RESUMO
Glucocorticoids are produced and released by the adrenal gland and become elevated in response to stress. Although glucocorticoids are well known for their immunosuppressive effects, less is known about their effects on B cells. ABCB1 is an efflux pump expressed in both cancer and normal cells, modulating the gradient of various metabolites, including hydrocortisone. Our goal was to evaluate the effect of this glucocorticoid on murine B cell differentiation and whether sensitivity to hydrocortisone could be related to ABCB1 activity in vivo. C57BL/6 mice received one or three consecutive i.p. injections of hydrocortisone (70, 140 and 200 mg/kg/day). ABCB1 activity was evaluated via the rhodamine-123 transport and inhibited by cyclosporin A in hydrocortisone-treated and control mice. Cells from bone marrow, spleen and blood were counted, incubated with antibodies and analyzed by flow cytometry. A single hydrocortisone injection did not alter the number of bone marrow subsets. Conversely, three daily injections were able to reduce the cell number of most bone marrow subsets, excepting c-kit-sca-1+ and mature B cells. This treatment reduced marginal zone, follicular and transitional B cells, though splenic subsets were more resistant than bone marrow B cells. Recirculating follicular B cells in the blood were resistant to hydrocortisone. With the exception of follicular B cells, all subpopulations exhibited ABCB1 activity. However, hydrocortisone treatment did not affect ABCB1 activity in most subsets analyzed. Results suggest that hydrocortisone is able to regulate B cell lymphopoiesis although ABCB1 activity is not related to the susceptibility to that glucocorticoid in B cell subsets.
Assuntos
Subpopulações de Linfócitos B/efeitos dos fármacos , Glucocorticoides/farmacologia , Hidrocortisona/farmacologia , Linfopoese/efeitos dos fármacos , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Animais , Subpopulações de Linfócitos B/citologia , Subpopulações de Linfócitos B/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Feminino , Citometria de Fluxo , Imunofenotipagem , Linfopoese/genética , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Introducción. El caseinato de sodio, una sal de la caseína utilizada como agente proinflamatorio en ratones, es capaz de inducir granulopoyesis en vivo e incrementar la producción de citocinas esenciales en dicho evento.Objetivo. Evaluar si el caseinato de sodio es capaz de inducir un efecto biológico en células de origen linfoide y la producción de citocinas involucradas con este linaje.Materiales y métodos: Se utilizaron ratones hembra BALB/c de 8 a 12 semanas de edad. Los animales se inyectaron cuatro veces, con intervalos de 48 horas, por vía intraperitoneal con 1 ml de caseinato de sodio (10 % de SFB p/v). La población de linfocitos B y la incorporación de bromodesoxiuridina (BrdU) se analizaron mediante citometría de flujo. La detección de la interleucina 7 se evaluó mediante la técnica de ELISA.Resultados. Tras la inyección por vía intraperitoneal, el número de linfocitos B 220+ provenientes del bazo de ratones tratados con caseinato de sodio aumentó comparados con los que solo recibieron el vehículo como tratamiento (89,01±1,03 Vs. 75,66±2,08), así como la incorporación de BrdU en células B220+ (38,59±4,48 Vs. 11,82±1,04). Se evidenció, asimismo, el incremento en la concentración de la interleucina 7 (IL-7) en el suero de los ratones tratados con caseinato de sodio, comparados con los que solo recibieron el vehículo (62,1±17,5 Vs. 26,9±4,4 pg/ml).Conclusión. El caseinato de sodio fue capaz de aumentar el número de linfocitos B en bazo de ratones, así como inducir la producción de IL-7, citocina clave para la linfopoyesis B.
Assuntos
Linfócitos B/efeitos dos fármacos , Caseínas/farmacologia , Linfopoese/efeitos dos fármacos , Animais , Medula Óssea/efeitos dos fármacos , Caseínas/administração & dosagem , Caseínas/toxicidade , Divisão Celular , Feminino , Injeções Intraperitoneais , Interleucina-7/biossíntese , Interleucina-7/sangue , Interleucina-7/genética , Contagem de Linfócitos , Linfocinas/biossíntese , Linfocinas/genética , Camundongos , Camundongos Endogâmicos BALB C , Baço/citologia , Baço/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
Ouabain (OUA) is an endogenous hormone released by the adrenal gland under stress situations. Steroid hormones and glucocorticoids have been characterized as selective inhibitors of lymphopoiesis. The present report shows in vivo modulation of mature B cells in bone marrow, spleen and peripheral blood by ouabain. Mice injected intraperitonially (i.p.) with ouabain 0.56 mg/kg for 3 consecutive days displayed, 24 h after last injection, a decreased cellularity in the bone marrow with diminution of the mature B cell subpopulation while the other B cell subpopulations were preserved. Percentually, the myeloid lineage in bone marrow was increased by ouabain. Numbers of mature B lymphocytes in spleen and peripheral blood were reduced following in vivo treatment. In vitro, the B cell populations were not affected. The effects appear to be independent of steroid hormones and strain. The presence of stable levels of glucocorticoids seems to be important because the effects could only be observed from the fourth week animal's life, when glucocorticoid levels are stable. These results open new perspectives for a potential use of ouabain as an immunomodulator.
Assuntos
Linfócitos B/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Linfopoese/efeitos dos fármacos , Ouabaína/farmacologia , Baço/efeitos dos fármacos , Animais , Antígenos CD/imunologia , Linfócitos B/imunologia , Medula Óssea/imunologia , Diferenciação Celular/imunologia , Linhagem da Célula/imunologia , Células Cultivadas , Feminino , Citometria de Fluxo , Glucocorticoides/imunologia , Glucocorticoides/farmacologia , Fatores Imunológicos/farmacologia , Injeções Intraperitoneais , Linfopoese/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ouabaína/imunologia , Baço/imunologiaRESUMO
Kalanchoe brasiliensis (Kb) is a medicinal plant from the Crassulaceae family, used in folk medicine to treat inflammatory and infectious diseases. Here we show that short-term treatment of mice with a highly purified compound named kalanchosine dimalate (KMC), obtained from Kb, led to a strong and selective inhibition of B cell development in the bone marrow, without affecting the myeloid lineage development. Numbers of mature B lymphocytes in bone marrow or peripheral lymphoid organs were preserved in KMC treated mice. The inhibitory effect of KMC was acute and rapidly reverted with the interruption of the treatment. In vitro, KMC, inhibited the interleukin-7 dependent proliferation of B cell precursors and do not induce cell death. Also in vitro, the maturation of B cell precursors was not affected by KMC. KMC does not inhibit the proliferative response to IL-3 or IL-2. These results suggest that KMC is selectively affecting B cell lymphopoiesis, possibly acting on the IL-7 signaling pathway, opening new perspectives for a potential therapeutic usage of Kb derived drugs.
Assuntos
Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Interleucina-2/metabolismo , Interleucina-3/metabolismo , Interleucina-7/metabolismo , Linfopoese/efeitos dos fármacos , Malatos/farmacologia , Animais , Linfócitos B/fisiologia , Medula Óssea/efeitos dos fármacos , Medula Óssea/imunologia , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Interleucina-2/imunologia , Interleucina-3/imunologia , Interleucina-7/imunologia , Kalanchoe , Linfopoese/imunologia , Malatos/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Lymphopoiesis and myelopoiesis continuously generate mature cells from hematopoietic cell progenitors during the lifetime of the organism. The identification of new endogenous or exogenous substances that can act specifically on the differentiation of distinct cell lineages is of relevance and has potential therapeutical use. Kalanchoe brasiliensis (Kb) is a medicinal plant from the Crassulaceae family, used in folk medicine to treat inflammatory and infectious diseases. Here, we show that short-term treatment of naïve mice with Kb led to a strong and selective inhibition of lymphopoiesis, affecting B and T cell lineages without reduction of the myeloid lineage development. Similar effects were observed after treatment with the highly purified compound kalanchosine dimalate (KMC), obtained from Kb. Numbers of mature lymphocytes in secondary lymphoid organs were preserved in Kb(KMC)-treated mice. The effect of Kb(KMC) was not a result of secondary augmentation of plasma levels of endogenous corticoids; neither involves TNF-alpha, type-I IFN, or TLR2/TLR4 ligands, which have all been described as selective inhibitors of lymphopoiesis. Flow cytometry analysis of the phenotypes of T and B cell precursors indicate a blockade of maturation on IL-7-dependent, proliferative stages. In vitro, Kb(KMC) inhibited the IL-7-dependent proliferation of pre-B cells and does not induce massive apoptosis of B and T cell precursors. These results suggest that Kb(KMC) is selectively blocking lymphopoiesis through a mechanism that does not involve the previously characterized substances, possibly acting on the IL-7 signaling pathway, opening new perspectives for a potential therapeutic use of Kb-derived drugs.