RESUMO
BACKGROUND: Despite remarkable progress, the immunotherapies currently used in the clinic, such as immune checkpoint blockade (ICB) therapy, still have limited efficacy against many types of solid tumors. One major barrier to effective treatment is the lack of a durable long-term response. Tumor-targeted superantigen (TTS) therapy may overcome this barrier to enhance therapeutic efficacy. TTS proteins, such as the clinical-stage molecule naptumomab estafenatox (NAP), increase tumor recognition and killing by both coating tumor cells with bacterial-derived superantigens (SAgs) and selectively expanding T-cell lineages that can recognize them. The present study investigated the efficacy and mechanism of action of repeated TTS (C215Fab-SEA) treatments leading to a long-term antitumor immune response as monotherapy or in combination with PD-1/PD-L1 inhibitors in murine tumor models. METHODS: We used syngeneic murine tumor models expressing the human EpCAM target (C215 antigen) to assess the efficacy and mechanism of action of repeated treatment with TTS C215Fab-SEA alone or with anti-PD-1/PD-L1 monoclonal antibodies. Tumor draining lymph nodes (TDLNs) and tumor tissues were processed and analyzed by immunophenotyping and immunohistochemistry. Isolated RNA from tumors was used to analyze gene expression and the TCR repertoire. Tumor rechallenge and T-cell transfer studies were conducted to test the long-term antitumor memory response. RESULTS: TTS therapy inhibited tumor growth and achieved complete tumor rejection, leading to a T-cell-dependent long-term memory response against the tumor. The antitumor effect was derived from inflammatory responses converting the immunosuppressive TME into a proinflammatory state with an increase in T-cell infiltration, activation and high T-cell diversity. The combination of TTS with ICB therapy was significantly more effective than the monotherapies and resulted in higher tumor-free rates. CONCLUSIONS: These new results indicate that TTSs not only can turn a "cold" tumor into a "hot" tumor but also can enable epitope spreading and memory response, which makes TTSs ideal candidates for combination with ICB agents and other anticancer agents.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Animais , Camundongos , Superantígenos/uso terapêutico , Linfócitos T , Neoplasias/patologia , Antineoplásicos/farmacologia , Imunoterapia , Microambiente Tumoral , Linhagem Celular TumoralRESUMO
Two signals are required for induction of cell proliferation and cytokine production in resting T cells. Occupancy of the T cell receptor by antigen/MHC complexes delivers the first signal to the T cell, while the second signal is provided by interaction with costimulatory ligands on APC. CD2, LFA-1, and CD28 are the major costimulatory and adhesive molecules on T cells and bind to the LFA-3, ICAM-1 and B7 ligands, respectively, on APC. LFA-3 plays a central role for naive and memory T helper cells during the early phase of an immune response. The LFA-3/CD2 pathway initiates strong antigen-independent cell adhesion, substantial expansion of naive T helper cells, and induction of large amounts of IFN-γ in memory cells. The release of IFN-γ may upregulate expression of ICAM-1 and B7 on APC and allows multiple adhesion pathways to amplify the immune response. The LFA- 1/ICAM-l pathway stimulates adhesion and cell proliferation more efficiently in memory T helper cells than in naive cells. Further, the results suggest that naive T helper cells express functionally inactive LFA-1 molecules on the cell surface, which may have a physiological role in keeping these cells in a resting state. B7 costimulation superinduces IL-2 production in both naive and memory T helper cells and generates long-lasting cell proliferation. This permits transition from an autocrine to a paracrine immune response. Coexpression of B7/LFA-3 provides an optimal APC function and enables a vigorous T cell response to minute amounts of antigen. AP-1 and NF-κB transcription factors are involved in the induction of several cytokine gene promoters and play a central role in the regulation of IL-2 gene transcription. LFA-3 costimulation only moderately enhances AP-1 DNA-binding activity and does not influence the NF-κB activity induced by TCR engagement, whereas B7 costimulation induces large amounts of NF-κB and AP-1 activity in T helper cells. The costimulatory ligands represent a family of adhesion molecules with considerable redundancy. Interfamily redundancy of LFA-3, B7, and ICAM ligands offers an opportunity to regulate distinct T cell response profiles in various microenvironments at separate time points of an immune response.
Assuntos
Antígenos B7/metabolismo , Antígenos CD58/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Antígenos B7/imunologia , Antígenos CD58/imunologia , Adesão Celular/imunologia , Proliferação de Células , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Imunidade Celular , Memória Imunológica/imunologia , Molécula 1 de Adesão Intercelular/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais/imunologia , Linfócitos T/metabolismoRESUMO
Improvement of cancer therapy by introducing new concepts is still urgent even though there have been major advancements lately. Immunotherapy is well on the way to becoming an established tool in the cancer treatment armory. It seems that a combination of (1) activation of immune effector cells and selective targeting of them to tumors and (2) the inhibition of immune suppression often induced by the tumor itself are necessary to achieve the therapeutic goal. The immunotoxin naptumomab estafenatox was developed in an effort to activate and target the patient's own T cells to their tumor, by fusing a superantigen (SAg) variant that activates T lymphocytes to the Fab moiety of a tumor-reactive monoclonal antibody. Naptumomab estafenatox targets the 5T4 tumor antigen, a 72-kDa oncofetal trophoblast protein expressed on many carcinomas, including renal cell carcinoma. The therapeutic effect is associated with activation of SAg-binding T cells. The SAg-binding T lymphocytes expand, differentiate to effector cells, and infiltrate the tumor. The therapeutic efficacy is most likely related to the dual mechanism of tumor cell killing: (1) direct lysis by cytotoxic T lymphocytes of tumor cells expressing the antigen recognized by the antibody moiety of the fusion protein and (2) secretion of cytokines eliminating antigen-negative tumor cell variants. Naptumomab estafenatox has been clinically tested in a range of solid tumors with focus on renal cell carcinoma. This review looks at the clinical experience with the new immunotoxin and its potential.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Enterotoxinas/uso terapêutico , Imunoconjugados/uso terapêutico , Imunoterapia/métodos , Neoplasias/tratamento farmacológico , Superantígenos/uso terapêutico , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Ensaios Clínicos como Assunto , Enterotoxinas/farmacologia , Humanos , Imunoconjugados/farmacologia , Neoplasias/imunologia , Superantígenos/farmacologia , Linfócitos T/efeitos dos fármacosRESUMO
In this study we explored the possibility of improving the anti-tumor potency of tumor-targeted superantigens (TTS) by combination treatment with interferon-alpha (IFN-alpha). TTS utilizes the powerful T cell activating property of the superantigen staphylococcal enterotoxin A (SEA) in fusion with an anti-tumor Fab-fragment to target this T cell activity against tumor cells. TTS fusion proteins have shown anti-tumor efficacy in a number of experimental tumor models including the B16 mouse melanoma transfected with a human tumor-associated antigen recognized by the C215 monoclonal antibody. IFN-alpha is approved for the treatment of solid tumors such as renal cell carcinoma and malignant melanoma and exerts immunomodulatory effects, which make it an appropriate candidate to combine with immunotherapy against cancer. Here we report that daily administration of IFN-alpha (20 000 U i.p.) enhances and sustains CD8+ T cell activation induced by the TTS C215Fab-SEA (10 microg i.v.) in C57Bl/6 mice, as reflected by increased and prolonged cell-mediated cytotoxicity against tumor cells ex vivo as well as by augmented serum IFN-gamma levels. C215Fab-SEA synergized with IFN-alpha in reducing the number of lung tumors in B16-C215 melanoma bearing mice as compared to mono therapy. In a long term tumor survival experiment, the prolonged median survival time of the combination treatment was 3.5 and 7.7 times the prolonged median survival times of C215Fab-SEA and IFN-alpha monotherapies, respectively. Hence, the combination treatment provoked synergistic anti-tumor effects as measured by the number of lung tumors and markedly prolonged survival. The enhanced therapeutic efficacy correlated with a striking and sustained increase of CD8- and perforin-expressing tumor-infiltrating cells. These results suggest significant potential of combining TTS with IFN-alpha for human cancer therapy.
Assuntos
Enterotoxinas/administração & dosagem , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Interferon-alfa/administração & dosagem , Melanoma Experimental/terapia , Superantígenos/administração & dosagem , Animais , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Feminino , Interferon gama/biossíntese , Linfócitos do Interstício Tumoral/imunologia , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Citotóxicos/imunologiaRESUMO
PURPOSE: To prospectively determine the efficacy of naptumomab estafenatox (Nap) + IFNα versus IFN in metastatic renal cell carcinoma (RCC). EXPERIMENTAL DESIGN: In a randomized, open-label, multicenter, phase II/III study, 513 patients with RCC received Nap (15 µg/kg i. v. in three cycles of four once-daily injections) + IFN (9 MU s.c. three times weekly), or the same regimen of IFN monotherapy. The primary endpoint was overall survival (OS). RESULTS: This phase II/III study did not meet its primary endpoint. Median OS/PFS for Nap + IFN patients was 17.1/5.8 months versus 17.5/5.8 months for the patients receiving IFN alone (P = 0.56; HR, 1.08/P = 0.41; HR, 0.92). Post hoc exploratory subgroup and trend analysis revealed that the baseline plasma concentrations of anti-SEA/E-120 (anti-Nap antibodies) for drug exposure and IL6 for immune status could be used as predictive biomarkers. A subgroup of patients (SG; n = 130) having concentrations below median of anti-SEA/E-120 and IL6 benefitted greatly from the addition of Nap. In SG, median OS/PFS for the patients treated with Nap + IFN was 63.3/13.7 months versus 31.1/5.8 months for the patients receiving IFN alone (P = 0.02; HR, 0.59/P = 0.02; HR, 0.62). Addition of Nap to IFN showed predicted and transient immune related AEs and the treatment had an acceptable safety profile. CONCLUSIONS: The study did not meet its primary endpoint. Nap + IFN has an acceptable safety profile, and results from post hoc subgroup analyses showed that the treatment might improve OS/PFS in a baseline biomarker-defined RCC patient subgroup. The results warrant further studies with Nap in this subgroup. Clin Cancer Res; 22(13); 3172-81. ©2016 AACR.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Enterotoxinas/uso terapêutico , Imunoconjugados/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos/sangue , Anticorpos Monoclonais/efeitos adversos , Antineoplásicos/efeitos adversos , Biomarcadores/sangue , Intervalo Livre de Doença , Enterotoxinas/efeitos adversos , Enterotoxinas/imunologia , Feminino , Humanos , Imunoconjugados/efeitos adversos , Interferon-alfa/efeitos adversos , Interferon-alfa/uso terapêutico , Interleucina-6/sangue , Masculino , Pessoa de Meia-IdadeRESUMO
Naptumomab estafenatox/ABR-217620/ANYARA (Nap) has been evaluated in clinical phase 1 and 2/3 studies. RCC patients in the phase 2/3 trial were randomized 1:1 in an open label study to receive Nap+IFN-α or IFN-α. In this study, we analyzed the UK patients for their immunological response in relation to prolonged overall survival (OS). We found that Nap-specific T cells were reduced after 3 treatment days in patients' peripheral blood. Levels of both Nap-specific CD4+ and CD8+ T cells were significantly higher 8 days after the first treatment. Patients with such pattern of reduction and expansion of Nap-binding T cells also showed increased levels of IL-2 and IFN-γ in plasma 3 hours after the first Nap treatment. In addition, Nap caused an increase of IL-6, IL-10 and TNF-α. The patients in the UK subset showed a tendency of OS benefit after Nap treatment. Most Nap treated patients with long OS had low baseline IL-6 and normal levels of anti-SEA/E-120 antibodies. Furthermore, patients with pronounced Nap induced IL-2 and T cell expansion had long OS. In conclusion, patients with low baseline IL-6 and normal anti-SEA/E-120 may respond well to Nap by T cell activation and expansion paving the way for anti-tumour effects.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Enterotoxinas/uso terapêutico , Imunoconjugados/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Subpopulações de Linfócitos T/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/mortalidade , Feminino , Citometria de Fluxo , Humanos , Interferon-alfa/uso terapêutico , Interleucina-6/sangue , Estimativa de Kaplan-Meier , Neoplasias Renais/imunologia , Neoplasias Renais/mortalidade , Masculino , Pessoa de Meia-Idade , Linfócitos T/efeitos dos fármacos , Adulto JovemRESUMO
Roquinimex-related 3-quinolinecarboxamide derivatives were prepared and evaluated for treatment of autoimmune disorders. The compounds were tested in mice for their inhibitory effects on disease development in the acute experimental autoimmune encephalomyelitis model and selected compounds in the beagle dog for induction of proinflammatory reaction. Structure-activity relationships are discussed. Compound 8c, laquinimod, showed improved potency and superior toxicological profile compared to the lead compound roquinimex (1b, Linomide) and was selected for clinical studies (currently in phase II).
Assuntos
Adjuvantes Imunológicos/síntese química , Doenças Autoimunes/tratamento farmacológico , Quinolonas/síntese química , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Animais , Cães , Encefalomielite Autoimune Experimental/tratamento farmacológico , Feminino , Hidroxiquinolinas/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Quinolonas/química , Quinolonas/uso terapêutico , Relação Estrutura-AtividadeRESUMO
A new orally active drug, laquinimod (ABR-215062), was shown to completely inhibit the development of murine acute experimental autoimmune encephalomyelitis (EAE). Furthermore, leukocyte infiltration into the central nervous system (CNS) was abolished in the laquinimod-treated animals. By direct comparison based on dose and total exposure, laquinimod was approximately 20 times more potent than the immunomodulator roquinimex. Laquinimod also had clear therapeutic effect when given after clinical onset in a chronic relapsing EAE model. It therefore represents a new orally active immunoregulatory drug without general immunosuppressive properties for the treatment of the autoimmune disease multiple sclerosis.
Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/prevenção & controle , Hidroxiquinolinas/farmacologia , Esclerose Múltipla/tratamento farmacológico , Neuroimunomodulação/efeitos dos fármacos , Adjuvantes Imunológicos/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Células Cultivadas , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/fisiopatologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Quimiotaxia de Leucócito/imunologia , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Encefalomielite Autoimune Experimental/imunologia , Feminino , Terapia de Imunossupressão , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/imunologia , Esclerose Múltipla/fisiopatologia , Neuroimunomodulação/imunologia , Quinolonas , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
The new orally active drug laquinimod (ABR-215062) was evaluated in experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. EAE shares important immunological and clinical features with multiple sclerosis (MS). Doses of 16, 1.6 and 0.16 mg/kg/day laquinimod dose-dependently inhibited disease and showed better disease inhibitory effects as compared to roquinimex (Linomide). Furthermore, laquinimod inhibited the inflammation of both CD4+ T cells and macrophages into central nervous tissues, i.e. the spinal cord. It also changed the cytokine balance in favour of TH2/TH3 cytokines IL-4, IL-10 and TGF-beta. Laquinimod therefore represents a new orally active immunoregulatory drug without general immunosuppressive properties with a potential for the treatment of severe autoimmune diseases like MS.
Assuntos
Encefalomielite Autoimune Experimental/prevenção & controle , Hidroxiquinolinas/uso terapêutico , Células Th1/efeitos dos fármacos , Células Th2/efeitos dos fármacos , Fator de Crescimento Transformador beta/biossíntese , Animais , Citocinas/biossíntese , Encefalomielite Autoimune Experimental/sangue , Encefalomielite Autoimune Experimental/imunologia , Feminino , Hidroxiquinolinas/farmacologia , Quinolonas , Ratos , Ratos Endogâmicos Lew , Células Th1/imunologia , Células Th1/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Fator de Crescimento Transformador beta/imunologiaRESUMO
The immunomodulator Linomide has been shown to protect against septic liver injury by reducing hepatic accumulation of leukocytes although the detailed anti-inflammatory mechanisms remain elusive. This study examined the effect of Linomide on the production of CXC chemokines, including macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (KC) and interleukin-10 (IL-10) in lipopolysaccharide (LPS)/d-galactosamine (Gal)-induced liver injury in mice. It was found that pretreatment with 300 mg kg(-1) of Linomide markedly suppressed leukocyte recruitment, perfusion failure, and hepatocellular damage and apoptosis in the liver of endotoxemic mice. Administration of Linomide inhibited endotoxin-induced gene expression of MIP-2 and KC and significantly reduced the hepatic production of MIP-2 and KC by 63 and 80%, respectively. Moreover, it was found that Linomide increased the liver content of IL-10 by more than three-fold in endotoxemic mice. The protective effect of Linomide against endotoxin-induced inflammation and liver injury was abolished in IL-10-deficient mice, suggesting that the beneficial effect of Linomide is dependent on the function of IL-10. Taken together, these novel findings suggest that the protective effect of Linomide is mediated via local upregulation of IL-10, which in turn decreases the generation of CXC chemokines and pathological recruitment of leukocytes in the liver of endotoxemic mice.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Quimiocinas CXC/biossíntese , Endotoxinas/toxicidade , Hidroxiquinolinas/farmacologia , Fatores Imunológicos/farmacologia , Interleucina-10/fisiologia , Fígado/metabolismo , Alanina Transaminase/sangue , Animais , Apoptose/efeitos dos fármacos , Aspartato Aminotransferases/sangue , Doença Hepática Induzida por Substâncias e Drogas/patologia , Quimiocina CXCL1 , Quimiocinas CXC/metabolismo , Ensaio de Imunoadsorção Enzimática , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Interleucina-10/genética , Interleucina-16/metabolismo , Leucócitos/efeitos dos fármacos , Leucócitos/fisiologia , Fígado/efeitos dos fármacos , Fígado/patologia , Testes de Função Hepática , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Linomide is an immunomodulator which has been shown to potently inhibit autoimmunity in several animal models for human autoimmune diseases, including type I diabetes in the nonobese diabetic (NOD) mouse. In this study, we investigate the basis for Linomide's protective effects in the NOD mouse by immunohistochemical and RT-PCR analysis of the phenotype and cytokine expression by cells infiltrating the islets of Langerhans in the pancreas. Linomide treatment was found to reduce the infiltration of T cells, B cells, dendritic cells (DC) and MHC class II(+) cells into the islets, but did not reduce macrophage (MPhi) infiltration. This was seen following Linomide treatment at 3-5, 4-8 and 14-24 weeks of age and thus appears to be independent of the stage of the autoreactive process and the extent of insulitis. The reduced insulitis may be due to reduced expression of adhesion molecules since decreased numbers of islet-associated blood vessels expressing CD106 and MAdCAM-1 were detected following Linomide treatment. Furthermore, short term Linomide treatment (3 or 7 days), which did not alter the number of infiltrating cells, was found to inhibit the production of TNF-alpha which is known to induce the expression of CD106 and MAdCAM-1. These results suggest that the reduced insulitis observed in Linomide-treated animals is secondary to a functional modulation of infiltrating cells.
Assuntos
Citocinas/biossíntese , Hidroxiquinolinas/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/patologia , Envelhecimento , Animais , Linfócitos B/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Citocinas/genética , Células Dendríticas/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Insulina/metabolismo , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos NOD , Linfócitos T/efeitos dos fármacos , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genéticaRESUMO
The T lymphocytes are the most important effector cells in immunotherapy of cancer. The conceptual objective for developing the tumor targeted superantigen (TTS) ABR-217620 (naptumomab estafenatox, 5T4Fab-SEA/E-120), now in phase 3 studies for advanced renal cell cancer, was to selectively coat tumor cells with cytotoxic T lymphocytes (CTL) target structures functionally similar to natural CTL pMHC target molecules. Here we present data showing that the molecular basis for the anti-tumor activity by ABR-217620 resides in the distinct interaction between the T cell receptor ß variable (TRBV) 7-9 and the engineered superantigen (Sag) SEA/E-120 in the fusion protein bound to the 5T4 antigen on tumor cells. Multimeric but not monomeric ABR-217620 selectively stains TRBV7-9 expressing T lymphocytes from human peripheral blood similar to antigen specific staining of T cells with pMHC tetramers. SEA/E-120 selectively activates TRBV7-9 expressing T lymphocytes resulting in expansion of the subset. ABR-217620 selectively triggers TRBV7-9 expressing cytotoxic T lymphocytes to kill 5T4 positive tumor cells. Furthermore, ABR-217620 activates TRBV7-9 expressing T cell line cells in the presence of cell- and bead-bound 5T4 tumor antigen. Surface plasmon resonance analysis revealed that ABR-217620 binds to 5T4 with high affinity, to TRBV7-9 with low affinity and to MHC class II with very low affinity. The T lymphocyte engagement by ABR-217620 is constituted by displaying high affinity binding to the tumor cells (KD approximately 1 nM) and with the mimicry of natural productive immune TCR-pMHC contact using affinities of around 1 µM. This difference in kinetics between the two components of the ABR-217620 fusion protein will bias the binding towards the 5T4 target antigen, efficiently activating T-cells via SEA/E-120 only when presented by the tumor cells.
Assuntos
Anticorpos Monoclonais/imunologia , Antineoplásicos/imunologia , Citotoxicidade Imunológica/imunologia , Enterotoxinas/imunologia , Imunoconjugados/imunologia , Mimetismo Molecular/imunologia , Neoplasias/imunologia , Superantígenos/imunologia , Linfócitos T/imunologia , Anticorpos Monoclonais/metabolismo , Linhagem Celular Tumoral , Clonagem Molecular , Primers do DNA/genética , Enterotoxinas/metabolismo , Citometria de Fluxo , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T/genética , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T/imunologia , Humanos , Imunoconjugados/metabolismo , Cinética , Luciferases , Glicoproteínas de Membrana/imunologia , Glicoproteínas de Membrana/metabolismo , Superantígenos/metabolismo , Ressonância de Plasmônio de SuperfícieRESUMO
Immunotherapy aiming to block immune suppression with anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) monoclonal antibodies is a recently clinically established strategy to enhance immune driven antitumor activities. To be successful, this approach depends on the existence of a suppressed immune response against the tumor that can be released by the treatment or alternatively needs to be combined with an immune-enhancing therapy. A tumor-targeted superantigen (TTS) fusion protein utilizes the strong T-cell activating property of bacterial superantigens in concert with the tumor cell binding capacity in antitumor Fab-fragments. Our purpose was to investigate the feasibility of combining anti-CTLA-4 with TTS therapy against the poorly immunogenic B16 mouse melanoma tumor transfected with the human tumor-associated antigen EpCAM recognized by the C215 monoclonal antibody. B16-EpCAM tumors growing in the lung were completely insensitive to anti-CTLA-4 monotherapy. C215Fab-SEA treatment of the B16-EpCAM tumors induced strong infiltration and targeting of both CD4(+) and CD8(+) T cells. In parallel, Foxp3(+)CTLA-4(high) regulatory T cells accumulated in the tumors. Combining activation with C215Fab-SEA and anti-CTLA-4 showed greatly enhanced antitumor effects and prolonged long-term survival. In parallel, when the expansion of regulatory T cells was inhibited, the number of specific effector T cells was enhanced and the cytotoxic T-lymphocyte activity was significantly improved. Collectively, these data emphasize the potential of combining cancer treatment using anti-CTLA-4 monoclonal antibodies with T-cell activation and directed killing by TTS therapy.
Assuntos
Antígeno CTLA-4/imunologia , Fragmentos Fab das Imunoglobulinas/imunologia , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Superantígenos/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Antígenos de Neoplasias/imunologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno CTLA-4/antagonistas & inibidores , Linhagem Celular Tumoral , Feminino , Imunoterapia , Linfócitos do Interstício Tumoral/imunologia , Melanoma Experimental/mortalidade , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
Antibody-targeted superantigens have a potential to become useful drugs for tumor therapy. However, clinical practice has identified several issues that need to be addressed to optimize such molecules. On the basis of the experience from superantigen products in clinical trials, a novel tumor-targeted superantigen, naptumomab estafenatox (5T4FabV18-SEA/E-120 or ABR-217620) has been designed. Critical properties, such as tumor reactivity, therapeutic window, and seroreactivity were all improved. The engineered 5T4Fab moiety recognizes the 5T4 antigen expressed on a large number of solid tumor forms with an affinity in the order of 1 nM. The fusion protein induces T-cell mediated killing of tumor cells at concentrations around 10 pM. Compared with a construct with a wild-type superantigen, it is more potent in mediating killing of tumor cells but a 10,000-fold less active in mediating killing of MHC class II positive cells. The target epitopes for naturally occurring antibodies toward bacterial superantigens are reduced. Only large excesses of human anti-SEA antibodies neutralize the antitumor effects of the antibody-targeted superantigen. Naptumomab estafenatox induces dramatic reduction of established human tumors in Severe Combined Immunodeficient mice grafted with human lymphocytes. Thus, naptumomab estafenatox is a novel optimized tumor-targeted superantigen currently investigated in clinical trials.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Carcinoma de Células Renais/imunologia , Enterotoxinas/administração & dosagem , Imunotoxinas/uso terapêutico , Proteínas Recombinantes de Fusão/administração & dosagem , Linfócitos T/metabolismo , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/metabolismo , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/metabolismo , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Enterotoxinas/genética , Enterotoxinas/metabolismo , Humanos , Imunoconjugados , Macaca fascicularis , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos SCID , Transplante de Neoplasias , Mutação Puntual/genética , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Superantígenos/administração & dosagem , Superantígenos/genética , Superantígenos/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
In this study we explored the possibility of combining immunotherapy against cancer with the well-established cytostatic drug docetaxel. Tumor-targeted superantigens (TTS) utilizes the powerful T cell activating property of a superantigen such as staphylococcal enterotoxin A (SEA) in fusion with an anti-tumor Fab-fragment to target this T cell activity against tumor cells. TTS fusion proteins are efficient in a number of experimental tumor models including the B16 mouse melanoma transfected with a human tumor-associated antigen (GA733-2 or EpCam) recognized by the C215 monoclonal antibody. The distinct mechanisms of action of TTS and docetaxel provide the prerequisites for successful combination treatment. However, as a result of the anti-proliferative properties of cytostatic drugs, chemotherapy may modify TTS induced immune activation during combination treatment. Here we evaluated the anti-tumor effects of combining C215Fab-SEA with docetaxel against B16-C215 tumors growing in the lung of C57Bl/6 mice. Both compounds generated a significant reduction in the number of B16-C215 lung tumors when administered alone. Prior treatment with docetaxel at therapeutic doses did not interfere with superantigen induced T cell activation but rather appeared to enhance the response, while simultaneous treatment was suppressive. Combining TTS and docetaxel significantly improved tumor therapy, further reducing the number of lung tumors as compared to mono therapies. Importantly, the combination treatment at timely settings synergistically prolonged long term survival in B16-C215 tumor bearing mice. The results of this study demonstrate that TTS immunotherapy is highly compatible with docetaxel and suggest a significant potential of the combination for human cancer therapy.
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Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Imunoterapia , Neoplasias Pulmonares/terapia , Linfoma de Células B/terapia , Melanoma Experimental/terapia , Proteínas Recombinantes de Fusão/administração & dosagem , Linfócitos T/metabolismo , Taxoides/administração & dosagem , Animais , Anticorpos Antineoplásicos/genética , Anticorpos Antineoplásicos/imunologia , Antígenos de Neoplasias/imunologia , Citotoxicidade Imunológica/efeitos dos fármacos , Docetaxel , Sinergismo Farmacológico , Enterotoxinas/genética , Enterotoxinas/imunologia , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/genética , Fragmentos Fab das Imunoglobulinas/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/secundário , Ativação Linfocitária/efeitos dos fármacos , Linfoma de Células B/imunologia , Linfoma de Células B/patologia , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/patologia , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/imunologiaRESUMO
PURPOSE: Two phase I studies were conducted of ABR-217620 alone or in combination with docetaxel. This is a recombinant fusion protein consisting of a mutated variant of the superantigen staphylococcal enterotoxin E (SEA/E-120) linked to fragment antigen binding moiety of a monoclonal antibody recognizing the tumor-associated antigen 5T4. PATIENTS AND METHODS: Patients with non-small-cell lung cancer (NSCLC), pancreatic cancer (PC), and renal cell cancer (RCC) received 5 daily boluses of ABR-217620 (3-month cycles) in escalating doses to determine the maximum-tolerated dose (MTD; ABR-217620 dose escalation monotherapy [MONO] study). Doses were selected based on individual patient anti-SEA/E-120 titers pretreatment. Patients with NSCLC received 4 daily, escalating doses of ABR-217620 followed by docetaxel in 21-day cycles (ABR-217620 dose escalation combination with docetaxel [COMBO] study). RESULTS: Thirty-nine patients were enrolled in the MONO study and 13 were enrolled in the COMBO study. The monotherapy MTD was 26 microg/kg (NSCLC and PC) and 15 microg/kg (RCC). Dose-limiting toxicities (DLTs) in the MONO study were fever, hypotension, acute liver toxicity, and vascular leak syndrome. In the COMBO study, the MTD was 22 microg/kg (neutropenic sepsis). Adverse events included grade 1 to 2 fever, hypotension, nausea, and chills. Treatment caused a systemic increase of inflammatory cytokines and selective expansion of SEA/E-120 reactive T-cells. Tumor biopsies demonstrated T-cell infiltration after therapy. Fourteen patients (36%) had stable disease (SD) on day 56 of the MONO study. Two patients (15%) in the COMBO study had partial responses, one in a patient with progressive disease on prior docetaxel, and five patients (38%) had SD on day 56. CONCLUSION: ABR-217620 was well tolerated with evidence of immunological activity and antitumor activity.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Citocinas/sangue , Docetaxel , Enterotoxinas/administração & dosagem , Europa (Continente) , Feminino , Humanos , Imunoconjugados , Neoplasias Renais/imunologia , Neoplasias Renais/patologia , Ativação Linfocitária/efeitos dos fármacos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Proteínas Recombinantes de Fusão/administração & dosagem , Taxoides/administração & dosagem , Fatores de Tempo , Resultado do Tratamento , Estados UnidosRESUMO
BACKGROUND/AIMS: Linomide is an immunomodulator that ameliorates several autoimmune and inflammatory diseases. We assessed the effect of Linomide on microvascular perfusion failure, leukocyte recruitment and hepatocellular injury induced by tumor necrosis factor alpha (TNF-alpha) and D-Galactosamine (Gal). METHODS: After 3 days of Linomide pretreatment (1, 10 and 100 mg/kg/day), rats were challenged with TNF-alpha/Gal for 24 h. Microvascular perfusion, leukocyte-endothelium interactions in hepatic postsinusoidal venules and leukocyte sequestration in sinusoids were evaluated using intravital microscopy. Liver enzymes were measured spectrophotometrically. RESULTS: Challenge with TNF-alpha/Gal significantly reduced sinusoidal perfusion, and increased leukocyte rolling, adhesion and liver enzymes. Interestingly, pretreatment with Linomide (10 and 100 mg/kg/day) significantly reduced TNF-alpha/Gal-induced leukocyte rolling by 65 and 63%, and leukocyte adhesion by 87 and 84%, respectively. Moreover, Linomide (10 and 100 mg/kg/day) decreased sinusoidal sequestration of leukocytes by 71 and 51%, and markedly improved sinusoidal perfusion. Moreover, Linomide reduced aspartate aminotransferase by 87-97%, and alanine aminotransferase by 79-96%. However, Linomide had no protective effect when administered concomitantly with TNF-alpha/Gal. CONCLUSIONS: These data demonstrate a dose-dependent inhibitory effect of Linomide on perfusion failure, leukocyte recruitment and hepatocellular injury provoked by TNF-alpha. Indeed, these findings suggest that Linomide may be an effective substance for protection of the liver in sepsis.