Essential Role of CARD14 in Murine Experimental Psoriasis.

Caspase recruitment domain family member 14 (CARD14) was recently identified as a psoriasis-susceptibility gene, but its immunological role in the pathogenesis of psoriasis in vivo remains unclear. In this study, we examined the role of CARD14 in murine experimental models of psoriasis induced by either imiquimod (IMQ) cream or recombinant IL-23 injection. In all models tested, the psoriasiform skin inflammation was abrogated in Card14-/- mice. Comparison of the early gene signature of the skin between IMQ-cream-treated Card14-/- mice and Tlr7-/-Tlr9-/- mice revealed not only their similarity, but also distinct gene sets targeted by IL-23. Cell type-specific analysis of these mice identified skin Langerinhigh Langerhans cells as a potent producer of IL-23, which was dependent on both TLR7 and TLR9 but independent of CARD14, suggesting that CARD14 is acting downstream of IL-23, not TLR7 or TLR9. Instead, a bone marrow chimera study suggested that CARD14 in radio-sensitive hematopoietic cells was required for IMQ-induced psoriasiform skin inflammation, controlling the number of Vγ4+ T cells producing IL-17 or IL-22 infiltrating through the dermis to the inflamed epidermis. These data indicate that CARD14 is essential and a potential therapeutic target for psoriasis.

C1r/C1s deficiency is insufficient to induce murine systemic lupus erythematosus.

C1s deficiency is strongly associated with the development of human systemic lupus erythematosus (SLE); however, the mechanisms by which C1s deficiency contributes to the development of SLE have not yet been elucidated in detail. Using ICR-derived-glomerulonephritis (ICGN) mouse strain that develops SLE and very weakly expresses C1s in the liver, we investigated the protective roles of C1s against SLE. A genetic sequence analysis revealed complete deletion of the C1s1 gene, a mouse homolog of the human C1s gene, with partial deletion of the C1ra and C1rb genes in the ICGN strain. This deletion led to the absence of C1r/C1s and a low level of C1q in the circulation. In order to investigate whether the C1r/C1s deficiency induces SLE, we produced a congenic mouse strain by introducing the deletion region of ICGN into the C57BL/6 strain. Congenic mice exhibited no C1r/C1s and a low level of C1q in the circulation, but did not have any autoimmune defects. These results suggest that C1r/C1s deficiency is not sufficient to drive murine SLE and also that other predisposing genes exist in ICGN mice.

Brazilian propolis inhibits the differentiation of Th17 cells by inhibition of interleukin-6-induced phosphorylation of signal transducer and activator of transcription 3.

Propolis is a resinous substance collected by honeybees from leaf buds and cracks in the bark of various plants. It has been reported to show immunomodulatory activity. Previously, we reported the protective effect of Brazilian propolis ethanolic extract against the pathogenesis of collagen-induced arthritis (CIA), an experimental animal model of rheumatoid arthritis (RA). Moreover, we found that the protective effect against CIA was involved in suppression of the production of interleukin-17 (IL-17) in CIA mice. In the present study, we demonstrated for the first time that propolis inhibited IL-6 plus transforming growth factor-ß induced Th17 differentiation in vitro. Propolis also suppressed the IL-6-induced phosphorylation of signal transducer and activator of transcription 3 (STAT3), a cytokine-activated essential transcription factor in Th17 development, concomitantly with the enhanced suppressor of cytokine signaling 3 expression involved in the downregulation of STAT3 phosphorylation. These data suggest that the suppressive effect of propolis on Th17 differentiation might be useful for controlling unbalanced cytokine networks in autoimmune diseases.

Suppression of interleukin 17 production by Brazilian propolis in mice with collagen-induced arthritis.

Propolis is a resinous substance collected by honeybees from leaf buds and cracks in the bark of various plants. Propolis has been reported to have immunomodulatory activity. We hypothesized that propolis would be able to reduce the disease severity of rheumatoid arthritis. We evaluated the effect of Brazilian propolis ethanolic extract on the pathogenesis of collagen-induced arthritis (CIA) in mice. Mice fed propolis exhibited significant lower clinical arthritis scores than those fed the control diet. To investigate the mechanism of the effect of propolis on CIA mice, we examined interleukin-17 (IL-17) production in CIA mice fed propolis using an enzyme-linked immunospot assay and flow cytometric analysis. The numbers of IL-17-producing cells in the CIA mice fed propolis were significantly decreased. To determine direct influence of propolis on cytokine production, splenocytes were stimulated with phorbol myristate acetate in the presence of propolis extract in vitro. Concentration-dependent declines in IL-17 expression were observed by ELISA and real-time PCR methods. We further found that propolis significantly inhibited the differentiation of Th17 cells from murine splenocytes in a concentration-dependent manner. Taken together, our results may provide a new light on the potential mechanism of the immunosuppressive and anti-inflammatory effects of propolis.

Age-Related Changes of Serum Soluble Interleukin 9 Receptor (sIL-9Rα) in Healthy Subjects.

Most cytokine receptors including interleukin (IL)-9 have soluble counterparts in body fluids. We planned to investigate the pathophysiological significance of the serum soluble IL-9 receptor (sIL-9R) level. We determined the serum sIL-9Rα chain (sIL-9Rα) levels in 96 healthy Japanese individuals to establish a control value by means of specific human sIL-9Rα ELISA, followed by a preliminary application in a patient with diarrhea positive hemolytic uremic syndrome. Age was negatively correlated with the sIL-9Rα level (Spearman r = -0.241, n = 96, p = 0.0180). The serum sIL-9Rα level showed a progressive decline to the normal adult level by the age of 30. The serum sIL-9Rα level of the patient with HUS was markedly higher than those of the age-matched control from the onset of the disease. Because of the remarkable age-dependent variability of sIL-9Rα in healthy subjects, disease-related changes, as well as therapy-dependent alterations, should be considered with caution. Thus, it is recommended that when the serum sIL-9Rα levels of patients are evaluated, the values should be compared with those of age-matched controls. The established control value will be used to discriminate between normal and the pathological conditions in our future studies.

Determination of soluble tumor necrosis factor-α receptor type I (TNFRI) and II (TNFRII) in the urine of healthy Japanese subjects.

We determined the urinary soluble tumor necrosis factor-α receptor type I (sTNFRI) and type II (sTNFRII) levels in healthy Japanese individuals to establish a reference value by means of specific ELISA. It was found that there were no significant differences between the urine sTNFRI and sTNFRII levels of children and adults. To demonstrate the usefulness of the reference value for children, we measured the urine sTNFRI and sTNFRII levels of children with diarrhea positive (D+) hemolytic uremic syndrome (HUS) as a preliminary study. The urine sTNFRI and sTNFRII levels of the patients with HUS were markedly higher than those of healthy children from the onset of D + HUS. Our reliable reference value for healthy children will allow us to discriminate between normal and pathological conditions in future studies.

Determination of the age-related changes of serum basic fibroblast growth factor (bFGF) level in healthy Japanese subjects.

We determined the serum basic fibroblast growth factor (bFGF) levels in healthy Japanese individuals to establish a reference value by means of specific human bFGF ELISA. It was found that there were no significant differences between the serum bFGF levels of children and adults. However, the reference value for children had a broader range than that of adults. Therefore, it is recommended that when the serum bFGF levels of patients are evaluated, the values should be compared with those of age-matched controls. To demonstrate the usefulness of the reference value for children, we measured the bFGF level of an 8-year boy with diarrhea positive (D+) hemolytic uremic syndrome (HUS), as a preliminary study. The serum bFGF level of the patient with HUS was markedly higher than those of healthy children from the onset of D+HUS. Our reliable reference value for healthy children will allow us to discriminate between normal and pathological conditions in future studies.

Age-dependent decreases in serum soluble interleukin-1 receptor type I (sIL-1RI) in healthy individuals: a population study of serum sIL-1RI levels in Japanese subjects.

The levels of several soluble cytokine receptors in body fluids of healthy individuals change with age. Clinical application of the measurement of the serum soluble interleukin-1 receptor type I (sIL-1RI) level depends critically on the samples used as the controls. At present, there is no information regarding the levels of serum sIL-1RI in healthy subjects. The purpose of this study is to reveal the age-related changes that occur in the serum sIL-1RIlevels of healthy individuals. We determined the serum sIL-1RI levels of healthy Japanese children using ELISA. The serum sIL-1RI level of children (0-14 years) was significantly higher than that of adults (more than 15 years) (P = 0.0138, n = 90). Thus, it is recommended that when the serum sIL-1RI level of patients is evaluated, it should be compared against age-matched controls.

Urinary evaluation of the balance between the soluble interferon-gamma receptor (IFN-gammaR1) and the interleukin-4 receptor (IL-4Ralpha) in children with vesicoureteral reflux.

We planned to investigate the urinary soluble cytokine receptor profile in patients with vesico-ureteric reflux (VUR). The urine levels of soluble interferon-gamma receptor R1 (sIFN-gammaR) and soluble interleukin-4 receptor alpha (sIL-4R) were measured using an ELISA technique. The urine levels of sIFN-gammaR in the patients with VUR were significantly higher than those in the healthy controls (p < 0.001). On the other hand, although the urine sIL-4R levels in the patients with VUR were also higher than those in the controls, there were no significant differences between them. The urinary soluble receptor levels did not correlate with the clinical severity of VUR. These results suggest that there may be an immunological basis to VUR complicatedly.

A synonymous splice site mutation in IL2RG gene causes late-onset combined immunodeficiency.

X-Linked severe combined immunodeficiency (X-SCID) is a severe form of primary immunodeficiency characterized by absence of T cells and NK cells. X-SCID is caused by a loss-of-function mutation in the IL2RG gene that encodes common gamma chain (γc), which plays an essential role in lymphocyte development. We report the first case of hypomorphic X-SCID caused by a synonymous mutation in the IL2RG gene leading to a splice anomaly, in a family including two patients with diffuse cutaneous warts, recurrent molluscum contagiosum, and mild respiratory infections. The mutation caused aberrant splicing of IL2RG mRNA, subsequently resulted in reduced γc expression. The leaky production of normally spliced IL2RG mRNA produced undamaged protein; thus, T cells and NK cells were generated in the patients. Functional assays of the patients' T cells and NK cells revealed diminished cytokine response in the T cells and absent cytokine response in the NK cells. In addition, the TCR repertoire in these patients was limited. These data suggest that a fine balance between aberrant splicing and leaky production of normally spliced IL2RG mRNA resulted in late-onset combined immunodeficiency in these patients.

Epithelial TRAF6 drives IL-17-mediated psoriatic inflammation.

Epithelial cells are the first line of defense against external dangers, and contribute to induction of adaptive immunity including Th17 responses. However, it is unclear whether specific epithelial signaling pathways are essential for the development of robust IL-17-mediated immune responses. In mice, the development of psoriatic inflammation induced by imiquimod required keratinocyte TRAF6. Conditional deletion of TRAF6 in keratinocytes abrogated dendritic cell activation, IL-23 production, and IL-17 production by γδ T cells at the imiquimod-treated sites. In contrast, hapten-induced contact hypersensitivity and papain-induced IgE production were not affected by loss of TRAF6. Loss of psoriatic inflammation was not solely due to defective imiquimod sensing, as subcutaneous administration of IL-23 restored IL-17 production but did not reconstitute psoriatic pathology in the mutant animals. Thus, TRAF6 was required for the full development of IL-17-mediated inflammation. Therefore, epithelial TRAF6 signaling plays an essential role in both triggering and propagating IL-17-mediated psoriatic inflammation.

Cancer-induced immunosuppressive cascades and their reversal by molecular-targeted therapy.

Immunological status in tumor tissues varies among patients. Infiltration of memory-type CD8(+) T cells into tumors correlates with prognosis of patients with various cancers. However, the mechanism of the differential CD8(+) T cell infiltration has not been well investigated. In general, tumor-associated microenvironments, including tumor and sentinel lymph nodes, are under immunosuppressive conditions such that the immune system is not able to eliminate cancer cells without immune-activating interventions. Constitutive activation of various signaling pathways in human cancer cells triggers multiple immunosuppressive cascades that involve various cytokines, chemokines, and immunosuppressive cells. Signaling pathway inhibitors could inhibit these immunosuppressive cascades by acting on either cancer or immune cells, or both. In addition, common signaling mechanisms are often utilized for multiple hallmarks of cancer (e.g., cell proliferation/survival, invasion/metastasis, and immunosuppression). Therefore, targeting these common signaling pathways may be an attractive strategy for cancer therapy including immunotherapy.