RESUMO
The use of T-cell engagers (TCEs) to treat solid tumors is challenging, and several have been limited by narrow therapeutic windows due to substantial on-target, off-tumor toxicities due to the expression of low levels of target antigens on healthy tissues. Here, we describe TNB-928B, a fully human TCE that has a bivalent binding arm for folate receptor alpha (FRα) to selectively target FRα overexpressing tumor cells while avoiding the lysis of cells with low levels of FRα expression. The bivalent design of the FRα binding arm confers tumor selectivity due to low-affinity but high-avidity binding to high FRα antigen density cells. TNB-928B induces preferential effector T-cell activation, proliferation, and selective cytotoxic activity on high FRα expressing cells while sparing low FRα expressing cells. In addition, TNB-928B induces minimal cytokine release compared to a positive control TCE containing OKT3. Moreover, TNB-928B exhibits substantial ex vivo tumor cell lysis using endogenous T-cells and robust tumor clearance in vivo, promoting T-cell infiltration and antitumor activity in mouse models of ovarian cancer. TNB-928B exhibits pharmacokinetics similar to conventional antibodies, which are projected to enable favorable administration in humans. TNB-928B is a novel TCE with enhanced safety and specificity for the treatment of ovarian cancer.
Assuntos
Anticorpos Biespecíficos , Neoplasias Ovarianas , Animais , Anticorpos Biespecíficos/uso terapêutico , Carcinoma Epitelial do Ovário , Feminino , Receptor 1 de Folato/metabolismo , Receptor 1 de Folato/uso terapêutico , Humanos , Camundongos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Linfócitos TRESUMO
The use of recombinant interleukin-2 (IL-2) as a therapeutic protein has been limited by significant toxicities despite its demonstrated ability to induce durable tumor-regression in cancer patients. The adverse events and limited efficacy of IL-2 treatment are due to the preferential binding of IL-2 to cells that express the high-affinity, trimeric receptor, IL-2Rαßγ such as endothelial cells and T-regulatory cells, respectively. Here, we describe a novel bispecific heavy-chain only antibody which binds to and activates signaling through the heterodimeric IL-2Rßγ receptor complex that is expressed on resting T-cells and NK cells. By avoiding binding to IL-2Rα, this molecule circumvents the preferential T-reg activation of native IL-2, while maintaining the robust stimulatory effects on T-cells and NK-cells in vitro. In vivo studies in both mice and cynomolgus monkeys confirm the molecule's in vivo biological activity, extended pharmacodynamics due to the Fc portion of the molecule, and enhanced safety profile. Together, these results demonstrate that the bispecific antibody is a safe and effective IL-2R agonist that harnesses the benefits of the IL-2 signaling pathway as a potential anti-cancer therapy.
Assuntos
Anticorpos Biespecíficos/farmacologia , Antineoplásicos Imunológicos/farmacologia , Subunidade gama Comum de Receptores de Interleucina/agonistas , Subunidade beta de Receptor de Interleucina-2/agonistas , Linfócitos/efeitos dos fármacos , Animais , Células CHO , Cricetulus , Avaliação Pré-Clínica de Medicamentos , Células HEK293 , Humanos , Subunidade gama Comum de Receptores de Interleucina/imunologia , Subunidade beta de Receptor de Interleucina-2/imunologia , Macaca fascicularis , Masculino , Camundongos Endogâmicos BALB CRESUMO
The therapeutic potential of targeting CD19 in B cell malignancies has garnered attention in the past decade, resulting in the introduction of novel immunotherapy agents. Encouraging clinical data have been reported for T cell-based targeting agents, such as anti-CD19/CD3 bispecific T-cell engager blinatumomab and chimeric antigen receptor (CAR)-T therapies, for acute lymphoblastic leukemia and B cell non-Hodgkin lymphoma (B-NHL). However, clinical use of both blinatumomab and CAR-T therapies has been limited due to unfavorable pharmacokinetics (PK), significant toxicity associated with cytokine release syndrome and neurotoxicity, and manufacturing challenges. We present here a fully human CD19xCD3 bispecific antibody (TNB-486) for the treatment of B-NHL that could address the limitations of the current approved treatments. In the presence of CD19+ target cells and T cells, TNB-486 induces tumor cell lysis with minimal cytokine release, when compared to a positive control. In vivo, TNB-486 clears CD19+ tumor cells in immunocompromised mice in the presence of human peripheral blood mononuclear cells in multiple models. Additionally, the PK of TNB-486 in mice or cynomolgus monkeys is similar to conventional antibodies. This new T cell engaging bispecific antibody targeting CD19 represents a novel therapeutic that induces potent T cell-mediated tumor-cell cytotoxicity uncoupled from high levels of cytokine release, making it an attractive candidate for B-NHL therapy.
Assuntos
Anticorpos Biespecíficos/farmacologia , Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos Imunológicos/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Citocinas/metabolismo , Citotoxicidade Imunológica/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Linfoma não Hodgkin/tratamento farmacológico , Animais , Anticorpos Biespecíficos/farmacocinética , Anticorpos Monoclonais Humanizados/farmacocinética , Antígenos CD19/imunologia , Antineoplásicos Imunológicos/farmacocinética , Complexo CD3/antagonistas & inibidores , Complexo CD3/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Técnicas de Cocultura , Humanos , Células K562 , Linfoma não Hodgkin/imunologia , Linfoma não Hodgkin/metabolismo , Macaca fascicularis , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We have developed an oncolytic Newcastle disease virus (NDV) that has potent in vitro and in vivo anti-tumor activities and attenuated pathogenicity in chickens. In this ex vivo study using the same recombinant NDV backbone with GFP transgene (NDV-GFP, designated as rNDV), we found that rNDV induces maturation of monocyte-derived immature dendritic cells (iDCs) by both direct and indirect mechanisms, which promote development of antigen-specific T cell responses. Addition of rNDV directly to iDCs culture induced DC maturation, as demonstrated by the increased expression of costimulatory and antigen-presenting molecules as well as the production of type I interferons (IFNs). rNDV infection of the HER-2 positive human breast cancer cell line (SKBR3) resulted in apoptotic cell death, release of proinflammatory cytokines, and danger-associated molecular pattern molecules (DAMPs) including high-mobility group protein B1 (HMGB1) and heat shock protein 70 (HSP70). Addition of rNDV-infected SKBR3 cells to iDC culture resulted in greatly enhanced upregulation of the maturation markers and release of type I IFNs by DCs than rNDV-infected DCs only. When co-cultured with autologous T cells, DCs pre-treated with rNDV-infected SKBR3 cells cross-primed T cells in an antigen-specific manner. Altogether, our data strongly support the potential of oncolytic NDV as efficient therapeutic agent for cancer treatment.
Assuntos
Apresentação Cruzada , Células Dendríticas/imunologia , Imunoterapia/métodos , Neoplasias/terapia , Terapia Viral Oncolítica/métodos , Animais , Chlorocebus aethiops , Técnicas de Cocultura , Células Dendríticas/metabolismo , Feminino , Células HeLa , Humanos , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Neoplasias/imunologia , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/imunologia , Vírus Oncolíticos/genética , Vírus Oncolíticos/imunologia , RNA/administração & dosagem , RNA/genética , RNA Viral/administração & dosagem , RNA Viral/genética , Linfócitos T/imunologia , Células VeroRESUMO
T-cell-recruiting bispecific antibodies (T-BsAbs) have shown potent tumor killing activity in humans, but cytokine release-related toxicities have affected their clinical utility. The use of novel anti-CD3 binding domains with more favorable properties could aid in the creation of T-BsAbs with improved therapeutic windows. Using a sequence-based discovery platform, we identified new anti-CD3 antibodies from humanized rats that bind to multiple epitopes and elicit varying levels of T-cell activation. In T-BsAb format, 12 different anti-CD3 arms induce equivalent levels of tumor cell lysis by primary T-cells, but potency varies by a thousand-fold. Our lead CD3-targeting arm stimulates very low levels of cytokine release, but drives robust tumor antigen-specific killing in vitro and in a mouse xenograft model. This new CD3-targeting antibody underpins a next-generation T-BsAb platform in which potent cytotoxicity is uncoupled from high levels of cytokine release, which may lead to a wider therapeutic window in the clinic.
Assuntos
Anticorpos Biespecíficos/metabolismo , Anticorpos Monoclonais/metabolismo , Complexo CD3/imunologia , Neoplasias/terapia , Linfócitos T/imunologia , Animais , Animais Endogâmicos , Antígenos de Neoplasias/imunologia , Citocinas/metabolismo , Citotoxicidade Imunológica , Feminino , Humanos , Células Jurkat , Ativação Linfocitária , Camundongos , Neoplasias/imunologia , Ratos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We created a novel transgenic rat that expresses human antibodies comprising a diverse repertoire of heavy chains with a single common rearranged kappa light chain (IgKV3-15-JK1). This fixed light chain animal, called OmniFlic, presents a unique system for human therapeutic antibody discovery and a model to study heavy chain repertoire diversity in the context of a constant light chain. The purpose of this study was to analyze heavy chain variable gene usage, clonotype diversity, and to describe the sequence characteristics of antigen-specific monoclonal antibodies (mAbs) isolated from immunized OmniFlic animals. Using next-generation sequencing antibody repertoire analysis, we measured heavy chain variable gene usage and the diversity of clonotypes present in the lymph node germinal centers of 75 OmniFlic rats immunized with 9 different protein antigens. Furthermore, we expressed 2,560 unique heavy chain sequences sampled from a diverse set of clonotypes as fixed light chain antibody proteins and measured their binding to antigen by ELISA. Finally, we measured patterns and overall levels of somatic hypermutation in the full B-cell repertoire and in the 2,560 mAbs tested for binding. The results demonstrate that OmniFlic animals produce an abundance of antigen-specific antibodies with heavy chain clonotype diversity that is similar to what has been described with unrestricted light chain use in mammals. In addition, we show that sequence-based discovery is a highly effective and efficient way to identify a large number of diverse monoclonal antibodies to a protein target of interest.
Assuntos
Anticorpos Monoclonais/imunologia , Descoberta de Drogas/métodos , Genes de Cadeia Pesada de Imunoglobulina/genética , Genes de Cadeia Leve de Imunoglobulina/genética , Cadeias kappa de Imunoglobulina/imunologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/uso terapêutico , Antígenos/administração & dosagem , Antígenos/imunologia , Linfócitos B/imunologia , Centro Germinativo/citologia , Centro Germinativo/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias kappa de Imunoglobulina/genética , Modelos Animais , Ratos , Ratos Sprague-Dawley , Ratos TransgênicosRESUMO
Newcastle disease virus (NDV) is an oncolytic virus being developed for the treatment of cancer. Following infection of a human ovarian cancer cell line (OVCAR3) with a recombinant low-pathogenic NDV, persistent infection was established in a subset of tumor cells. Persistently infected (PI) cells exhibited resistance to superinfection with NDV and established an antiviral state, as demonstrated by upregulation of interferon and interferon-induced genes such as myxoma resistance gene 1 (Mx1) and retinoic acid-inducing gene-I (RIG-I). Viruses released from PI cells induced higher cell-to-cell fusion than the parental virus following infection in two tumor cell lines tested, HT1080 and HeLa, and remained attenuated in chickens. Two mutations, one in the fusion (F) protein cleavage site, F117S (F117S), and another in hemagglutinin-neuraminidase (HN), G169R (HN169R), located in the second sialic acid binding region, were responsible for the hyperfusogenic phenotype. F117S improves F protein cleavage efficiency, facilitating cell-to-cell fusion, while HN169R possesses a multifaceted role in contributing to higher fusion, reduced receptor binding, and lower neuraminidase activity, which together result in increased fusion and reduced viral replication. Thus, establishment of persistent infection in vitro involves viral genetic changes that facilitate efficient viral spread from cell to cell as a potential mechanism to escape host antiviral responses. The results of our study also demonstrate a critical role in the viral life cycle for the second receptor binding region of the HN protein, which is conserved in several paramyxoviruses.IMPORTANCE Oncolytic Newcastle disease virus (NDV) could establish persistent infection in a tumor cell line, resulting in a steady antiviral state reflected by constitutively expressed interferon. Viruses isolated from persistently infected cells are highly fusogenic, and this phenotype has been mapped to two mutations, one each in the fusion (F) and hemagglutinin-neuraminidase (HN) proteins. The F117S mutation in the F protein cleavage site improved F protein cleavage efficiency while the HN169R mutation located at the second receptor binding site of the HN protein contributed to a complex phenotype consisting of a modest increase in fusion and cell killing, lower neuraminidase activity, and reduced viral growth. This study highlights the intricate nature of these two mutations in the glycoproteins of NDV in the establishment of persistent infection. The data also shed light on the critical balance between the F and HN proteins required for efficient NDV infection and their role in avian pathogenicity.
Assuntos
Proteína HN/metabolismo , Vírus da Doença de Newcastle/crescimento & desenvolvimento , Proteínas Virais de Fusão/metabolismo , Animais , Sítios de Ligação , Fusão Celular , Linhagem Celular Tumoral , Galinhas , Proteína HN/genética , Humanos , Mutação de Sentido Incorreto , Ácido N-Acetilneuramínico/metabolismo , Ligação Proteica , Proteínas Virais de Fusão/genéticaRESUMO
Newcastle disease virus (NDV) is being developed as an oncolytic virus for virotherapy. In this study we analysed the regulation of complement-mediated inactivation of a recombinant NDV in different host cells. NDV grown in human cells was less sensitive to complement-mediated virus inactivation than NDV grown in embryonated chicken eggs. Additionally, NDV produced from HeLa-S3 cells is more resistant to complement than NDV from 293F cells, which correlated with higher expression and incorporation of complement regulatory proteins (CD46, CD55 and CD59) into virions from HeLa-S3 cells. Further analysis of the recombinant NDVs individually expressing the three CD molecules showed that CD55 is the most potent in counteracting complement-mediated virus inactivation. The results provide important information on selecting NDV manufacture substrate to mitigate complement-mediated virus inactivation.
Assuntos
Antígenos CD55/metabolismo , Proteínas Inativadoras do Complemento/metabolismo , Proteínas do Sistema Complemento/metabolismo , Interações Hospedeiro-Patógeno , Fatores Imunológicos/metabolismo , Vírus da Doença de Newcastle/imunologia , Vírus da Doença de Newcastle/fisiologia , Animais , Antígenos CD59/metabolismo , Linhagem Celular , Galinhas , Humanos , Proteína Cofatora de Membrana/metabolismoRESUMO
A common strategy shared by all known gammaherpesviruses is their ability to establish a latent infection in lymphocytes--predominantly in B cells. In immunocompromised patients, such as transplant recipients or AIDS patients, gammaherpesvirus infections can lead to the development of lymphoproliferative disease and lymphoid malignancies. The human gamma-herpesviruses, EBV and KSHV, encode proteins that are capable of modulating the host immune signaling machinery, thereby subverting host immune responses. Murine gamma-herpesvirus 68 (MHV68) infection of laboratory strains of mice has proven to be useful small-animal model that shares important pathogenic strategies with the human gamma-herpesviruses. The MHV68 M2 protein is known to manipulate B cell signaling and, dependent on route and dose of virus inoculation, plays a role in both the establishment of latency and virus reactivation. M2 contains two tyrosines that are targets for phosphorylation, and have been shown to interact with the B cell signaling machinery. Here we describe in vitro and in vivo studies of M2 mutants which reveals that while both tyrosines Y120 and Y129 are required for M2 induction of IL-10 expression from primary murine B cells in vitro, only Y129 is critical for reactivation from latency and plasma cell differentiation in vivo.
Assuntos
Gammaherpesvirinae/fisiologia , Infecções por Herpesviridae/virologia , Proteínas Virais/metabolismo , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos B/virologia , Diferenciação Celular/imunologia , Infecções por Herpesviridae/imunologia , Interleucina-10/biossíntese , Ativação Linfocitária/imunologia , Camundongos , Mutação , Fosforilação , Plasmócitos/imunologia , Plasmócitos/metabolismo , Plasmócitos/virologia , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais , Tirosina/química , Proteínas Virais/química , Proteínas Virais/genética , Ativação Viral , Latência ViralRESUMO
Reactivation of the gammaherpesviruses Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV) and murine gammaherpesvirus 68 (MHV68) from latently infected B cells has been linked to plasma cell differentiation. We have previously shown that the MHV68 M2 protein is important for virus reactivation from B cells and, when expressed alone in primary murine B cells, can drive B cell differentiation towards a pre-plasma cell phenotype. In addition, expression of M2 in primary murine B cells leads to secretion of high levels of IL-10 along with enhanced proliferation and survival. Furthermore, the absence of M2 in vivo leads to a defect in the appearance of MHV68 infected plasma cells in the spleen at the peak of MHV68 latency. Here, employing an inducible B cell expression system, we have determined that M2 activates the NFAT pathway in a Src kinase-dependent manner--leading to induction of the plasma cell-associated transcription factor, Interferon Regulatory Factor-4 (IRF4). Furthermore, we show that expression of IRF4 alone in a B cell line up-regulates IL-10 expression in culture supernatants, revealing a novel role for IRF4 in B cell induced IL-10. Consistent with the latter observation, we show that IRF4 can regulate the IL-10 promoter in B cells. In primary murine B cells, addition of cyclosporine (CsA) resulted in a significant decrease in M2-induced IL-10 levels as well as IRF4 expression, emphasizing the importance of the NFAT pathway in M2- -mediated induction of IL-10. Together, these studies argue in favor of a model wherein M2 activation of the NFAT pathway initiates events leading to increased levels of IRF4--a key player in plasma cell differentiation--which in turn triggers IL-10 expression. In the context of previous findings, the data presented here provides insights into how M2 facilitates plasma cell differentiation and subsequent virus reactivation.