RESUMO
In this chapter we outline a RNA extraction method for very low immune cell populations isolated from the central nervous system of mice undergoing experimental autoimmune encephalomyelitis. We compare various normalization and quantification techniques to examine miRNA expression. Our data highlight that employing a mean normalization procedure using a number of well-selected housekeeping miRNA genes, followed by absolute quantification with a standard curve generated from a commercial miRNA oligo, gave the most robust and reproducible miRNA expression results.
Assuntos
Sistema Nervoso Central/imunologia , Sistema Nervoso Central/metabolismo , Encefalomielite Autoimune Experimental/genética , MicroRNAs/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Projetos de Pesquisa , Animais , Sistema Nervoso Central/patologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/isolamento & purificação , MicroRNAs/metabolismo , Padrões de ReferênciaRESUMO
In this chapter, we describe simple methods to investigate microRNA (miRNA) induction in response to lipopolysaccharide, the ligand for Toll-Like Receptor-4 activation. In brief, we demonstrate how to investigate global miRNA induction and/or repression in bone marrow-derived macrophages using TaqMan MicroRNA Arrays, followed by methods to measure individual miRNAs and target mRNA expression. Moreover, we explain step-by-step instructions on how to modulate endogenous miRNA expression through the use of miRNA inhibitors and mimics as well as highlight how miRNA modulation can be used to confirm mRNA targeting via Luciferase reporter assay. Moreover, these methods can be applied to whichever cell type and cellular function under investigation.
Assuntos
Regulação da Expressão Gênica , MicroRNAs/genética , Receptores Toll-Like/metabolismo , Animais , Expressão Gênica , Perfilação da Expressão Gênica , Genes Reporter , Ativação de Macrófagos/genética , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Interferência de RNA , Reação em Cadeia da Polimerase em Tempo Real , Transcriptoma , TransfecçãoRESUMO
Invariant NK T (iNKT) cells can provide help for B cell activation and Ab production. Because B cells are also capable of cytokine production, Ag presentation, and T cell activation, we hypothesized that iNKT cells will also influence these activities. Furthermore, subsets of iNKT cells based on CD4 and CD8 expression that have distinct functional activities may differentially affect B cell functions. We investigated the effects of coculturing expanded human CD4(+), CD8α(+), and CD4(-)CD8α(-) double-negative (DN) iNKT cells with autologous peripheral B cells in vitro. All iNKT cell subsets induced IgM, IgA, and IgG release by B cells without needing the iNKT cell agonist ligand α-galactosylceramide. Additionally, CD4(+) iNKT cells induced expansions of cells with phenotypes of regulatory B cells. When cocultured with α-galactosylceramide-pulsed B cells, CD4(+) and DN iNKT cells secreted Th1 and Th2 cytokines but at 10-1000-fold lower levels than when cultured with dendritic cells. CD4(+) iNKT cells reciprocally induced IL-4 and IL-10 production by B cells. DN iNKT cells expressed the cytotoxic degranulation marker CD107a upon exposure to B cells. Remarkably, whereas iNKT cell subsets could induce CD40 and CD86 expression by B cells, iNKT cell-matured B cells were unable to drive proliferation of autologous and alloreactive conventional T cells, as seen with B cells cultured in the absence of iNKT cells. Therefore, human CD4(+), CD8α(+), and DN iNKT cells can differentially promote and regulate the induction of Ab and T cell responses by B cells.
