RESUMO
Leucine-rich repeat kinase 2 (LRRK2) is the causal molecule of familial Parkinson's disease. Although the characteristics of LRRK2 have gradually been revealed, its true physiological functions remain unknown. LRRK2 is highly expressed in immune cells such as B2 cells and macrophages, suggesting that it plays important roles in the immune system. In the present study, we investigate the roles of LRRK2 in the immune functions of dendritic cells (DCs). Bone marrow-derived DCs from both C57BL/6 wild-type (WT) and LRRK2 knockout (KO) mice were induced by culture with granulocyte/macrophage-colony stimulating factor (GM/CSF) in vitro. We observed the differentiation of DCs, the phosphorylation of the transcriptional factors NF-κB, Erk1/2, and p-38 after lipopolysaccharide (LPS) stimulation and antigen-presenting ability by flow cytometry. We also analyzed the production of inflammatory cytokines by ELISA. During the observation period, there was no difference in DC differentiation between WT and LRRK2-KO mice. After LPS stimulation, phosphorylation of NF-κB was significantly increased in DCs from the KO mice. Large amounts of inflammatory cytokines were produced by DCs from KO mice after both stimulation with LPS and infection with Leishmania. CD4+ T-cells isolated from antigen-immunized mice proliferated to a significantly greater degree upon coculture with antigen-stimulated DCs from KO mice than upon coculture with DCs from WT mice. These results suggest that LRRK2 may play important roles in signal transduction and antigen presentation by DCs.
Assuntos
Células da Medula Óssea/citologia , Células Dendríticas/citologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Lipopolissacarídeos/efeitos adversos , NF-kappa B/metabolismo , Animais , Apresentação de Antígeno , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação/efeitos dos fármacosRESUMO
LRRK2 is the causal molecule of autosomal dominant familial Parkinson's disease. B2 cells express a much higher LRRK2 mRNA level than B1 cells. To reveal the function of LRRK2 in B cells, we analyzed B cell functions in LRRK2-knockout (LRRK2(-/-)) mice. LRRK2(-/-) mice had significantly higher counts of peritoneal B1 cells than wild-type mice. After BCR stimulation, phosphor-Erk1/2 of splenic B2 cells was enhanced to a higher degree in LRRK2(-/-) mice. LRRK2(-/-) mice had a significantly higher serum IgA level, and TNP-Ficoll immunization increased the titer of serum anti-TNP IgM antibody. LRRK2 may play important roles in B cells.