RESUMEN
During cognate interaction with CD40 ligand (CD154)-expressing T cells, Ag-presenting accessory cells are activated for increased cytokine synthetic and costimulatory function. We examined whether CD40 modulates in vivo innate immune function over time, hypothesizing that distinct cytokine responses evolve to delayed microbial exposure. C3H/HeN mice pretreated with activating anti-CD40 Ab (FGK45) produced 10-fold more serum IFN-gamma and IL-12 p70 to delayed, but not synchronous, challenge with LPS. A novel finding was that LPS-induced IFN-alpha increased by 20-fold in mice pretreated for 24 h, but not 6 h or less, with anti-CD40. Anti-CD40-pretreated C57BL/6 RAG-2(-/-) mice similarly increased IFN-alpha responses to delayed LPS challenge, confirming mediation by innate immunity. Type I IFNR- and IFN-gamma-deficient mice treated with anti-CD40 failed to expand serum IFN-alpha responses to LPS challenge. Combined pretreatment with anti-CD40 and anti-IFN-gamma mAb showed that IFN-gamma produced after anti-CD40 pretreatment, but before LPS challenge, was necessary for IFN-alpha synthetic enhancement. Anti-CD40 also increased polyinosinic-polycytidylic acid (poly(I:C))-inducible IFN-alpha by 5-fold in an IFN-gamma-dependent fashion, but did not significantly increase IFN-alpha production to CpG or Pam(3)Cys challenges. Poly(IC)-stimulated splenocytes from anti-CD40-pretreated mice produced 4-fold more IFN-alpha than controls and production associated with CD11c(+) cells. Finally, rIFN-gamma and anti-CD40 combined synergistically to increase poly(IC)-inducible IFN-alpha synthetic capacity in bone marrow dendritic cells. We conclude that innate immune production of IFN-alpha is cooperatively regulated by CD40 and IFN-gamma acting on dendritic cells, suggesting a unique mechanism by which innate immune function evolves in response to specific adaptive immune signals.
Asunto(s)
Adyuvantes Inmunológicos/fisiología , Antígenos CD40/fisiología , Interferón Tipo I/biosíntesis , Interferón gamma/fisiología , Adyuvantes Inmunológicos/deficiencia , Adyuvantes Inmunológicos/genética , Animales , Anticuerpos Monoclonales/administración & dosificación , Células de la Médula Ósea/inmunología , Células de la Médula Ósea/metabolismo , Antígenos CD40/inmunología , Células Cultivadas , Citocinas/biosíntesis , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Femenino , Inmunidad Innata/genética , Interferón gamma/deficiencia , Interferón gamma/genética , Lipopolisacáridos/administración & dosificación , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Noqueados , Factores de TiempoRESUMEN
Traumatic or inflammatory injury associates with deactivation of monocytes and impaired synthesis of proinflammatory cytokines. We conducted a prospective, observational study to test whether cardiac surgery additionally impaired dendritic and natural killer (NK) cell functions responsible for innate immune production of interleukin (IL)-12-dependent interferon (IFN)-gamma in response to bacteria or toll-like receptor agonists. Blood samples were taken just before induction of anesthesia and 24 h postoperatively. LPS- and fixed Staphylococcus aureus-inducible IFNgamma synthesis in whole blood culture after surgery was reduced to 5% of preoperative values (P < 0.001). Production of IL-12 p70, a critical inducer of IFNgamma in the innate immune response, was reduced to 30% of that produced by preoperative samples (P = 0.013). Circulating CD11c, DR myeloid dendritic cells (DC) that are known sources of IL-12 p70 in normal blood, declined to approximately 25% of presurgical numbers (P = 0.004). Experimental depletion of CD11c, but not CD14, cells from normal peripheral blood mononuclear cell (PBMC) similarly disabled Staphylococcus aureus Cowan 1 (SAC)-induced production of IL-12 p70 and IFNgamma. Consistent with SAC-induced IFNgamma expression in CD56 NK and NK-T cells, CD56 depletion ablated IFNgamma production in normal whole blood. However, repletion of IL-12 p70, IL-18, IL-15, and IL-23 in postoperative blood failed to restore presurgical levels of IFNgamma synthesis (P < 0.05). We conclude that DC cytopenia after major surgery is sufficient to explain postoperative IL-12 p70 and IFNgamma synthetic deficiency. In addition, postoperative blood became hyporesponsive to IFNgamma-inducing cytokines as a further contribution to IFNgamma insufficiency. The novel finding of DC cytopenia after major surgery may portend a lack of other immunologic functions provided by this potent accessory cell population.
Asunto(s)
Células Dendríticas/inmunología , Células Dendríticas/patología , Interferón gamma/deficiencia , Interleucina-12/deficiencia , Cirugía Torácica , Interferón gamma/biosíntesis , Interleucina-10/farmacología , Interleucina-18/farmacología , Interleucina-23 , Interleucinas/farmacología , Pruebas de Neutralización , Complicaciones Posoperatorias/inmunología , Subunidades de Proteína , Proteínas Recombinantes/metabolismoRESUMEN
Defects in immune reconstitution after hematopoietic stem cell transplantation confer extreme infection risk on to the transplant recipient. Perturbations in adaptive immune reconstitution have been well characterized, yet defects in reconstituted innate cellular-mediated immunity remain largely unstudied. Recovery in innate effector cells was defined by using an established murine model of autologous bone marrow transplantation. Cytokine induction after cell culture and systemic stimulation with pathogen-associated molecular patterns was also measured for control, transplant-recipient, and irradiated-only animals. Early reconstitution (7 to 14 days) of donor-derived macrophages, dendritic cells, and polymorphonuclear cells was associated with recovery in interleukin (IL)-12p70 and IL-6 production. Later reconstitution (21 days) of natural killer cells was associated with interferon (IFN)-gamma recovery. Hence, splenocyte innate cellular-mediated immunity recovered to normal levels in cellularity and IL-12p70, IFN-gamma, and IFN-alpha production by 21 days after transplantation. In contrast, levels of systemic cytokine production from transplant-recipient and irradiated-only animals were preserved despite incomplete or absent hematopoietic reconstitution. These results suggest that innate immune responses to systemic inflammatory challenges are largely intact after autologous bone marrow transplantation, whereas local innate cellular-mediated immunity within reconstituting lymphoid organs may be impaired. The disparate effects of autologous hematopoietic stem cell transplantation on host immune function may translate to differences in susceptibility to local versus systemic infectious challenges.
Asunto(s)
Trasplante de Médula Ósea/inmunología , Inmunidad Celular , Trasplante Isogénico/inmunología , Animales , Antígenos de Diferenciación/inmunología , Células Cultivadas , Fosfatos de Dinucleósidos/farmacología , Femenino , Citometría de Flujo , Lipopolisacáridos/farmacología , Activación de Linfocitos , Depleción Linfocítica/métodos , Transfusión de Linfocitos , Ratones , Ratones Endogámicos C57BL , Bazo/inmunología , Trasplante de Células Madre/métodos , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Trasplante Autólogo/inmunologíaRESUMEN
Innate cellular production of IFN-gamma is suppressed after repeated exposure to LPS, whereas CpG-containing DNA potentiates IFN-gamma production. We compared the modulatory effects of LPS and CpG on specific cellular and cytokine responses necessary for NK-cell dependent IFN-gamma synthesis. C3H/HeN mice pretreated with LPS for 2 days generated 5-fold less circulating IL-12 p70 and IFN-gamma in response to subsequent LPS challenge than did challenged control mice. In contrast, CpG-pretreated mice produced 10-fold more circulating IFN-gamma without similar changes in IL-12 p70 levels, but with 10-fold increases in serum IL-18 relative to LPS-challenged control or endotoxin-tolerant mice. The role of IL-18 in CpG-induced immune potentiation was studied in splenocyte cultures from control, LPS-conditioned, or CpG-conditioned mice. These cultures produced similar amounts of IFN-gamma in response to rIL-12 and rIL-18. However, only CpG-conditioned cells produced IFN-gamma when cultured with LPS or CpG, and production was ablated in the presence of anti-IL-18R Ab. Anti-IL-18R Ab also reduced in vivo IFN-gamma production by >2-fold in CpG-pretreated mice. Finally, combined pretreatment of mice with LPS and CpG suppressed the production of circulating IFN-gamma, IL-12 p70, and IL-18 after subsequent LPS challenge. We conclude that CpG potentiates innate IFN-gamma production from NK cells by increasing IL-18 availability, but that the suppressive effects of LPS on innate cellular immunity dominate during combined LPS and CpG pretreatment. Multiple Toll-like receptor engagement in vivo during infection can result in functional polarization of innate immunity dominated by a specific Toll-like receptor response.
Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Islas de CpG/inmunología , Interferón gamma/biosíntesis , Interleucina-18/fisiología , Lipopolisacáridos/administración & dosificación , Oligodesoxirribonucleótidos/administración & dosificación , Adyuvantes Inmunológicos/sangre , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Supervivencia Celular/inmunología , Células Cultivadas , Células Dendríticas/inmunología , Sinergismo Farmacológico , Femenino , Inmunidad Celular , Inmunización Secundaria , Inmunosupresores/administración & dosificación , Inmunosupresores/sangre , Interferón gamma/sangre , Interleucina-18/biosíntesis , Interleucina-18/sangre , Subunidad alfa del Receptor de Interleucina-18 , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Lipopolisacáridos/sangre , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Oligodesoxirribonucleótidos/inmunología , Receptores de Interleucina/biosíntesis , Receptores de Interleucina-18 , Bazo/citología , Bazo/inmunología , Bazo/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Vacunas de ADN/administración & dosificación , Vacunas de ADN/inmunologíaRESUMEN
CD40 ligand (CD40L)-deficient C57BL/6 mice failed to control intracellular Leishmania donovani visceral infection, indicating that acquired resistance involves CD40-CD40L signaling and costimulation. Conversely, in wild-type C57BL/6 and BALB/c mice with established visceral infection, injection of agonist anti-CD40 monoclonal antibody (MAb) induced killing of approximately 60% of parasites within liver macrophages, stimulated gamma interferon (IFN-gamma) secretion, and enhanced mononuclear cell recruitment and tissue granuloma formation. Comparable parasite killing was also induced by MAb blockade (inhibition) of cytotoxic T lymphocyte antigen-4 (CTLA-4) which downregulates separate CD28-B7 T-cell costimulation. Optimal killing triggered by both anti-CD40 and anti-CTLA-4 required endogenous IFN-gamma and involved interleukin 12. CD40L(-/-) mice also failed to respond to antileishmanial chemotherapy (antimony), while in normal animals, anti-CD40 and anti-CTLA-4 synergistically enhanced antimony-associated killing. CD40L-CD40 signaling regulates outcome and response to treatment of experimental visceral leishmaniasis, and MAb targeting of T-cell costimulatory pathways (CD40L-CD40 and CD28-B7) yields macrophage activation and immunotherapeutic and immunochemotherapeutic activity.
Asunto(s)
Leishmaniasis Visceral/terapia , Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales/uso terapéutico , Antígenos CD , Antígenos de Diferenciación/fisiología , Antígenos CD40/fisiología , Ligando de CD40/fisiología , Antígeno CTLA-4 , Femenino , Inmunoterapia , Interferón gamma/fisiología , Interleucina-12/sangre , Subunidad p40 de la Interleucina-12 , Leishmaniasis Visceral/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Subunidades de Proteína/sangreRESUMEN
In established Leishmania donovani visceral infection in normal mice, anti-interleukin (IL)-10 receptor (IL-10R) monoclonal antibody (MAb) treatment induced intracellular parasite killing within liver macrophages. IL-10R blockade maintained IL-12 protein 40, markedly increased interferon (IFN)-gamma serum levels, and enhanced tissue inducible nitric oxide synthase (iNOS) expression and granuloma assembly. Optimal MAb-induced killing, including synergism with antimony chemotherapy, required endogenous IL-12 and/or IFN-gamma and at least one IFN-gamma-regulated macrophage mechanism-iNOS or phagocyte oxidase. However, in IFN-gamma knockout mice, anti-IL-10R also induced both granuloma formation and leishmanistatic activity. As judged by IL-10R blockade, endogenous IL-10 primarily regulates killing in L. donovani infection by suppressing production of and responses to the Th1 cell-type cytokines, IL-12, and IFN-gamma. However, because anti-IL-10R also released IFN-gamma-independent effects, IL-10 appears to act more broadly and suppresses multiple antileishmanial mechanisms.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Leishmania donovani , Leishmaniasis Visceral/terapia , Receptores de Interleucina/inmunología , Animales , Modelos Animales de Enfermedad , Femenino , Granuloma/parasitología , Granuloma/patología , Interferón gamma/sangre , Interferón gamma/deficiencia , Interferón gamma/genética , Interleucina-12/sangre , Interleucina-12/deficiencia , Interleucina-12/genética , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/patología , Neoplasias Hepáticas/parasitología , Neoplasias Hepáticas/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico Sintasa/análisis , Óxido Nítrico Sintasa/deficiencia , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa de Tipo II , Receptores de Interleucina-10RESUMEN
To determine if stimulation of Th1-cell-associated immune responses, mediated by interleukin 12 (IL-12) and gamma interferon (IFN-gamma), enhance the antileishmanial effect of amphotericin B (AMB), Leishmania donovani-infected BALB/c mice were first treated with (i) exogenous IL-12 to induce IFN-gamma, (ii) agonist anti-CD40 monoclonal antibody (MAb) to maintain IL-12 and induce IFN-gamma, or (iii) anti-IL-10 receptor (IL-10R) MAb to blockade suppression of IL-12 and IFN-gamma. In animals with established visceral infection, low-dose AMB alone (two injections of 1 mg/kg of body weight; total dose, 2 mg/kg) killed 15 to 29% of liver parasites; by themselves, the immunointerventions induced 16 to 33% killing. When the interventions were combined, the leishmanicidal activities increased 3.4-fold (anti-CD40), 6.3-fold (anti-IL-10R), and 9-fold (IL-12) compared with the activities of AMB plus the control preparations; and overall killing (76 to 84%) approximated the 84 to 92% killing effect of 7.5-fold more AMB alone (three injections of 5 mg/kg; total dose, 15 mg/kg). These results suggest that strengthening the host Th1-cell response may be a strategy for the development of AMB-sparing regimens in visceral leishmaniasis.