RESUMO
Rituximab, a monoclonal antibody targeting CD20 on B cells, is currently used to treat many subtypes of B cell lymphomas. However, treatment is not curative and response rates are variable. Recombinant interleukin-21 (rIL-21) is a cytokine that enhances immune effector function and affects both primary and transformed B cell differentiation. We hypothesized that the combination of rIL-21 plus rituximab would be a more efficacious treatment for B cell malignancies than rituximab alone. We cultured human and cynomolgus monkey NK cells with rIL-21 and found that their activity was increased and proteins associated with antibody dependent cytotoxicity were up-regulated. Studies in cynomolgus monkeys modeled the effects of rIL-21 on rituximab activity against CD20 B cells. In these studies, rIL-21 activated innate immune effectors, increased ADCC and mobilized B cells into peripheral blood. When rIL-21 was combined with rituximab, deeper and more durable B cell depletion was observed. In another series of experiments, IL-21 was shown to have direct antiproliferative activity against a subset of human lymphoma cell lines, and combination of murine IL-21 with rituximab yielded significant survival benefits over either agent alone in xenogeneic mouse tumor models of disseminated lymphoma. Therefore, our results do suggest that the therapeutic efficacy of rituximab may be improved when used in combination with rIL-21.
Assuntos
Anticorpos Monoclonais Murinos/farmacologia , Antineoplásicos/farmacologia , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Interleucinas/farmacologia , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/imunologia , Animais , Anticorpos Monoclonais Murinos/uso terapêutico , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Antineoplásicos/uso terapêutico , Linfócitos B/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Sinergismo Farmacológico , Feminino , Humanos , Imunidade Inata/efeitos dos fármacos , Linfoma de Células B/patologia , Macaca fascicularis , Masculino , Camundongos , Rituximab , Análise de SobrevidaRESUMO
We evaluated the abilities of an antisense oligonucleotide (ASO), a small interfering RNA (siRNA), and a single-stranded siRNA (ss-siRNA) to inhibit expression from the PTEN gene in mice when formulated identically with lipid nanoparticles (LNPs). Significantly greater reductions in levels of PTEN mRNA were observed for LNP-formulated agents compared to unformulated drugs when gene silencing was evaluated after a single dose in the livers of mice. An unformulated ss-siRNA modified with a metabolically stable phosphate mimic 5'-(E)-vinylphosphonate showed dose-dependent reduction of PTEN mRNA in mice, albeit at doses significantly higher than those observed for formulated ss-siRNA. These results demonstrate that LNPs can be used to deliver functional antisense and ss-siRNA therapeutics to the liver, indicating that progress in the field of siRNA delivery is transferable to other classes of nucleic acid-based drugs.
Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Lipídeos/química , Nanopartículas/química , Oligonucleotídeos Antissenso , PTEN Fosfo-Hidrolase/genética , RNA Interferente Pequeno , Animais , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos , Células HeLa , Humanos , Concentração Inibidora 50 , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Antissenso/farmacologia , RNA Interferente Pequeno/química , RNA Interferente Pequeno/farmacologiaRESUMO
IL-21 is a cytokine that regulates the activation of T and NK cells and promotes the proliferation of B cells activated via CD40. In this study, we show that rIL-21 strongly induces the production of all IgG isotypes by purified CD19(+) human spleen or peripheral blood B cells stimulated with anti-CD40 mAb. Moreover, it was found to specifically induce the production of IgG(1) and IgG(3) by CD40-activated CD19(+)CD27(-) naive human B cells. Although stimulation of CD19(+) B cells via CD40 alone induced gamma 1 and gamma 3 germline transcripts, as well as the expression of activation-induced cytidine deaminase, only stimulation with both anti-CD40 mAb and rIL-21 resulted in the production of S gamma/S mu switch circular DNA. These results show that IL-21, in addition to promoting growth and differentiation of committed B cells, is a specific switch factor for the production of IgG(1) and IgG(3).
Assuntos
Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Imunoglobulina G/biossíntese , Imunoglobulina G/classificação , Isotipos de Imunoglobulinas/biossíntese , Região de Troca de Imunoglobulinas , Interleucinas/fisiologia , Antígenos CD19/biossíntese , Subpopulações de Linfócitos B/citologia , Antígenos CD40/farmacologia , Divisão Celular/genética , Divisão Celular/imunologia , Células Cultivadas , Citidina Desaminase , Citosina Desaminase/biossíntese , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina E/biossíntese , Imunoglobulina G/genética , Isotipos de Imunoglobulinas/genética , Cadeias gama de Imunoglobulina/biossíntese , Cadeias gama de Imunoglobulina/genética , Cadeias mu de Imunoglobulina/biossíntese , Cadeias mu de Imunoglobulina/genética , Ativação Linfocitária/genética , Baço/citologia , Baço/imunologiaRESUMO
IL-21 is a recently characterized T cell-derived cytokine that regulates NK and T cell function. IL-21R shares the common gamma-chain (gamma(c)) with the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15. Despite the same gamma(c), these cytokines have different effects on diverse cells. In this study, we have studied IL-15- and IL-21-induced gene expression in human primary NK and T cells and the NK-92 cell line. Both IL-15 and IL-21 rapidly induced mRNA synthesis for IFN-gamma, T-bet, IL-2Ralpha, IL-12Rbeta2, IL-18R, and myeloid differentiation factor 88 (MyD88), the genes that are important in activating innate immunity and Th1 response. IL-15 induced STAT5 DNA binding to the IL-2Ralpha IFN-gamma-activated sequence (GAS), MyD88 GAS, and c-cis-inducible elements, whereas IL-21 induced STAT3 DNA binding to MyD88 GAS and c-sis-inducible elements. IL-21-induced STAT3 activation was verified by immunoprecipitation and Western blotting with anti-phosphotyrosine Ab. In addition, pretreatment of NK-92 cells with IL-15 or IL-21 strongly enhanced IL-12-induced STAT4 DNA binding to IL-2Ralpha GAS. The induction of IFN-gamma, T-bet, IL-12Rbeta2, and IL-18R gene expression in NK cells, along with STAT3 activation, suggests that IL-21 is involved in the activation of innate immune responses. Moreover, the enhanced transcription of these genes in T cells establishes a significant role for IL-21 also in the Th1 response.