IL-27-producing B-1a cells suppress neuroinflammation and CNS autoimmune diseases.

Regulatory B cells (Breg cells) that secrete IL-10 or IL-35 (i35-Breg) play key roles in regulating immunity in tumor microenvironment or during autoimmune and infectious diseases. Thus, loss of Breg function is implicated in development of autoimmune diseases while aberrant elevation of Breg prevents sterilizing immunity, exacerbates infectious diseases, and promotes cancer metastasis. Breg cells identified thus far are largely antigen-specific and derive mainly from B2-lymphocyte lineage. Here, we describe an innate-like IL-27-producing natural regulatory B-1a cell (i27-Breg) in peritoneal cavity and human umbilical cord blood. i27-Bregs accumulate in CNS and lymphoid tissues during neuroinflammation and confers protection against CNS autoimmune disease. i27-Breg immunotherapy ameliorated encephalomyelitis and uveitis through up-regulation of inhibitory receptors (Lag3, PD-1), suppression of Th17/Th1 responses, and propagating inhibitory signals that convert conventional B cells to regulatory lymphocytes that secrete IL-10 and/or IL-35 in eye, brain, or spinal cord. Furthermore, i27-Breg proliferates in vivo and sustains IL-27 secretion in CNS and lymphoid tissues, a therapeutic advantage over administering biologics (IL-10, IL-35) that are rapidly cleared in vivo. Mutant mice lacking irf4 in B cells exhibit exaggerated increase of i27-Bregs with few i35-Bregs, while mice with loss of irf8 in B cells have abundance of i35-Bregs but defective in generating i27-Bregs, identifying IRF8/BATF and IRF4/BATF axis in skewing B cell differentiation toward i27-Breg and i35-Breg developmental programs, respectively. Consistent with its developmental origin, disease suppression by innate i27-Bregs is neither antigen-specific nor disease-specific, suggesting that i27-Breg would be effective immunotherapy for a wide spectrum of autoimmune diseases.

Sirt6 Activation Ameliorates Inflammatory Bone Loss in Ligature-Induced Periodontitis in Mice.

Periodontitis is an inflammatory disease caused by microorganisms that induce the destruction of periodontal tissue. Inflamed and damaged tissue produces various inflammatory cytokines, which activate osteoclasts and induce alveolar bone loss and, eventually, tooth loss. Sirt6 expression suppresses inflammation and bone resorption; however, its role in periodontitis remains unclear. We hypothesized that Sirt6 has a protective role in periodontitis. To understand the role of Sirt6 in periodontitis, we compared periodontitis with ligature placement around the maxillary left second molar in 8-week-old control (C57BL/6J) male mice to Sirt6-overexpressing Tg (Sirt6Tg) mice, and we observed the resulting phenotypes using micro-CT. MDL801, a Sirt6 activator, was used as a therapy for periodontitis through oral gavage. Pro-inflammatory cytokines and increased osteoclast numbers were observed in alveolar bone tissue under periodontitis surgery. In the same condition, interestingly, protein levels from Sirt6 were the most downregulated among sirtuins in alveolar bone tissue. Based on micro-CT and CEJ-ABC distance, Sirt6Tg was observed to resist bone loss against ligature-induced periodontitis. Furthermore, the number of osteoclasts was significantly reduced in Sirt6Tg-ligated mice compared with control-ligated mice, although systemic inflammatory cytokines did not change. Consistent with this observation, we confirmed that bone loss was significantly reduced when MDL801, a Sirt6 activator, was included in the ligation mouse model. Our findings demonstrate that Sirt6 activation prevents bone loss against ligature-induced periodontitis. Thus, a Sirt6 activator may provide a new therapeutic approach for periodontitis.

Dermatophagoides farinae Extract Induces Interleukin 33-Mediated Atopic Skin Inflammation via Activation of RIP1.

Receptor-interacting protein kinase (RIP) family 1 signaling has complex effects on inflammatory processes and cell death, but little is known concerning allergic skin diseases. We examined the role of RIP1 in Dermatophagoides farinae extract (DFE)-induced atopic dermatitis (AD)-like skin inflammation. RIP1 phosphorylation was increased in HKCs treated with DFE. Nectostatin-1, a selective and potent allosteric inhibitor of RIP1, inhibited AD-like skin inflammation and the expression of histamine, total IgE, DFE-specific IgE, IL-4, IL-5, and IL-13 in an AD-like mouse model. The expression of RIP1 was increased in ear skin tissue from a DFE-induced mouse model with AD-like skin lesions and in the lesional skin of AD patients with high house dust mite sensitization. The expression of IL-33 was down-regulated after RIP1 inhibition, and the levels of IL-33 were increased by over-expression of RIP1 in keratinocytes stimulated with DFE. Nectostatin-1 reduced IL-33 expression in vitro and in the DFE-induced mouse model. These results suggest that RIP1 can be one of the mediators that regulate IL-33-mediated atopic skin inflammation by house dust mites.

Deletion of Irf4 in T Cells Suppressed Autoimmune Uveitis and Dysregulated Transcriptional Programs Linked to CD4+ T Cell Differentiation and Metabolism.

Interferon regulatory factor-4 (IRF4) and IRF8 regulate differentiation, growth and functions of lymphoid and myeloid cells. Targeted deletion of irf8 in T cells (CD4-IRF8KO) has been shown to exacerbate colitis and experimental autoimmune uveitis (EAU), a mouse model of human uveitis. We therefore generated mice lacking irf4 in T cells (CD4-IRF4KO) and investigated whether expression of IRF4 by T cells is also required for regulating T cells that suppress autoimmune diseases. Surprisingly, we found that CD4-IRF4KO mice are resistant to EAU. Suppression of EAU derived in part from inhibiting pathogenic responses of Th17 cells while inducing expansion of regulatory lymphocytes that secrete IL-10 and/or IL-35 in the eye and peripheral lymphoid tissues. Furthermore, CD4-IRF4KO T cells exhibit alterations in cell metabolism and are defective in the expression of two Ikaros zinc-finger (IKZF) transcription factors (Ikaros, Aiolos) that are required for lymphocyte differentiation, metabolism and cell-fate decisions. Thus, synergistic effects of IRF4 and IkZFs might induce metabolic reprogramming of differentiating lymphocytes and thereby dynamically regulate relative abundance of T and B lymphocyte subsets that mediate immunopathogenic mechanisms during uveitis. Moreover, the diametrically opposite effects of IRF4 and IRF8 during EAU suggests that intrinsic function of IRF4 in T cells might be activating proinflammatory responses while IRF8 promotes expansion of immune-suppressive mechanisms.

Extract of Boehmeria nivea Suppresses Mast Cell-Mediated Allergic Inflammation by Inhibiting Mitogen-Activated Protein Kinase and Nuclear Factor-κB.

Mast cells are effector cells that initiate allergic inflammatory immune responses by inducing inflammatory mediators. Boehmeria nivea (Linn.) Gaudich is a natural herb in the nettle family Urticaceae that possesses numerous pharmacological properties. Despite the various pharmacological benefits of Boehmeria nivea, its effects on allergic inflammation have not yet been determined. Here, we investigated the effect of the ethanol extract of Boehmeria nivea (BNE) on degranulation rat basophilic leukemia (RBL)-2H3 mast cells stimulated with anti-dinitrophenyl (anti-DNP) and bovine serum albumin (BSA) during immunoglobulin E (IgE)-mediated allergic immune response. The results showed inhibition of the release of ß-hexosaminidase and histamine from the cells. BNE suppressed pro-inflammatory cytokines (Tumor necrosis factor (TNF)-α, Interleukin (IL)-1ß, and IL-6) and reduced T helper (Th)2 cytokine IL-4 expression and/or secretion correlated with the downregulation of p38, extracellular signal-regulated kinases (ERK) mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) signaling pathways in treated RBL-2H3 mast cells. In passive cutaneous anaphylaxis, treatment with BNE during IgE-mediated local allergic reaction triggered a reduction in mouse ear pigmentation and thickness. Taken together, these results indicated that BNE suppressed mast cell-mediated inflammation, suggesting that BNE might be a candidate for the treatment of various allergic disorders.

2-Hydroxy-3-methoxybenzoic acid attenuates mast cell-mediated allergic reaction in mice via modulation of the FcεRI signaling pathway.

Mast cells are important effector cells in immunoglobulin (Ig) E-mediated allergic reactions such as asthma, atopic dermatitis and rhinitis. Vanillic acid, a natural product, has shown anti-oxidant and anti-inflammatory activities. In the present study, we investigated the anti-allergic inflammatory effects of ortho-vanillic acid (2-hydroxy-3-methoxybenzoic acid, o-VA) that was a derivative of vanillic acid isolated from Amomum xanthioides. In mouse anaphylaxis models, oral administration of o-VA (2, 10, 50 mg/kg) dose-dependently attenuated ovalbumin-induced active systemic anaphylaxis and IgE-mediated cutaneous allergic reactions such as hypothermia, histamine release, IgE production and vasodilation; administration of o-VA also suppressed the mast cell degranulator compound 48/80-induced anaphylaxis. In cultured mast cell line RBL-2H3 and isolated rat peritoneal mast cells in vitro, pretreatment with o-VA (1-100 µmol/L) dose-dependently inhibited DNP-HSA-induced degranulation of mast cells by decreasing the intracellular free calcium level, and suppressed the expression of pro-inflammatory cytokines TNF-α and IL-4. Pretreatment of RBL-2H3 cells with o-VA suppressed DNP-HSA-induced phosphorylation of Lyn, Syk, Akt, and the nuclear translocation of nuclear factor-κB. In conclusion, o-VA suppresses the mast cell-mediated allergic inflammatory response by blocking the signaling pathways downstream of high affinity IgE receptor (FcεRI) on the surface of mast cells.

Oleanolic acid acetate inhibits rheumatoid arthritis by modulating T cell immune responses and matrix-degrading enzymes.

Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with a combination of synovium joint inflammation, synovium hyperplasia, and destruction of cartilage and bone. Oleanolic acid acetate (OAA), a compound isolated from Vigna angularis, has been known to possess pharmacological activities, including anti-inflammation and anti-bone destruction. In this study, we investigated the effects of OAA on RA and the underlying mechanisms of action by using a type-II collagen-induced arthritis (CIA) mouse model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. Oral administration of OAA decreased the clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum total and anti-type II collagen IgG, IgG1, and IgG2a levels. OAA administration reduced Th1/Th17 phenotype CD4(+) T lymphocyte expansions and inflammatory cytokine productions in T cell activated draining lymph nodes and spleen. OAA reduced the expression and production of inflammatory mediators, such as cytokines and matrix metalloproteinase (MMP)-1/3, in the ankle joint tissue and RA synovial fibroblasts by down-regulating Akt, mitogen-activated protein kinases, and nuclear factor-κB. Our results clearly support that OAA plays a therapeutic role in RA pathogenesis by modulating helper T cell immune responses and matrix-degrading enzymes. The immunosuppressive effects of OAA were comparable to dexamethasone and ketoprofen. We provide evidences that OAA could be a potential therapeutic candidate for RA.

1,2,4,5-Tetramethoxybenzene Suppresses House Dust Mite-Induced Allergic Inflammation in BALB/c Mice.

BACKGROUND: Atopic dermatitis (AD) is the most common allergic inflammatory skin disease. The activation of innate immunity by house dust mite (Dermatophagoides farinae extract, DFE) allergen plays an important role in the pathogenesis of AD. We previously showed the inhibitory effect of an extract of Amomum xanthioides on allergic diseases, and isolated 1,2,4,5-tetramethoxybenzene (TMB) as a major active component. In this study, we investigated whether TMB relieves DFE-induced allergic inflammation symptoms. METHODS: We established a DFE-induced allergic inflammation model in BALB/c mice by repeated skin exposure to DFE. To define the underlying mechanisms of action, we used a tumor necrosis factor-α and interferon-x03B3;-activated human keratinocytes (HaCaT cell line) and mouse keratinocytes (3PC cell line) cell line model. RESULTS: Oral administration of TMB suppressed allergic inflammation symptoms, such as histopathological analysis and ear thickness, in addition to serum IgE, DFE-specific IgE and IgG2a levels. TMB decreased the serum histamine levels and tissue infiltration of inflammatory cells, including mast cells and eosinophils. TMB also inhibited CD4+IFN-x03B3;+, CD4+IL-4+, and CD4+IL-17A+ lymphocyte expansion in the draining lymph nodes and expression of the Th2 cytokines in the ear tissue. TMB significantly inhibited the expression of cytokines and chemokines by the downregulation of the mitogen-activated protein kinases and nuclear factor of activated cytoplasmic T cells in HaCaT cells. CONCLUSIONS: TMB improved DFE-induced allergic inflammation by suppressing the production of proinflammatory cytokines and chemokines. Our results suggest that TMB might be a potential therapeutic agent for AD.

Inhibitory effect of 1,2,4,5-tetramethoxybenzene on mast cell-mediated allergic inflammation through suppression of IκB kinase complex.

As the importance of allergic disorders such as atopic dermatitis and allergic asthma, research on potential drug candidates becomes more necessary. Mast cells play an important role as initiators of allergic responses through the release of histamine; therefore, they should be the target of pharmaceutical development for the management of allergic inflammation. In our previous study, anti-allergic effect of extracts of Amomum xanthioides was demonstrated. To further investigate improved candidates, 1,2,4,5-tetramethoxybenzene (TMB) was isolated from methanol extracts of A. xanthioides. TMB dose-dependently attenuated the degranulation of mast cells without cytotoxicity by inhibiting calcium influx. TMB decreased the expression of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-4 at both the transcriptional and translational levels. Increased expression of these cytokines was caused by translocation of nuclear factor-κB into the nucleus, and it was hindered by suppressing activation of IκB kinase complex. To confirm the effect of TMB in vivo, the ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) and IgE-mediated passive cutaneous anaphylaxis (PCA) models were used. In the ASA model, hypothermia was decreased by oral administration of TMB, which attenuated serum histamine, OVA-specific IgE, and IL-4 levels. Increased pigmentation of Evans blue was reduced by TMB in a dose-dependent manner in the PCA model. Our results suggest that TMB is a possible therapeutic candidate for allergic inflammatory diseases that acts through the inhibition of mast cell degranulation and expression of pro-inflammatory cytokines.

Inflammation-Targeting Mesenchymal Stem Cells Combined with Photothermal Treatment Attenuate Severe Joint Inflammation.

Current clinical therapeutic efficacy for the treatment of osteo- and rheumatoid-arthritis is obviously limited. Although mesenchymal stem cells (MSCs) are considered as a source of promising regenerative therapy, un-modified or genetically engineered MSCs injected in vivo restrict their clinical utility because of the low drug efficacy and unpredicted side effect, respectively. Herein, a strategy to enhance the migration efficacy of MSCs to inflamed joints via an inflammation-mediated education process is demonstrated. To reinforce the limited anti-inflammatory activity of MSCs, gold nanostar loaded with triamcinolone is conjugated to MSC. Furthermore, near-infrared laser-assisted photothermal therapy (PTT) induced by gold nanostar significantly elevates the anti-inflammatory efficacy of the developed drugs, even in advanced stage arthritis model. An immunological regulation mechanism study of PTT is first suggested in this study; the expression of the interleukin 22 receptor, implicated in the pathogenesis of arthritis, is downregulated in T lymphocytes by PTT, and Th17 differentiation from naïve CD4 T cell is inhibited. Collectively, inflammation-targeting MSCs conjugated with triamcinolone-loaded gold nanostar (Edu-MSCs-AuS-TA) promote the repolarization of macrophages and decrease neutrophil recruitment in joints. In addition, Edu-MSCs-AuS-TA significantly alleviate arthritis-associated pain, improve general locomotor activity, and more importantly, induce cartilage regeneration even for severe stages of arthritis model.

Aspalathin, a Primary Rooibos Flavonoid, Alleviates Mast Cell-Mediated Allergic Inflammation by the Inhibition of FcεRI Signaling Pathway.

Mast cells are primary cells initiating allergic inflammation by the release of various allergic mediators, such as histamine and pro-inflammatory cytokines. Aspalathin (ASP) is the predominant flavonoid found exclusively in rooibos, an herb that has been traditionally used in allergy relief therapy. In the present study, we investigated the beneficial effects of ASP on mast cell-mediated allergic inflammation. For in vivo study, two well-known mast cell-mediated local and systemic allergic inflammation mouse models were used: passive cutaneous anaphylaxis (PCA) and active systemic anaphylaxis mouse models (ASA). Oral administration of ASP dose-dependently suppressed immunoglobulin (Ig)E-mediated PCA responses evidenced by Evans blue extravasation, ear thickening, and mast cell degranulation. ASP also significantly mitigated ovalbumin-induced ASA responses, including hypothermia, histamine secretion, and the production of IgE and interleukin-4. Notably, ASP was more effective in suppressing allergic inflammation than nothofagin, another prominent flavonoid known as an anti-allergic component of rooibos. The regulatory mechanism of mast cell activation by ASP was clarified using mast cell line and primary cultured mast cells (RBL-2H3 and mouse bone marrow-derived mast cells). ASP reduced IgE-stimulated mast cells degranulation and intracellular calcium influx by the inhibition of FcεRI signaling pathway (Lyn, Fyn, and Syk). Moreover, ASP reduced pro-inflammatory cytokine expressions by inhibiting two major transcription factors, nuclear factor of activated T cells and nuclear factor-κB. Collectively, we proposed that ASP could be a potential therapeutic candidate for the treatment of mast cell-mediated allergic inflammatory diseases.

Imidazole propionate ameliorates atopic dermatitis-like skin lesions by inhibiting mitochondrial ROS and mTORC2.

Background: Imidazole propionate (IMP) is a histidine metabolite produced by some gut microorganisms in the human colon. Increased levels of IMP are associated with intestinal inflammation and the development and progression of cardiovascular disease and diabetes. However, the anti-inflammatory activity of IMP has not been investigated. This study aimed to elucidate the role of IMP in treating atopic dermatitis (AD). Methods: To understand how IMP mediates immunosuppression in AD, IMP was intraperitoneally injected into a Dermatophagoides farinae extract (DFE)/1-chloro-2,4 dinitrochlorobenzene (DNCB)-induced AD-like skin lesions mouse model. We also characterized the anti-inflammatory mechanism of IMP by inducing an AD response in keratinocytes through TNF-α/IFN-γ or IL-4 stimulation. Results: Contrary to the prevailing view that IMP is an unhealthy microbial metabolite, we found that IMP-treated AD-like skin lesions mice showed significant improvement in their clinical symptoms, including ear thickness, epidermal and dermal thickness, and IgE levels. Furthermore, IMP antagonized the expansion of myeloid (neutrophils, macrophages, eosinophils, and mast cells) and Th cells (Th1, Th2, and Th17) in mouse skin and prevented mitochondrial reactive oxygen species production by inhibiting mitochondrial energy production. Interestingly, we found that IMP inhibited AD by reducing glucose uptake in cells to suppress proinflammatory cytokines and chemokines in an AD-like in vitro model, sequentially downregulating the PI3K and mTORC2 signaling pathways centered on Akt, and upregulating DDIT4 and AMPK. Discussion: Our results suggest that IMP exerts anti-inflammatory effects through the metabolic reprogramming of skin inflammation, making it a promising therapeutic candidate for AD and related skin diseases.

Oleanolic acid acetate inhibits atopic dermatitis and allergic contact dermatitis in a murine model.

Atopic dermatitis (AD) and allergic contact dermatitis (ACD) are common allergic and inflammatory skin diseases caused by a combination of eczema, scratching, pruritus, and cutaneous sensitization with allergens. This paper examines whether oleanolic acid acetate (OAA) modulates AD and ACD symptoms by using an existing AD model based on the repeated local exposure of mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene to the ears of BALB/c mice. In addition, the paper uses a 2,4-dinitrofluorobenzene-sensitized local lymph node assay (LLNA) for the ACD model. The oral administration of OAA over a four-week period attenuated AD symptoms in terms of decreased skin lesions, epidermal thickness, the infiltration of immune cells (CD4⁺ cells, eosinophils, and mast cells), and serum IgE, IgG2a, and histamine levels. The gene expression of Th1, Th2, Th17, and Th22 cytokines was reduced by OAA in the lymph node and ear tissue, and the LLNA verified that OAA suppressed ACD. The oral administration of OAA over a three-day period attenuated ACD symptoms in terms of ear thickness, lymphocyte proliferation, and serum IgG2a levels. The gene expression of Th1, Th2, and Th17 cytokines was reduced by OAA in the thymus and ear tissue. Finally, to define the underlying mechanism, this paper uses a TNF-α/IFN-γ-activated human keratinocyte (HaCaT) model. OAA inhibited the expression of cytokines and chemokines through the downregulation of NF-κB and MAPKs in HaCaT cells. Taken together, the results indicate that OAA inhibited AD and ACD symptoms, suggesting that OAA may be effective in treating allergic skin disorders.

Extracts of Grifola frondosa inhibit the MAPK signaling pathways involved in keratinocyte inflammation and ameliorate atopic dermatitis.

BACKGROUND/OBJECTIVES: Grifola frondosa, commonly referred to as the maitake mushroom, has been studied extensively to explore its potential health benefits. However, its anti-inflammatory effects in skin disorders have not been sufficiently elucidated. This study aimed to elucidate the anti-inflammatory role of the ethanol extract of G. frondosa in atopic dermatitis (AD) using in vivo and in vitro models. MATERIALS/METHODS: We investigated its impact on skin and spleen inflammatory responses in Dermatophagoides farinae extract (DFE)/1-chloro-2,4 dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in a mouse model. Additionally, we determined the immunosuppressive response and mechanism of G. frondosa by inducing atopic-like immune reactions in keratinocytes through tumor necrosis factor (TNF)-α/interferon (IFN)-γ stimulation. RESULTS: Our study revealed that G. frondosa ameliorates clinical symptoms in an AD-like mouse model. These effects contributed to the suppression of Th1, Th2, Th17, and Th22 immune responses in the skin and spleen, leading to protection against cutaneous inflammation. Furthermore, G. frondosa inhibited the production of antibodies immunoglobulin (Ig)E and IgG2a in the serum of AD mice. Importantly, the inhibitory effect of G. frondosa on inflammatory cytokines in TNF-α/IFN-γ-stimulated AD-like keratinocytes was associated with the suppression of MAPK (Mitogen Activated Protein Kinase) pathway activation. CONCLUSIONS: Collectively, these findings highlight the potential of G. frondosa as a novel therapeutic agent for AD treatment and prevention.

Aminooxy acetic acid suppresses Th17-mediated psoriasis-like skin inflammation by inhibiting serine metabolism.

Background: Psoriasis is a common chronic inflammatory skin disease characterized by an external red rash that is caused by abnormal proliferation and differentiation of keratinocytes and immune T cells. This study aimed to elucidate the role of aminooxy acetic acid (AOA) in alleviating psoriasis from the perspective of immunology and metabolomics. Therefore, contributing to the development of new drugs as candidates for psoriasis treatment. Methods: To investigate the symptom-alleviating effects and the related mechanisms of AOA on the treatment of psoriasis, we used a 12-O-tetradecanoylphorbol-13-acetate-induced psoriasis-like skin mouse model and interleukin (IL)-17-stimulated human keratinocytes. Results: The results showed that AOA ameliorated psoriasis-related symptoms and decreased inflammation-associated antimicrobial peptides and T-helper 17 (Th17)-associated cytokines in a mouse model of psoriasis. Furthermore, AOA inhibited the activation of mechanistic target of rapamycin (mTOR) by suppressing serine metabolism-related genes. Importantly, mTOR inhibition ameliorated psoriatic disease by affecting the differentiation of various T cells and normalizing the Th17/regulatory T (Treg) cell balance. In addition, IL-17-stimulated human keratinocytes showed the same results as in the in vivo experiments. Conclusion: Taken together, these results suggest that targeting the serine metabolism pathway in the treatment of psoriasis is a novel strategy, and that AOA could be utilized as a novel biologic to treat psoriasis.

Temporal Dynamics of Serum Perforin and Granzymes in Three Different Clinical Stages of Virus-Induced Severe Fever with Thrombocytopenia Syndrome.

Virus-induced severe fever with thrombocytopenia syndrome (SFTS) induces a cell-mediated immune response that likely contributes to virus control in SFTS patients. To identify the temporal changes of the cell-mediated immune response, we investigated the changes in serum levels of perforin and granzymes at early periods after illness onset in SFTS patients. We analyzed 32 SFTS patients and compared the temporal patterns of serum perforin and granzyme A and B to that of 20 healthy control adults using the Mann-Whitney U test. Compared with healthy controls, the mean level of perforin was significantly reduced by 81% (P < 0.01) during the first week after illness onset, whereas granzyme B significantly increased by 4.6-fold (P = 0.02) in the first week after illness onset and decreased to normal afterward. During the study period, there was no significant difference in serum perforin and granzyme. These findings indicate that perforin and granzyme B in serum can be considered possible serologic markers that reflect the clinical stage of SFTS. Additional study is warranted for tracking circulating perforin and granzyme in different ages and for an extended period after illness onset.

Greater Plasma Protein Adsorption on Mesoporous Silica Nanoparticles Aggravates Atopic Dermatitis.

Purpose: The protein corona surrounding nanoparticles has attracted considerable attention as it induces subsequent inflammatory responses. Although mesoporous silica nanoparticles (MSN) are commonly used in medicines, cosmetics, and packaging, the inflammatory effects of the MSN protein corona on the cutaneous system have not been investigated till date. Methods: We examined the greater plasma protein adsorption on MSN leads to serious inflammatory reactions in Dermatophagoides farinae extract (DFE)-induced mouse atopic dermatitis (AD)-like skin inflammation because of increased uptake by keratinocytes. Results: We compare the AD lesions induced by MSN and colloidal (non-porous) silica nanoparticles (CSN), which exhibit different pore architectures but similar dimensions and surface chemistry. MSN-corona treatment of severe skin inflammation in a DFE-induced in vivo AD model greatly increases mouse ear epidermal thickness and infiltration of immune cells compared with the CSN-corona treatment. Moreover, MSN-corona significantly increase AD-specific immunoglobulins, serum histamine, and Th1/Th2/Th17 cytokines in the ear and lymph nodes. MSN-corona induce more severe cutaneous inflammation than CSN by significantly decreasing claudin-1 expression. Conclusion: This study demonstrates the novel impact of the MSN protein corona in inducing inflammatory responses through claudin-1 downregulation and suggests useful clinical guidelines for MSN application in cosmetics and drug delivery systems.

Analysis of Regulatory B Cells in Experimental Autoimmune Uveitis.

Regulatory B cells (Bregs) that produce IL-35 and IL-10 (i35-Bregs) regulate central nervous system (CNS) autoimmune diseases including uveitis. In the mouse model of uveitis, i35-Breg cells suppress intraocular inflammation by inducing expansion of IL-10-producing B cells (B10), IL-10-producing T cells (Tregs), and IL-35-producing T cells (iTR35), suggesting that i35-Bregs orchestrate an immune-suppressive milieu that regulates immunity during autoimmune diseases. In this chapter, we discuss uveitis and therapeutic challenges that necessitate the development of cell-based therapies for the treatment of these potentially blinding diseases that cause 10% visual handicap. We then describe the methods we set up for ex vivo generation of i35-Breg cells employed in i35-Breg immunotherapy in uveitis and in other CNS autoimmune diseases.

Interleukin 35 Regulatory B Cells.

B lymphocytes play a central role in host immunity. They orchestrate humoral immune responses that modulate activities of other immune cells and produce neutralizing antibodies that confer lasting immunity to infectious diseases including smallpox, measles and poliomyelitis. In addition to these traditional functions is the recent recognition that B cells also play critical role in maintaining peripheral tolerance and suppressing the development or severity of autoimmune diseases. Their immune suppressive function is attributed to relatively rare populations of regulatory B cells (Bregs) that produce anti-inflammatory cytokines including interleukin 10 (IL-10), IL-35 and transforming growth factor-ß. The IL-35-producing B cell (i35-Breg) is the newest Breg subset described. i35-Bregs suppress central nervous system autoimmune diseases by inducing infectious tolerance whereby conventional B cells acquire regulatory functions that suppress pathogenic Th17 responses. In this review, we discuss immunobiology of i35-Breg cell, i35-Breg therapies for autoimmune diseases and potential therapeutic strategies for depleting i35-Bregs that suppress immune responses against pathogens and tumor cells.