RESUMO
BACKGROUND: The effect of a humanized anti-human leukocyte antigen-DR monoclonal antibody, IMMU-114, on the allogeneic immune response was investigated in vitro. METHODS: Responder peripheral blood mononuclear cells were cocultured with inactivated self or allogeneic stimulator peripheral blood mononuclear cells in the presence of control antibody or IMMU-114. Thymidine incorporation rates were then measured. Phenotypic changes in peripheral blood mononuclear cells and the intracellular Th1-type cytokines interleukin-2, interferon-γ, and tumor necrosis factor-α were analyzed using flow cytometry. The concentrations of interleukin-2, interferon-γ, and tumor necrosis factor-α in the mixed lymphocyte reaction culture medium were measured. RESULTS: Thymidine incorporation rates at a 1:1 responder/stimulator ratio of allogeneic, allogeneic + IMMU-114, self, and self + IMMU-114 were 22,080.7 ± 602.4, 2,254.5 ± 118.1, 1,284.0 ± 227.8, and 494.5 ± 27.5 cpm, respectively (P = .038). IMMU-114 decreased the frequencies of human leukocyte antigen-DR-expressing CD16+56+ NK cells, CD19+ B cells, and CD3+25+ activated T cells. CONCLUSION: Intracellular cytokine assay and measurement of Th1-type cytokines in the mixed lymphocyte reaction culture medium revealed that IMMU-114 significantly decreased the titers of interleukin-2, interferon-γ, and tumor necrosis factor-α. IMMU-114 significantly suppresses the allogeneic immune response in vitro, partly through inhibition of the Th1 response.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Linfócitos B/efeitos dos fármacos , Antígenos HLA-DR/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Imunossupressores/farmacologia , Interferon gama/metabolismo , Interleucina-2/metabolismo , Células Matadoras Naturais/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Transplante Homólogo/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Antígenos CD19/imunologia , Linfócitos B/imunologia , Complexo CD3/imunologia , Antígeno CD56/imunologia , Técnicas de Cocultura , Citometria de Fluxo , Rejeição de Enxerto/prevenção & controle , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Interferon gama/efeitos dos fármacos , Subunidade alfa de Receptor de Interleucina-2/imunologia , Células Matadoras Naturais/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Ativação Linfocitária , Transplante de Órgãos , Receptores de IgG/imunologia , Transplante de Células-Tronco , Linfócitos T/imunologia , Timidina/metabolismo , Fator de Necrose Tumoral alfa/efeitos dos fármacosRESUMO
UNLABELLED: The effect of an anti-human leukocyte antigen-DR (MHC class II) humanized monoclonal antibody, IMMU-114, against the human to bovine cellular response was investigated. METHODS: Human peripheral mononuclear cells (PBMCs) were cocultured with inactivated self-PBMCs (Self), bovine PBMCs with control antibody (Xeno), or bovine PBMCs with IMMU-114 (IMMU-114). Cellular responses were investigated by thymidine incorporation assay, CFSE (carboxyfluorescein diacetate succinimidyl ester)-mixed lymphocyte reaction, and cytokine production in culture medium. RESULTS: Thymidine incorporation rates at a 1:1 responder to stimulator ratio for Xeno + control antibody, Xeno + IMMU-114, Self + control antibody, and Self + IMMU-114 were 14201.3 ± 1968.4, 513.0 ± 49.5, 952.7 ± 128.7, and 423.3 ± 138.8 cpm, respectively (P = 0.032). Those at a 1:2 ratio were 6518.0 ± 690.1, 896.6 ± 92.9, 1051.0 ± 123.6, and 736.0 ± 35.6 cpm, respectively (P = 0.036). CFSE-mixed lymphocyte reaction demonstrated that the frequencies of CFSE-low, CD4(+), and CD25(+) activating T cells in Self, Xeno, and IMMU-114 were 0.27 ± 0.04%, 3.65 ± 0.53%, and 1.23 ± 0.15%, respectively (P = 0.027). Cytokine production in culture medium indicated that IMMU-114 decreased Th1-type cytokines, including interleukin-2, interferon-γ, and tumor necrosis factor-α. CONCLUSION: IMMU-114 effectively suppresses human to bovine cellular responses. The mechanism involves direct inhibition of the interaction between class II human leukocyte antigen-DR-positive cells and CD4(+) T cells, and indirect suppression of Th1 cytokine production.
