Chun-Kwok Wong

Proinflammatory cytokines (IL‐17, IL‐6, IL‐18 and IL‐12) and Th cytokines (IFN‐γ, IL‐4, IL‐10 and IL‐13) in patients with allergic asthma

Allergen‐reactive T helper type‐2 (Th2) cells and proinflammatory cytokines have been suggested to play an important role in the induction and maintenance of the inflammatory cascade in allergic asthma. We compared the plasma concentrations of novel proinflammatory cytokines IL‐17 and IL‐18, other proinflammatory cytokines IL‐6 and IL‐12, Th2 cytokines IL‐10 and IL‐13, and intracellular interferon‐γ (IFN‐γ) and IL‐4 in Th cells of 41 allergic asthmatics and 30 sex‐ and age‐matched health control subjects. Plasma cytokines were measured by enzyme‐linked immunosorbent assay. Intracellular cytokines were quantified by flow cytometry. Plasma IL‐18, IL‐12, IL‐10, IL‐13 concentrations were significantly higher in allergic asthmatic patients than normal control subjects (IL‐18: median 228·35 versus 138·72 pg/ml, P < 0·001; IL‐12: 0·00 versus 0·00 pg/ml, P = 0·001; IL‐10: 2·51 versus 0·05 pg/ml, P < 0·034; IL‐13: 119·38 versus 17·89 pg/ml, P < 0·001). Allergic asthmatic patients showed higher plasma IL‐17 and IL‐6 concentrations than normal controls (22·40 versus 11·86 pg/ml and 3·42 versus 0·61 pg/ml, respectively), although the differences were not statistically significant (P = 0·077 and 0·053, respectively). The percentage of IFN‐γ‐producing Th cells was significantly higher in normal control subjects than asthmatic patients (23·46 versus 5·72%, P < 0·001) but the percentage of IL‐4 producing Th cells did not differ (0·72 versus 0·79%, P > 0·05). Consequently, the Th1/Th2 cell ratio was significantly higher in normal subjects than asthmatic patients (29·6 versus 8·38%, P < 0·001). We propose that allergic asthma is characterized by an elevation of both proinflammatory and Th2 cytokines. The significantly lower ratio of Th1/Th2 cells confirms a predominance of Th2 cells response in allergic asthma.

Plasma inflammatory cytokines and chemokines in severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) is a recently emerged infectious disease caused by a novel coronavirus, but its immunopathological mechanisms have not yet been fully elucidated. We investigated changes in plasma T helper (Th) cell cytokines, inflammatory cytokines and chemokines in 20 patients diagnosed with SARS. Cytokine profile of SARS patients showed marked elevation of Th1 cytokine interferon (IFN)‐γ, inflammatory cytokines interleukin (IL)‐1, IL‐6 and IL‐12 for at least 2 weeks after disease onset, but there was no significant elevation of inflammatory cytokine tumour necrosis factor (TNF)‐α, anti‐inflammatory cytokine IL‐10, Th1 cytokine IL‐2 and Th2 cytokine IL‐4. The chemokine profile demonstrated significant elevation of neutrophil chemokine IL‐8, monocyte chemoattractant protein‐1 (MCP‐1), and Th1 chemokine IFN‐γ‐inducible protein‐10 (IP‐10). Corticosteroid reduced significantly IL‐8, MCP‐1 and IP‐10 concentrations from 5 to 8 days after treatment (all P < 0·001). Together, the elevation of Th1 cytokine IFN‐γ, inflammatory cytokines IL‐1, IL‐6 and IL‐12 and chemokines IL‐8, MCP‐1 and IP‐10 confirmed the activation of Th1 cell‐mediated immunity and hyperinnate inflammatory response in SARS through the accumulation of monocytes/macrophages and neutrophils.

Haematological manifestations in patients with severe acute respiratory syndrome: retrospective analysis

Abstract Objectives To evaluate the haematological findings of patients with severe acute respiratory syndrome (SARS). Design Analysis of the demographic, clinical, and laboratory characteristics of patients with SARS. Setting Prince of Wales Hospital, Hong Kong. Subjects All patients with a diagnosis of SARS between 11 March and 29 March 2003 who had no pre-existing haematological disorders. Main outcome measures Clinical end points included the need for intensive care and death. Univariate and multivariate analyses were performed to examine factors associated with adverse outcome. Results 64 male and 93 female patients were included in this study. The most common findings included lymphopenia in 153 (98%) of the 157 patients, neutrophilia in 129 (82%), thrombocytopenia in 87 patients (55%), followed by thrombocytosis in 77 (49%), and isolated prolonged activated partial thromboplastin time in 96 patients (63%). The haemoglobin count dropped by more than 20 g/l from baseline in 95 (61%) patients. Four patients (2.5%) developed disseminated intravascular coagulation. Lymphopenia was shown in haemato-lymphoid organs at postmortem examination. Multivariate analysis showed that advanced age and a high concentration of lactate dehydrogenase at presentation were independent predictors of an adverse outcome. Subsets of peripheral blood lymphocytes were analysed in 31 patients. The counts of CD4 positive and CD8 positive T cells fell early in the course of illness. Low counts of CD4 and CD8 cells at presentation were associated with adverse outcomes. Conclusions Abnormal haematological variables were common among patients with SARS. Lymphopenia and the depletion of T lymphocyte subsets may be associated with disease activity.

Raised plasma concentration and ex vivo production of inflammatory chemokines in patients with systemic lupus erythematosus

Background: Chemokines are involved in leucocyte chemotaxis. Infiltrating leucocytes play an important role of tissue injury in systemic lupus erythematosus (SLE). Objective: To investigate the role of inflammatory chemokines and their association with interleukin 18 (IL18) in SLE pathogenesis and disease activity. Methods: Plasma concentrations and ex vivo peripheral blood mononuclear cell production of inflammatory chemokines IP-10, RANTES, MIG, MCP-1, TARC, IL8, and GROα, and proinflammatory cytokines IL18, IFNγ, IL2, IL4, and IL10 were assayed in 80 SLE patients with or without renal disease and 40 healthy controls by immunofluorescence flow cytometry and enzyme linked immunosorbent assay. Results: Plasma IP10, RANTES, MIG, MCP-1, GROα, and IL18 concentrations in all SLE patients were higher than in controls, and correlated significantly with SLEDAI score (all p<0.05). In SLE patients without renal disease, IP10, RANTES, MIG, MCP-1, IL8, and IL18 correlated positively with SLEDAI score, while in those with renal derangement, IP10, IL8, IL10, and IL18 correlated with disease activity (all p<0.05). Plasma IL18 concentration correlated positively with IP10, MIG, GROα, and IL8 in all SLE patients (all p<0.005). Mitogen induced increases in ex vivo production of IP10, MCP-1, TARC, IFNγ, IL4, and IL10 were higher in all SLE patients regardless of their difference in disease activity (all p<0.05). Patients with renal disease had an augmented ex vivo release of RANTES. Conclusions: The correlation of raised plasma concentration and ex vivo production of inflammatory chemokines with disease activity, and their association with IL18, supports the view that chemotaxis of Th1/Th2 lymphocytes and neutrophils is important in SLE pathogenesis.

Elevated Production of B Cell Chemokine CXCL13 is Correlated with Systemic Lupus Erythematosus Disease Activity

IntroductionB lymphocyte chemoattractant (BLC/CXCL13), a CXC chemokine, is involved in B1 and B2 cell trafficking for the activation of autoreactive T helper (Th) cells and autoantibody production in target organs during the development of lupus. CXCL13 can induce the trafficking of CXCR5+ T lymphocyte subset designated as follicular helper T lymphocytes (TFH) which are specifically involved in autoantibody production.Materials and MethodsWe herein measured the plasma concentrations of CXCL13, B-cell-activating factor of the TNF family (BAFF), and TFH-cells-related cytokine IL-21 and cell surface expression of TFH-related receptor CXCR5 and IL-21R on CD4+Th and CD19+B cells in 35 systemic lupus erythematosus (SLE) patients and 23 sex- and age-matched control subjects (NC) using enzyme-linked immunosorbent assay and flow cytometry, respectively.Results and DiscussionPlasma CXCL13, BAFF, and IL-21 concentrations were significantly higher in SLE patients than NC group (all p < 0.0001). Increase in CXCL13 concentration correlated positively and significantly with SLEDAI score in SLE patients (r = 0.399, p = 0.032). Cell surface expression of CXCR5 on Th and B cells and IL-21R on B cells was however significantly lower in SLE patients than controls (both p < 0.01). It may indicate that most differentiated TFH cells migrate out from circulation into lymphoid organ upon activation during the disease development of SLE.ConclusionsThe above results suggest that the elevated production of CXCL13, BAFF, and IL-21 may be associated with the function of TFH for the immunopathogenesis in SLE, and CXCL13 may serve as a potential disease marker of SLE.

Interleukin (IL)-4 and IL-13 up-regulate monocyte chemoattractant protein-1 expression in human bronchial epithelial cells: involvement of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase 1/2 and Janus kinase-2 but not c-Jun NH2-terminal kinase 1/2 signalling pathways

The Th2 cytokines interleukin (IL)‐4 and IL‐13 and chemokine monocyte chemoattractant protein‐1 (MCP‐1) are significantly involved in bronchial hyperreactivity (BHR) and remodelling in allergic asthma. Although IL‐4 and IL‐13 can regulate a number of chemokines from bronchial epithelium, their regulatory effect on the expression of MCP‐1 is as yet unproved. We aim to investigate the intracellular signalling mechanisms of IL‐4 and IL‐13 regulating the expression and secretion of MCP‐1 from human bronchial epithelial cells. BEAS‐2B cells, derived from a human bronchial epithelial cell line, were activated with or without IL‐4 and/or IL‐13 for different time intervals. MCP‐1 gene expression and protein secretion were measured by reverse transcription–polymerase chain reaction and enzyme‐linked immunosorbent assay, respectively. Activation of signalling molecules p38 mitogen‐activated protein kinase (MAPK), extracellular signal‐regulated kinase (ERK), c‐Jun NH2‐terminal kinase (JNK) and Janus kinase‐2 (JAK‐2) was accessed by Western blotting. IL‐4 and IL‐13 were found to up‐regulate gene expression and significantly increase the release of MCP‐1 from BEAS‐2B cells. Both cytokines could activate p38 MAPK, ERK and JAK‐2, but not JNK activity. Inhibition of p38 MAPK, ERK and JAK‐2 activities by pretreating the cells with their corresponding inhibitors SB203580, PD98059 and AG490, respectively, significantly suppressed IL‐4‐ and IL‐13‐induced MCP‐1 production in BEAS‐2B cells. Together, the above results illustrate that the activation of p38 MAPK, ERK and JAK‐2 but not JNK is crucial for IL‐4‐ and IL‐13‐induced MCP‐1 release in human bronchial epithelial cells. Our findings may provide insight into the future development of more effective therapeutic agents for treating allergic asthma.

Early Enhanced Expression of Interferon-Inducible Protein-10 (CXCL-10) and Other Chemokines Predicts Adverse Outcome in Severe Acute Respiratory Syndrome

Abstract Background: Exaggerated activation of cytokines/chemokines has been proposed as a factor in adverse outcome of severe acute respiratory syndrome (SARS). Previous studies on chemokines have included only small numbers of patients, and the utility of plasma chemokines as prognostic indicators is unclear. Methods: We studied 255 archival plasma samples collected during the first or second week after disease onset. The chemokines interferon-inducible protein-10 (IP-10), monokine induced by interferon-γ (MIG), interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and regulated upon activation normal T cell expressed and secreted (RANTES) were measured by cytometric bead array with a 4-color FACSCalibur flow cytometer. Reverse transcription and real-time quantitative PCR and immunohistochemical staining were performed to analyze the production of IP-10 in lung tissue at autopsy. Conditional logistic regression was used to identify independent predictors for adverse disease outcome. Results: Increases in IP-10, MIG, and IL-8 during the first week after onset of fever were associated with adverse outcome (intensive care unit admission or death) in the univariate analysis. During the second week, only MIG concentration was associated with prognosis. After adjusting for other risk factors, plasma IP-10 concentration at the first week remained as an independent prognostic factor, with an odds ratio for adverse outcome of 1.52 (95% confidence interval, 1.05–2.55) per fold increase in plasma IP-10 concentration above the median. During the second week, chemokines provided little independent prognostic information. IP-10 was increased in lung tissue from patients who died of SARS. Conclusions: Increased plasma IP-10 during the first week of SARS symptoms is an independent predictor of outcome. Chemokine activation may be an early event in SARS, and an exaggerated host response may produce complications.

Immunomodulatory and Anti-Tumour Polysaccharides from Medicinal Plants

Many Chinese medicinal plants have immunomodulatory and anti-tumour activities. Most of the anti-tumour activities of these Chinese herbs are probably due to their immunostimulating polysaccharide components. A general scheme for the isolation and purification of the bioactive polysaccharides from naturally occurring medicinal plants is described. Hot-water extraction followed by various chromatographic methods are usually used to purify the bioactive polysaccharides. The different fractions separated from Chinese medicinal plants show a range of immunomodulatory and anti-tumour activities. The analytical methods used for monosaccharide sequence determination and structural elucidation of the bioactive polysaccharides are described, as are the tests used to evaluate their immunopharmacological activities, both in vitro and in vivo. The purification, characterization and structural elucidation of immunomodulatory polysaccharides from medicinal plants may have important implications in the immunotherapy of cancer and in the treatment of various other diseases.

Immunomodulatory and anti-SARS activities of Houttuynia cordata.

Abstract Background Severe acute respiratory syndrome (SARS) is a life-threatening form of pneumonia caused by SARS coronavirus (SARS-CoV). From late 2002 to mid 2003, it infected more than 8000 people worldwide, of which a majority of cases were found in China. Owing to the absence of definitive therapeutic Western medicines, Houttuynia cordata Thunb. (Saururaceae) (HC) was shortlisted by Chinese scientists to tackle SARS problem as it is conventionally used to treat pneumonia. Aim of the study The present study aimed to explore the SARS-preventing mechanisms of HC in the immunological and anti-viral aspects. Results Results showed that HC water extract could stimulate the proliferation of mouse splenic lymphocytes significantly and dose-dependently. By flow cytometry, it was revealed that HC increased the proportion of CD4+ and CD8+ T cells. Moreover, it caused a significant increase in the secretion of IL-2 and IL-10 by mouse splenic lymphocytes. In the anti-viral aspect, HC exhibited significant inhibitory effects on SARS-CoV 3C-like protease (3CLpro) and RNA-dependent RNA polymerase (RdRp). On the other hand, oral acute toxicity test demonstrated that HC was non-toxic to laboratory animals following oral administration at 16g/kg. Conclusion The results of this study provided scientific data to support the efficient and safe use of HC to combat SARS.

Elevated production of interleukin-18 is associated with renal disease in patients with systemic lupus erythematosus

Summary To investigate the production mechanism and proinflammatory role of the cytokine interleukin (IL‐18) in lupus nephritis, we investigated the plasma concentrations of IL‐18 and nitric oxide (NO) and the release of IL‐18 and NO from mitogen‐activated peripheral blood monomuclear cells (PBMC), in 35 SLE patients with renal disease (RSLE), 37 patients without renal disease (SLE) and 28 sex‐ and age‐matched healthy control subjects (NC). IL‐18 and NO concentrations were measured by ELISA and colourimetric non‐enzymatic assay, respectively. Gene expressions of IL‐18 and IL‐18 receptor were analysed by RT‐PCR. Plasma IL‐18 and NO concentrations were significantly higher in RSLE than NC (both P < 0·01). Elevation of plasma IL‐18 in RSLE correlated positively and significantly with SLE disease activity index and plasma NO concentration (r = 0·623, P < 0·0001 and r = 0·455, P = 0·017, respectively), and the latter also showed a positive and significant correlation with plasma creatinine (r = 0·410, P = 0·034) and urea (r = 0·685, P < 0·0001). There was no significant difference in gene expressions of IL‐18 and IL‐18 receptor in PBMC among RSLE, SLE and NC. Percentage increase in culture supernatant IL‐18 concentration was significantly higher in RSLE than SLE and NC (both P < 0·05). The basal NO release was significantly higher in RSLE than that in SLE and NC (both P < 0·005). IL‐18 is therefore suggested to play a crucial role in the inflammatory processes of renal disease in SLE.