Substance P induces localization of MIF/α1-inhibitor-3 complexes to umbrella cells via paracellular transit through the urothelium in the rat bladder

BACKGROUND: Macrophage migration inhibitory factor (MIF) is released into the intraluminal fluid during bladder inflammation in the rat complexed to α1-inhibitor-3 (A1-I3; a rodent proteinase inhibitor in the α-macroglobulin family). The location of A1-I3 in the bladder had not been investigated. Therefore, we examined the location of A1-I3 and MIF/A1-I3 complexes in the bladder and changes due to experimental inflammation. METHODS: Anesthetized male rats had bladders removed with no treatment (intact) or were injected with Substance P (SP; s.c.; saline vehicle). After one hour intraluminal fluid was removed, bladder was excised and MIF and A1-I3 levels were determined using ELISA and/or western-blotting. MIF co-immunoprecipitation determined MIF/A1-I3 complexes in the bladder. Bladder sections were immunostained for A1-I3 and MIF/A1-I3. RESULTS: A1-I3 immunostaining was observed in interstitial spaces throughout the bladder (including submucosa) but not urothelium in intact and saline-treated rats. RT-PCR showed that the bladder does not synthesize A1-I3, therefore, A1-I3 in the interstitial space of the bladder must be plasma derived. In SP-treated rats, A1-I3 in the bladder increased and A1-I3 was observed traversing through the urothelium. Umbrella cells that do not show MIF and/or A1-I3 immunostaining in intact or saline-treated rats, showed co-localization of MIF and A1-I3 after SP-treatment. Western blotting demonstrated that in the bladder MIF formed non-covalent interactions and also binds covalently to A1-I3 to form high molecular weight MIF/A1-I3 complexes (170, 130 and 75-kDa, respectively, verified by co-immunoprecipitation). SP-induced inflammation selectively reduced 170-kDa MIF/A1-I3 in the bladder while increasing 170 and 130-kDa MIF/A1-I3 in the intraluminal fluid. CONCLUSION: A1-I3 and MIF/A1-I3 complexes are resident in bladder interstitium. During SP-induced inflammation, MIF/A1-I3 complexes are released from the bladder into the lumen. Binding of MIF/A1-I3 complexes to urothelial cells during inflammation suggests these complexes participate in the inflammatory reaction through activation of receptors for MIF and/or for A1-I3

Oncostatin M induces IL-33 expression in liver endothelial cells in mice and expands ST2+CD4+ lymphocytes

International audienceInterleukin (IL)-33 is crucially involved in liver pathology and drives hepatoprotective functions. However, the regulation of IL-33 by cytokines of the IL-6 family, including oncostatin M (OSM) and IL-6, is not well studied. The aim of the present study was to determine whether OSM mediates regulation of IL-33 expression in liver cells. Intramuscular administration in mice of an adenovirus encoding OSM (AdOSM) leads to increase in expression of OSM in muscles, liver, and serum of AdOSM-infected mice compared with control mice. The increase of circulating OSM markedly regulated mRNA of genes associated with blood vessel biology, chemotaxis, cellular death, induction of cell adhesion molecules, and the alarmin cytokine IL-33 in liver. Steady-state IL-33 mRNA was upregulated by OSM at an early phase (8 h) following AdOSM infection. At the protein level, the expression of IL-33 was significantly induced in liver endothelial cells [liver sinusoidal endothelial cells (LSEC) and vascular endothelial cells] with a peak at 8 days post-AdOSM infection in mice. In addition, we found OSM-stimulated human microvascular endothelial HMEC-1 cells and human LSEC/TRP3 cells showed a significant increase in expression of IL-33 mRNA in a dose-dependent manner in cell culture. The OSM-mediated overexpression of IL-33 was associated with the activation/enrichment of CD4(+)ST2(+) cells in liver of AdOSM-infected mice compared with adenovirus encoding green fluorescent protein-treated control mice. In summary, these data suggest that the cytokine OSM regulates the IL-33 expression in liver endothelial cells in vivo and in HMEC-1/TRP3 cells in vitro and may specifically expand the target CD4(+)ST2(+) cells in live

TAP1(–/–) mice present oligoclonal BV-BJ expansions following the rejection of grafts bearing self antigens

Our previous work showed that transporter associated with antigen processing 1 (TAP1)(–/–) (H-2(b)) mice rejected grafts from H-2(b) mice which display a normal density of class I major histocompatibility complex (MHC) molecules at the cell surface. Our results indicated that H-2(b) molecules themselves may be a target in this kind of rejection and that CD4(+) T cells play a major role in this autoreactive process. Our data also suggested that TAP1(–/–) mice, in addition to the well-recognized phenotype of class I and CD8(+) T-cell deficiency, present a functional alteration in their autoreactive CD4(+) T-cell repertoires. In this model of inflammatory autoreactivity to modified self, we have analysed T-cell receptor (TCR) V-beta–J-beta (BV-BJ) usage by complementarity determining region 3 (CDR3) length spectratyping in splenocytes from naïve TAP1(–/–) mice and transplanted TAP1(–/–) mice that rejected B6 heart grafts or responded to synthetic self H-2K(b) peptides. Importantly, oligoclonal T-cell expansions shared by different animals were detected in the peripheral T-cell repertoire of transplanted TAP1(–/–) mice. Such public expansions were also induced in vitro by H-2K(b) peptides, suggesting that dominant class I peptides can induce preferential expansions of restricted T-cell populations during rejection. Some of these public T-cell expansions were also detected in transplanted mice even before in vitro stimulation with peptides, indicating that post-transplantation expansion of these populations had occurred in vivo. The functional activity of these T-cell populations awaits elucidation, as do the underlying mechanisms involved in the inflammatory autoreactive process, in TAP1(–/–) mice

The secretory immunoglobulin A response to Mycobacterium tuberculosis in a childhood population Resposta da imunoglobulina A secretória ao Mycobacterium tuberculosis em população infantil

We report on the measurement of saliva anti-Purified Protein Derivative sIgA and 38kDa antibodies from 127 children, of whom 31 were strong tuberculosis suspects and 96 were healthy contact children. The results concerning the percentage of children with antibody reactivity to PPD and 38kDa antigens showed that, of these 2 antigens, 38kDa induced higher reactivity in patients positive and negative for the Tuberculin Skin Test (28% and 16.6%, respectively) in comparison to controls positive and negative for the TST (11.7% and 7.1%, respectively). There was a statistically significant difference between patients positive and controls negative for the TST. In relation to the Purified Protein Derivative antigen, while 14.2% of patients positive for the TST showed antibody reactivity to the PPD antigen, no patients negative for the TST had reactivity to this antigen. The findings suggest that these two antigens seem be associated with a different development of the mucosal defence mechanisms mediated by sIgA against Mycobacterium tuberculosis.<br>Foram dosados anticorpos sIgA anti-Purified Protein Derivative e 38kDa da saliva de 127 crianças, das quais 31 eram de pacientes altamente suspeitos de tuberculose e 96 eram provenientes de crianças saudáveis, que tiveram contato com pacientes. Os resultados referentes à porcentagem de crianças, reativas ao PPD e ao antígeno 38kDa, mostraram que destes dois antígenos, o 38kDa induziu maior reatividade em pacientes positivos e negativos ao Tuberculin Skin Test (28% e 16,6%, respectivamente), em comparação aos controles positivos e negativos ao TST (11,7% e 7,1%, respectivamente). Houve diferença estatisticamente significativa entre pacientes positivos e controles negativos ao Tuberculin Skin Test. Em relação ao antígeno PPD, enquanto 14,2% de pacientes positivos ao TST mostraram anticorpos reativos ao antígeno Purified Protein Derivative, nenhum paciente negativo ao TST foi reativo ao antígeno. Os achados sugerem que, aparentemente, estes dois antígenos estão associados a desenvolvimento distinto dos mecanismos de defesa da mucosa mediados por sIgA contra Mycobacterium tuberculosis