RESUMO
During microbial infection, neutrophils (polymorphonuclear leukocytes; PMNs) activate dendritic cells (DCs). However, early reports illustrated that neutrophil-derived mediators may suppress responses to mitogens. In the present study, we investigated the mechanism used by PMNs to modulate the immunostimulatory ability of DCs. Autologous syngeneic PMNs decreased T-cell proliferation induced by allogeneic DCs. Culture supernatant (CS) derived from PMNs also decreased allostimulation ability of immature DCs and increased the expression of transforming growth factor (TGF)-beta1 on DCs. A TGF-beta1 monoclonal antibody, a CD40 monoclonal antibody, or a serine protease inhibitor reversed the effect of PMN CS on DC allostimulatory ability. Furthermore, elastase reproduced the inhibitory effect of PMN CS on DC allostimulatory ability and the TGF-beta1 production. The role of elastase was confirmed by examining PMN CS from two patients with cyclic neutropenia, a disease due to mutations in the neutrophil elastase gene. These PMN CS samples had reduced elastase activity and were unable to increase DC TGF-beta1 production. Moreover, elastase and PMN CS induced IkappaBalpha degradation in DCs. We conclude that PMNs decrease DC allostimulatory ability via production of elastase leading to a switch of immature DCs into TGF-beta1-secreting cells.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Elastase de Leucócito/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Adolescente , Adulto , Regulação Alostérica , Células Cultivadas , Meios de Cultivo Condicionados/metabolismo , Células Dendríticas/citologia , Feminino , Humanos , Masculino , Neutrófilos/citologia , Neutrófilos/metabolismoRESUMO
The aim of this work was to evaluate the ability of polymorphonuclear leukocytes (PMNL) to modulate the function of dendritic cells (DCs). Human DCs were used to analyze the effect of PMNL on DCs. The allostimulatory proliferation of T cells induced by DCs incubated with PMNL was lower (42 +/- 14%, n:8, p<0.05) compared with untreated DCs. The decreased proliferation correlated with lower IFNgamma production (DCs: 781 +/- 3 pg/ ml; DCs-CS: 343 +/- 178 pg/ml, p<0.05). The same effect was observed in an antigen specific assay. However, the effect was not observed when PMNL where incubated with mature DCs. Indeed, the effect of PMNL was partially reverted with serine proteases inhibitors. Overall, these results suggest that PMNL modulates DCs activity by serine proteases.
Assuntos
Antígenos CD/imunologia , Células Dendríticas/imunologia , Leucócitos/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Inflamação/imunologia , Linfócitos T/imunologiaRESUMO
El objetivo de este trabajo fue evaluar la capacidad de los leucocitos polimorfonucleares (PMNL) de modular la fisiología de las células dendríticas (CDs). Utilizando CDs humanas analizamos el efecto de los PMNL sobre las CDs. Las CDs incubadas con los PMNL mostraron una menor capacidad aloestimuladora de linfocitos T (LT) (42 +/- 14%, n=8, p<0.05), la cual se correlacionó con una menor concentración de IFNgamma (CDs: 781 +/- 3 pg/ml; CDs-PMNL: 343 +/- 178 pg/ml, p<0.05). También se pudo observar el efecto inhibitorio de los PMNL sobre las CDs en un cultivo antígeno específico. Sin embargo, el efecto inhibitorio no se pudo observar sobre CDs maduras. Además, la inhibición de la capacidad aloestimuladora de las CDs tratadas con los PMNL fue revertida utilizando inhibidores de serino proteasas. Estos resultados indican que los PMNL modulan la actividad de las CDs inmaduras a través de la liberación de serino proteasas.
Assuntos
Humanos , Antígenos CD/imunologia , Células Dendríticas/imunologia , Leucócitos/imunologia , Ensaio de Imunoadsorção Enzimática , Inflamação/imunologia , Leucócitos/metabolismo , Linfócitos T/metabolismoRESUMO
El objetivo de este trabajo fue evaluar la capacidad de los leucocitos polimorfonucleares (PMNL) de modular la fisiología de las células dendríticas (CDs). Utilizando CDs humanas analizamos el efecto de los PMNL sobre las CDs. Las CDs incubadas con los PMNL mostraron una menor capacidad aloestimuladora de linfocitos T (LT) (42 +/- 14%, n=8, p<0.05), la cual se correlacionó con una menor concentración de IFNgamma (CDs: 781 +/- 3 pg/ml; CDs-PMNL: 343 +/- 178 pg/ml, p<0.05). También se pudo observar el efecto inhibitorio de los PMNL sobre las CDs en un cultivo antígeno específico. Sin embargo, el efecto inhibitorio no se pudo observar sobre CDs maduras. Además, la inhibición de la capacidad aloestimuladora de las CDs tratadas con los PMNL fue revertida utilizando inhibidores de serino proteasas. Estos resultados indican que los PMNL modulan la actividad de las CDs inmaduras a través de la liberación de serino proteasas. (AU)
Assuntos
Humanos , Antígenos CD/imunologia , Leucócitos/imunologia , Células Dendríticas/imunologia , Ensaio de Imunoadsorção Enzimática , Inflamação/imunologia , Leucócitos/metabolismo , Linfócitos T/metabolismoRESUMO
The aim of this work was to evaluate the ability of polymorphonuclear leukocytes (PMNL) to modulate the function of dendritic cells (DCs). Human DCs were used to analyze the effect of PMNL on DCs. The allostimulatory proliferation of T cells induced by DCs incubated with PMNL was lower (42 +/- 14
, n:8, p<0.05) compared with untreated DCs. The decreased proliferation correlated with lower IFNgamma production (DCs: 781 +/- 3 pg/ ml; DCs-CS: 343 +/- 178 pg/ml, p<0.05). The same effect was observed in an antigen specific assay. However, the effect was not observed when PMNL where incubated with mature DCs. Indeed, the effect of PMNL was partially reverted with serine proteases inhibitors. Overall, these results suggest that PMNL modulates DCs activity by serine proteases.
