Yuka Shimada

Enhanced production of CC-chemokines (RANTES, MCP-1, MIP-1α, MIP-1β, and eotaxin) in patients with atopic dermatitis

Abstract CC-chemokines are potent molecules that direct the migration of leukocytes to inflammatory foci. To determine their role in inflammation associated with atopic dermatitis (AD), we determined serum levels and spontaneous production of CC-chemokines by peripheral blood mononuclear cells (PBMC) in AD patients using an ELISA. Serum levels of RANTES, MCP-1, MIP-1β, and eotaxin were increased in AD patients ( n = 52) compared with normal controls ( n = 22). Serum levels of RANTES, MCP-1, and MIP-1β were increased in AD patients with severe disease ( n = 19) compared with normal controls ( n = 22). Spontaneous production of RANTES, MCP-1, MIP-1α and MIP-1β by PBMC was augmented in AD patients ( n = 39) and in patients with severe AD ( n = 14) compared with normal controls ( n = 20). Serum RANTES levels correlated with total serum IgE levels, eosinophil numbers, and serum lactate dehydrogenase levels. Our results suggest that augmented production of CC-chemokines correlates with inflammation associated with AD.

L-Selectin or ICAM-1 Deficiency Reduces an Immediate-Type Hypersensitivity Response by Preventing Mast Cell Recruitment in Repeated Elicitation of Contact Hypersensitivity

Repeated Ag exposure results in a shift in the time course of contact hypersensitivity (CH) from a typical delayed-type to an immediate-type response followed by a late phase reaction. Chronic CH responses are clinically relevant to human skin allergic diseases, such as atopic dermatitis, that are usually caused by repeated stimulation with environmental Ags. Chronic inflammatory responses result in part from infiltrating leukocytes. To determine the role of leukocyte adhesion molecules in chronic inflammation, chronic CH responses were assessed in mice lacking L-selectin, ICAM-1, or both adhesion molecules. Following repeated hapten sensitization for 24 days at 2-day intervals, wild-type littermates developed an immediate-type response at 30 min after elicitation, followed by a late phase reaction. By contrast, loss of ICAM-1, L-selectin, or both, eliminated the immediate-type response and inhibited the late phase reaction. Similar results were obtained when wild-type littermates repeatedly exposed to hapten for 22 days were treated with mAbs to L-selectin and/or ICAM-1 before the elicitation on day 24. The lack of an immediate-type response on day 24 paralleled a lack of mast cell accumulation after 30 min of elicitation and decreased serum IgE production. Repeated Ag exposure in wild-type littermates resulted in increased levels of serum L-selectin, a finding also observed in atopic dermatitis patients. The current study demonstrates that L-selectin and ICAM-1 cooperatively regulate the induction of the immediate-type response by mediating mast cell accumulation into inflammatory sites and suggests that L-selectin and ICAM-1 are potential therapeutic targets for regulating human allergic reactions.

Intercellular adhesion molecule-1 and L-selectin regulate bleomycin-induced lung fibrosis.

The development of bleomycin-induced lung injury, a model of pulmonary fibrosis, results from inflammatory cell infiltration, a process highly regulated by the expression of multiple adhesion molecules. At present, the identity and role of the adhesion molecules involved in the fibrotic process are unknown. Therefore, bleomycin-induced pulmonary fibrosis was examined in mice lacking L-selectin (L-selectin(-/-)) expression, intercellular adhesion molecule-1 (ICAM-1) expression, or both. After 16 days of intratracheal bleomycin challenge, collagen deposition was inhibited in both L-selectin(-/-) and ICAM-1(-/-) mice when compared with wild-type littermates. Interestingly, collagen deposition was virtually eliminated in L-selectin/ICAM-1(-/-) mice relative to either the L-selectin(-/-) or ICAM-1(-/-) mice. Decreased pulmonary fibrosis was associated with reduced accumulation of leukocytes, including neutrophils and lymphocytes. Decreased mRNA expression of proinflammatory cytokines and transforming growth factor (TGF)-beta1 paralleled the inhibition of collagen deposition. The present study indicates that L-selectin and ICAM-1 play a critical role in pulmonary fibrosis by mediating the accumulation of leukocytes, which regulate the production of proinflammatory cytokines and TGF-beta1. This suggests that these adhesion molecules are potential therapeutic targets for inhibiting human pulmonary fibrosis.

The Cutaneous Reverse Arthus Reaction Requires Intercellular Adhesion Molecule 1 and L-Selectin Expression

The deposition of immune complexes (IC) induces an acute inflammatory response with tissue injury. IC-induced inflammation is mediated by inflammatory cell infiltration, a process highly regulated by expression of multiple adhesion molecules. To assess the role of L-selectin and ICAM-1 in this pathogenetic process, the cutaneous reverse passive Arthus reaction was examined in mice lacking L-selectin (L-selectin−/−), ICAM-1 (ICAM-1−/−), or both (L-selectin/ICAM-1−/−). Edema and hemorrhage, which peaked 4 and 8 h after IC challenge, respectively, were significantly reduced in L-selectin−/−, ICAM-1−/−, and L-selectin/ICAM-1−/− mice compared with wild-type littermates. In general, edema and hemorrhage were more significantly inhibited in ICAM-1−/− mice than in L-selectin−/− mice, but were most significantly reduced in L-selectin/ICAM-1−/− mice compared with ICAM-1−/− or L-selectin−/− mice. Decreased edema and hemorrhage correlated with reduced neutrophil and mast cell infiltration in all adhesion molecule-deficient mice, but leukocyte infiltration was most affected in L-selectin/ICAM-1−/− mice. Reduced neutrophil and mast cell infiltration was also observed for all mutant mice in the peritoneal Arthus reaction. Furthermore, cutaneous TNF-α production was inhibited in each deficient mouse, which paralleled the reductions in cutaneous inflammation. These results indicate that ICAM-1 and L-selectin cooperatively contribute to the cutaneous Arthus reaction by regulating neutrophil and mast cell recruitment and suggest that ICAM-1 and L-selectin are therapeutic targets for human IC-mediated disease.

Elevated serum L-selectin levels and abnormal regulation of L-selectin expression on leukocytes in atopic dermatitis: Soluble L-selectin levels indicate disease severity

BACKGROUND L-selectin mediates leukocyte rolling on endothelium at sites of inflammation, suggesting that L-selectin may be involved in the development of cutaneous lesions of atopic dermatitis (AD). After leukocyte activation, L-selectin is rapidly shed from the cell surface. OBJECTIVE The purpose of this study was to assess leukocyte L-selectin expression and quantitate levels of serum soluble L-selectin (sL-selectin) in patients with AD. METHODS Serum sL-selectin levels in patients with AD (n = 70), contact dermatitis (n = 18), and psoriasis (n = 23), as well as normal control subjects (n = 30), were examined by using an ELISA. The L-selectin expression on leukocytes in heparinized blood samples from patients with AD (n = 18) and normal control subjects (n = 10) was also examined by flow cytometry. RESULTS Serum levels of sL-selectin in patients with AD were significantly higher than those found in normal control subjects. Furthermore, sL-selectin levels correlated positively with disease severity and total serum IgE levels in AD. The expression of L-selectin on B cells, monocytes, and neutrophils was significantly decreased in patients with AD compared with normal control subjects, although those on CD4(+) or CD8(+) T cells from patients with AD were similar to those from normal control subjects. CONCLUSION Elevated sL-selectin levels and the abnormal expression of L-selectin on some leukocyte subsets in patients with AD may correlate with inflammation associated with AD. Furthermore, the level of sL-selectin may be a useful immunologic indicator for disease activity in AD.

Both Th1 and Th2 chemokines are elevated in sera of patients with autoimmune blistering diseases

Although chemokines are critical elements for the selective attraction and activation of various leukocyte subsets in the inflammatory process, there are few findings concerning T helper (Th) 1 or Th2 chemokines in autoimmune blistering disease (ABD). To determine whether serum levels of chemokines that are preferentially chemotactic for Th1 (monokine induced by IFN-γ (MIG/CXCL9)) and Th2 (thymus and activation regulated chemokine (TARC/CCL17) and macrophage derived chemokine (MDC/CCL22)) cells were elevated and whether they correlated with the clinical features in patients with ABD. Serum chemokine levels were examined using ELISA in patients with pemphigus vulgaris (PV, n=19), pemphigus foliaceous (PF, n=14), or bullous pemphigoid (BP, n=27) and normal controls (n=20). Serum MIG levels were significantly higher in patients with PV, PF, or BP than those in the control subjects. Serum levels of TARC and MDC were also significantly elevated in patients with PV, PF, or BP relative to the normal controls. Among the ABD subgroups, the levels of each chemokine tended to be higher in BP patients than in PV patients. Furthermore, serum TARC levels correlated positively with serum IgE levels in patients with ABD. Levels of TARC, MDC, and MIG were significantly decreased after treatment when the skin lesions disappeared in these patients. Furthermore, serum MIG levels correlated positively with serum levels of TARC and MDC in the ABD patients. These results suggest that both a Th1 chemoattractant MIG and Th2 chemoattractants, TARC and MDC, cooperatively play a role in the development of ABD.

Elevated serum L-selectin levels and decreased L-selectin expression on CD8+ lymphocytes in systemic sclerosis

L‐selectin is expressed on most circulating leucocytes and mediates leucocyte rolling on endothelium at sites of inflammation. Following rolling or activation of leucocytes, cell surface L‐selectin is released as soluble L‐selectin (sL‐selectin). In the present study, we assessed serum levels of sL‐selectin by ELISA and blood leucocyte L‐selectin expression by flow cytometry in patients with systemic sclerosis (SSc). Serum levels of sL‐selectin in patients with SSc (n = 51) were significantly higher than in normal controls (n = 30) while sL‐selectin levels were similar for systemic lupus erythematosus patients (n = 20) and normal controls. Furthermore, SSc patients with elevated sL‐selectin levels had inflammatory joint involvement, pitting scar/ulcers, and diffuse pigmentation more frequently than those with normal sL‐selectin levels. The frequency of L‐selectin+ population among CD8+ T cells was significantly decreased in SSc patients (n = 30) compared with normal controls (n = 20), while that among CD4+ T cells, B cells, monocytes, and neutrophils was similar for SSc patients and normal controls. These suggest that elevated sL‐selectin levels and decreased frequency of L‐selectin+ CD8+ T cells in SSc patients may be involved in inflammation associated with SSc.

Elevated serum levels of APRIL, but not BAFF, in patients with atopic dermatitis.

Abstract:  Elevated serum levels of B‐cell‐activating factor belonging to the tumor necrosis factor family (BAFF) and/or a proliferation‐inducing ligand (APRIL) are shown in autoimmune diseases. We determined serum levels of BAFF and APRIL, and clinical association in patients with atopic dermatitis (AD). Serum levels of BAFF and APRIL from 35 patients with AD, 25 patients with psoriasis vulgaris, 25 patients with systemic lupus erythematosus and 25 normal healthy subjects were examined by enzyme‐linked immunosorbent assay. Serum levels of APRIL, but not BAFF, were significantly elevated in patients with AD than in healthy controls or patients with psoriasis vulgaris. Patients with severe AD exhibited significantly increased APRIL levels compared to patients with moderate AD and mild AD, and serum APRIL levels were significantly decreased after treatment compared with those before treatment. In addition, increased APRIL levels were significantly associated with serum immunoglobulin E levels and blood eosinophil numbers. These results suggest that elevated serum levels of APRIL are associated with disease severity and activity in AD, and APRIL may have an important role in the pathogenesis of AD.

Autoantibodies directed against the protease inhibitor calpastatin in psoriasis

Psoriasis is believed to be a T cell‐mediated autoimmune disease, but also exhibits autoantibody production. Calpastatin is an endogenous inhibitor of calpain, a ubiquitous protease that regulates inflammatory processes. Anti‐calpastatin autoantibody was first identified as an autoantibody specific to rheumatoid arthritis, but has been also detected in other autoimmune diseases. In this study, we examined the presence and levels of anti‐calpastatin antibody in 77 psoriasis patients by enzyme‐linked immunosorbent assay. Compared with normal controls, psoriasis patients exhibited significantly elevated IgG anti‐calpastatin antibody levels that were similar to those found in rheumatoid arthritis patients. Remarkably, IgG anti‐calpastatin autoantibody in sera from psoriasis patients inhibited calpastatin activity. Calpain II expression was up‐regulated in psoriasis skin lesions compared with normal skin while calpastatin expression was normal. The results of this study reveal the presence of anti‐calpastatin autoantibody in psoriasis.

Decreased expression levels of L‐selectin on subsets of leucocytes and increased serum L‐selectin in severe psoriasis

L‐selectin is a leucocyte adhesion molecule involved in leucocyte interactions with vascular endothelial cells. Following leucocyte activation L‐selectin is endoproteolytically released from the cell surface. To assess whether psoriasis vulgaris results in systemic leucocyte activation, we examined expression levels of L‐selectin on subsets of peripheral blood leucocytes from patients with psoriasis (n = 25) and normal control subjects. Serum levels of soluble L‐selectin were quantified by ELISA in patients with psoriasis (n = 75), pustulosis palmaris et plantaris, and contact dermatitis, as well as normal control subjects. Psoriasis severity was evaluated by psoriasis area and severity index (PASI). L‐selectin expression levels on CD4+ T cells, B cells, monocytes, and neutrophils from patients with severe‐type psoriasis (PASI ≥ 15) was significantly decreased compared with leucocytes from normal control subjects. Furthermore, L‐selectin expression on CD4+ T cells showed good inverse correlation with PASI scores. Monocyte L‐selectin expression was restored when the skin lesions of psoriasis were remitted. The frequencies of L‐selectin+ CD4+ T cells or L‐selectin+ CD8+ T cells from patients with psoriasis were almost normal. Serum L‐selectin levels in patients with severe‐type psoriasis were significantly higher than those in normal control subjects. These results suggest that subsets of leucocytes may be activated in psoriasis, and that L‐selectin expression levels on some leucocyte subsets, especially CD4+ T cells, tend to correlate with disease severity of psoriasis.