RESUMO
Objectives: Mesenchymal Stem/Stromal Cells (MSC) are promising therapeutic tools for inflammatory diseases due to their potent immunoregulatory capacities. Their suppressive activity mainly depends on inflammatory cues that have been recently associated with changes in MSC bioenergetic status towards a glycolytic metabolism. However, the molecular mechanisms behind this metabolic reprogramming and its impact on MSC therapeutic properties have not been investigated. Methods: Human and murine-derived MSC were metabolically reprogramed using pro-inflammatory cytokines, an inhibitor of ATP synthase (oligomycin), or 2-deoxy-D-glucose (2DG). The immunosuppressive activity of these cells was tested in vitro using co-culture experiments with pro-inflammatory T cells and in vivo with the Delayed-Type Hypersensitivity (DTH) and the Graph versus Host Disease (GVHD) murine models. Results: We found that the oligomycin-mediated pro-glycolytic switch of MSC significantly enhanced their immunosuppressive properties in vitro. Conversely, glycolysis inhibition using 2DG significantly reduced MSC immunoregulatory effects. Moreover, in vivo, MSC glycolytic reprogramming significantly increased their therapeutic benefit in the DTH and GVHD mouse models. Finally, we demonstrated that the MSC glycolytic switch effect partly depends on the activation of the AMPK signaling pathway. Conclusion: Altogether, our findings show that AMPK-dependent glycolytic reprogramming of MSC using an ATP synthase inhibitor contributes to their immunosuppressive and therapeutic functions, and suggest that pro-glycolytic drugs might be used to improve MSC-based therapy.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Glicólise/efeitos dos fármacos , Doença Enxerto-Hospedeiro/imunologia , Hipersensibilidade Tardia/imunologia , Células-Tronco Mesenquimais/efeitos dos fármacos , ATPases Mitocondriais Próton-Translocadoras/antagonistas & inibidores , Animais , Antimetabólitos/farmacologia , Linfócitos T CD4-Positivos , Desoxiglucose/farmacologia , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Humanos , Imunoterapia , Ácido Láctico/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Oligomicinas/farmacologia , Fosforilação Oxidativa , Consumo de OxigênioRESUMO
Although acute stress generally exerts positive effects on the immune system, chronic stress typically causes immunosuppression via the hypothalamic-pituitary-adrenal (HPA) axis. In this study, the effects of capsaicin (1.28 mg/kg intraperitoneally [i.p.] for 7 days) on immune parameters were evaluated under conditions of chronic stress. Capsaicin treatment significantly increased the immune response as evaluated by the delayed-type hypersensitivity (DTH) reaction to dinitrofluorobenzene (DNFB) and splenocyte proliferation assays- It also is able to rescue the splenocytes of the apoptosis induced by stress. The capsaicin treatment increased the production of Th1 cytokines and decreased the production of Th2 cytokines and TGF-ß1 in the plasma and culture supernatants of immunosuppressed mice, which is associated with the modulation of Th2 induced by stress cells. Moreover, the production of corticosterone significantly decreased in capsaicin-treated animals as compared to control groups. The capsaicin treatment further attenuated the immunosuppression induced by the corticosterone treatment (40 mg/kg i.p. for 7 days), albeit less potently, as exhibited in the DTH response. Intriguingly, the capsaicin treatment decreased the induction of IL-10, IL-4, and TGF-ß1 through high doses of corticosterone, indicating direct cellular immunomodulation. These results show, that capsaicin is able to modulate chronic stress-induced immunosuppression, mediating corticosterone released inhibition, but also, that capsaicin significantly modulates the pharmacological action of corticosterone in vivo.
Assuntos
Capsaicina/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Corticosterona/farmacologia , Citocinas/sangue , Citocinas/imunologia , Dinitrofluorbenzeno , Hipersensibilidade Tardia/imunologia , Masculino , Camundongos Endogâmicos BALB C , Baço/citologia , Estresse Fisiológico/imunologia , Fator de Crescimento Transformador beta1/sangue , Fator de Crescimento Transformador beta1/imunologiaRESUMO
Delayed-type hypersensitivity (DTH) has been used in human and veterinary medicine as a skin testing for evaluating in vivo cell-mediated immune responses (CMIR). Whereas CMIR is a key process to control intracellular pathogens, its value at identifying cattle exposed to the abortigenic intracellular coccidian parasite Neospora caninum is unknown. In this work, we have evaluated a DTH skin testing in cattle exposed to N. caninum and still seronegative. Female calves were experimentally sensitized by subcutaneous (SC) inoculation with live tachyzoites of N. caninum (NC-Argentina LP1) in sterile phosphate-buffered saline (PBS) (group A; n: 8) whereas other calveswere mock-sensitized with PBS (group B; n: 6). Two DTH skin tests were performed by intradermal inoculation with a soluble lysate of N. caninum tachyzoites (NC-Argentina LP1) in the neck region at 60d and 960 d after sensitization. Skinfold thickness at the intradermal inoculation site was measured at 0, 24, 48 h post each DTH skin test and skin biopsies taken for microscopic evaluation. Specific N. caninum antibodies kinetics was evaluated all throughthe experiment. We found that whereas N. caninum specific antibodies remained below the ELISA cut-off, a distinctive skinfold thickness increase was detected in sensitized animals (group A) at the DTH skin test site, showing induration, swelling and inflammatory infiltration. Mock sensitized animals (group B) showed no skinfold thickness growth and lacked specific antibody response. Thus, N. caninum DTH skin testing could be a useful diagnostic tool for the detection of CMIR during N. caninum infection in non-humoral responders.
Assuntos
Doenças dos Bovinos , Coccidiose , Hipersensibilidade Tardia/parasitologia , Testes Cutâneos/veterinária , Animais , Anticorpos Antiprotozoários/imunologia , Argentina , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/parasitologia , Coccidiose/diagnóstico , Coccidiose/veterinária , Feminino , Hipersensibilidade Tardia/imunologia , Neospora/imunologiaRESUMO
It has been hypothesized that anterior chamber-associated immune deviation (ACAID) to neural antigens induced prior to central nervous system injury can inhibit self-reactivity and lessen secondary degeneration. This work evaluated the effect of ACAID induced to three neural tissue-derived extracts (whole extract, cytosolic extract, CE; or organelle-membrane extract) prior to optic nerve injury on retinal ganglion cell (RGC) survival. The results show that only ACAID to the CE increased RGC survival at 7 and14 days post-injury (dpi). This effect was achieved by retinal polarization towards an anti-inflammatory profile, driven by regulatory T cells and M2-type macrophages at 7 dpi.
Assuntos
Câmara Anterior/imunologia , Autoantígenos/imunologia , Privilégio Imunológico/imunologia , Traumatismos do Nervo Óptico/imunologia , Retina/imunologia , Animais , Autoimunidade , Citosol/imunologia , Feminino , Hipersensibilidade Tardia/imunologia , Macrófagos/imunologia , Compressão Nervosa , Fatores de Crescimento Neural/biossíntese , Fatores de Crescimento Neural/genética , Ratos , Ratos Wistar , Células Ganglionares da Retina/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
The aim of this study was to evaluate delayed type hypersensitivity (DTH) induced by the intradermal inoculation of a Neospora caninum tachyzoite soluble lysate in cattle previously exposed with the protozoa. Four experimental groups were selected according to the prior exposure to N. caninum antigen. All cows were intradermally injected with a N. caninum tachyzoite soluble lysate and skinfold thickness growth at the inoculation sites was measured at 0, 24, 48, 72 and 96 h post inoculation (hpi). Additionally, specific antibodies and IFN-γ production were assessed. Cows experimentally infected with live N. caninum tachyzoites and cows naturally exposed to N. caninum developed skin reactions compatible with DTH between 24 and 96 hpi (p < 0.05). Moreover, cows inoculated with an experimental N. caninum vaccine and cows without evidence of exposure to N. caninum did not show a significant increase in skin thickness (p > 0.05). Furthermore, serological status of the animals was not modified due to the intradermal inoculation. The highest IFN-γ production was observed at 15 days after intradermal inoculation (p < 0.05). Therefore, these results suggest that cattle previously exposed to N. caninum develop a reaction compatible with DTH which could be useful as in vivo cell mediated immunity parameter for assessed bovine neosporosis.
Assuntos
Antígenos de Protozoários/imunologia , Hipersensibilidade Tardia/veterinária , Neospora/imunologia , Animais , Antígenos de Protozoários/administração & dosagem , Bovinos/imunologia , Bovinos/parasitologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Coccidiose/veterinária , Relação Dose-Resposta Imunológica , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/parasitologia , Imunoglobulina G/imunologia , Injeções Intradérmicas/veterináriaRESUMO
Oral tolerance is defined as a state of systemic hyporesponsiveness to an antigen that has been previously administered by the oral route. Many factors affect oral tolerance induction; some of them related to antigen, and some related to the animal. The age of the animal is one of the most important factors that affect oral tolerance as ageing brings many alterations in immune responses. Herein, we demonstrated that both the oral tolerance and pattern of immune reactivity triggered in early life were kept up to 15 months regarding the magnitude of antibody production, cell proliferation and cytokine profile when compared to immune responses induced in old mice. Therefore, our results corroborate with a promising proposal for prevaccination during childhood and young age, and a booster in older age, to make sure that the primary immunization in early life is not lost in aged individuals.
Assuntos
Antígenos/imunologia , Hipersensibilidade Tardia/imunologia , Tolerância Imunológica , Administração Oral , Animais , Proliferação de Células , Células Cultivadas , Citocinas/metabolismo , Exposição Ambiental , Feminino , Humanos , Imunidade Humoral , Imunização , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , VacinasRESUMO
Betulinic acid (BA) is a naturally occurring triterpenoid with several biological properties already described, including immunomodulatory activity. Here we investigated the immunomodulatory activity of eight semi-synthetic amide derivatives of betulinic acid. Screening of derivatives BA1-BA8 led to the identification of compounds with superior immunomodulatory activity than BA on activated macrophages and lymphocytes. BA5, the most potent derivative, inhibited nitric oxide and TNFα production in a concentration-dependent manner, and decreased NF-κB activation in Raw 264.7 cells. Additionally, BA5 inhibited the proliferation of activated lymphocytes and the secretion of IL-2, IL-4 IL-6, IL-10, IL-17A and IFNÉ£, in a concentration-dependent manner. Flow cytometry analysis in lymphocyte cultures showed that treatment with BA5 induces cell cycle arrest in pre-G1 phase followed by cell death by apoptosis. Moreover, BA5 also inhibited the activity of calcineurin, an enzyme that plays a critical role in the progression of cell cycle and T lymphocyte activation. BA5 has a synergistic inhibitory effect with dexamethasone on lymphoproliferation, showing a promising profile for drug combination. Finally, we observed immunosuppressive effects of BA5 in vivo in mouse models of lethal endotoxemia and delayed type hypersensitivity. Our results reinforce the potential use of betulinic acid and its derivatives in the search for potent immunomodulatory drugs.
Assuntos
Hipersensibilidade Tardia/tratamento farmacológico , Hipersensibilidade Tardia/imunologia , NF-kappa B/antagonistas & inibidores , Choque Séptico/tratamento farmacológico , Choque Séptico/imunologia , Triterpenos/química , Triterpenos/farmacologia , Amidas/química , Animais , Inibidores de Calcineurina/química , Inibidores de Calcineurina/farmacologia , Inibidores de Calcineurina/uso terapêutico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citocinas/biossíntese , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Hipersensibilidade Tardia/induzido quimicamente , Hipersensibilidade Tardia/metabolismo , Imunomodulação/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Triterpenos Pentacíclicos , Células RAW 264.7 , Choque Séptico/induzido quimicamente , Choque Séptico/metabolismo , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Triterpenos/uso terapêutico , Ácido BetulínicoRESUMO
Studies have revealed that impairment of the pregnant body weight reduces the fetal body weight and causes minor changes in skeletal development. The aim of the present study was to assess the effects of maternal feed restriction during pregnancy in offspring immune system development. Pregnant Wistar rats were distributed into 5 groups: 1 control in which dams received food ad libitum and 4 experimental groups in which dams were fed restricted amounts of rodent ration (16, 12, 9, or 6 g/rat/day) from the 6th to 17th gestation day. Teratogenicity was assessed using classical teratological evaluation and developmental immunotoxicology protocols. Maternal body weight gain, fetus weight, and placenta weight were reduced for feed-restricted females from the groups fed 12, 9, and 6 g/rat/day ( p < 0.05). No pup mortality was observed immediately after cesarean sections among the groups, and no visceral or skeletal malformations were detected. An immunoteratological study revealed an increase in the relative weight of the thymus and an increase in the phorbol myristate-acetate solution-induced hydrogen peroxide release by inflammatory cells in 21-day-old pups. Alterations in the delayed-type hypersensitivity response and the humoral immune response against sheep red blood cells were observed in pups from feed-restricted mothers. Feed restriction in Wistar rats during organogenesis did not promote structural malformations but resulted in offspring with lower birth weights and promoted significant changes in the immune responses of the rat pups.
Assuntos
Restrição Calórica , Troca Materno-Fetal , Animais , Peso ao Nascer , Peso Corporal , Eritrócitos/imunologia , Feminino , Peso Fetal , Peróxido de Hidrogênio/metabolismo , Hipersensibilidade Tardia/imunologia , Macrófagos Peritoneais/imunologia , Masculino , Placenta , Gravidez , Ratos Wistar , Soroalbumina Bovina/imunologia , Ovinos , Baço/imunologia , Acetato de Tetradecanoilforbol/farmacologia , Timo/imunologiaRESUMO
The aim of the present study was to assess the presence of antissaliva antibodies of Lutzomyia longipalpis in human hosts living in area of visceral leishmaniasis, located in the Center-West region of Brazil. The presence of antissaliva antibodies of L. longipalpis exhibited a strong correlation with the protection and development of antibodies against Leishmania sp. Of the 492 children studied, elevated antissaliva antibodies of L. longipalpis were detected in 38.4% of the participants. There was a higher percentage of positivity (64.7%) among children who exhibited anti-Leishmania sp. antibodies and among those who were positive in the delayed hypersensitivity test (34.8%).
Assuntos
Anticorpos/sangue , Leishmaniose Visceral/imunologia , Psychodidae/imunologia , Saliva/imunologia , Proteínas e Peptídeos Salivares/imunologia , Adolescente , Animais , Anticorpos/isolamento & purificação , Anticorpos Antiprotozoários/imunologia , Brasil , Criança , Pré-Escolar , Doenças do Cão/parasitologia , Cães , Feminino , Humanos , Hipersensibilidade Tardia/imunologia , Insetos Vetores , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/prevenção & controle , Masculino , Psychodidae/parasitologia , Saliva/química , Glândulas Salivares/imunologia , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/químicaRESUMO
The voltage-gated potassium channel Kv1.3 is a novel target for immunomodulation of autoreactive effector memory T cells, which play a major role in the pathogenesis of autoimmune diseases. In this study, the Ts6 and Ts15 toxins isolated from Tityus serrulatus (Ts) were investigated for their immunosuppressant roles on CD4(+) cell subsets: naive, effector (TEF ), central memory (TCM) and effector memory (TEM). The electrophysiological assays confirmed that both toxins were able to block Kv1.3 channels. Interestingly, an extended Kv channel screening shows that Ts15 blocks Kv2.1 channels. Ts6 and Ts15 significantly inhibit the proliferation of TEM cells and interferon-γ production; however, Ts15 also inhibits other CD4(+) cell subsets (naive, TEF and TCM). Based on the Ts15 inhibitory effect of proliferation of all CD4(+) cell subsets, and based on its blocking effect on Kv2.1, we investigated the Kv2.1 expression in T cells. The assays showed that CD4(+) and CD8(+) cells express the Kv2.1 channels mainly extracellularly with TCM cells expressing the highest number of Kv2.1 channels. We also provide in vivo experimental evidence to the protective effect of Ts6 and Ts15 on delayed-type hypersensitivity reaction. Altogether, this study presents the immunosuppressive behaviour of Ts6 and Ts15 toxins, indicating that these toxins could be promising candidates for autoimmune disease therapy. Moreover, this is the first report illustrating the involvement of a novel K(+) channel subtype, Kv2.1, and its distribution in T-cell subsets.