Immunological and In-Vivo Neurological Studies on a Benzoic Acid-Specific T-Cell-Derived Antigen-Binding Molecule from the Serum of a Toluene-Sensitive Patient

BackgroundBioengineered T cell treatments for acute myeloid leukemia (AML) are challenged by near universal expression of leukemia antigens on normal hematopoietic stem/progenitor cells:1 2 ‘on target/off tumor‘ activity may cause myelosuppression while sustained antigen exposure can lead to T cell exhaustion.3 In addition, splicing variants may allow antigen escape. We hypothesize that by using a novel CD33-C2-specific single domain VHH antibody as the antigen targeting domain in dimerizing agent-regulated immunoreceptor complex T cells (DARIC T cells), we will enable pharmacologically-controllable targeting of CD33, allowing eradication of leukemia expressing either of the major splice variants of CD33: i.e., full-length CD33 or CD33ΔE2.MethodsWe engineered DARIC-expressing lentiviral vectors containing encoding separated CD33-C2-specific antigen binding and 41BB-CD3zeta signaling chains that heterodimerize following addition of rapamycin via embedded FKBP12 and FRB* domains.4 Peripheral blood mononuclear cells were stimulated with IL-2, anti-CD3, and anti-CD28 antibodies 24h prior to transduction with DARIC33 lentiviral vector. Surface expression of antigen binding or signaling chains was assessed using biotinylated CD33, or antibodies to VHH-domains or FRB* respectively. Rapamycin-dependent in vitro activity was measured by IFNg release. To evaluate in vivo activity, NSG mice injected with 1 × 105 MOLM-14/luc cells were treated 5-7 days later with 1 × 107 DARIC33 T cells in the presence or absence of rapamycin and tumor progression followed by luciferase activity.ResultsDARIC33+ T cells bound biotinylated-CD33, anti-VHH and anti-FRB* antibodies. Rapamycin addition increased expression of both signaling and antigen-recognition chains, suggesting augmented receptor stability in the presence of dimerizing drug. In the presence of rapamycin, coculture of DARIC33 T cells with cell lines expressing either full length or CD33ΔE25 showed equivalent rapamycin-dependent activation, demonstrating DARIC33 responds to both splice variants. Titration experiments showed rapamycin-dependent activation with EC50 = 25pM. Negligible IFNg release was observed in the absence of drug. DARIC33 T cells significantly extended survival of AML-bearing mice, but only when treated with rapamycin. The DARIC33 T cells were activated in vivo by sub-immunosuppressive rapamycin dosing, as weekly or 0.1 mg/kg QOD dosing led to similar levels of tumor suppression.ConclusionsDARIC33 T cells appear to be potent antileukemic agents: they are activated by AML cell lines in vitro as demonstrated by cytokine release and cytotoxicity, and significantly extend survival in an aggressive xenograft model. Temporal control provided by the DARIC architecture promises to enhance safety and potentially efficacy of CAR T therapy for AML, for example by enabling hematopoietic recovery or providing T cell rest.ReferencesPerna F, Berman SH, Soni RK, Mansilla-Soto J, Eyquem J, Hamieh M, et al. Integrating proteomics and transcriptomics for systematic combinatorial chimeric antigen receptor therapy of AML. Cancer Cell 2017 Oct 9;32(4):506–519.e5.Haubner S, Perna F, Köhnke T, Schmidt C, Berman S, Augsberger C, et al. Coexpression profile of leukemic stem cell markers for combinatorial targeted therapy in AML. Leukemia. 2019 Jan;33(1):64.Lamarche C, Novakovsky GE, Qi CN, Weber EW, Mackall CL, Levings MK. Repeated stimulation or tonic-signaling chimeric antigen receptors drive regulatory T cell exhaustion. bioRxiv. 2020 Jun 28;2020.06.27.175158.Leung W-H, Gay J, Martin U, Garrett TE, Horton HM, Certo MT, et al. Sensitive and adaptable pharmacological control of CAR T cells through extracellular receptor dimerization. JCI Insight [Internet]. 2019 Jun 6 [cited 2019 Jun 11];4(11). Available from: https://insight.jci.org/articles/view/124430Pérez-Oliva AB, Martínez-Esparza M, Vicente-Fernández JJ, Corral-San Miguel R, García-Peñarrubia P, Hernández-Caselles T. Epitope mapping, expression and post-translational modifications of two isoforms of CD33 (CD33M and CD33m) on lymphoid and myeloid human cells. Glycobiology 2011;21(6):757–770.

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An in vivo method for diversifying the functions of therapeutic antibodies

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2025596118 ◽

2021 ◽

Vol 118 (10) ◽

pp. e2025596118

Author(s):

Ming Tian ◽

Hwei-Ling Cheng ◽

Michael T. Kimble ◽

Kelly McGovern ◽

Peyton Waddicor ◽

...

Keyword(s):

T Cell ◽

B Cells ◽

Mouse Models ◽

De Novo ◽

Variable Region ◽

Affinity Maturation ◽

Antigen Binding ◽

Therapeutic Antibodies ◽

Ligand Interaction

V(D)J recombination generates mature B cells that express huge repertoires of primary antibodies as diverse immunoglobulin (Ig) heavy chain (IgH) and light chain (IgL) of their B cell antigen receptors (BCRs). Cognate antigen binding to BCR variable region domains activates B cells into the germinal center (GC) reaction in which somatic hypermutation (SHM) modifies primary variable region-encoding sequences, with subsequent selection for mutations that improve antigen-binding affinity, ultimately leading to antibody affinity maturation. Based on these principles, we developed a humanized mouse model approach to diversify an anti-PD1 therapeutic antibody and allow isolation of variants with novel properties. In this approach, component Ig gene segments of the anti-PD1 antibody underwent de novo V(D)J recombination to diversify the anti-PD1 antibody in the primary antibody repertoire in the mouse models. Immunization of these mouse models further modified the anti-PD1 antibodies through SHM. Known anti-PD1 antibodies block interaction of PD1 with its ligands to alleviate PD1-mediated T cell suppression, thereby boosting antitumor T cell responses. By diversifying one such anti-PD1 antibody, we derived many anti-PD1 antibodies, including anti-PD1 antibodies with the opposite activity of enhancing PD1/ligand interaction. Such antibodies theoretically might suppress deleterious T cell activities in autoimmune diseases. The approach we describe should be generally applicable for diversifying other therapeutic antibodies.

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An In Vivo Method for Diversifying the Functions of Therapeutic Antibodies

10.1101/2020.12.12.421834 ◽

2020 ◽

Author(s):

Ming Tian ◽

Hwei-Ling Cheng ◽

Michael T Kimble ◽

Kelly McGovern ◽

Peyton Waddicor ◽

...

Keyword(s):

T Cell ◽

B Cells ◽

Mouse Models ◽

De Novo ◽

Variable Region ◽

Affinity Maturation ◽

Antigen Binding ◽

Therapeutic Antibodies ◽

Ligand Interaction

V(D)J recombination generates mature B cells that express huge repertoires of primary antibodies as diverse immunoglobulin heavy (IgH) and light chains (IgL) of their B cell antigen receptors (BCRs). Cognate antigen binding to BCR variable region domains activates B cells into the germinal center (GC) reaction in which somatic hypermutation (SHM) modifies primary variable region-encoding sequences, with subsequent selection for mutations that improve antigen-binding affinity, ultimately leading to antibody affinity maturation. Based on these principles, we developed a humanized mouse model approach to diversify an anti-PD1 therapeutic antibody and allow isolation of variants with novel properties. In this approach, component Ig gene segments of the anti-PD1 antibody underwent de novo V(D)J recombination to diversify the anti-PD1 antibody in the primary antibody repertoire in the mouse models. Immunization of these mouse models further modifies the anti-PD1 antibodies through SHM. Known anti-PD1 antibodies block interaction of PD1 with its ligands to alleviate PD1-mediated T cell suppression, thereby boosting anti-tumor T cell responses. By diversifying one such anti-PD1 antibody, we derived many new anti-PD1 antibodies, including anti-PD1 antibodies with the opposite activity of enhancing PD1/ligand interaction. Such antibodies theoretically might suppress deleterious T cell activities in autoimmune diseases. The approach we describe should be generally applicable for diversifying other therapeutic antibodies.

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Low-Dose Lenalidomide Improves CAR-Based Immunotherapy In CLL By Reverting T-Cell Defects In Vivo

Blood ◽

10.1182/blood.v122.21.4171.4171 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4171-4171

Author(s):

Maria Teresa Sabrina Bertilaccio ◽

Sarah Tettamanti ◽

Greta Maria Paola Giordano Attianese ◽

Giovanni Galletti ◽

Silvia Arcangeli ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Low Dose ◽

Leukemic Cells ◽

Antigen Binding ◽

Low Doses ◽

Car T Cells ◽

Car T

Abstract Chronic Lymphocytic Leukemia (CLL) is a chronic lymphoid malignancy characterized by immune suppression that is responsible for an increase in infection susceptibility but also concurs to a reduced ability of the immune system to promote an effective response against the leukemic cells. Tumor-immunosuppressive mechanisms are essentially due to the capacity of CLL cells of modifying the surrounding microenvironment including immune effectors likely contributing to disease progression but also to limited effectiveness of current immunotherapy approaches. Lenalidomide is an immunomodulatory agent (IMID) able to induce significant long-lasting responses in CLL patients. The exact mechanism of anti-tumor activity of lenalidomide remains undefined, but it also implies the modulation of tumor microenvironment through down-regulation of critical cytokines and activation of immune effector cells. In addition, lenalidomide was shown to reverse, in vitro, defects in immunological synapse formation between T cells and CLL cells, by interfering with several cytoskeletal molecules. Chimeric antigen receptors (CARs) molecules are emerging as a powerful tool to redirect T-cell specificity against leukemia. CARs are artificial molecules constituted by an extracellular-antigen-binding domain consisting of the variable chains of a monoclonal antibody, linked together as a single chain Fv (scFV), and an intracellular signaling region, usually the zeta chain of the TCR/CD3 complex, that is immediately triggered after antigen recognition. Therefore, CARs take advantage of both the antigen binding non MHC-restricted-properties of monoclonal antibodies and of the typical T-cell mediated effector functions. Given the characteristic T cell defects occurring in vivo in CLL patients, it becomes very intriguing to explore the possibility of a novel CLL therapy combining a CAR-based immunotherapy with low doses of lenalidomide, in order to maximize the effect of the immune attack by reverting in vivo the acquired T cell defects. We studied the in vivo cytotoxic effects on the tumor microenvironment upon lenalidomide treatment utilizing the Rag2-/-γc-/--xenograft model of human CLL based on transplantation of the CLL cell line MEC1 into Rag2-/-γc-/--mice. Utilizing the CAR.CD23 tool as previously published by our group, we also performed experiments where MEC-1-trasplanted-Rag2-/-γc-/- mice were injected with CAR.CD23 T cells from CLL patients together with lenalidomide at low concentrations, uneffective in monotherapy. In these animals, a decrease of the percentage of CD19+leukemic cells was observed in all lymphoid and non-lymphoid tissues after 20 days of treatment, as compared to controls treated with CAR.CD23 T cells or lenalidomide alone. This combination resulted also in improved survival of the treated cohort (NT+lenalidomide vs CAR+lenalidomide: p<0.03, n=7). The effect of the combination with low dose lenalidomide was more effective also when compared to the addition of human recombinant IL-2 as in traditional immunotherapeutic settings. In accordance to the in vivo efficacy, CAR T cells were observed in all leukemic sites suggesting an ability to migrate and home in vivo. In addition, when purified from the bone marrow CD23.CAR+T cells were still able to mount a tumor-specific cytotoxic response in vitro, reaching more than 50% of tumor lysis in both the conditions with lenalidomide and IL-2, compared to 20% of tumor lysis exerted by unmanipulated T cells. Indeed, ex vivo T cells were for the majority effector memory cells and the CD23.CAR was still expressed on their surface. These results conceivably support the use in the CLL therapeutical setting of low doses lenalidomide to improve CARs cytotoxic response and avoid the potential impairment of an effective immune response. Disclosures: No relevant conflicts of interest to declare.

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A novel T-cell bispecific antibody platform for efficient T-cell mediated killing of tumor cells with minimal cytokine release.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.5_suppl.209 ◽

2018 ◽

Vol 36 (5_suppl) ◽

pp. 209-209 ◽

Cited By ~ 1

Author(s):

Udaya Rangaswamy ◽

Andrew Boudreau ◽

Ben Buelow ◽

Starlynn Clarke ◽

Kevin Dang ◽

...

Keyword(s):

T Cell ◽

Tumor Cells ◽

Tumor Antigen ◽

Bispecific Antibodies ◽

Antigen Binding ◽

Human Pbmcs ◽

Cytokine Release ◽

In Vivo Efficacy

209 Background: Bispecific antibodies that recruit cytotoxic T cells to kill tumor cells are popular due to their targeted mechanism of action. Despite their attractiveness, there are limitations in the clinic due to undesirable toxicities associated with cytokine release. We describe here a platform for generation of a large collection of human anti-CD3 antibodies obtained from custom transgenic rats. Combining these unique anti-CD3 arms with different tumor targeting arms enables creation of bispecific antibodies of varying tumor cell killing capability. These anti-CD3 arms were combined with tumor antigen binding arms, namely, an anti-BCMA arm for multiple myeloma therapy, or an anti-CD22 arm for B-cell acute lymphoblastic leukemia therapy. Methods: Our platform utilizes a discovery approach involving antibody repertoire deep sequencing, high-throughput gene assembly, and recombinant expression, generating a highly diverse panel of antibodies with varying affinities. The CD3 antibodies were tested in in vitro T cell assays using human PBMCs to measure activation and cytokine release. Bispecific antibodies were evaluated for their ability to kill target cell lines upon co-culture with primary human PBMCs. The in vivo efficacy of bispecific antibodies was evaluated in a xenograft mouse model. Results: The in vitro T cell activity of these antibodies as measured by interleukin-2, interferon gamma levels and upregulation of the activation marker CD69 covered a broad spectrum of EC50 values. In co-culture systems with human PBMCs, anti-BCMA or anti-CD22 bispecific antibodies potently killed their respective target expressing cells with varying strengths. Additionally, the cytokine release from T cell activation correlated with the affinity of the anti-CD3 arms. The in vivo efficacy of the bispecific antibodies in a xenograft model with human PBMCs transferred into NSG mice showed striking tumor clearance at a wide range of doses. Conclusions: Our platform is highly suitable for creation of an extensive collection of bispecific antibodies for a variety of disease models by selecting the ideal anti-CD3 arm for each unique tumor antigen binding arm.

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