expression of the CLDN6-CAR or the CAR against an unrelated tumor antigen used as a negative control the retroviral SIN vector ES12.6 was used (
(69) Transduction of Human T Cells
(70) For the mouse adoptive cell transfer (ACT) experiments, human T lymphocytes were enriched from PBMCs of healthy donors by removal of monocytes after 2 h of plastic adherence. T lymphocytes were cultured in X-Vivo15 (Lonza) medium supplemented with 5% human AB serum (Invitrogen), 100 U/ml IL2 (Proleukin S, Novartis), 20 ng/ml IL7 (Miltenyi), 10 ng/ml IL15 (Miltenyi) and stimulated with magnetic anti-CD3/anti-CD28 beads (Dynabeads; Invitrogen) at a 1:3 CD3 cell to bead ratio and transduced on days 3 and 4 post stimulation with retroviral supernatants. Cells were expanded in X-Vivo15 medium supplemented with 5% human AB serum, 300 U/ml IL2, 20 ng/ml IL7 and 10 ng/ml IL15. Incubation 37 C., 5% CO.sub.2, 95% rH (
(71) Mouse Model for In-Vivo Validation of Antitumoral Activity
(72) Xenograft tumors were established by subcutaneous injection of 110.sup.7 OV90-SC12 human ovarian tumor cells into 8-14 week-old NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice (The Jackson Laboratory, Bar Harbor, ME). After 4 days, mice were treated with a single intravenous injection of 110.sup.7 of CAR transduced T cells (20-37% CAR positive). Tumor monitoring was performed weekly by volume measurements using caliper (
Example 2: Isolation of High-Affinity HLA-A*02-Restricted Murine TCRs Specific for Claudin-6
(73) We validated the immunogenic potential of CLDN6 in A2/DR1 mice by repetitive intranodal immunization with CLDN6 encoding IVT-RNA and used spleen cells of these mice for isolation of CLDN6-specific T cells and subsequent cloning of the corresponding TCR genes (
(74) Significant frequencies of CLDN6-specific T cells could be induced In all three mice by RNA immunization, whereas T cell reactivity was focused on two CLDN6 peptides predicted, that were with the best HLA-A*02 binding score (Cl6-A2-1 and Cl6-A2-2).
(75) For isolation of CLDN6-specific T cells, spleen cells of immunized mice were restimulated in-vitro and sorted by flow cytometry based on the activation-induced upregulation of CD137 (
(76) CLDN6-specific CD8+ T cells could be retrieved from all three immunized A2/DR1 mice and a total of 11 CLDN6-specific TCRs were cloned from single-sorted murine T cells.
(77) TCRs were subjected to immunological validation assays, which revealed that six CLDN6-TCRs recognized the HLA-A*0201-restricted epitope CLDN6-91-99 (Cl6-A2-1) and four CLDN6-TCRs were specific for CLDN6-14-22 (Cl6-A2-2), whereas both epitopes were previously identified by ex-vivo ELISPOT analysis (
Example 3: Comparative Testing of Murine TCRs Specific for CLDN6 91-99
(78) In total six murine TCRs were identified that all recognize the HLA-A*02-restricted epitope CLDN6-91-99. In order to confirm that this epitope is naturally processed and presented by endogenously CLDN6 expressing tumor cell lines and to evaluate the potential of the identified murine TCRs to mediate killing of such cells a luciferase-based cytotoxicity assay was performed. Human preactivated CD8+ T cells were transfected with TCR RNA and surface expression was analyzed by flow cytometry (
Example 4: Generation and In-Vitro Validation of Claudin-6-Specific CARs
(79) We evaluated two different CAR formats to specifically target CLDN6 on CLDN6 expressing target cells. One of them represents a novel format based on the linkage of the scFv with the constant domain of the murine TCR chain and coexpression of the constant domain of the TCR chain (CAR/C) (Voss R H et al., (2011) Molecular Therapy 19, supplement, S86) (
(80) As CARs provide HLA independent scFv-mediated antigen-binding they are functional in both CD4+ and CD8+ T cells. Therefore, we first analyzed the CAR surface expression on CD4+ and CD8+ T cells after transfection of CAR RNA into bulk PBMCs.
(81) Both, the novel CAR/C and the classical 2nd generation CAR (CAR-28) are expressed on the surface of human T cells after RNA transfer (
(82) To analyze the specific tumor cell lysis mediated by the different CLDN6-targeting receptor formats a luciferase-based cytotoxicity assay was performed. CAR- or TCR-transfected preactivated CD8+ T cells were cultured with CLDN6-positive or negative tumor cell lines at different effector-to-target ratios and the specific lysis was calculated after 4 h of coculture (
(83) A prerequisite for the proliferation and persistence of CAR-engineered T cells in the patient is the presence of antigen as demonstrated by promising clinical trial results of CD19-specific CARs in hematologic malignancies. In analogy to the expansion of endogenous T cells by RNA immunization, we wanted to analyze, if CAR T cells could also be expanded using RNA-vaccination of target cells to provide natural CLND6 for CAR T cell stimulation. An in vitro proliferation assay was performed using CAR-transfected CD8+ T cells together with CLDN6 or control RNA-transfected autologous iDCs (
Example 5: CLDN6-CAR-28 Lead Structure Selection for Preclinical and Clinical Testing
(84) The CLDN6-CAR-2 scFv fragment that is responsible for antigen recognition contains an unpaired cysteine. As such a free cysteine could result in misfolding of the CAR protein under certain circumstances or in unwanted interactions with other cyteines by the formation of disulfide bonds, we decided to eliminate this cysteine and exchanged it by a serine, a glycine or an alanine.
(85) We than comparatively analyzed the resulting CLDN6-CAR-2 constructs regarding surface expression (
(86) In order to compare the affinity of the mutated CAR constructs their cytotoxic potential in response to autologous iDCs transfected with titrated amounts of CLDN6 RNA was analyzed. Even extremely little amounts of CLDN6 RNA (0.001 g) resulted in significant lysis of target cells mediated by all CAR constructs. As the serine variant of the CLDN6-CAR-28 showed slightly better results regarding surface expression and cytotoxicity, we decided to use this variant for preclinical testing.
Example 6: In-Vivo Antitumoral Activity of the CLDN6-CAR
(87) After having determined the antitumor activity against CLDN6 expressing tumor cell lines in-vitro the antitumor ability in tumor-bearing mice was determined. Therefore, the potency of CLDN6-CAR transduced human T cells was compared to T cells transduced with a control CAR against an unrelated tumor antigen and untransduced T cells in a xenograft model. A total of 110.sup.7 cells of the human ovarian carcinoma cell line OV90-SC12 were injected subcutaneously in NSG mice. Four days after tumor engraftment the mice were treated with a single intravenous injection of 110.sup.7 of CAR-transduced T cells. Tumor monitoring was performed weekly by volume measurements using caliper. Treatment of the mice with CLDN6-CAR-transduced T cells significantly slowed tumor growth compared to control groups treated with unrelated tumor antigen-CAR-transduced, untransduced T cells or a group not receiving T cells (
Example 7: In-Vitro Proliferation of CLDN6-CAR T Cells in Response to CLDN6-Expressing Target Cells
(88) In analogy to the expansion of endogenous T cells by RNA immunization, the stimulation and expansion of CAR T cells using RNA-vaccination of target cells to provide natural CLND6 was analyzed by in vitro proliferation assay. CD8.sup.+ T cells were transfected with IVT-RNA encoding a CAR against CLDN6 or an unrelated tumor antigen as negative control, labeled with CFSE (carboxyfluorescein succinimidyl ester) and cocultured with CLDN6-transfected autologous iDCs for 4 days (
(89) TABLE-US-00001 CLDN6-specificTcellepitopes A2-1(aa91-99) ALFGLLVYL A2-2(aa14-22) TLLGWVNGL A2-3(7-15) QILGVVLTL CLDN6-specificTcellreceptors TCR.sub.CD8-mC16#1: SEQIDNO:6;>V9N.3J13C MLLALLSVLGIHFLLRDAQAQSVTQPDARVTVSEGASLQLRCKYSYFGTPYLFWYVQY PRQGLQLLLKYYPGDPVVQGVNGFEAEFSKSNSSFHLRKASVHWSDWAVYFCAVSMSS GTYQRFGTGTKLQVVPNIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFI TDKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETD MNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:7;>V29D1J2.5C2 MRVRLISAVVLCFLGTGLVDMKVTQMPRYLIKRMGENVLLECGQDMSHETMYWYRQ DPGLGLQLIYISYDVDSNSEGDIPKGYRVSRKKREHFSLILDSAKTNQTSVYFCASSSQNQ DTQYFGPGTRLLVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELSW WVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEED KWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVSGL VLMAMVKKKNS TCR.sub.CD8-mC16#2: SEQIDNO:8;>V6N.6J23C MDSFPGFVAVILLILGRTHGDSVTQTEGQVTVSESKSLIINCTYSATSIGYPNLFWYVRYP GEGLQLLLKVITAGQKGSSRGFEATYNKEATSFHLQKASVQESDSAVYYCALNNQGKLI FGQGTKLSIKPNIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFITDKTVL DMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETDMNLNFQ NLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:9;>V13.2D1J2.4C2 MGSRLFFVLSSLLCSKHMEAAVTQSPRNKVAVTGGKVTLSCNQTNNHNNMYWYRQDT GHGLRLIHYSYGAGSTEKGDIPDGYKASRPSQENFSLILELATPSQTSVYFCASGGDSQN TLYFGAGTRLSVLEDLRNVTPPKVSLFE,PSKAEIANKQKATLVCLARGFFPDHVELSWW VNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEEDK WPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVSGLVL MAMVKKKNS TCR.sub.CD8-mC16#3: SEQIDNO:18;>V16NJ6C MLILSLLGAAFGSICFAATSMAQKVTQTQTSISVVEKTTVTMDCVYETRDSSYFLFWYK QTASGEIVFLIRQDSYKKENATVGHYSLNFQKPKSSIGLIITATQIEDSAVYFCAMRDSSG GNYKPTFGKGTSLVVHPYIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTF ITDKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFET DMNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:19;>V2D2J2.4C2 MGSIFLSCLAVCLLVAGPVDPKIIQKPKYLVAVTGSEKILICEQYLGHNAMYWYRQSAK KPLEFMFSYSYQKLMDNQTASSRFQPQSSKKNHLDLQITALKPDDSATYFCASSQEDWG SQNTLYFGAGTRLSVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELS WWVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSE EDKWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVS GLVLMAMVKKKNS TCR.sub.CD8-mC16#7: SEQIDNO:28;>V6N.7orV6D.7_4J26C MDSFPGFMTVMLLIFTRAHGDSVTQTEGQVALSEEDFLTIHCNYSASGYPALFWYVQYP GEGPQFLFRASRDKEKGSSRGFEATYDKGTTSFHLRKASVQESDSAVYYCALGNNYAQ GLTFGLGTRVSVFPYIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFITDK TVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETDMNL NFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:29;>V13.3D1J1.4_02C1 MGSRLFFVVLILLCAKHMEAAVTQSPRSKVAVTGGKVTLSCHQTNNHDYMYWYRQDT GHGLRLIHYSYVADSTEKGDIPDGYKASRPSQENFSLILELASLSQTAVYFCASSTGNERL FFGHGTKLSVLEDLRNVTPPKVSLl-E,PSKAEIANKQKATLVCLARGFFPDHVELSWWVN GKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEEDKWP EGSPKPVTQNISAEAWGRADCGITSASYQQGVLSATILYEILLGKATLYAVLVSTLVVM AMVKRKNS TCR.sub.CD8-mC16#8: SEQIDNO:10;>V16NJ13C MLILSLLGAAFGSICFATSMAQKVTQTQTSISVVEKTTVTMDCVYETRDSSYFLFWYKQ TASGEIVFLIRQDSYKKENATVGHYSLNFQKPKSSIGLIITATQIEDSAVYFCAMREAANS GTYQRFGTGTKLQVVPNIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFI TDKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETD MNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:11;>V2D1J1.3C1 MGSIFLSCLAVCLLVAGPVDPKIIQKPKYLVAVTGSEKILICEQYLGHNAMYWYRQSAK KPLEFMFSYSYQKLMDNQTASSRFQPQSSKKNHLDLQITALKPDDSATYFCASSQQNSG NTLYFGEGSRLIVVEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELSW WVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEED KWPEGSPKPVTQNISAEAWGRADCGITSASYQQGVLSATILYEILLGKATLYAVLVSTLV VMAMVKRKNS TCR.sub.CD8-mC16#10: SEQIDNO:20;>V13D.4_03J42C MKRLVCSLLGLLCTQVCWVKGQQVQQSPASLVLQEGENAELQCNFSSTATRLQWFYQ RPGGSLVSLLYNPSGTKHTGRLTSTTVTKERRSSLHISSSQTTDSGTYFCAMSSNSGGSN AKLTFGKGTKLSVKSNIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFIT DKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETD MNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:21;>V4_02D2J2.7C2 MGCRLLSCVAFCLLGIGPLETAVFQTPNYRVTRVGNEVSFNCEQTLDHNTMYWYKQDS KKLLKIMFSYNNKQLIVNETVPRRFSPQSSDKAHLNLRIKSVELEDSAVYLCASSDWGDS YEQYFGPGTRLTVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELSW WVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEED KWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVSGL VLMAMVKKKNS TCR.sub.CD8-mC16#12: SEQIDNO:12;>V3.3J50C MKTVTGPLFLCFWLQLNCVSRGEQVEQRPPHLSVREGDSAVITCTYTDPNSYYFFWYK QEPGASLQLLMKVFSSTEINEGQGFTVLLNKKDKRLSLNLTAAHPGDSAAYFCAVESSS FSKLVFGQGTSLSVVPNIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFIT DKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETD MNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:13;>V26D2J2.5C2 MATRLLCYTVLCLLGARILNSKVIQTPRYLVKGQGQKAKMRCIPEKGHPVVFWYQQNK NNEFKFLINFQNQEVLQQIDMTEKRFSAECPSNSPCSLEIQSSEAGDSALYLCASSLTGGA QDTQYFGPGTRLLVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELS WWVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSE EDKWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVS GLVLMAMVKKKNS TCR.sub.CD8-mC16#13: SEQIDNO:22;>V16NJ22C MLILSLLGAAFGSICFAATSMAQKVTQTQTSISVVEKTTVTMDCVYETRDSSYFLFWYK QTASGEIVFLIRQDSYKKENATVGHYSLNFQKPKSSIGLIITATQIEDSAVYFCAMRVASS GSWQLIFGSGTQLTVMPDIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTF ITDKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFET DMNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:23;>V2D1J2.1C2 MGSIFLSCLAVCLLVAGPVDPKIIQKPKYLVAVTGSEKILICEQYLGHNAMYWYRQSAK KPLEFMFSYSYQKLMDNQTASSRFQPQSSKKNHLDLQITALKPDDSATYFCASSQGDNN YAEQFFGPGTRLTVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELS WWVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSE EDKWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVS GLVLMAMVKKKNS TCR.sub.CD8-mC16#14: SEQIDNO:14;>V4N.4orV4D.4_03J6C MQRNLVAVLGILWVQICWVRGDQVEQSPSALSLHEGTGSALRCNFTTTMRAVQWFRK NSRGSLINLFYLASGTKENGRLKSAFDSKERYSTLHIRDAQLEDSGTYFCAAEGGGNYK PTFGKGTSLVVHPYIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFITDKT VLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETDMNL NFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:15;>V31D1J1.1C1 MLYSLLAFLLGMFLGVSAQTIHQWPVAEIKAVGSPLSLGCTIKGKSSPNLYWYWQATG GTLQQLFYSITVGQVESVVQLNLSASRPKDDQFILSTEKLLLSHSGFYLCAWSPPINTEVF FGKGTRLTVVEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELSWWVN GKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEEDKWP EGSPKPVTQNISAEAWGRADCGITSASYQQGVLSATILYEILLGKATLYAVLVSTLVVM AMVKRKNS TCR.sub.CD8-mC16#15: SEQIDNO:24;>V3.1J39C MKTVTGPLLLCFWLQLNCVSRGEQVEQRPPHLSVREGDSAIIICTYTDSATAYFSWYKQ EAGAGLQLLMSVLSNVDRKEEQGLTVLLNKKDKRLSLNLTAAHPGDSAVYFCATNAG AKLTFGGGTRLTVRPDIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFIT DKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETD MNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:25;>V4D2J2.7C2 MGCRLLSCVAFCLLGIGPLETAVFQTPNYHVTQVGNEVSFNCKQTLGHDTMYWYKQD SKKLLKIMFSYNNKQLIVNETVPRRFSPQSSDKAHLNLRIKSVEPEDSAVYLCASSLYWG DSYEQYFGPGTRLTVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELS WWVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSE EDKWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVS GLVLMAMVKKKNS TCR.sub.CD8-mC16#17: SEQIDNO:26;>V14.3orV14D.3/DV8_08J22C MDKNLTASFLLLGLHLAGVSGQQEKRDQQQVRQSPQSLTVWEGETAILNCSYENSAFD YFPWYQQFPGEGPALLISILSVSDKKEDGRFTIFFNKREKKLSLHIADSQPGDSATYFCAA SLSSGSWQLIFGSGTQLTVMPDIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTME SGTFITDKTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEK SFETDMNLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:27;>V3D2J2.7C2 MDIWLLGWIIFSFLEAGHTGPKVLQIPSHQIIDMGQMVTLNCDPVSNHLYFYWYKQILG QQMEFLVNFYNGKVMEKSKLFKDQFSVERPDGSYFTLKIQPTALEDSAVYFCASSLVGG YEQYFGPGTRLTVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELSW WVNGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEED KWPEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVSGL VLMAMVKKKNS TCR.sub.CD8-mC16#18: SEQIDNO:16;>V6D.6_02J4C MDSSPGFVAVILLILGRTHGDSVTQTEGPVTVSESESLIINCTYSATSIAYPNLFWYVRYP GEGLQLLLKVITAGQKGSSRGFEATYNKETTSFHLQKASVQESDSAVYYCALGETGSFN KLTFGAGTRLAVCPYIQNPEPAVYQLKDPRSQDSTLCLFTDFDSQINVPKTMESGTFITD KTVLDMKAMDSKSNGAIAWSNQTSFTCQDIFKETNATYPSSDVPCDATLTEKSFETDM NLNFQNLSVMGLRILLLKVAGFNLLMTLRLWSS SEQIDNO:17;>V26D1J2.7C2 MATRLLCYTVLCLLGARILNSKVIQTPRYLVKGQGQKAKMRCIPEKGHPVVFWYQQNK NNEFKFLINFQNQEVLQQIDMTEKRFSAECPSNSPCSLEIQSSEAGDSALYLCASSLGIYE QYFGPGTRLTVLEDLRNVTPPKVSLFEPSKAEIANKQKATLVCLARGFFPDHVELSWWV NGKEVHSGVSTDPQAYKESNYSYCLSSRLRVSATFWHNPRNHFRCQVQFHGLSEEDKW PEGSPKPVTQNISAEAWGRADCGITSASYHQGVLSATILYEILLGKATLYAVLVSGLVLM AMVKKKNS