Evidence for superantigen involvement in skin homing of T cells in atopic dermatitis

The environmental factors that contribute to the homing of T cells in skin disease is unknown. The skin lesions of atopic dermatitis (AD) are frequently colonized with superantigen (SAg), producing strains of Staphylococcus aureus. In vitro, these superantigens have the capacity to activate and expand T cells expressing specific T cell receptor BV gene segments, and also to increase their skin homing capacity via upregulation of the skin homing receptor, cutaneous lymphocyte-associated antigen (CLA). These activities have been proposed to enhance the chronic cutaneous inflammation of AD, but an in vivo role for SAg has not been conclusively demonstrated. In this study, we sought direct evidence for in vivo SAg activity by comparing the SAg profiles of S. aureus cultured from the skin of AD subjects to the T cell receptor Vbeta repertoire of their skin homing (CLA+) T cells in peripheral blood. SAg secreting S. aureus strains were identified in six of 12 AD patients, and all of these subjects manifested significant SAg-appropriate Vbeta skewing within the CLA+ subsets of both their CD4+ and their CD8+ T cells. T cell receptor Vbeta skewing was not detectable among the overall CD4+ or CD8+ T cell subsets of these subjects, and was not present within the CLA+ T cell subsets of five patients with plaque psoriasis and 10 normal controls. T cell receptor BV genes from the presumptively SAg-expanded populations of skin homing T cells were cloned and sequenced from three subjects and, consistent with a SAg-driven effect, were found to be polyclonal. We conclude that SAg can contribute to AD pathogenesis by increasing the frequency of memory T cells able to migrate to and be activated within AD lesions.     

Membrane localisation of a UDP-sugar hydrolase, in Salmonella, is by an uncleaved N-terminal signal peptide

Many immunologic aspects of atopic dermatitis have been studied, but basic pathobiologic mechanisms of this disease remain unknown. In this study, we measured the production of interleukin-6 (IL-6) by peripheral blood T cells and monocytes from patients with atopic dermatitis in comparison to normal control subjects and patients with chronic psoriasis. We found that peripheral blood T cells isolated from patients with atopic dermatitis produced significantly higher levels of IL-6 (36.1 +/- 5.1 units/ml, n = 22) than T cells derived from either normal subjects (12.6 +/- 1.9 units/ml, n = 22) or patients with chronic psoriasis (26.7 +/- 4.1 units/ml, n = 7). T-cell activation was also measured in the patients with atopic dermatitis by soluble serum IL-2 receptor levels and were found to be significantly higher (623.7 +/- 8.1 units/ml, n = 8) than normal subjects (357.2 +/- 26.0 units/ml, n = 8). In contrast to the increased production of IL-6 by T cells in atopic dermatitis, there was no significant difference in the IL-6 production by peripheral blood monocytes derived from patients with atopic dermatitis compared to normal subjects. Thus, peripheral blood T cells derived from patients with AD spontaneously produce increased amounts of IL-6 compared to T cells from normal subjects, which may reflect the increased activation state of T cells in atopic dermatitis. These data support the concept that activated T cells or subsets of T cells may be important effector cells in mediating inflammatory activity in atopic disease.     

Allergen specificity of skin-infiltrating T cells is not restricted to a type-2 cytokine pattern in chronic skin lesions of atopic dermatitis

The majority of allergen-specific T cells derived from inhalant allergen patch test lesions in patients with atopic dermatitis were previously found to produce a restricted type-2 cytokine pattern. Recent studies, however, have revealed that in chronic eczematous skin lesions of patients with atopic dermatitis, expression of the type-1 cytokine interferon-gamma predominates. To evaluate cytokine production by allergen-specific T cells in chronic atopic dermatitis, we established house dust mite (Dermatophagoides pteronyssinus)-specific T-cell clones from the dermis of chronic skin lesions of sensitized adult patients with atopic dermatitis. Frequencies of skin-derived T cells proliferating in the presence of Dermatophagoides pteronyssinus were between one in 138 and one in 4255, indicating that only a minority of skin-infiltrating T cells are allergen specific. When these cells were analyzed for their capacity to produce interferon-gamma, the majority (71%) of these cells were found to express interferon-gamma mRNA and to secrete interferon-gamma protein, either alone or in combination with interleukin-4. Phenotypic analysis revealed that 15% of skin-infiltrating allergen-specific T cells were CD8+. No selection of Vbeta elements was detected in Dermatophagoides pteronyssinus-specific T-cell clones. These studies demonstrate that allergen specificity of skin-infiltrating T cells is not restricted to a type-2 cytokine pattern in lesional atopic dermatitis. The notion that the majority of allergen-specific, skin-infiltrating T cells are capable of producing interferon-gamma further supports the concept that interferon-gamma expression has major pathogenetic relevance for the chronic phase of atopic dermatitis.     

Predominance of epidermal CD8+ T lymphocytes in bullous cutaneous reactions caused by beta-lactam antibiotics

The phenotype and functional characteristics of skin-infiltrating lymphocytes in beta-lactam antibiotic-induced vesiculobullous exanthemas were studied in vivo and in vitro. Immunohistochemical analysis demonstrated that CD8+ T lymphocytes were the predominant epidermal T-cell subset in these reactions. Epidermal T lymphocytes were isolated and expanded for in vitro studies. Fluorescence-activated cell sorter analysis showed the majority of epidermal T cells to be CD3+, T-cell receptor alpha/beta+, CD4-, CD8+, and HLA-DR+, which correlated with the predominance of epidermal CD8+ T lymphocytes found in situ. Three CD8+ epidermal T-cell clones derived from cutaneous lesions proliferated in response to penicillin-pulsed autologous antigen-presenting cells but not allogeneic antigen-presenting cells, indicating that those clones were antigen and major histocompatibility complex specific. All T-cell clones produced significant amounts of interleukin-2, interferon-gamma, and granulocyte-macrophage colony-stimulating factor. Additionally, the T-cell clones displayed cytotoxicity against epidermal cells in lectin-mediated cytotoxicity and against B-cell lines in T-cell receptor-triggered cytotoxicity. These data demonstrate the presence of epidermal drug-specific CD8+ T cells in bullous drug reactions. Because these CD8+ T cells have a cytotoxic potential, they may contribute to the necrosis of keratinocytes associated with drug-induced blister formation.     

Expression of CD30 on T helper cells in the inflammatory infiltrate of acute atopic dermatitis but not of allergic contact dermatitis

The CD30 molecule has been proposed as a marker for a subset of CD4+CD45RO+ (memory) T cells with potent B cell helper activity producing IL-5 and IFN-gamma and as a specific marker for Th2 cells. Recently, an association has been demonstrated between elevated serum levels of soluble CD30, which is shed by CD30+ cells in vitro and in vivo, and atopic dermatitis but not respiratory atopic disorders or allergic contact dermatitis. We studied the expression of CD30 in the inflammatory infiltrate of atopic dermatitis compared with that of allergic contact dermatitis, with special regard to skin disease activity (acute vs subacute/ chronic). Biopsies were obtained from 16 patients suffering from atopic dermatitis (acute n = 6, subacute/ chronic n = 10), from 7 patients with acute allergic contact dermatitis and from 5 positive patch-test reactions. Paraffin-embedded as well as snap-frozen material was stained with anti-CD30 and anti-CD45RO mAbs according to standard procedures. Double-staining procedures for CD30CD3, CD30CD4, CD30CD45RO and CD30CD68 were also performed. Abundant CD45RO+ cells were detected both in atopic dermatitis and in allergic contact dermatitis lesions. We found scattered CD30+ cells in only one of six formalin-fixed paraffin-embedded acute atopic dermatitis biopsies, but in all of the respective snap-frozen specimens, possibly because CD30 expression on atopic dermatitis infiltrating cells is weak and sensitive to formalin fixation and paraffin embedding. CD30CD3 and CD30CD4 double staining identified CD30+ cells to be helper T lymphocytes. No significant CD30 expression (either in paraffin-embedded or in frozen material) could be found in subacute/chronic atopic dermatitis lesions or in any of the specimens of allergic contact dermatitis. The results suggest a specific regulatory function of CD30+ T cells in acute atopic dermatitis. With respect to the view that CD30 is a marker for Th2 cells, our observations confirm previous findings that Th2 cells predominate in the infiltrate particularly of acute atopic dermatitis. CD30 expression in acute atopic dermatitis but not in acute allergic contact dermatitis might be helpful in the histological differentiation of these disorders and in the further characterization of atopy patch testing.     

T lymphocytes bearing the gamma/delta T-cell receptor in cutaneous lesions of dermatitis herpetiformis

T lymphocytes bearing the gamma/delta T-cell receptor are a rare component of normal human GI epithelium and skin. Recently, however, an unusually high percentage of T lymphocytes with gamma/delta receptors has been described in gastrointestinal biopsies from patients with dermatitis herpetiformis, implicating the gamma/delta T cell subset in the pathogenesis of this disease. We investigated a possible role for this subset of lymphocytes in the pathogenesis of the cutaneous lesions of dermatitis herpetiformis. Using a standard immunoperoxidase technique, we labelled perilesional skin biopsies from patients with dermatitis herpetiformis and other inflammatory dermatoses with monoclonal antibodies to CD3, CD4, CD8, alpha/beta T cell receptor, gamma/delta T cell receptor, and IL-2 receptor. We found no differences in the percentage of gamma/delta positive T lymphocytes in skin lesions of dermatitis herpetiformis as compared to other selected inflammatory conditions. These findings suggest that the pathogenesis of the cutaneous lesions of dermatitis herpetiformis is not mediated through gamma/delta T cells, and that the cutaneous lesions may develop through mechanisms different from those operative in the gastrointestinal tract.     

Analysis of tumor-infiltrating lymphocytes in cutaneous squamous cell carcinoma

OBJECTIVE: To characterize tumor-infiltrating lymphocytes (TILs) within lesions of cutaneous squamous cell carcinoma (SCC) and related disorders. DESIGN: Case series with 1- and 2-color immunohistologic, molecular biological analysis of T-cell clonality and in vitro cytotoxicity assays. SETTING: Academic medical center. PATIENTS: Twenty-one patients, including 6 with actinic keratoses, 4 with SCC in situ, and 11 with invasive SCC. RESULTS: CD8+ TILs were present within lesions of cutaneous SCC and AK. These cells constituted a variable minority of the total T-cell infiltrate, and many expressed a phenotype consistent with major histocompatibility complex-restricted cytotoxic T lymphocytes: CD3+, TIA1+, CD16-, CD56-, CD57-. They also expressed HLA-DR, suggesting their activation in vivo. Virtually all T cells were T-cell receptor (TCR)-beta + delta, indicating that they expressed the TCR-alpha beta protein heterodimer. Molecular biological analysis of TCR-gamma gene rearrangements by the polymerase chain reaction and denaturing gradient gel electrophoresis technique indicated that the TILs were polyclonal. Functional studies suggested that TILs derived from SCC lesions were cytotoxic for autologous tumor cell targets. CONCLUSION: Tumor-infiltrating lymphocytes within cutaneous SCC lesions contain a subpopulation of polyclonal, major histocompatibility complex-restricted cytotoxic T lymphocytes expressing the TCR-alpha beta heterodimer.     

Demonstration of frequent occurrence of clonal T cells in the peripheral blood of patients with primary cutaneous T-cell lymphoma

Clonal T cells have been demonstrated in skin lesions of all stages of cutaneous T-cell lymphomas (CTCLs). However, there are conflicting data regarding the CTCL stage at which dissemination of clonal cells into peripheral blood occurs. Although the multifocal occurrence of cutaneous CTCL lesions and T-cell recirculation suggest an early appearance of neoplastic cells in the blood, circulating clonal T cells have only been detected in advanced stages. We investigated their occurrence by a highly sensitive polymerase chain reaction (PCR) assay amplifying T-cell receptor gamma rearrangements and subsequent heteroduplex temperature gradient gel electrophoresis (HD-TGGE) of the amplification products. Circulating clonal T cells were found in 26 of 45 patients with mycosis fungoides (MF), six of seven with Sezary's syndrome (SS), 10 of 13 pleomorphic CTCLs, and three of four unclassified CTCLs. Corresponding skin specimens carried clonal T cells in 29 of 40 MF, three of four SS, 12 of 12 pleomorphic, and two of two unclassified CTCL patients. Except for the blood specimen of a psoriatic patient, all samples of 60 controls (psoriasis vulgaris, atopic dermatitis, and healthy volunteers) revealed polyclonal amplification products. In 30 of 32 CTCL patients carrying a clonal rearrangement in blood and skin, identity of both clones was indicated by HD-TGGE and confirmed by sequencing six of these cases. We found an unexpected high frequency of identical clonal T cells in peripheral blood and skin of CTCL patients, including early stages of MF. This supports the concept of an early systemic disease in CTCL and raises new questions concerning the pathogenesis.     

Two distinct pathways of interleukin-5 synthesis in allergen-specific human T-cell clones are suppressed by glucocorticoids

Glucocorticoids (GC) have long been used as the most effective agents for the treatment of allergic diseases accompanied by eosinophilia such as chronic asthma and atopic dermatitis. The development of chronic eosinophilic inflammation is dependent on interleukin-5 (IL-5), a selective eosinophil-activating factor, produced by helper T cells. To delineate the regulatory mechanisms of human IL-5 synthesis, we established allergen-specific CD4+ T-cell clones from asthmatic patients. GC efficiently suppressed IL-5 synthesis of T-cell clones activated via either T-cell receptor (TCR) or IL-2 receptor (IL-2R). Induction of IL-5 mRNA upon TCR and IL-2R stimulation was totally inhibited by dexamethasone. Human IL-5 promoter/enhancer-luciferase gene construct transfected to T-cell clones was transcribed on either TCR or IL-2R stimulation and was clearly downregulated by dexamethasone, indicating that the approximately 500-bp human IL-5 gene segment located 5' upstream of the coding region contains activation-inducible enhancer elements responsible for the regulation by GC. Electrophoretic mobility shift assay analysis suggested that AP-1 and NF-kappaB are among the possible targets of GC actions on TCR-stimulated T cells. NF-AT and NF-kappaB were not significantly induced by IL-2 stimulation. Our results showing that GC suppressed IL-5 production by human CD4+ T cells activated by two distinct stimuli, TCR and IL-2R stimulation, underscore the efficacy of GC in the treatment of allergic diseases via suppression of T-cell IL-5 synthesis.     

IL-17 is produced by nickel-specific T lymphocytes and regulates ICAM-1 expression and chemokine production in human keratinocytes: synergistic or antagonist effects with IFN-gamma and TNF-alpha

IL-17 is a novel T cell-derived cytokine that can regulate the functions of a variety of cell types. In this study, we investigated whether hapten-specific T cells isolated from patients with allergic contact dermatitis (ACD) to nickel produce IL-17 and the effects of IL-17 alone or in combination with IFN-gamma or TNF-alpha on the immune activation of keratinocytes. Skin affected with ACD to nickel and skin-derived, nickel-specific CD4+ T cell lines expressed IFN-gamma, TNF-alpha, and IL-17 mRNAs. Four of seven nickel-specific CD4+ T cell clones positive for the skin-homing receptor, cutaneous lymphocyte-associated Ag, were shown to corelease IL-17, IFN-gamma, and TNF-alpha. In contrast, two nickel-specific CD8+ T cell clones failed to synthesize IL-17. Normal human keratinocytes were found to express constitutively the IL-17 receptor gene. IL-17 specifically and dose-dependently augmented IFN-gamma-induced ICAM-1 expression on keratinocytes at both the mRNA and the protein level, whereas HLA-DR, MHC class I, and CD40 levels were not modulated by IL-17. On the other hand, IL-17 alone did not affect ICAM-1 or enhance TNF-alpha-induced ICAM-1. In addition, IL-17, both directly and in synergism with IFN-gamma and/or TNF-alpha, stimulated synthesis and release of IL-8 by keratinocytes. In contrast, IFN-gamma- and TNF-alpha-induced production of RANTES was markedly inhibited by IL-17, and the synthesis of macrophage chemotactic protein 1 was not changed. Taken together, the results suggest that IL-17 is an important player of T cell-mediated skin immune responses, with synergistic or antagonist effects on IFN-gamma- and TNF-alpha-stimulated keratinocyte activation.     

In vivo relevance of CD30 in atopic dermatitis

CD30 expression was evaluated by immunohistochemistry in lesional skin biopsies of eight patients with active atopic dermatitis (AD) and three patients with allergic contact (nickel-induced) dermatitis (ACD). CD30 expression was also assessed in a large panel of CD4+ and CD8+ T-cell clones generated from the skin biopsies of four patients with AD. Finally, the levels of soluble CD30 (sCD30) were measured in the serum of 41 patients with AD, 19 patients with ACD, and 60 healthy controls. In all specimens of lesional AD skin, where the great majority of infiltrating cells were CD4+ T cells, remarkable numbers of cells were CD30+, whereas virtually no CD30+ cells were found in the skin of patients with ACD. In CD4+ T-cell clones generated from the lesional AD skin, most of which produced both interleukin (IL)-4 and interferon-gamma (IFN-gamma) (Th0-like cells) or IL-4 and IL-5, but not IFN-gamma (Th2-like cells), CD30 expression directly correlated with the ability to produce IL-4 and IL-5, but was inversely related to IFN-gamma production. High levels of sCD30 (correlated with disease activity: r = 0.618) were detected in the serum of most AD patients, whereas there was no increase of sCD30 levels in the serum of patients with ACD. These data support the view that Th0/Th2-type responses predominate in the skin of patients with AD and suggest that the presence of CD30+ T cells in tissues and/or increased levels of sCD30 in biologic fluids are indicative of Th2-dominated responses.     

Spindle-cell lipoma of the preseptal eyelid

To identify immunological markers that could be used to monitor relapsing-remitting multiple sclerosis (RRMS) course/activity during interferon beta 1b (IFN beta 1b) therapy, we longitudinally studied HLA-DR and CD25 expression by T lymphocytes in 15 IFN beta 1b-treated RRMS patients. Peripheral blood T cell subsets were analysed before therapy (T0), and after 1 (T1), 2 (T2), 3 (T3), 6 (T4) and 12 (T5) months after therapy initiation. HLA-DR expression and the CD3+HLA-DR+ T cell number showed a peculiar trend in almost all (14/15) the patients: a significant decrease at T1 and T2 followed by a return to pre-treatment levels from T3 to T5. At T1 and T2, eight patients showed an up-regulation of CD25 on CD4, as well as an increase in the CD4+CD25+ cell number. However, a marked, significant reduction of this T cell subset was observed in all the patients at T3, followed by the progressive return to pre-treatment values from T4 to T5. All the patients developed anti-IFN beta 1b 'binding' antibodies within the first three months of therapy. Our findings demonstrate that: (1) the expression of HLA-DR and CD25 on T cells, as well as the number of circulating CD3+HLA-DR+ and CD4+CD25+ cells, are only transiently reduced in vivo in IFN beta 1b-treated RRMS patients, (2) the expression of HLA-DR and CD25 on T lymphocytes cannot be used to monitor MS course/activity during IFN beta 1b therapy, (3) the long-lasting beneficial effect of IFN beta 1b on RRMS reported in the literature cannot be explained by the down-regulation of MHC class II antigens and/or interleukin-2 receptor expression induced by this cytokine.     

Increased CD69 and human leukocyte antigen-DR expression on T lymphocytes in insulin-dependent diabetes mellitus of long standing

To better define prevailing activation of circulating T cell subsets in insulin-dependent diabetes mellitus (IDDM) of recent onset (DM; n = 31; median age +/- SD, 28 +/- 6.9 yr) and of long standing (DML; n = 27; age, 33 +/- 10.4 yr; median duration of disease, 105 months), CD4+ and CD8+ T cells were analyzed to determine their naive and memory subsets as well as their expression of human leukocyte antigen (HLA)-DR, interleukin-2 receptor alpha-chain (CD25), and CD69 by three-color flow cytometry. Twenty-six healthy subjects (HS; age, 32.0 +/- 8.2 yr) served as controls. No deviation was seen in either IDDM group compared to HS in CD25 expression on CD4+ or CD8+ cells or in their CD45RA+ or CD45RA- subsets. HLA-DR expression, however, was increased (P < 0.05) in total CD8+ cells and CD45RA+ cells, with CD45RA- CD8+ cells joining the prevailing pattern only in DML. Among CD4+ cells, increased expression of HLA-DR molecules was restricted to total and CD45RA- cells in DML. CD69 expression did not differ between IDDM and HS, but differed between DML (CD4+, CD8+, and CD45RA- CD4+) and DM only. In conclusion, our data demonstrate that HLA-DR expression in IDDM is restricted to memory cells (CD45RA-) among CD4+ cells in DML and is more markedly confined to naive (CD45RA+) than to memory CD8+ cells, whereas the early activation antigen CD69 is more readily expressed in DML than in DM. The observed activation of circulating T cells suggests an ongoing immune process in IDDM both at clinical manifestation and after long duration.     

Knowledge of community based practitioners regarding vaccine preventable diseases

Previous studies have shown that leukocytes from patients with atopic dermatitis have increased levels of cyclic adenosine monophosphate (cAMP)-phosphodiesterase activity. This increased activity accounts for subnormal cAMP responses and correlates with increased in vitro immunoglobulin E production. To better understand the mechanism of this effect, we studied the relationship between phosphodiesterase activity and interleukin-4, a T-cell-derived cytokine that is a major regulator of immunoglobulin E production. Cultures stimulated with anti-CD3 or with phorbol myristate acetate plus ionophore significantly increased interleukin-4 production, and levels were consistently highest in cells from atopic subjects. Interleukin-4 production was higher, on a per T-cell basis, in mononuclear leukocyte cultures than in cultures of pure T cells, suggesting the possibility of a monocyte factor acting to increase interleukin-4 production. We next examined the effect of the phosphodiesterase inhibitor Ro 20-1724 on interleukin-4 production and found a significant reduction in cultures of atopic mononuclear leukocytes. This phosphodiesterase inhibitor effect appeared to act primarily on monocytes and correlated with increased intracellular cAMP levels. These studies demonstrate increased interleukin-4 production by atopic T cells. This abnormality can be reversed by inhibition of cAMP-phosphodiesterase, suggesting a possible therapeutic target for control of atopic disease.     

Quantitative peripheral computed tomodensitometric study of cortical and trabecular bone mass in relation with menopause

Lymphocyte subpopulations (B cells, CD4, CD8), interleukin-20 receptors (IL-2), monocytes/macrophages (Leu M5), and HLA-DR antigen expression were studied immunohistochemically on frozen sections from 38 bladder cancer specimens. T cells predominated over B cells in all tumours. CD4-positive lymphocytes predominated over CD8 in the stroma (CD4/CD8: 1.35/l), while in epithelial tumour cells CD8 was the prominent subpopulation (CD8/CD4: 1.75/l). Aberrant HLA-DR expression was found in 21.05 per cent of bladder tumours. A strong correlation between CD4 and CD8 population densities and macrophages with the other subpopulations was noticed. In HLA-DR-positive tumours, there was no correlation of the percentage of positive cells with CD4- and CD8-positive lymphocyte populations. Various parameters including IL-2 receptors, B cells, CD8- and CD4-positive cells, and macrophages did not differ significantly between the groups of tumours expressing and not expressing HLA-DR antigen. There were no statistically significant differences in the population densities of B cells, CD8- or CD4-positive cells, IL-2 receptor, monocytes/macrophages, and HLA-DR antigen expression among various clinicopathological parameters, including growth pattern, histological grade and clinical stage or patient's age and sex. These findings suggest that in transitional cell carcinoma of the urinary bladder, HLA-DR antigen expression is independent of lymphocyte subpopulations. It is therefore possible that HLA-DR expression by tumour cells reflect the existence of separate HLA-DR-positive or HLA-DR-negative tumour clones.     

The immunomodulatory effect of topical cyclosporin A in atopic keratoconjunctivitis

PURPOSE: To perform a detailed examination of the immunomodulatory effects of topical cyclosporin A (CsA) in conjunctival tissue from patients with atopic keratoconjunctivitis (AKC). METHODS: Patients with active AKC were randomly allocated into two groups of four patients. For 3 months one group received 2% CsA drops, and the other group received placebo drops. Superior tarsal conjunctival biopsy specimens were harvested before and after treatment and examined by one- and two-color immunohistochemistry to compare leukocyte counts, HLA-DR+ and IL-2R+ cell counts, HLA-DR positivity of conjunctival epithelial cells, and counts of T cells expressing the cytokines interleukin (IL)-2, IL-3, IL-4, IL-5, and interferon (IFN)-gamma. RESULTS: Posttreatment values were significantly less than pretreatment values for the total number of leukocytes and in the numbers of CD3+ T cells, CD4+ cells, CD8+ cells, CD20+ B cells, neutrophils, and macrophages, and there was a decrease in the CD4-CD8 ratio (P = 0.03) in the CsA group. There was a reduction from before CsA treatment to after CsA-treatment in the numbers of HLA-DR+ and IL-2R+ cells (P = 0.03), but the reduction in the epithelial cell HLA-DR expression did not reach significance. The number of T cells staining for IL-3 and IL-5 was reduced, although not to statistical significance, but there was a significant reduction in the number of T cells expressing IL-2 and IFN-gamma (P = 0.03) after CsA treatment compared with initial values. There were no statistically significant differences between pretreatment and posttreatment values in the placebo group. There was a clinical improvement in the CsA group and a clinical worsening in the placebo group. CONCLUSIONS: The in vitro effects of CsA translate into a reduction in T cells, a normalization of the CD4-CD8 ratio, a decrease in T-cell activation, and a reduction in T-cell cytokine expression, especially IL-2 and IFN-gamma. The decrease in HLA-DR expression may be mediated by the change in IFN-gamma. There were fewer B cells but not fewer plasma cells after CsA and no change in IL-4 expression, suggesting minimal effects on type I hypersensitivity responses. There was no significant reduction in mast cell or eosinophil numbers, but direct effects of topical CsA on their function may play a role in the therapy of ocular allergic disease. These results show that the beneficial effects of topical CsA in AKC are accompanied by important changes in conjunctival immune cell profiles.     

Inhibition of human T-cell responses to house dust mite allergens by a T-cell receptor peptide

Recent analysis of the usage of T-cell receptor (TcR) beta chain variable region (V beta) gene elements by house dust mite (HDM)-reactive T cells from an atopic donor suggested that TcR-V beta 3 gene products may form a major component of the human T-cell repertoire reactive to this common allergen. In this study a peptide analog of the TcR-V beta 3 complementarity determining region 2 (CDR2) is shown to inhibit the polyclonal human T-cell response to HDM; this effect is specific because inhibition is dependent on the presence of V beta 3 + T cells. This experimental approach has been used to determine whether the pattern seen in T-cell clones derived from one atopic donor reflects TcR-V beta usage in the polyclonal response to allergen in the general population. Inhibition of more than 50% of the polyclonal response to allergen by V beta 3-CDR2 peptide was observed in 16 of 21 donors tested, suggesting that TcR-V beta 3 gene usage may form a major component of the human HDM repertoire and as such offer a suitable target for T cell-directed specific immunotherapy in HDM-allergic individuals. Depletion of CD8+ T cells abolishes peptide-mediated inhibition of CD4+ T-cell proliferation to HDM, suggesting that induction of a CD8+ regulatory T-cell subset by the CDR2 peptide may modulate HDM-specific allergic T-cell responses.     

Changes of immunological markers after autologous peripheral blood stem cell transplantation

PURPOSE: Recently high-dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) has become an important treatment for hematological and solid tumors. METHODS: Immunological parameters were examined before and after PBSCT in 9 patients with lung cancer and 13 patients with malignant lymphoma. Findings were compared with those for bone marrow transplantation (BMT). Peripheral blood cells were analyzed for phenotype and the levels of cytokines and soluble factors were measured. RESULTS: After PBSCT, activated T cells (CD3+HLA-DR+ cells, CD8+HLA-DR+ cells) and suppressor/cytotoxic T cells (CD8+CD11b- cells) were significantly higher in the patients with lung cancer than in those with malignant lymphoma. Serum levels of interleukin-4 and soluble interleukin-2 receptor were also significantly higher in the patients with lung cancer than in those with lymphoma. On the other hand, the serum levels of interferon gamma, tumor necrosis factor alpha, interleukin-6, soluble human leukocyte antigen class 1, and soluble thrombomodulin were significantly increased after bone marrow transplantation. The transfused peripheral stem cells of lung cancer and lymphoma patients had a similar number of granulocyte/macrophage-colony-forming units, but lung cancer patients had significantly more CD34-positive cells. CONCLUSION: By reinfusing large numbers of autologous immune cells, PBSCT may accelerate immune reconstitution, with T cells being likely to have a marked therapeutic potential. The changes after PBSCT were greater in patients with lung cancer than in lymphoma patients. These blood cells are potent mediators of anticancer activity and could play an important role in the elimination of autologous malignant cells.