RESUMEN
Influenza virus contributes substantially to the global human and animal disease burden. To protect individuals against disease, strategies are needed to minimize the time an individual is at risk of developing disease symptoms. Passive immunization using avian IgY antibodies can protect individuals against a variety of pathogens, including influenza virus. Yet the effect of IgY administration on generation of protective immunity is largely unknown. To address the effect of passive immunization on the host immune response development, adult or aged, male and female C57BL/6NCrl mice received chicken IgY anti-H5N1, normal IgY or PBS intranasally four hours before, and 20 hours after intranasal infection with H1N1 influenza A virus (PR8). The mice receiving cross-reactive IgY anti-H5N1 were protected from disease and developed influenza virus-specific memory T cells similar to control-treated mice. When re-challenged with PR8 35 days post primary infection IgY anti-H5N1-treated mice were fully protected. Moreover, when challenged with heterologous H3N2 influenza A virus (X-31) or with PR8 three months post infection the mice were protected against severe disease and death, albeit a slight transient weight loss was noted. The results show that passive immunization with IgY anti-H5N1 is safe and protects mice against disease induced by influenza virus without inhibiting development of protective immunity after virus exposure. This indicate that passive immunization can be used as prophylactic therapy in combination with immunization to prevent disease.
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Apolipoprotein E (ApoE) has been associated with several diseases including Parkinson's disease, Alzheimer's and multiple sclerosis. ApoE also has documented immunomodulatory functions. We investigated gene expression in circulating monocytes and in bone marrows of patients with visceral leishmaniasis (VL) living in an endemic area in Bihar, India, and contrasted these with control healthy subjects or other diagnostic bone marrows from individuals in the same region. Samples from VL patients were obtained prior to initiating treatment. Our study revealed significant upregulated expression of the apoE transcript in patients with VL. Furthermore, the levels of ApoE protein were elevated in serum samples of subjects with VL compared with healthy endemic controls. These observations may provide clues regarding the complex interactions between lipid metabolism and immunoregulation of infectious and inflammatory diseases.
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Apolipoproteínas E , Leishmaniasis Visceral , Monocitos , Regulación hacia Arriba , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Apolipoproteínas E/genética , Médula Ósea , India/epidemiología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/parasitología , Monocitos/inmunologíaRESUMEN
Visceral leishmaniasis (VL) is a potentially fatal parasitic infection caused by Leishmania donovani in India. L. donovani is an obligate intracellular protozoan residing mostly in macrophages of the reticuloendothelial system throughout chronic infection. Monocytic phagocytes are critical in the pathogenesis of different forms of leishmaniasis. Subsets of monocytes are distinguished by their surface markers into CD14+CD16- classical monocytes, CD14+CD16+ intermediate monocytes, and CD16++CD14low non-classical monocyte subsets. During cutaneous leishmaniasis (CL), intermediate monocyte are reported to be a source of inflammatory cytokines IL-1ß and TNF, and they express CCR2 attracting them to sites of inflammatory pathology. We examined monocyte subsets in the blood and bone marrow of patients with VL from an endemic site in Bihar, India, and found these contrasted with the roles of monocytes in CL. During VL, intermediate and non-classical CD16+ monocyte subsets expressed instead a non-inflammatory phenotype with low CCR2, high CX3CR1 and low microbicidal oxidant generation, making them more similar to patrolling monocytes than inflammatory cells. Bone marrow CD16+ monocyte subsets expressed a phenotype that might be more similar to the inflammatory subsets of CL, although our inability to obtain bone marrow from healthy donors in the endemic region hampered this interpretation Overall the data suggest that CD16+ intermediate monocyte subsets in VL patients express a phenotypes that contributes to an immunosuppressed pathologic immune state, but in contrast to CL, these do not mediate localized inflammatory responses.
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Médula Ósea , Leishmaniasis Visceral , Monocitos , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/parasitología , Humanos , Monocitos/inmunología , India , Adulto , Masculino , Médula Ósea/parasitología , Femenino , Receptores de IgG/análisis , Receptores de IgG/metabolismo , Leishmania donovani/inmunología , Leishmania donovani/fisiología , Adulto Joven , Adolescente , Receptores CCR2/metabolismo , Persona de Mediana Edad , Niño , Receptores de Quimiocina/metabolismo , Receptor 1 de Quimiocinas CX3C/genética , Receptor 1 de Quimiocinas CX3C/metabolismo , Citocinas/metabolismoRESUMEN
In contrast to delayed-type hypersensitivity (DTH) and other hallmark reactions of cell-mediated immunity that correlate with vaccine-mediated protection against Mycobacterium tuberculosis, the contribution of vaccine dose on responses that emerge early after infection in the skin with Bacille Calmette-Guérin (BCG) is not well understood. We used a mouse model of BCG skin infection to study the effect of BCG dose on the relocation of skin Dendritic cells (DCs) to draining lymph node (DLN). Mycobacterium antigen 85B-specific CD4+ P25 T cell-receptor transgenic (P25 TCRTg) cells were used to probe priming to BCG in DLN. DC migration and T cell priming were studied across BCG inocula that varied up to 100-fold (104 to 106 Colony-forming units-CFUs). In line with earlier results in guinea pigs, DTH reaction in our model correlated with BCG dose. Importantly, priming of P25 TCRTg cells in DLN also escalated in a dose-dependent manner, peaking at day 6 after infection. Similar dose-escalation effects were seen for DC migration from infected skin and the accompanying transport of BCG to the DLN. BCG-triggered upregulation of co-stimulatory molecules on migratory DCs was restricted to the first 24 hour after infection and was independent of BCG dose over a 10-fold range (105 to 106 CFUs). The dose seemed to be a determinant of the number of total skin DCs that move to the DLN. In summary, our results support the use of higher BCG doses to detect robust DC migration and T cell priming.
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Vacuna BCG , Linfocitos T , Ratones , Animales , Cobayas , Inmunidad Celular , Células de Langerhans , Ganglios LinfáticosRESUMEN
BACKGROUND: CD4+ T cells play a central role in control of L. donovani infection, through IFN-γ production required for activation of macrophages and killing of intracellular parasites. Impaired control of parasites can in part be explained by hampered CD4+ T cells effector functions in visceral leishmaniasis (VL) patients. In a recent studies that defined transcriptional signatures for CD4+ T cells from active VL patients, we found that expression of the IL-7 receptor alpha chain (IL-7Rα; CD127) was downregulated, compared to CD4+ T cells from endemic controls (ECs). Since IL-7 signaling is critical for the survival and homeostatic maintenance of CD4+ T cells, we investigated this signaling pathway in VL patients, relative to ECs. METHODS: CD4+ T cells were enriched from peripheral blood collected from VL patients and EC subjects and expression of IL7 and IL7RA mRNA was measured by real time qPCR. IL-7 signaling potential and surface expression of CD127 and CD132 on CD4+ T cell was analyzed by multicolor flow cytometry. Plasma levels of soluble IL-7 and sIL-7Rα were measured by ELISA. RESULT: Transcriptional profiling data sets generated previously from our group showed lower IL7RA mRNA expression in VL CD4+ T cells as compared to EC. A significant reduction was, however not seen when assessing IL7RA mRNA by RT-qPCR. Yet, the levels of soluble IL-7Rα (sIL-7Rα) were reduced in plasma of VL patients compared to ECs. Furthermore, the levels of soluble IL-7 were higher in plasma from VL patients compared to ECs. Interestingly, expression of the IL-7Rα protein was higher on VL patient CD4+ T cells as compared to EC, with activated CD38+ CD4+ T cells showing higher surface expression of IL-7Rα compared to CD38- CD4+ T cells in VL patients. CD4+ T cells from VL patients had higher signaling potential baseline and after stimulation with recombinant human IL-7 (rhIL-7) compared to EC, as measured by phosphorylation of STAT5 (pSTAT5). Interestingly, it was the CD38 negative cells that had the highest level of pSTAT5 in VL patient CD4+ T cells after IL-7 stimulation. Thus, despite unaltered or potentially lowered IL7RA mRNA expression by CD4+ T cells from VL patients, the surface expression of the IL-7Rα was higher compared to EC and increased pSTAT5 was seen following exposure to rhIL-7. Accordingly, IL-7 signaling appears to be functional and even enhanced in VL CD4+ T cells and cannot explain the impaired effector function of VL CD4+ T cells. The enhanced plasma IL-7 may serve as part of homeostatic feedback mechanism regulating IL7RA expression in CD4+ T cells.
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Linfocitos T CD4-Positivos , Leishmaniasis Visceral , Humanos , Interleucina-7 , Leishmaniasis Visceral/parasitología , Transducción de Señal , ARN Mensajero/genéticaRESUMEN
Control of visceral leishmaniasis (VL) depends on proinflammatory Th1 cells that activate infected tissue macrophages to kill resident intracellular parasites. However, proinflammatory cytokines produced by Th1 cells can damage tissues and require tight regulation. Th1 cell IL-10 production is an important cell-autologous mechanism to prevent such damage. However, IL-10-producing Th1 (type 1 regulatory; Tr1) cells can also delay control of parasites and the generation of immunity following drug treatment or vaccination. To identify molecules to target in order to alter the balance between Th1 and Tr1 cells for improved antiparasitic immunity, we compared the molecular and phenotypic profiles of Th1 and Tr1 cells in experimental VL caused by Leishmania donovani infection of C57BL/6J mice. We also identified a shared Tr1 cell protozoan signature by comparing the transcriptional profiles of Tr1 cells from mice with experimental VL and malaria. We identified LAG3 as an important coinhibitory receptor in patients with VL and experimental VL, and we reveal tissue-specific heterogeneity of coinhibitory receptor expression by Tr1 cells. We also discovered a role for the transcription factor Pbx1 in suppressing CD4+ T cell cytokine production. This work provides insights into the development and function of CD4+ T cells during protozoan parasitic infections and identifies key immunoregulatory molecules.
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Interleucina-10 , Infecciones por Protozoos , Células TH1 , Células TH1/inmunología , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-10/metabolismo , Linfocitos T Reguladores/inmunología , Ratones Endogámicos C57BL , Leishmania donovani , Leishmaniasis Visceral/inmunología , Factor de Transcripción 1 de la Leucemia de Células Pre-B/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/parasitología , Infecciones por Protozoos/inmunología , Humanos , Animales , Ratones , Proteína del Gen 3 de Activación de Linfocitos/antagonistas & inhibidores , Interferón gamma/metabolismo , Unión Proteica , Regiones Promotoras Genéticas/inmunología , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: Co-endemicity of neglected tropical diseases (NTDs) necessitates that these diseases should be considered concomitantly to understand the relationship between pathology and to support disease management and control programs. The aims of the study were to assess the prevalence of filarial infection in asymptomatic Leishmania donovani infected individuals and the correlation of Wuchereria bancrofti infection with progression to clinical visceral leishmaniasis (VL) in Bihar, India. METHODOLOGY/PRINCIPAL FINDINGS: Within the Muzaffarpur-TMRC Health and Demographic Surveillance System (HDSS) area, a cohort of Leishmania seropositive (n = 476) or seronegative individuals (n = 1130) were sampled annually for three years for filarial infection and followed for progression to clinical VL. To corroborate the results from the cohort study, we also used a retrospective case-control study of 36 VL cases and 71 controls selected from a subset of the HDSS population to investigate the relationship between progression to clinical VL and the prevalence of filarial infection at baseline. Our findings suggest a higher probability of progression to clinical VL in individuals with a history of filarial infection: in both the cohort and case-control studies, progression to clinical VL was higher among filaria infected individuals (RR = 2.57, p = 0.056, and OR = 2.52, p = 0.046 respectively). CONCLUSION: This study describes that progression to clinical VL disease is associated with serological evidence of prior infection with W. bancrofti. The integration of disease programs for Leishmania and lymphatic filariasis extend beyond the relationship of sequential or co-infection with disease burden. To ensure elimination targets can be reached and sustained, we suggest areas of co-endemicity would benefit from overlapping vector control activities, health system networks and surveillance infrastructure.
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Filariasis Linfática , Leishmania donovani , Leishmaniasis Visceral , Animales , Humanos , Leishmaniasis Visceral/epidemiología , Wuchereria bancrofti , Estudios de Cohortes , Estudios Retrospectivos , Estudios de Casos y Controles , India/epidemiología , Filariasis Linfática/epidemiologíaRESUMEN
Allergic disorders are caused by a combination of hereditary and environmental factors. The hygiene hypothesis postulates that early-life microbial exposures impede the development of subsequent allergic disease. Recently developed "wildling" mice are genetically identical to standard laboratory specific pathogen-free (SPF) mice but are housed under seminatural conditions and have rich microbial exposures from birth. Thus, by comparing conventional SPF mice with wildlings, we can uncouple the impact of lifelong microbial exposures from genetic factors on the allergic immune response. We found that wildlings developed larger populations of antigen-experienced T cells than conventional SPF mice, which included interleukin-10-producing CD4 T cells specific for commensal Lactobacilli strains and allergy-promoting T helper 2 (TH2) cells. In models of airway exposure to house dust mite (HDM), recombinant interleukin-33, or Alternaria alternata, wildlings developed strong allergic inflammation, characterized by eosinophil recruitment, goblet cell metaplasia, and antigen-specific immunoglobulin G1 (IgG1) and IgE responses. Wildlings developed robust de novo TH2 cell responses to incoming allergens, whereas preexisting TH2 cells could also be recruited into the allergic immune response in a cytokine-driven and TCR-independent fashion. Thus, wildling mice, which experience diverse and lifelong microbial exposures, were not protected from developing pathological allergic immune responses. Instead, wildlings mounted robust allergic responses to incoming allergens, shedding new light on the hygiene hypothesis.
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Hipersensibilidad , Células Th2 , Ratones , Animales , Citocinas , Alérgenos , InmunidadRESUMEN
BACKGROUND: Dendritic cell (DC) vaccines for cancer therapy offer the possibility to let the patient's own immune system kill cancer cells. However, DC vaccines have shown less efficacy than expected due to failure to induce cancer cell killing and by activating T regulatory cells. METHODS: We tested if inhibition of signalling via WASp and Arp2/3 using the small molecule CK666 would enhance DC-mediated killing of tumour cells in vitro and in vivo. RESULTS: Using CK666 during the ex vivo phase of antigen processing of ovalbumin (OVA), murine and human DCs showed decreased phagosomal acidification, indicating activation of the cross-presentation pathway. When compared to untreated DCs, DCs treated with CK666 during uptake and processing of OVA-induced increased proliferation of OVA-specific CD8+ OT-I T cells in vitro and in vivo. Using the aggressive B16-mOVA melanoma tumour model, we show that mice injected with CK666-treated DCs and OVA-specific CD8+ OT-I T cells showed higher rejection of B16 melanoma cells when compared to mice receiving non-treated DCs. This resulted in the prolonged survival of tumour-bearing mice receiving CK666-treated DCs. Moreover, combining CK666-treated DCs with the checkpoint inhibitor anti-PD1 further prolonged survival. CONCLUSION: Our data suggest that the small molecule inhibitor CK666 is a good candidate to enhance DC cross-presentation for cancer therapy.
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Reactividad Cruzada , Vacunas , Ratones , Animales , Humanos , Linfocitos T CD8-positivos , Células Dendríticas , Presentación de Antígeno , Ovalbúmina/metabolismo , Vacunas/metabolismo , Ratones Endogámicos C57BLRESUMEN
Influenza virus infection is restricted to airway-associated tissues and elicits both cellular and humoral responses ultimately resulting in generation of memory cells able to initiate a rapid immune response against re-infections. Resident memory T cells confer protection at the site of infection where lung-resident memory T cells are important for protecting the host against homologous and heterologous influenza virus infections. Mapping kinetics of local and systemic T cell memory formation is needed to better understand the role different T cells have in viral control and protection. After infecting BALB/c mice with influenza virus strain A/Puerto Rico/8/1934 H1N1 the main proportion of activated T cells and B cells expressing the early activation marker CD69 was detected in lungs and lung-draining mediastinal lymph nodes. Increased frequencies of activated cells were also observed in the peripheral lymphoid organs spleen, inguinal lymph nodes and mesenteric lymph nodes. Likewise, antigen-specific T cells were most abundant in lungs and mediastinal lymph nodes but present in all organs studied. CD8+CD103-CD49a+ lung-resident T cells expanded simultaneously with timing of viral clearance whereas CD8+CD103+CD49a+ lung-resident T cells was the most abundant subset after resolution of infection and antigen-specific, lung-resident T cells were detected up to seven months after infection. In conclusion, the results in this detailed kinetic study demonstrate that influenza virus infection elicits adaptive immune responses mainly in respiratory tract-associated tissues and that distinct subsets of lung-resident T cells expand at different time points during infection. These findings contribute to the understanding of the adaptive immune response locally and systemically following influenza virus infection and call for further studies on the roles of the lung-resident T cell subsets.
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Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Ratones , Animales , Humanos , Memoria Inmunológica , Integrina alfa1 , Cinética , Subgrupos de Linfocitos T , Pulmón , Ratones Endogámicos BALB CRESUMEN
Diabetes mellitus (DM) increases the risk of developing tuberculosis (TB), but the mechanisms behind diabetes-TB comorbidity are still undefined. Here, we studied the role of hypoxia-inducible factor-1 (HIF-1), a main regulator of metabolic and inflammatory responses, in the outcome of Mycobacterium tuberculosis infection of bone marrow-derived macrophages (BMM). We observed that M. tuberculosis infection of BMM increased the expression of HIF-1α and HIF-1-regulated genes. Treatment with the hypoxia mimetic deferoxamine (DFO) further increased levels of HIF-1-regulated immune and metabolic molecules and diminished the intracellular bacterial load in BMM and in the lungs of infected mice. The expression of HIF-1-regulated immunometabolic genes was reduced, and the intracellular M. tuberculosis levels were increased in BMM incubated with high-glucose levels or with methylglyoxal (MGO), a reactive carbonyl compound elevated in DM. In line with the in vitro findings, high M. tuberculosis levels and low HIF-1-regulated transcript levels were found in the lungs from hyperglycemic Leprdb/db compared with wild-type mice. The increased intracellular M. tuberculosis growth and the reduced expression of HIF-1-regulated metabolic and inflammatory genes in BMM incubated with MGO or high glucose were reverted by additional treatment with DFO. Hif1a-deficient BMM showed ablated responses of immunometabolic transcripts after mycobacterial infection at normal or high-glucose levels. We propose that HIF-1 may be targeted for the control of M. tuberculosis during DM. IMPORTANCE People living with diabetes who are also infected with M. tuberculosis are more likely to develop tuberculosis disease (TB). Why diabetic patients have an increased risk for developing TB is not well understood. Macrophages, the cell niche for M. tuberculosis, can express microbicidal mechanisms or be permissive to mycobacterial persistence and growth. Here, we showed that high glucose and carbonyl stress, which mediate diabetes pathogenesis, impair the control of intracellular M. tuberculosis in macrophages. Infection with M. tuberculosis stimulated the expression of genes regulated by the transcription factor HIF-1, a major controller of the responses to hypoxia, resulting in macrophage activation. High glucose and carbonyl compounds inhibited HIF-1 responses by macrophages. Mycobacterial control in the presence of glucose or carbonyl stress was restored by DFO, a compound that stabilizes HIF-1. We propose that HIF-1 can be targeted to reduce the risk of developing TB in people with diabetes.
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Mycobacterium tuberculosis , Tuberculosis , Ratones , Animales , Mycobacterium tuberculosis/fisiología , Factor 1 Inducible por Hipoxia/metabolismo , Piruvaldehído/metabolismo , Deferoxamina/farmacología , Deferoxamina/metabolismo , Óxido de Magnesio/metabolismo , Tuberculosis/microbiología , Macrófagos/microbiología , Hipoxia/metabolismo , Glucosa/metabolismoRESUMEN
A series of 1-aryl-4-(phthalimidoalkyl) piperazines and 1-aryl-4-(naphthalimidoalkyl) piperazines were retrieved from a proprietary library based on their high structural similarity to haloperidol, an antipsychotic with antiparasitic activity, and assessed as potential antileishmanial scaffolds. Selected compounds were tested for antileishmanial activity against promastigotes of Leishmania major and Leishmania mexicana in dose-response assays. Two of the 1-aryl-4-(naphthalimidoalkyl) piperazines (compounds 10 and 11) were active against promastigotes of both Leishmania species without being toxic to human fibroblasts. Their activity was found to correlate with the length of their alkyl chains. Further analyses showed that compound 11 was also active against intracellular amastigotes of both Leishmania species. In promastigotes of both Leishmania species, compound 11 induced collapse of the mitochondrial electrochemical potential and increased the intracellular Ca2+ concentration. Therefore, it may serve as a promising lead compound for the development of novel antiparasitic drugs.
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Antiprotozoarios , Leishmania major , Leishmania mexicana , Antiparasitarios , Antiprotozoarios/química , Antiprotozoarios/farmacología , Humanos , Piperazinas/farmacologíaRESUMEN
Objectives: There is an urgent need to be able to identify individuals with asymptomatic Leishmania donovani infection, so their risk of progressing to VL and transmitting parasites can be managed. This study examined transcriptional markers expressed by CD4+ T cells that could distinguish asymptomatic individuals from endemic controls and visceral leishmaniasis (VL) patients. Methods: CD4+ T cells were isolated from individuals with asymptomatic L. donovani infection, endemic controls and VL patients. RNA was extracted and RNAseq employed to identify differentially expressed genes. The expression of one gene and its protein product during asymptomatic infection were evaluated. Results: Amphiregulin (AREG) was identified as a distinguishing gene product in CD4+ T cells from individuals with asymptomatic L. donovani infection, compared to VL patients and healthy endemic control individuals. AREG levels in plasma and antigen-stimulated whole-blood assay cell culture supernatants were significantly elevated in asymptomatic individuals, compared to endemic controls and VL patients. Regulatory T (Treg) cells were identified as an important source of AREG amongst CD4+ T-cell subsets in asymptomatic individuals. Conclusion: Increased Treg cell AREG expression was identified in individuals with asymptomatic L. donovani infection, suggesting the presence of an ongoing inflammatory response in these individuals required for controlling infection and that AREG may play an important role in preventing inflammation-induced tissue damage and subsequent disease in asymptomatic individuals.
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Inoculation of Mycobacterium bovis Bacille Calmette-Guérin (BCG) in the skin mobilizes local dendritic cells (DC) to the draining lymph node (dLN) in a process that remains incompletely understood. In this study, a mouse model of BCG skin infection was used to investigate mechanisms of skin DC migration to dLNs. We found enhanced transcription of cyclooxygenase (COX)-2 and production of COX-derived PGE2 early after BCG infection in skin. Animals treated with antagonists for COX or the PGE2 receptors EP2 and EP4 displayed a marked reduction in the entry of skin DCs and BCG to dLNs, uncovering an important contribution of COX-derived PGE2 in this migration process. In addition, live BCG bacilli were needed to invoke DC migration through this COX-PGE2 pathway. Having previously shown that IL-1R partially regulates BCG-induced relocation of skin DCs to dLNs, we investigated whether PGE2 release was under control of IL-1. Interestingly, IL-1R ligands IL-1α/ß were not required for early transcription of COX-2 or production of PGE2 in BCG-infected skin, suggesting that the DC migration-promoting role of PGE2 is independent of IL-1α/ß in our model. In DC adoptive transfer experiments, EP2/EP4, but not IL-1R, was needed on the moving DCs for full-fledged migration, supporting different modes of action for PGE2 and IL-1α/ß. In summary, our data highlight an important role for PGE2 in guiding DCs to dLNs in an IL-1-independent manner.
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Mycobacterium bovis , Animales , Vacuna BCG , Ciclooxigenasa 2/metabolismo , Células Dendríticas , Dinoprostona/farmacología , Interleucina-1/metabolismo , Células de Langerhans , Ganglios Linfáticos , Ratones , Subtipo EP4 de Receptores de Prostaglandina E/metabolismoRESUMEN
Intestinal helminth parasites can alter immune responses to vaccines, other infections, allergens and autoantigens, implying effects on host immune responses in distal barrier tissues. We herein show that the skin of C57BL/6 mice infected with the strictly intestinal nematode Heligmosomoides polygyrus contain higher numbers of CD4+ T cells compared to the skin of uninfected controls. Accumulated CD4+ T cells were H. polygyrus-specific TH2 cells that skewed the skin CD4+ T cell composition towards a higher TH2/TH1 ratio which persisted after worm expulsion. Accumulation of TH2 cells in the skin was associated with increased expression of the skin-homing chemokine receptors CCR4 and CCR10 on CD4+ T cells in the blood and mesenteric lymph nodes draining the infected intestine and was abolished by FTY720 treatment during infection, indicating gut-to-skin trafficking of cells. Remarkably, skin TH2 accumulation was associated with impaired capacity to initiate IFN-γ recall responses and develop skin-resident memory cells to mycobacterial antigens, both during infection and months after deworming therapy. In conclusion, we show that infection by a strictly intestinal helminth has long-term effects on immune cell composition and local immune responses to unrelated antigens in the skin, revealing a novel process for T cell colonisation and worm-mediated immunosuppression in this organ.
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Parasitosis Intestinales , Nematospiroides dubius , Infecciones por Strongylida , Animales , Ratones , Ratones Endogámicos C57BL , Células Th2RESUMEN
Dendritic cells (DCs) devoid of the actin regulator Wiskott-Aldrich syndrome protein (WASp) show reduced directed migration and decreased formation of podosome adhesion structures. We examined DCs expressing a gain-of-function mutation in WASp, WASp L272P, identified in X-linked neutropenia patients. Analysis of WASp L272P DCs was compared to WASp-deficient DCs to examine how WASp activity influences DC migratory responses. In confined space, WASp-deficient DCs had increased migration speed whereas WASp L272P DCs had similar average speed but increased speed fluctuations, reduced displacement, and atypical rounded morphology, compared to wild-type (WT) DCs. Using an ear inflammation model and flow cytometry analysis, WT, WASp-deficient, and WASp L272P DCs were found to migrate in comparable numbers to the draining lymph nodes (LNs). However, histology analysis revealed that migratory DCs of WASp deficient and WASp L272P mice were mainly located in the collagenous capsule of the LN whereas WT DCs were located inside the LN. Analysis of ultrastructural features revealed that WASp L272P DCs had reduced cell area but formed larger podosome structures when compared to WT DCs. Together, our data suggest that WASp activity regulates DC migration and that loss-of-function and gain-of-function in WASp activity lead to different and phenotype-specific DC migratory behavior.
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Neutropenia , Proteína del Síndrome de Wiskott-Aldrich/genética , Actinas/metabolismo , Animales , Movimiento Celular/fisiología , Células Dendríticas/metabolismo , Mutación con Ganancia de Función , Humanos , Ratones , Neutropenia/genética , Proteína del Síndrome de Wiskott-Aldrich/metabolismoRESUMEN
Visceral leishmaniasis (VL; Leishmania donovani) cases produce interferon-γ and tumor necrosis factor in response to soluble leishmanial antigen (SLA) in whole-blood assays. Using transcriptional profiling, we demonstrate the impact of interleukin-10 (IL-10), a cytokine implicated in VL, on this response. SLA stimulation identified 28 differentially expressed genes (DEGs), 17/28 in a single network with TNF as hub. SLA plus anti-IL-10 produced 454 DEGs, 292 in a single network with TNF, IFNG, NFKBIA, IL6, and IL1B as hubs in concert with a remarkable chemokine/cytokine storm. Our data demonstrate the singular effect of IL-10 as a potent immune modulator in VL.
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Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/inmunología , Interleucina-10/inmunología , Leishmaniasis Visceral/inmunología , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/genética , Antígenos de Protozoos/sangre , Citocinas/inmunología , Expresión Génica , Humanos , Interferón gamma/inmunología , Leishmania donovani/inmunología , Factor de Necrosis Tumoral alfaRESUMEN
Type I interferons (IFNs) play critical roles in anti-viral and anti-tumor immunity. However, they also suppress protective immune responses in some infectious diseases. Here, we identify type I IFNs as major upstream regulators of CD4+ T cells from visceral leishmaniasis (VL) patients. Furthermore, we report that mice deficient in type I IFN signaling have significantly improved control of Leishmania donovani, a causative agent of human VL, associated with enhanced IFNγ but reduced IL-10 production by parasite-specific CD4+ T cells. Importantly, we identify a small-molecule inhibitor that can be used to block type I IFN signaling during established infection and acts synergistically with conventional anti-parasitic drugs to improve parasite clearance and enhance anti-parasitic CD4+ T cell responses in mice and humans. Thus, manipulation of type I IFN signaling is a promising strategy for improving disease outcome in VL patients.
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Inmunidad/efectos de los fármacos , Interferón Tipo I/farmacología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/parasitología , Parásitos/inmunología , Anfotericina B/farmacología , Animales , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Epítopos , Humanos , Inflamación/inmunología , Inflamación/patología , Interferón gamma/farmacología , Ratones Endogámicos C57BL , Nitrilos , Parásitos/efectos de los fármacos , Pirazoles/farmacología , Pirimidinas , Receptor de Interferón alfa y beta/deficiencia , Receptor de Interferón alfa y beta/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Immunity to intestinal helminths is known to require both innate and adaptive components of the immune system activated along the Type 2 IL-4R/STAT6-dependent pathway. We have found that macrophage migration inhibitory factor (MIF) is essential for the development of effective immunity to the intestinal helminth Heligmosomoides polygyrus, even following vaccination which induces sterile immunity in wild-type mice. A chemical inhibitor of MIF, 4-IPP, was similarly found to compromise anti-parasite immunity. Cellular analyses found that the adaptive arm of the immune response, including IgG1 antibody responses and Th2-derived cytokines, was intact and that Foxp3+ T regulatory cell responses were unaltered in the absence of MIF. However, MIF was found to be an essential cytokine for innate cells, with ablated eosinophilia and ILC2 responses, and delayed recruitment and activation of macrophages to the M2 phenotype (expressing Arginase 1, Chil3, and RELM-α) upon infection of MIF-deficient mice; a macrophage deficit was also seen in wild-type BALB/c mice exposed to 4-IPP. Gene expression analysis of intestinal and lymph node tissues from MIF-deficient and -sufficient infected mice indicated significantly reduced levels of Arl2bp, encoding a factor involved in nuclear localization of STAT3. We further found that STAT3-deficient macrophages expressed less Arginase-1, and that mice lacking STAT3 in the myeloid compartment (LysMCrexSTAT3fl/fl) were unable to reject a secondary infection with H. polygyrus. We thus conclude that in the context of a Type 2 infection, MIF plays a critical role in polarizing macrophages into the protective alternatively-activated phenotype, and that STAT3 signaling may make a previously unrecognized contribution to immunity to helminths.