Th1 cytokine pattern in sarcoidosis is expressed by bronchoalveolar CD4+ and CD8+ T cells

The pathogenesis of pulmonary sarcoidosis has been related to an increased production of Th1-like cytokines. However, cytokine expression in sarcoidosis has not been systematically studied at a single-cell level. We therefore investigated the expression of IL-2, IL-4, IL-13, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) intracellularly in bronchoalveolar lavage (BAL) and peripheral blood CD3+ T lymphocytes from patients with pulmonary sarcoidosis (radiologic stage II-III, n = 8) and normal controls (n = 9) by flow cytometry. In contrast to IL-4 and IL-13, the percentage of T lymphocytes expressing intracellular IL-2 (49.3 +/- 21.3% versus 14.5 +/- 15.6%), IFN-gamma (75.5 +/- 14.9% versus 32.6 +/- 18.7%) and TNF-alpha (68.3 +/- 18.7% versus 36.8 +/- 20.8%) was significantly higher in patients with sarcoidosis than in normal controls (each P < 0.005). In contrast to BAL lymphocytes, expression of these cytokines in peripheral blood lymphocytes did not differ between patients with sarcoidosis and normal controls. Close correlations were observed between the percentages of BAL lymphocytes expressing intracellular IL-2, IFN-gamma and TNF-alpha, but not for IL-4 or IL-13. Analysis of the expression of these cytokines in T lymphocyte subsets revealed IL-2, IFN-gamma, and TNF-alpha in CD4+ as well as CD8+ T lymphocytes, suggesting a contribution of TC1 cells to the production of proinflammatory cytokines in sarcoidosis. We conclude that a Th1-like cytokine pattern can be observed in CD4+ as well as in CD8+ BAL T lymphocytes in patients with pulmonary sarcoidosis.     

Increased T helper 1 cytokine responses by circulating T cells are present in women with recurrent pregnancy losses and in infertile women with multiple implantation failures after IVF

BACKGROUND: We aimed to study T-helper 1 (Th1) and Th2 intracellular cytokine expression in peripheral blood lymphocytes of women with recurrent spontaneous abortions (RSA) or infertility with multiple implantation failures after IVF cycles. METHODS: Twenty-six women with three or more RSA and 23 with two or more IVF failures (14 with no history of spontaneous abortion (SAB) and nine with more than one SAB) comprised the two study groups. Twenty-one non-pregnant healthy multiparous women served as controls. Proportions (%) of lymphocytes containing IFN-gamma, TNF-alpha, IL-4 and IL-10 and the Th1/Th2 ratios of IFN-gamma/IL-4, IFN-gamma/IL-10, TNF-alpha/IL-4 and TNF-alpha/IL-10 in CD3+, CD3+/CD8- (T helper) and CD3+/CD8+ (T suppressor) cells were measured by 4-colour flow cytometry. RESULTS: RSA women demonstrated significantly higher Th1/Th2 ratios of IFN-gamma/IL-4 (P < 0.01), TNF-alpha/IL-4 and TNF-alpha/IL-10 (P < 0.05 each) in CD3+/CD8- T helper cells than those of controls. The proportion of TNF-alpha producing CD3+/CD8- cells (P < 0.05), and the Th1/Th2 ratios of TNF-alpha/IL-4 (P < 0.05) and TNF-alpha/IL-10 (P < 0.005) in CD3+/CD8- cells were significantly higher in women with multiple IVF failures without SAB as compared with those of controls. CONCLUSIONS: The prevalence of dominant Th1 immune responses in peripheral blood lymphocytes may reflect the systemic contribution of Th1 cytokines to RSA or multiple implantation failures in IVF cycles.     

Altered naive CD4 and CD8 T cell homeostasis in patients with relapsing-remitting multiple sclerosis: thymic versus peripheral (non-thymic) mechanisms

We have reported previously that naive T cells from relapsing-remitting multiple sclerosis (RRMS) patients have T cell receptor (TCR) repertoire shifts, but the basis of these TCR repertoire shifts was uncertain. Here, we questioned whether RRMS patients have altered naive CD4 and CD8 T cell homeostasis by studying homeostatic proliferation and thymic production in RRMS patients and healthy controls. We measured thymic production by quantifying signal joint T cell receptor excision circles (sjTRECs). Both naive T subsets from controls showed an age-associated decrease in sjTRECs, i.e. evidence of progressive thymic involution, but we detected no age-associated decrease in sjTRECs in RRMS patients. Instead, naive CD8 T cells from patients had lower sjTRECs (P = 0.012) and higher Ki-67 proliferation levels (P = 0.04) than controls. Naive CD4 T cell sjTRECs did not differ between patients and controls. However, in RRMS these sjTRECs correlated strongly with CD31, a marker expressed by newly generated CD4 T cells but not by naive CD4 T cells that have undergone homeostatic proliferation. HLA-DR2 positivity correlated negatively with naive CD4 T cell CD31 expression in RRMS (P = 0.002). We conclude in RRMS that naive T subsets have homeostatic abnormalities due probably to peripheral (non-thymic) mechanisms. These abnormalities could have relevance for MS pathogenesis, as naive T cell changes may precede MS onset.     

Resident CD8+ T cells suppress CD4+ T cell-dependent late allergic airway responses

BACKGROUND: The role of CD8+ T cells in the immune response to airway challenge with an allergen is poorly understood. OBJECTIVE: The aim of this study was to test the hypothesis that resident naive CD8+ T cells modulate the magnitude of CD4+ T cell-dependent allergic airway responses. METHODS: Cervical lymph node CD4+ T cells (2 x 10(6)) were harvested from ovalbumin (OVA)- or sham-sensitized rats and injected intraperitoneally into naive Brown Norway recipients. The recipients were treated with a CD8alpha mAb (OX-8) to deplete the resident CD8+ T cells (n = 12) or mouse ascites (n = 12). Two days after adoptive transfer, the recipient animals were OVA challenged, lung resistance was measured for 8 hours, and bronchoalveolar lavage (BAL) was performed. RESULTS: After OVA challenge, primed CD4-transferred CD8-depleted rats had larger early airway responses and late airway responses compared with primed CD4-transferred CD8-nondepleted rats (early airway responses: 158.6% +/- 19.2% vs 115.7% +/- 5.9%, P < .05; late airway responses: 8.5% +/- 1.7% vs 4.4% +/- 0.9%, P < .05). BAL eosinophilia was also greater (4.67% +/- 0.45% vs 2.34 +/- 0.26%, P < .01). The cells in BAL fluid expressing IL-4 mRNA were not significantly changed by CD8 depletion, but IL-5 mRNA+ cells were higher in number, and IFN-gamma mRNA+ cells were fewer in the CD8-depleted group. CONCLUSIONS: Resident CD8+ T cells downregulate the late allergic response and airway inflammation evoked by CD4+ T-cell transfers in Brown Norway rats. This downregulation does not require antigen priming.     

The presence of cytokine-suppressive CD4+CD25+ T cells in the peripheral blood and synovial fluid of patients with rheumatoid arthritis

CD4+CD25+ T cells have been shown to play a regulatory or suppressive role in the immune response and are possibly relevant to the pathogenesis of autoimmune diseases. In the present study, we attempted to investigate the levels of CD4+CD25+ T cells in the peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and the effects of CD4+CD25+ T cells on the in vitro cytokine production by stimulated SF mononuclear cells (SFMC). The results showed that RA patients had similar frequencies of CD4+CD25+ T cells in PB, expressed as a percentages of the lymphocyte population, as did healthy subjects (mean +/- SD: 10.52 +/- 5.87% versus 11.11 +/- 4.58%., respectively). But in contrast to PB, the SF of RA patients contained significantly higher levels of CD4+CD25+ T cells (17.77 +/- 7.92% versus 10.52 +/- 5.87%, respectively. P < 0.001). When cocultured in vitro with SFMC, CD4+CD25+ T cells purified from either PB or SF were found to exert a considerable suppressive effect on the production of cytokines including TNF-alpha, IFN-gamma and interleukin-10 (IL-10). The percentages of inhibition of each cytokines ranged from 41.8 to 98.4% (mean, 80.0%) for TNF-alpha, 42.8 to 98.9% (mean, 83.2%) for IFN-gamma and 59.3 to 96.6% (mean, 80.0%) for IL-10. Because both pro-inflammatory and anti-inflammatory cytokines were suppressed by CD4+CD25+ T cells, whether CD4+CD25+ T cells might play a beneficial role in the suppression of sustained inflammation in rheumatoid synovium remains to be elucidated.     

Critical role of the liver CD8+ CD122+ T cells in the generalized Shwartzman reaction of mice

We examined the role of mouse CD8+ CD122+ T cells, which increase in number with age, in the generalized Shwartzman reaction. This reaction was induced by IL-12 priming and subsequent LPS challenge (after 24 h) in mice of various ages (4-50 weeks of age). Although most young mice (4 or 6 weeks of age) survived, mortality essentially increased with increasing age of the mice, and all mice of 20 weeks of age or older died within 48 h. Serum TNF-alpha levels after LPS challenge also increased age dependently. The neutralization of either IL-12-induced IFN-gamma or LPS-induced TNF-alpha improved the survival of middle-aged (25-week-old) mice. Both IFN-gamma production after IL-12 priming and TNF-alpha production from the liver mononuclear cells after LPS challenge were also prominent in the middle-aged mice. CD8+CD122+ T cells cultured with IL-12 produced a much larger amount of IFN-gamma than CD8+CD122- T cells. Although the depletion of NK/NK T cells did not decrease the IFN-gamma or TNF-alpha production in the Shwartzman reaction of the middle-aged mice, an additional depletion of CD8+CD122+ T cells did decrease such production and also improved mouse survival. Furthermore, young mice transferred with CD8+CD122+ T cells from aged B6 nude mice showed an enhanced Shwartzman reaction.     

Increased expression of membrane TNF-alpha on activated peripheral CD8+ T cells in systemic lupus erythematosus

Membrane TNF-alpha is a precursor form of soluble TNF-alpha and exerts pro-inflammatory functions in a cell-to-cell contact manner. We showed that membrane TNF-alpha is induced upon activation on the cell surface of CD4+ T cells and CD8+ T cells. In patients with systemic lupus erythematosus (SLE), the percentage of membrane TNF-alpha-bearing CD8+ T cells (41.5+/-12.3%) was significantly higher compared with those of healthy controls (26.7+/-3.9%) (p=0.007) or patients with rheumatoid arthritis (29.8+/-15.4%) (p=0.038). Membrane TNF-alpha-bearing CD8+ T cells from SLE patients displayed cytotoxic activity against L929 cells. It is possible that membrane TNF-alpha may be involved in the increased apoptosis and the generation of autoantigens in SLE.     

Characterization of CD4 and CD8 T cell responses in MuSK myasthenia gravis

Muscle specific tyrosine kinase myasthenia gravis (MuSK MG) is a form of autoimmune MG that predominantly affects women and has unique clinical features, including prominent bulbar weakness, muscle atrophy, and excellent response to therapeutic plasma exchange. Patients with MuSK MG have predominantly IgG4 autoantibodies directed against MuSK on the postsynaptic muscle membrane. Lymphocyte functionality has not been reported in this condition. The goal of this study was to characterize T cell responses in patients with MuSK MG. Intracellular production of IFN-gamma, TNF-alpha, IL-2, IL-17, and IL-21 by CD4+ and CD8+ T cells was measured by polychromatic flow cytometry in peripheral blood samples from 11 Musk MG patients and 10 healthy controls. Only one MuSK MG patient was not receiving immunosuppressive therapy. Regulatory T cells (Treg) were also included in our analysis to determine if changes in T cell function were due to altered Treg frequencies. CD8+ T cells from MuSK MG patients had higher frequencies of polyfunctional responses than controls, and CD4+ T cells had higher IL-2, TNF-alpha, and IL-17. MuSK MG patients had a higher percentage of CD4+ T cells producing combinations of IFN-gamma/IL-2/TNF-gamma, TNF-alpha/IL-2, and IFN-gamma/TNF-alpha. Interestingly, Treg numbers and CD39 expression were not different from control values. MuSK MG patients had increased frequencies of Th1 and Th17 cytokines and were primed for polyfunctional proinflammatory responses that cannot be explained by a defect in CD39 expression or Treg number.     

Elevated rate of Thelper1 (T(H)1) lymphocytes and serum IFN-gamma levels in psoriatic patients

Several disorders are known to be associated with altered Thelper1/Thelper2 (T(H)1/T(H)2) cytokine balance. Psoriasis is characterized by increased systemic and local production of T(H)1 and pro-inflammatory cytokines. Furthermore recent data indicate the dominant presence of T(H)1 lymphocytes in the circulation and T(H)1 and Tcytotoxic1 (T(C)1) cells in lesional skin of psoriatic patients. In order to assess the systemic T(H)1/T(H)2 imbalance in psoriasis most of the studies so far tested isolated peripheral mononuclear cells. As a new approach we applied a whole blood flow cytometric assay to determine the rate of circulating T(H)1/T(H)2 and T(C)1/Tcytotoxic2 (T(C)2) lymphocytes based on their intracellular IFN-gamma, IL-4 and IL-10 expression. Besides, serum levels of these cytokines were determined in healthy controls and psoriatic patients by commercial ELISAs. In psoriatic patients we found significantly (P<0.02) increased rates of CD4(+)/IFN-gamma(+) lymphocytes (30.3+/-8.8%) while the percent of CD4(+)/IL-4(+) cells (0.37+/-0.31%) were significantly (P<0.03) lower compared to healthy controls (CD4(+)/IFN-gamma(+): 20.1+/-7.3% and CD4(+)/IL-4(+): 0.78+/-0.44%). The IL-10-positive CD4(+) and CD8(+) cells also had higher rate in psoriasis, but the difference between patients and controls was not significant, similarly to the rate of CD8(+)/IFN-gamma(+) and CD8(+)/IL-4(+) lymphocytes. Beside cellular expression, serum IFN-gamma levels were also significantly higher (control: 4.9+/-6.4 pg/ml; psoriatic patients: 35.9+/-47.0 pg/ml; P<0.05). Our results provide further evidence for an altered T(H)1/T(H)2 balance in psoriasis measured in non-separated whole blood T cells.     

Early Emergence of CD8+ T Cells Primed for Production of Type 1 Cytokines in the Lungs of Mycobacterium tuberculosis-Infected Mice

Several lines of evidence suggest that CD8 T cells are important in protection against tuberculosis. To understand the function of this cell population in the immune response against Mycobacterium tuberculosis, T cells from lungs of M. tuberculosis-infected mice were examined by flow cytometry. The kinetics of the appearance of CD8 T cells in lungs of infected mice closely paralleled that of CD4 T cells. Both CD4(+) and CD8(+) T cells displaying an activated phenotype were found in the lungs as early as 1 week postinfection. By 2 weeks, total cell numbers in the lungs had tripled and percentages of T cells were increased two- to threefold; the percentages of CD4(+) T cells were ca. twofold higher than those of CD8(+) T cells. Short-term stimulation with M. tuberculosis-infected antigen-presenting cells induced cytokine production by primed CD4(+) and CD8(+) T cells. Intracellular cytokine staining revealed that 30% +/- 5% of CD4(+) and 23% +/- 4% of CD8(+) T cells were primed for production of gamma interferon (IFN-gamma). However, a difference in in vivo IFN-gamma production by T cells was observed with approximately 12% of CD4(+) T cells and approximately 5% of CD8(+) T cells secreting cytokine in the lungs at any given time during infection. The data presented indicate that although early in infection the majority of IFN-gamma is produced by CD4(+) T cells, cytokine-producing CD8(+) T cells are readily available when triggered by the appropriate stimuli.     

Glucocorticoid treatment reduces T-bet and pSTAT1 expression in mononuclear cells from relapsing remitting multiple sclerosis patients

High dose glucocorticoid (GC) treatment has been demonstrated to have a short-term beneficial effect on functional recovery in relapsing multiple sclerosis (MS) patients but the exact mechanism of action of GCs in MS is unclear. We found that high dose intravenous GCs strongly reduced T-bet and pSTAT1 expression in CD4+, CD8+, CD14+ circulating cells in RRMS patients in relapse. pSTAT1and T-bet reduction was associated with the decline of IFNgamma production by PBMCs. A significant increase of AV-positive CD4+ and CD8+ T cells was detectable after GC treatment without any variation in the percentage of annexin V-positive monocytes. By in vitro analysis, patients during relapse, either before or after GC treatment, exhibited a lower proportion of apoptotic lymphocytes than remitting patients and controls. Our study suggests that GCs can modulate T-bet and STAT1 expression and that IFNgamma signalling inhibition contributes to anti-inflammatory action of GCs in the treatment of relapses of MS patients.     

High TNF-alpha and low IL-2 producing T cells characterize active disease in Takayasu's arteritis

We have investigated intracellular production by T cells and plasma levels of TNF-alpha, IL-2 and IFN-gamma in 12 active and 10 inactive Takayasu's arteritis (TA) patients and 12 healthy controls. The active TA compared to inactive TA and controls had higher TNF-alpha (52.7 +/- 22.3% vs. 32.9 +/- 14.2% and 35.2 +/- 14.5%, respectively; P = 0. 020), lower IL-2 (19.6 +/- 13.2% vs. 36.1 +/- 10.1% and 31.2 +/- 10.3%, respectively; P = 0.010) and comparable IFN-gamma (38.6 +/- 13.9% vs. 34.2 +/- 12.4% and 34.9 +/- 11.1%, respectively; P = 0.581) producing CD3+ T cells. There was no difference in the plasma levels of the cytokines between active TA, inactive TA and controls (TNF-alpha: 79.1 +/- 94.5 vs. 72.9 +/- 120.0 and 9.5 +/- 6.7 pg/ml, P = 0.110; IL-2: 4.3 +/- 4.8 vs. 6.6 +/- 4.7 and 8.6 +/- 4.5 pg/ml, P = 0.094 and IFN-gamma: 10.1 +/- 11.3 vs. 8.8 +/- 8.7 and 8.2 +/- 6.5 pg/ml, P = 0.871, respectively). The data show an important role of these high TNF-alpha and low IL-2 producing T cells in TA.     

A novel population of B7-1+ T cells producing intracellular IL-4 is decreased in patients with multiple sclerosis

We identified a novel population of human T cells, studied directly ex vivo, that co-express surface B7-1 and intracellular IL-4. These peripheral blood B7-1+/CD4+ T cells expressed cell surface molecules associated with differentiation including CD45RO and MHC class II, yet were CD69(-) and CD25(-). In short-term cultures, T cell receptor (TCR) cross-linking induced further IL-4 production with little IFN-gamma or TNF-alpha. In marked contrast, CD4+ T cells negative for B7-1 expressed intracellular IFN-gamma and high amounts of TNF-alpha but little IL-4 upon TCR cross-linking. The CD4+/B7-1+/IL-4-expressing T cells were of polyclonal origin based on their diverse TCR repertoire. To explore the biological significance of this B7-1+/IL-4+ T cell population and to assess its potential regulatory role in autoimmune disease, we examined whether these T cells isolated ex vivo were altered in subjects with multiple sclerosis (MS). While the frequency of B7-1+ T cells was enhanced in patients with MS as compared to normal subjects, there was a significant diminution of B7-1+/IL-4+ T cells in the patients. The decrease in these IL-4-producing T cells in patients with autoimmune disease is consistent with a possible role as immunoregulatory T cells.     

Decreases in interleukin-4 secretion by invariant CD4(-)CD8(-)V alpha 24J alpha Q T cells in peripheral blood of patientswith relapsing-remitting multiple sclerosis

The cytokine profile of invariant CD4(-)CD8(-)V alpha 24J alpha Q T cells from patients with multiple sclerosis (MS) was compared with that of healthy controls. CD4(-)CD8(-)V alpha 24(+) T cells from the peripheral blood of 12 patients with relapsing-remitting MS (RR-MS), 5 patients with progressive MS (CP-MS), and 9 control individuals were directly sorted into single wells and expanded in vitro for analysis of IL-4 and IFN-gamma secretion; 315 V alpha 24J alpha Q T cell clones were generated and their T cell receptor (TCR) sequenced. T cell functionality was determined by examining cytokine secretion upon TCR cross-linking. RR-MS patients exhibited lower frequencies of IL-4 secreting CD4(-)CD8(-)V alpha 24J alpha Q T cell clones than patients with CP-MS and controls. No differences in IFN-gamma secretion were observed between the groups. An IL-4 positive cytokine profile could be correlated to the cloning efficiency of the V alpha 24J alpha Q T cells. We conclude that alterations in cytokine secretion patterns of CD4(-)CD8(-)V alpha 24J alpha Q T cells may influence the immune system and thus contribute to relapsing-remitting MS.     

Expression of intracellular Th1 and Th2 cytokines in women with recurrent spontaneous abortion,implantation failures after IVF/ET or normal pregnancy

PROBLEM: We aimed to investigate absolute counts of intracellular T helper 1 (Th1) and Th2 cytokine expressing T-cell subpopulations in women with three or more recurrent spontaneous abortions (RSA), multiple implantation failures after in-vitro fertilization and embryo transfer (IVF/ET) (three or more) or during normal pregnancy. METHOD OF STUDY: Absolute cell counts and percentages of CD3+, CD3+/CD4+, and CD3+/CD8+ T-cell populations expressing intracellular cytokines [interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-4 and IL-10] was studied by four-color flow cytometry in 15 RSA and 13 implantation failure patients. Eighteen fertile non-pregnant and 47 normal pregnant women were also compared with regard to intracellular cytokine expression. RESULTS: Interleukin-10 producing CD3+/CD8+ T-cell counts were significantly lower in women with RSA (P < 0.05) and implantation failures (P < 0.05), and TNF-alpha producing CD3+/CD4+ T-cell counts were higher in women with RSA (P < 0.05) and implantation failures (P < 0.005) than those of non-pregnant fertile controls. During normal pregnancies, first trimester IL-4 expressing CD3+, CD3+/CD4+ T-cell counts (P < 0.05) and IFN-gamma expressing CD3+ T-cell counts (P < 0.05) were significantly higher than those of third trimester (P < 0.05). First trimester TNF-alpha expressing CD3+/CD8+ T-cell counts were significantly higher than those of second and third trimester women (P < 0.05). However, there are no differences in cytokine expression between non-pregnant and first trimester pregnant women. CONCLUSION: Absolute counts of IFN-gamma, IL-4, and TNF-alpha expressing T cells decrease with the progress of gestation (third trimester) during normal pregnancies. In women with implantation failures, absolute cell counts of TNF-alpha expressing CD3+/ 4- cells reflects the presence of dominant Th1 immune response. A significantly increased Th1 cytokine expression may be the underlying immune etiology for reproductive failures.     

Intracellular production of type I and type II cytokines during HIV-1 progression in Thai patients

A type I to type II cytokine switch on cells of the immune system has been suggested as a critical step in the etiology of HIV infection. In this study, type I and type II cytokine production of both CD4+ and CD8+ T cells activated by superantigen were investigated in 10 healthy donors and 39 HIV-1 infected patients. Patients were divided into 3 groups based on their CD4 count (< 200, 200-500, > 500 cells/microl). Whole blood from each subject was activated by staphylococcal enterotoxin B (SEB) and anti-CD28. Intracellular cytokine stainings for proinflamatory cytokine (TNF-alpha), type I cytokines (IFN-gamma and IL-2) and type II cytokines (IL-4 and IL-5) in CD4+ and CD8+ T lymphocytes were determined by flow cytometer. Type I cytokine (IFN-gamma) expression in CD4+ T cells co-expressing with CD69 were significantly increased in HIV infected patients, particularly in patients with CD4 counts < 200 and 200-500 cells/microl (means +/- S.D. of 20.7 +/- 18.7% and 10.5 +/- 5.9%, respectively) when compared with 4.8 +/- 1.8% in the normal group (p < 0.05). But IL-2 production in both groups of patients was significantly lower than the normal (3.8 +/- 2.6% and 3.2 +/- 1.4% in patients with < 200, 200-500 cells/microl, and 5.9 +/- 1.5% in the normal group) (p < 0.05). For type II cytokines, there was no difference in all groups of subjects when IL-4 was determined. However, IL-5 production was significantly higher in patients with a CD4 count < 200 cells/microl (0.6 +/- 0.5%) than that in the normal group (0.1 +/- 0.1%) (p < 0.005). CD8+ T cells also showed higher IFN-gamma production in patients with a CD4 count < 200 cells/microl (11.9 +/- 4.7%) and 200-500 cells/microl (12.0 +/- 4.3%) than the normal group (5.3 +/- 2.5%) (p < 0.005). In contrast, IL-2 production in CD8+ T cells was low in these HIV infected patients (0.3 +/- 0.2%, 0.3 +/- 0.2%, and 0.3 +/- 0.4% in patients with < 200, 200-500, and > 500 cells/microl, respectively), which was significantly different compared to the control group (1.2 +/- 0.8%) (p < 0.05). For type II cytokines, only IL-4 production in patients with a CD4 count < 200 cells/microl (0.1 +/- 0.1%) was significantly reduced when compared to the other groups (p < 0.05). This study shows that although HIV infection alters the production of both type I and type II cytokines, it does not induce a polarized type I or type II state in the course of HIV-1 progression in Thai patients.     

Regulation of CD23 in the chronic inflammatory response in asthma: a role for interferon-gamma and heat shock protein 70 in the TH2 environment.

BACKGROUND: Monocytic cells and alveolar macrophages (AMs) are activated in patients with asthma, producing inflammatory cytokines. This occurs despite a TH2 environment that consists of the cytokines interleukin (IL) 4, IL-10, and IL-13. The mechanism by which this occurs may involve cross-linking of the low-alphaffinity IgE receptor CD23. OBJECTIVE: To determine the effect of the TH2 environment with interferon-gamma (IFN-gamma) and heat shock protein 70 (HSP 70) on CD23 receptor expression and tumor necrosis factor alpha (TNF-alpha) production. METHODS: We examined the effect of IL-4 and IL-13 in culture with IFN-gamma and HSP 70 on CD23 expression in both THP-1 cells and AMs from healthy controls via flow cytometry. AMs from mild asthmatic patients and THP-1 cells were evaluated for TNF-alpha production after cross-linking CD23 with immune complexes. RESULTS: Asthmatic AMs stimulated with anti-IgE exhibited a 5.7- +/- 1.9-fold increase in TNF-alpha protein. AMs from healthy controls increased the geometric mean +/- SD of CD23 2.00- +/- 0.50-fold in IL-4 and 2.14- +/- 0.50-fold in IL-13. THP-1 cells cultured with IL-4 and IL-13 then stimulated with IFN-gamma or HSP 70 increased CD23 expression above baseline as follows: IL-4, 2.16- +/- 0.31-fold; IL-13, 2.66- +/- 0.43-fold; IFN-gamma, 2.03- +/- 0.34-fold; IL-4/IFN-gamma, 9.14- to 4.02-fold; IL-13/IFN-gamma, 11.51- +/- 5.51-fold; IL-4/HSP, 5.20- +/- 0.61-fold; and IL-13/HSP, 5.60- +/- 0.79-fold. Stimulating the CD23 receptor with immune complexes significantly increased TNF-alpha production by THP-1 cells stimulated with IFN-gamma, IL-4, IL-13, or a combination of these. CONCLUSIONS: Both IFN-gamma and HSP 70, in the TH2 environment, up-regulate CD23 expression and thus may play an important role in maintaining the chronic inflammatory state in asthma.     

Increased CD8+ T Cell Apoptosis in Scleroderma Is Associated with Low Levels of NF-κB

Our objectives were (1) to compare lymphocyte subpopulation apoptosis rates in SSc patients versus healthy controls and (2) to compare Bcl-2 and NF-kappa B expression in cultured CD8 lymphocytes of SSc patients versus controls. Peripheral blood samples were obtained from 27 SSc patients meeting the American College of Rheumatology criteria for SSc and 28 healthy individuals. Mononuclear cells were isolated by Ficoll-Hypaque density gradient separation and cultured for 48 hr. For determination of apoptosis within specific cell populations, samples were labeled with PE-conjugated monoclonal antibody to CD8, CD4, and a FITC-conjugated monoclonal antibody to Annexin V. Flow cytometry was carried out with a FACS operating with Cellquest software. CD8+ lymphocytes were positively selected with magnetic microbeads conjugated to antihuman CD8. CD8 T cells were separated, then incubated with activation for 48 hr, and NF-kappa B and Bcl-2 analysis was carried out using Western immunoblotting. The CD4:CD8 ratio was increased in SSc compared to controls (2.6 +/- 1.13 vs.1.87 +/- 0.76; P = 0.018). The spontaneous apoptosis rate of SSc CD8 lymphocytes was increased compared to that of controls of (21.9 +/- 13.7 vs. 13.3 +/- 9.9; P = 0.019). No difference was found in the rate of CD4 apoptosis of SSc patients versus controls (9.8 +/- 5.2 vs. 7.18 +/- 4.89%; P = ns). The expression of NF-kappa B in SSc CD8 lymphocytes was decreased compared with that of CD8 lymphocytes from healthy controls (144 +/- 13 vs. 188 +/- 11; P = 0.018). Whereas expression of Bcl-2 was similar in activated CD8+ T cells of SSc patients and healthy controls, CD8+ T cell apoptosis rate was found to be in reverse correlation with expression of NF-kappa B in these cells ( r = - 0.53, P = 0.029). The increased CD4:CD8 ratio in SSC may result from increased CD8+ T cell apoptosis. Increased SSc CD8 T cell apoptosis is associated with low levels of NF-kappa B.     

Memory B cells from a subset of treatment‐naïve relapsing‐remitting multiple sclerosis patients elicit CD4+ T‐cell proliferation and IFN‐γ production in response to myelin basic protein and myelin oligodendrocyte glycoprotein

Recent evidence suggests that B‐ and T‐cell interactions may be paramount in relapsing‐remitting MS (RRMS) disease pathogenesis. We hypothesized that memory B‐cell pools from RRMS patients may specifically harbor a subset of potent neuro‐APC that support neuro‐Ag reactive T‐cell proliferation and cytokine secretion. To test this hypothesis, we compared CD80 and HLA‐DR expression, IL‐10 and lymphotoxin‐α secretion, neuro‐Ag binding capacity, and neuro‐Ag presentation by memory B cells from RRMS patients to naïve B cells from RRMS patients and to memory and naïve B cells from healthy donors (HD). We identified memory B cells from some RRMS patients that elicited CD4⁺ T‐cell proliferation and IFN‐γ secretion in response to myelin basic protein and myelin oligodendrocyte glycoprotein. Notwithstanding the fact that the phenotypic parameters that promote efficient Ag presentation were observed to be similar between RRMS and HD memory B cells, a corresponding capability to elicit CD4⁺ T‐cell proliferation in response to myelin basic protein and myelin oligodendrocyte glycoprotein was not observed in HD memory B cells. Our results demonstrate for the first time that the memory B‐cell pool in RRMS harbors neuro‐Ag specific B cells that can activate T cells.