CCR4 memory CD4+ T lymphocytes are increased in peripheral blood and lesional skin from patients with atopic dermatitis

BACKGROUND: Recent studies have reported that TH1 and TH2 cells express CXCR3 and CCR4, respectively. OBJECTIVE: Our goal was to assess the association of CCR4 and CXCR3 expression with TH2 and TH1 cells and association of CCR4 and CXCR3 expression with inflammation in patients with atopic dermatitis (AD). METHODS: Intracellular cytokine production and chemokine receptor expression in blood T cells were examined by flow cytometry. Immunohistochemical expression of chemokine receptors was also investigated in chronically lesional skin. RESULTS: CCR4+ and CXCR3+ CD4+ T cells predominantly produced IL-4 and IFN-gamma, respectively. Although the frequency of CXCR3+ cells among CD4+ CD45RO+ T cells was similar for patients with AD (n = 29) and healthy control subjects (n = 19), patients with severe AD (n = 14) had a reduced frequency of CXCR3+ cells. In contrast, the frequency of CCR4+ cells and the CCR4/CXCR3 ratio were higher in patients with AD (n = 22) than healthy control subjects (n = 16) and correlated with disease severity of AD. The frequency of CCR4+ cells correlated positively with eosinophil numbers and serum IgE levels, whereas the frequency of CXCR3+ cells correlated inversely with eosinophil numbers. The frequency of CCR4+ or CXCR3+ cells was similar in patients with psoriasis (n = 6) and healthy control subjects. Immunohistochemical analysis showed that the frequency of CCR4+ cells among CD4+ T cells in chronically lesional skin of patients with AD (n = 9) was higher than that of patients with psoriasis (n = 4). CONCLUSION: Our data suggest the association of CCR4 expression with TH2 cells, the predominance of CCR4+ cells in blood from patients with AD, and an important role of CCR4 in the migration of TH2 cells from blood into AD lesional skin.     

Activated CD4+ and CD8+ T Cell Proportions in Multiple Sclerosis Patients

The goal of this study was to trace the course of multiple sclerosis (MS) by evaluating the lymphocyte subpopulation counts and the levels of CD4+ and CD8+ T cell activation using flow cytometry. Samples obtained from healthy subjects (N?=?40) and patients with MS (N?=?290) were analyzed. Lymphocytes were labeled for the surface markers CD4+, CD8+, CD3+, CD16+, CD19+, CD45+, and CD53+ and the activation marker HLA-DR+. Cell counts were then determined using flow cytometry. A high degree of inter-individual variability was observed in the counts of all lymphocyte subtypes in the MS group. A significantly lower proportion of CD3+ T cells (69?±?14 % in healthy subjects and 60?±?17 % as a percent of total lymphocytes in MS patients), CD4+ T cells (41?±?11 and 28?±?18 %, respectively), and a significantly higher proportion of NK T cells (12?±?5 and 25?±?21 %, respectively) were observed in patients with MS than in healthy subjects. These differences led to a lowered CD4+/CD8+ T cell ratio. Furthermore, a significantly lower proportion of activated CD4+ T cells (HLA-DR+ CD4+; from 48?±?10 to 38?±?15 % as a percent of CD4+ cells) was observed in patients with MS than in healthy subjects. The high level of inter-individual variability in lymphocyte cell counts and the counts of activated T cells suggest that MS is a complex and heterogeneous disease.     

Abnormal distribution of gammadelta T lymphocytes in Graves' disease and insulin-dependent diabetes type 1

There is an increasing evidence that CD3+ cells, bearing gammadelta T cell receptors representing a minor subpopulation of T cells in the peripheral blood of humans are involved in the development of autoimmunity. The aim of the present study was determination of the gammadelta T cell subpopulation levels in the peripheral blood of subjects with Graves' disease and newly diagnosed type 1 diabetes in comparison to age-matched healthy controls. The percentages of CD3+, CD8+, gammadelta TCR+CD8+, gammadelta TCR+CD8- lymphocyte subsets were measured by flow cytometry. In the peripheral blood of newly diagnosed Graves' disease patients we showed a significant decrease of gammadelta TCR+ cells and gammadelta TCR+CD8- subset content in comparison to the percentages observed in subjects after methimazole treatment and in healthy controls. We also found a significant increase of gammadelta TCR+CD8+ cells in the peripheral blood of subjects with insulin-dependent diabetes, treated with insulin for 3-6 months. The present findings confirm our previous hypothesis that gammadelta TCR+CD8+ lymphocyte subset could play a role in the pathogenesis of diabetes type 1, probably as regulatory T cells and could be induced by delivery of exogenous insulin. Our results suggest that gammadelta T cells (gammadelta TCR+CD8- subset) could also play an important role in the development of Graves' disease and that their levels are modulated by thyreostatic treatment.     

T lymphocytes in rat germinal centres belong to an ER3+ subpopulation of CD4+ cells.

Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germinal centre T cells in rat spleen or lymph node examined 7 days after immunization bear the antigen recognized by the monoclonal antibody (mAb) ER3. By contrast, only 30-40% of all thoracic duct or lymph node CD4+ cells were ER3+, as determined by two-colour flow cytometry. CD8+ cells were ER3+, but nearly all B cells were ER3-. Thus, germinal centre T cells belong to a subpopulation of CD4+ cells. Because only 25-30% of CD4+ cells that lack higher molecular weight forms of CD45 (i.e. mAb MRC OX32 cells, equivalent to MRC OX22 cells) express ER3, the CD4+ subpopulations defined by ER3 are neither identical nor complementary to the subsets defined by restricted expression of CD45 epitopes.     

Decreased T lymphocyte infiltration in bronchial biopsies of subjects with severe chronic obstructive pulmonary disease

BACKGROUND: Studies on the inflammatory process in the large airways of patients with mild/moderate COPD have shown a prevalent T lymphocyte and macrophage infiltration of the bronchial mucosa. However, bronchial inflammation in more severe disease has not been extensively studied. OBJECTIVE: The aim of the present study was to characterize the lymphocyte infiltration in the bronchial mucosa of subjects with severe, compared to mild, COPD, and to examine the relationship between airflow limitation and T lymphocyte numbers in the bronchial mucosa. METHODS: We examined bronchial biopsies obtained from nine smokers with severe airflow limitation, nine smokers with mild/moderate airflow limitation and 14 smokers with normal lung function. Immunohistochemical methods on cryostat sections were used to assess the number of CD3+, CD4+, CD8+ cells and the number of CD3+ cells coexpressing the chemokine receptor CCR5 (CCR5+CD3+) in the subepithelium. RESULTS: Subjects with severe COPD had lower numbers of CD3+, CD8+ and CCR5+CD3+ cells than mild/moderate COPD (P < 0.012, P < 0.02 and P < 0.02, respectively) and control smokers (P < 0.015, P < 0.005 and P < 0.015, respectively). In subjects with airflow limitation the number of CD3+ and CD8+ cells was inversely correlated with the degree of airway obstruction (r = 0.59, P < 0.015 and r = 0.52, P < 0.032, respectively). CONCLUSIONS: Bronchial inflammation in severe COPD is characterized by lower numbers of CD3+ and CD8+ cells and decreased numbers of CD3+ cells coexpressing the chemokine receptor CCR5. T lymphocyte infiltration is inversely correlated with the degree of airflow limitation.     

Mucosal T-cell phenotypes in persistent atopic and nonatopic rhinitis show an association with mast cells

Background: Allergic rhinitis is characterized by selective expansion of T cell subsets with a CD4+ phenotype. Recently, we identified a subpopulation of nonallergic rhinitis subjects with increased epithelial mast cell and eosinophil populations, suggestive of local mucosal allergy. Previously, T cell subsets have not been characterized in this subselection of nonallergic subjects and furthermore, their relationship to mast cell and basophil effector cells remain unidentified. Objective: To determine if a subpopulation of nonallergic subjects with idiopathic rhinitis (IR) have localized allergy confined to their nasal mucosa by comparing the T cell subsets and major histocompatibility complex (MHC) II expressing cells to persistent allergic rhinitis (PAR). Furthermore, the relationship between T cell subsets and mast cells/basophils was investigated. Methods: None of the symptomatic patients in this study were clinically allergen‐challenged. Nasal turbinate mucosa was removed from patients with PAR, IR and normal controls. Morphometry was performed on immunostained sections for T cell subset populations including CD3+, CD4+, CD8+, CD25+, CD45RA+, CD45RO+, human leucocyte antigen (HLA)‐DRα (MHC class II), mast cell tryptase and for basophils. Results: Subjects with persistent allergic rhinitis differed to normal controls in showing significantly increased numbers of total (CD3+), activated (CD25+) and allergen‐naïve (CD45RA+) T lymphocytes in their nasal mucosa (P < 0.025). The naïve CD45RA+ memory T cells correlated to mucosal mast cells in PAR (P = 0.03). IR patients differ to allergic subjects in showing significantly reduced numbers of epithelial HLA‐DRα+ cells (P = 0.007), but increased numbers of CD8+ lymphocytes (P = 0.02). The CD8+ T cells correlated with mucosal mast cell numbers (P = 0.02). In both rhinitis groups, basophils were present in very low numbers obviating the need for statistical analysis. Conclusion: PAR is characterized by increased numbers of CD3+, CD25+ and CD45RA+ T lymphocytes compared with normal mucosa. Allergic and nonallergic rhinitis groups can be separated by significant differences in the number of epithelial antigen presenting cells (APCs) (HLA‐DRα+) and sub‐epithelial activated (CD25+) T cells. Moreover, IR patients do not significantly differ to their allergic counterparts with respect to total (CD3+) and naïve (CD45RA+) T cell numbers, or numbers of epithelial activated (CD25+) lymphocytes. IR subjects show significantly increased numbers of CD8+ lymphocytes compared with control mucosa and although our findings suggest that the initiating inflammatory events may differ, both rhinitis groups show a similarity in pathology involving mucosal mast cells with an association to infiltrating T cells.     

成人隐匿性自身免疫性糖尿病患者CD4+CD25+T细胞的变化研究

目的：通过观察成人隐匿性自身免疫性糖尿病（LADA）患者CD4^＋CD25^＋T细胞的变化并与速发性1型糖尿病（T1 DM）比较，了解成人隐匿性自身免疫性糖尿病患者T细胞免疫功能的变化及与1型糖尿病的异同点。方法：LADA组24例，速发性T1DM18例，对照组20例，应用流式细胞技术测定3组人选者T细胞表面分子CD4、CD8、CD25、CD4^＋CD25^＋、CD8^＋CD25^＋、CD4^＋CD25^＋CD62L^＋，以百分比表示各表面分子阳性T细胞占外周血淋巴细胞的比例。结果：LADA与T1DM组CD4^＋T细胞、CD4／CD8比值明显高于健康对照组（P〈0．01），LADA与T1DM对比无差异。LADA组CD25^＋、CD4^＋CD25^＋、CD4^＋CD25^＋CD62L^＋T细胞高于健康对照组（P〈0．05），明显高于T1 DM组（P〈0．01）。T1 DM组CD25^＋、CD4^＋CD25^＋、CD4^＋CD25^＋CD62L^＋T细胞略低于健康对照组，但无统计学意义（P〉0．05）。结论：LADA患者外周血中诱导免疫耐受的CD4^＋CD25^＋、CD4^＋CD25^＋CD62L^＋T细胞较对照组升高并明显高于T1 DM患者。LADA患者胰岛B细胞功能下降较速发性T1 DM患者相对缓慢可能与CD4^＋CD25^＋T细胞的免疫保护有关。     

Expression of CD6 and the UCHL1-defined CD45 (p180) antigen by human colonic T lymphocytes

Cryostat sections of histologically normal human colon were studied by double-label immunofluorescence techniques using a panel of monoclonal antibodies to T-lineage antigens and activation markers, with particular reference to the CD6 antigen. In the lamina propria, the majority population of T cells was of the CD3+, CD6+, CD4+ subset, of which virtually all were of the UCHL1+, CD45R-, Leu 8- phenotype of antigen-committed helper T cells. This majority lamina propria population did not express markers associated with blastogenesis (CD7), activation (MHC class II, CD25, CD38) or proliferation (OKT9, Ki67). In both intra-epithelial and lamina propria compartments, a subpopulation of CD3+ T cells was identified which did not express either the CD6 or CD5 peripheral 'pan T' markers. Most of the CD3+, CD6- cells were of the CD8+ (cytotoxic-suppressor) subset which co-expressed the CD7 antigen with a much higher frequency than did the CD6+ subpopulation. Expression of CD25, CD38 and HLA-D antigens, although infrequent, was confined to this CD8+, CD5-, CD6- population. Our data thus imply that the colonic mucosa is largely populated by mature, antigen-committed resting T cells of the helper-inducer phenotype.     

T lymphocytes expressing CCR3 are increased in allergic rhinitis compared with non-allergic controls and following allergen immunotherapy

BACKGROUND: In T cell-associated allergic inflammation, homing of T-helper 2 (Th2) effector cells to mucosal sites may be influenced by chemokine receptor expression. Previous studies have identified CCR3 and CCR4 as putative markers of Th2 cells and CCR5 and CXCR3 as markers of Th1 cells. The aim of this study was to assess differential chemokine receptor expression from symptomatic atopic grass pollen-sensitive subjects, compared with patients on high-dose allergen injection immunotherapy (IT) and healthy controls. METHODS: We examined chemokine receptor expression (CCR1-7 and CXCR1-4) by flow cytometry of peripheral blood CD4+ and CD8+ T cells. We also depleted peripheral blood mononuclear cell (PBMC) populations of CCR3+ CD4+ cells by magnetic bead separation and cells were stimulated with grass pollen allergen for 6 days. Cytokine production was measured by enzyme-linked immunosorbent assay. RESULTS: On freshly isolated PBMC, atopic individuals exhibited increased numbers of CCR3+ CD4+ cells compared with normal controls (P < 0.01). CCR3 expression in IT patients was reduced compared with matched atopic rhinitic controls (P < 0.05) and comparable with that observed in normal subjects. Depletion of CCR3+ CD4+ cells from allergen-stimulated PBMC cultures resulted in decreased interleukin (IL)-5 production compared with whole CD4+ populations (P < 0.05). Freshly isolated CCR3+ CD4+ cells have significantly higher intracellular IL-4 and lower IFN-gamma levels than CCR3- CD4+ cells. CD4+ T cells cultured from both peripheral cells and nasal biopsies demonstrated increased expression of CCR3 in the presence of IL-4 (P < 0.05). CONCLUSION: CCR3+ CD4+ T cells are increased in allergic rhinitis, are reduced by allergen IT, have a Th2 phenotype and contribute to allergen-specific responses. Strategies against CCR3+ T cells may be effective in human allergic diseases.     

Lymphocyte activation markers in idiopathic myositis: changes with disease activity and differences among clinical and autoantibody subgroups

We studied the immunologic correlates of disease activity and differences among subgroups of patients with idiopathic inflammatory myopathy by analysing phenotypic and activation marker expression on peripheral blood mononuclear cells (PBMC). Compared with controls, myositis patients with clinically active disease (n = 51) had significantly lower proportions of CD8+ cells and higher proportions of PBMC that expressed DR, CD3- DR, CD14- DR, interleukin-2 receptors, and the late T cell activation markers CD26 and TLiSA1. TLiSA1 expression, a marker for cytotoxic differentiation, correlated significantly with both clinical activity indices and serum levels of muscle-associated enzymes. In serial studies of seven patients, the proportion of PBMC expressing MHC class II antigen and late T cell activation markers decreased as myositis disease activity decreased, independent of type of therapy. Among the clinical subgroups, polymyositis (n = 21) and inclusion body myositis (n = 11) were virtually indistinguishable; dermatomyositis patients (n = 19) showed decreased proportions of CD3+DR+ and TLiSA1+ cells, and increased proportions of CD20+ and CD20+DR+ cells compared with the other two groups. Patients with autoantibodies to histidyl-tRNA synthetase (Jo-1 antigen, n = 11) had significantly lower proportions of CD3+ and CD4+ cells, lower CD4/CD8 ratios, and higher proportions of CD+ cells expressing CD20, compared with patients without anti-Jo-1 antibodies. These findings support the concept that activated lymphocytes, especially cells undergoing anamnestic responses and cytotoxic differentiation, are important in the pathogenesis of idiopathic myositis. Moreover, taken together with other studies, these data suggest that groups of patients segregated by clinical or autoantibody status have different mechanisms of systemic immune activation and immunopathology.     

Characterization of chemokine receptor expression and cytokine production in circulating CD4+ T cells from patients with atopic dermatitis: up-regulation of C-C chemokine receptor 4 in atopic dermatitis

BACKGROUND: Th2 and Th1 cells have been suggested to express CCR3/CCR4 and CCR5/CXCR3, respectively. OBJECTIVE: We examined CCR3, CCR4, CCR5 and CXCR3 expression and cytokine production in peripheral blood CD4+ T cells from patients with atopic dermatitis (AD), which has been postulated to be a Th2-type cell-mediated disease, and then analysed the possible correlation between these values and the levels of several clinical parameters. METHODS: Intracellular cytokine production and chemokine receptor expression in peripheral blood CD4+ T cells from 40 AD patients and 20 sex- and age-matched healthy control subjects were studied by flow cytometry. RESULTS: The frequencies of IL-4- and IL-13-producing CD4+ T cells from patients with AD were significantly higher than those from healthy control subjects (IL-4:3.9 +/- 2.1% vs. 1.6 +/- 0.7%, P = 0.0005, IL-13:4.0 +/- 2.1% vs. 1.8 +/- 0.8%, P = 0.0023), whereas the frequencies of IL-2- and IFN-gamma-producing CD4+ T cells were significantly decreased in AD patients (IL-2:38.1 +/- 10.3% vs. 51.3 +/- 6.3%, P = 0.0003, IFN-gamma: 9.9 +/- 3.5% vs. 26.4 +/- 4.6%, P < 0.0001). The percentage of CCR4+ cells in CD4+ CD45RO+ T cells in AD patients was significantly higher than that in healthy control subjects (24.4 +/- 8.0% vs. 10.9 +/- 2.3%, P < 0.0001) and was correlated positively with the total serum IgE, serum lactic dehydrogenase (LDH) level, eosinophil number, eruption score, and IL-4 and IL-13 secretion in CD4+ T cells, and inversely with IL-2 and IFN-gamma secretion in CD4+ T cells. In contrast, CCR3 was not detected on circulating CD4+ T cells even in AD patients. On the other hand, the percentage of CCR5+ or CXCR3+ cells in CD4+ CD45RO+ T cells in AD patients was significantly decreased (CCR5:23.2 +/- 7.0% vs. 28.4 +/- 5.4%, P = 0.023, CXCR3:29.9 +/- 11.4% vs. 38.5 +/- 6.7%, P = 0.028) and was positively correlated with eruption score (P < 0.05). Multiple regression analyses showed that the percentage of CCR4 expression highly correlated with serum IgE, LDH, eosinophil number and eruption in AD patients. CONCLUSION: CCR4+ cells might be involved in the aetiopathogenesis of AD.     

Altered T cell subpopulations and lymphocytes expressing natural killer cell phenotypes in patients with progressive systemic sclerosis

Scleroderma (progressive systemic sclerosis [PSS]) is known to be associated with abnormal T cell immunoregulation. In the present study, we evaluated lymphocyte phenotypes in patients with PSS and normal control subjects by flow cytometry and monoclonal antibodies for total T (CD3), T suppressor (CD8), T helper (CD4), T helper-inducer (CDw29), T suppressor-inducer (CD45R), human leukocyte antigen, DR+B (CD19), DR+T, and natural killer subsets, HNK-1 (CD57) and NKH-1 (CD56) cells. Patients with PSS compared to normal subjects had significantly lower percentages of CD3+ (p less than 0.005) and CD8+ (p less than 0.05) (similar to several patients with rheumatoid arthritis also evaluated), as well as CD45R (p less than 0.05), T+DR+ (p less than 0.05), and NKH-1 (CD56) (p less than 0.0005) cells. Patients with PSS with late-limited or generalized disease had lower percentages of CD8+, CD19, NKH-1+, and CDw29, but higher percentages of CD4+, HNK-1, and CD45R cells compared to patients with early stage disease, but these results were not statistically significant. These unique alterations in patients with PSS may prove to be useful in monitoring the stage of disease activity for therapy and further define immunologic defects.     

Increased circulating CCR3+ type 2 helper T cells in house dust mite-sensitive Chinese patients with allergic diseases

Chemokine receptor expression has been shown to be associated with the differentiation of T helper cells. The CCR3, CXCR4 and CCR5 expression on circulating T cells were studied in 30 house dust mite sensitive-patients with allergic diseases and in another 30 healthy controls. The expression was analyzed in CD4, CD8 and double negative (DN) T cells by triple fluorescence staining. In addition, intracellular cytokine staining was performed in the CCR3+ CD4+ T cells. Increased circulating portions of CCR3+ CD4+ T cells and CCR3+ DN T cells were found in these patients (p < 0.01). There was no statistically significant difference in the expression of CXCR4 and CCR5 on T cells. The follow-up data of the patients did not show a statistically significant change in the CCR3 expression. IL-4 was expressed within CCR3+ CD4+ T cells upon activation. The IL-4 secreting CCR3+ type 2 T helper cells may play a pathogenetic role in immune responses of house dust mite-sensitive Chinese patients with allergic diseases.     

Intrathyroidal HLA-DR-positive lymphocytes in Hashimoto's disease: increases in CD8 and Leu7 cells

The peripheral and intrathyroidal HLA-DR-positive (DR+) lymphocyte subsets that were activated in vivo in patients with Hashimoto's disease (HD) were examined by two-color flow cytometry with monoclonal antibodies against CD3, CD4, CD8, Leu7, CD19, and HLA-DR antigens. The proportions of total DR+ cells in peripheral lymphocytes and the proportions of DR+ cells in the CD3+, CD4+, and Leu7+ lymphocytes were higher in patients with HD than in normal controls. Furthermore, the proportions of total DR+ cells among intrathyroidal lymphocytes isolated from thyroid tissue of individuals with HD were higher than those in their peripheral lymphocytes. Interestingly, the proportions of DR+ cells among the CD3+, CD8+, and Leu7+ lymphocytes in the thyroid were greatly increased. These data indicate that (i) CD3+ T, especially CD4+ T helper/inducer, lymphocytes and Leu7+ NK/K cells are activated in peripheral blood in Hashimoto's disease and that (ii) CD3+ T, especially CD8+ T suppressor/cytotoxic, lymphocytes and Leu7+ NK/K cells are predominantly activated in Hashimoto's goiter, suggesting an increase of cell-mediated cytotoxicity in the thyroid in Hashimoto's disease.     

Immunohistological relation between DR antigen expression on melanoma cells and infiltration by CD8+ T cells

Previous studies have suggested that class II major histocompatibility (MHC) antigen expression on melanoma cells may influence immune responses against melanoma and the nature of lymphocytic infiltrates against the tumor. This question was examined further by immunoperoxidase studies on sections from 29 primary and 30 metastatic melanoma with monoclonal antibodies (MAbs) against different lymphocyte subsets. The results indicated that expression of MHC class II DR* antigens on melanoma cells was associated with increased overall lymphocytic infiltration and that this applied particularly to the CD8+ subset of T cells. The CR3 receptor (CD 11b) was expressed predominantly on T cells and not macrophages but infiltration by CD11b+ cells did not correlate strongly with DR expression on melanoma cells. Dual staining with MAbs to CD8 and CD11b revealed that, whereas most of the CD8+ cells in DR- primary melanoma and DR+ metastatic melanoma were CD11b+, only approximately 50% of the CD8+ cells in DR+ primary melanoma were also CD11b+. Expression of CD11b on T cells was reported to define a suppressor subset of T cells. If the latter is correct the present results suggest that DR expression on primary melanoma is associated with infiltration by the cytotoxic T cell subset, whereas in the absence of DR antigens and in metastases this subset is absent and the predominant subset appears to be CD8+ CD11b+ T cells with suppressor activity. The biologic and prognostic significance of these findings remains to be determined.     

CRTH2 is the most reliable marker for the detection of circulating human type 2 Th and type 2 T cytotoxic cells in health and disease

Cells expressing the chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) and the chemokine C receptor (CCR)4 were consistently detected in the circulation of healthy subjects, whereas numbers of cells expressing CCR3 were much lower. While all CCR4+ cells were T cells, a small proportion of CRTH2+, and about a half of the few CCR3+ cells were basophils. Only CRTH2+ T cells contained Th2 or Tc2 cells, but neither Th0 or Tc0, nor Th1 or Tc1 cells, although not all of them produced Th2-type cytokines. By contrast, CCR4+ T cells contained both Th2 or Tc2 and Th0 or Tc0 cells and even Th1 or Tc1 cells, whereas the few CCR3+ T cells were not clearly classifiable for their cytokine profile. CRTH2+ T lymphocytes were virtually devoid of chemokine CX receptor (CXCR)3+ and CCR5+ cells, but enriched in CCR3+ and CCR4+ cells. By contrast, CCR3+ or CCR4+ T cells did not show a similar clear-cut dichotomy in the expression of CCR5/CXCR3 or CCR3/ CCR4. Subjects with atopic dermatitis or HIV infection with low levels of circulating CD4+ T cells revealed a significant increase of CRTH2+ cells within both the CD4+ and the CD8+ T cell subset. These data support the concept that at present CRTH2 is the more reliable marker for detection of both human Th2 and Tc2 cells in health and disease.     

Chemokine receptors support infiltration of lymphocyte subpopulations in human hepatocellular carcinoma

The presence of lymphocyte infiltration in human hepatocellular carcinoma (HCC) is evident. However, immune regulation of lymphocytes in HCC is poorly characterized. In this study, we investigated the chemokine receptor and memory, activation and adhesion markers of major leukocyte subsets present in tumor, nontumor liver, and peripheral blood. T cells from both tumor and peritumor liver displayed high levels of activation and homing markers. CCR5 and CXCR3 were expressed in a large proportion of CD45RO+, CD69+, CD27+, and CD11a+ T cells from tumor compared with T cells from circulation. The proportion of CCR6- and CXCR3-expressing natural killer cells (NK) and natural killer T cells (NKT) was significantly increased in the tumor and nontumor liver compared with peripheral blood. This study demonstrates the role of chemokine receptors in the recruitment of specific lymphocyte subsets to the liver in HCC and suggests the importance of these receptors in regulation of immune defense against HCC.     

Comparative study of GAD65-specific CD4+ T cells in healthy and type 1 diabetic subjects

Glutamic acid decarboxylase 65 (GAD65) is a putative autoantigen associated with the pathogenesis of type 1 diabetes (T1D). The prevalence of autoreactive CD4+ T cells towards the immunodominant GAD65(555-567) epitope in DR4 healthy and T1D subjects was investigated with class II tetramers. A slightly higher percentage of diabetic subjects had GAD65(555-567) tetramer-positive T cells upon GAD65(555-567) peptide stimulation on the total CD4+ T-cell populations compared to healthy subjects. In contrast, three quarters of subjects in both groups had tetramer-positive T cells resulting from stimulation of the CD4+CD25+ regulatory T-cell depleted CD4+ T cells. The frequencies and TCR Vbeta gene usages of GAD65(555-567) T cells were also similar in both groups. Experiments demonstrated that GAD65(555-567)-reactive T cells in healthy and diabetic subjects had different CD45RA phenotypes. For the healthy group, GAD65(555-567)-reactive T cells were generally found in the CD45RA+ na?ve T-cell pool while GAD65(555-567)-reactive T cells from T1D subjects were present in both CD45RA+ na?ve and CD45RA- memory T-cell pools. These findings suggested that there is no difference in thymic selection of DR4 restricted GAD-reactive T cells amongst healthy and T1D individuals but GAD65(555-567)-reactive T cells have been preferentially activated in diabetic patients.