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.     

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.     

苦参素对HBsAg转基因小鼠血清Th1和Th2细胞因子水平的影响

目的　探讨苦参素对HBsAg转基因小鼠外周血Th1 Th2细胞因子水平的影响。方法　HBsAg转基因小鼠分成苦参素组和对照组 ,分别每天腹腔注射苦参素注射液 2 0 0mg kg 0 2ml和生理盐水 0 2ml,共 30d。处理前后 ,检测外周血清细胞因子水平。结果　对照组处理前后γ 干扰素(IFN γ)与白细胞介素 4 (IL 4 )水平差异无显著意义 ;苦参素组处理前后IFN γ分别为 (3 10 8± 3 172 )pg ml和 (11 0 5 9± 6 971)pg ml,IL 4分别为 (2 9 0 4 5± 13 2 35 )pg ml和 (13 0 2 4± 9 0 0 2 )pg ml(均P <0 0 0 1)。处理后对照组与苦参素组IL 2分别为 (1 0 70± 0 4 4 7)pg ml和 (5 5 37± 2 887)pg ml(P <0 0 0 0 1) ;IL 10分别为 (97 2 2 6± 73 30 6 )pg ml和 (33 6 0 7± 2 3 15 4 )pg ml(P <0 0 1)。结论　在苦参素作用后 ,HBsAg转基因小鼠体内的Th1型细胞因子明显升高 ,Th2型细胞因子明显降低。这将有助于研究苦参素临床治疗乙型肝炎的机制。     

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.     

Quantitative analysis of peripheral blood Th0, Th1, Th2 and the Th1:Th2 cell ratio during normal human pregnancy and preeclampsia.

We calculated the percentage of Th1, Th2, Th0 cells and the Th1:Th2 cell ratio of peripheral blood from normal pregnant subjects and preeclampsia patients using flow cytometry which can analyse both the surface marker, CD4, and intracellular cytokines, interleukin (IL)-4 and interferon (IFN)-gamma. In normal pregnancy, the percentage of Th1 cells was significantly lower in the third trimester, and the ratios of Th1:Th2 were significantly lower in the second and third trimester than in nonpregnant subjects. In contrast, the percentage of Th1 cells and the ratios of Th1:Th2 in preeclampsia were significantly higher than in normal third trimester pregnant subjects. The percentage of Th2 cells in preeclampsia was significantly lower than in third trimester of normal pregnancy. Additionally, peripheral blood mononuclear cells from these subjects and patients were cultured with phytohemagglutinin stimulation, and IL-4 and IFN-gamma concentrations were determined in the supernatant by enzymed linked immunosorbent assays. The percentage of Th1 and Th2, and the ratios of Th1:Th2 were correlated with cytokine (IFN-gamma and IL-4) secretion level. These results demonstrated that Th2 cells were predominant in the second and third trimesters of normal pregnancy, but Th1 cells predominated in preeclamptic patients.     

Serial estimation of Th1:th2 cytokines profile in women undergoing in-vitro fertilization-embryo transfer

PROBLEM: To investigate changes in the ratio of T-cell subpopulations expressing intracellular T helper1 (Th1) and T helper 2 (Th2) cytokines in women with a history of recurrent failed implantation under going in-vitro fertilization (IVF)-embryo transfer. METHOD OF STUDY: Twenty-eight peripheral blood samples were obtained at two time points, from 14 women undergoing IVF treatment; eight women with a history of recurrent failed implantation, who did not get pregnant in the index IVF cycle and six who had one or more previous successful IVF pregnancy and who became pregnant in the index IVF cycle. The proportion of lymphocytes expressing interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), and interleukin 4 (IL-4) and the Th1:Th2 ratios of IFN-gamma:IL-4, and TNF-alpha:IL-4 in T helper cells was measured by flow cytometry, in samples obtained before commencing IVF treatment and in samples obtained after ovarian stimulation (on the day of oocyte retrieval). RESULTS: In samples collected during oocyte retrieval, women with a history of recurrent failed implantation had a higher IFN-gamma:IL-4 and TNF-alpha:IL-4 ratio than the control group, (18.6+/-9.3 versus 6.47+/-1.68, P=0.009) and (39.1+/-15.7 versus 11.53+/-3.76, P=0.001) respectively. In women with a history of recurrent failed implantation the ratio of IFN-gamma:IL-4 and TNF-alpha:IL-4 at oocyte retrieval was higher than pre-treatment ratios (18.6+/-9.3 versus 12.01+/-9.8, P=0.018) and 39.10+/-15.7 versus 18.66+/-11.42, P=0.010) respectively, showing a Th1 bias. In women with a successful IVF the converse was true; the ratio at oocyte retrieval was significantly lower than pre-treatment ratios (6.47+/-1.68 versus 9.37+/-6.8, P=0.035) and 11.53+/-3.76 versus 18.60+/-12.9, P=0.027) respectively, representing a Th2 bias. CONCLUSION: Women with a history of unexplained recurrent failed IVF treatment have a Th1 bias and this polarization is more enhanced following hormonal manipulations during IVF treatment. Comparing pre-treatment ratios of IFN-gamma:IL-4 and TNF-alpha:IL-4 to ratios obtained at oocyte retrieval may be clinically useful. Women with recurrent failed IVF have increasing ratios.     

Role of Th1 and Th2 cytokines in immune response to uncomplicated Plasmodium falciparum malaria

The relative balance between Th1 and Th2 cytokines appears crucial, since the role of cytokines has been evaluated in several studies by comparison of clinically heterogeneous groups of patients. The aim of this study is to determine the role of proinflammatory Th1 cytokines, interleukin-12 (IL-12) and gamma interferon (IFN-gamma), and anti-inflammatory Th2 cytokines, IL-4 and IL-10, in a homogeneous group of patients with uncomplicated Plasmodium falciparum malaria. Levels of IL-12, IFN-gamma, Il-4, and IL-10 in serum for 20 adult patients and 15 healthy control subjects were determined by an immunoenzymatic assay. Serum levels of Th1 cytokines, IL-12 (8.6 +/- 2.8 pg/ml; controls, 3.2 +/- 0.7 pg/ml) and IFN-gamma (39.2 +/- 67.6 pg/ml; controls, 8.4 +/- 6.3 pg/ml), were significantly increased at admission; 3 days later, levels of IL-12 in serum remained significantly high (8.8 +/- 2.6 pg/ml), whereas IFN-gamma levels returned to control values. The anti-inflammatory response of Th2 cytokines (IL-10 and IL-4) was distinct. Levels of IL-10 in serum were not significantly increased at day 0 and day 3 (306.6 +/- 200.4 pg/ml and 56.6 +/- 38.4 pg/ml, respectively; controls, 17.4 +/- 9.0 pg/ml). In contrast, levels of IL-4 in serum were not increased on admission (3.4 +/- 1.2 pg/ml; controls, 2.4 +/- 0.8 pg/ml), but at day 3 a moderate and significant increase of IL-4 levels was observed (4.5 +/- 1.7 pg/ml). In conclusion, the increase of Th1 cytokine IL-12 and IFN-gamma levels during the acute phase of uncomplicated P. falciparum malaria may reflect an early and effective immune response regulated by proinflammatory Th1 cytokines, and in particular IFN-gamma may play a role in limiting progression from uncomplicated malaria to severe and life-threatening complications.     

Monophosphoryl lipid A (MPL) promotes allergen-induced immune deviation in favour of Th1 responses

BACKGROUND: Monophosphoryl lipid A (MPL) is a nontoxic derivative of the lipopolysaccharide (LPS) of Salmonella minnesota R595. MPL has been used as an adjuvant in grass and tree pollen vaccines for the treatment of seasonal allergic rhinitis. Little is known about the influence of MPL on cellular responses to allergens in man. We therefore studied the effects of MPL in vitro on peripheral blood mononuclear cells (PBMC) obtained from patients with grass pollen hay fever. METHODS: The PBMCs from 13 subjects were cultured with grass pollen Phleum pratense extract (0, 2 and 20 microg/ml) and MPL (0 and 10 microg/ml; defined as an optimal concentration in preliminary studies) and after 6 days proliferative responses were measured by thymidine incorporation and cytokine production by enzyme-linked immunosorbent assay (ELISA). RESULTS: Proliferative responses were unaffected by the presence of MPL whereas MPL induced a significant increase in allergen-induced interferon (IFN)-gamma production [allergen alone, 645 +/- 466 pg/ml (mean +/- SE) vs allergen + MPL, 3232 +/- 818 pg/ml; P < 0.001]. In addition, there was a significant decrease in interleukin (IL)-5 production (4307 +/- 1030 pg/ml vs 2997 +/- 826 pg/ml; P < 0.01). Although MPL alone could induce modest increases in IL-10 production, MPL did not influence the production of this cytokine in allergen-stimulated cultures. Addition of neutralizing antibody against IL-12 resulted in 95% inhibition of MPL-induced IFN-gamma production. Depletion of monocytes from the culture system abrogated the effects of MPL on elevated cytokine production. CONCLUSIONS: In summary, use of MPL with grass pollen extract results in immune deviation of allergen-induced peripheral Th2-cell responses in favour of 'protective' Th1 responses in an IL-12 and monocyte-dependent fashion.     

Nickel-induced IL-10 down-regulates Th1- but not Th2-type cytokine responses to the contact allergen nickel

Whereas the involvement of Th1- and Th2-type cytokines in contact allergy to nickel (Ni) is well documented, the role of the regulatory cytokine IL-10 is less clear. We therefore investigated the impact of IL-10 on Ni-induced Th1- (IFN-gamma) and Th2-type (IL-4 and IL-13) cytokine responses in human peripheral blood mononuclear cells (PBMC). PBMC from 15 blood donors with reactivity to Ni (Ni-PBMC) and 8 control donors devoid of reactivity (control PBMC) were stimulated with Ni and the frequency of cytokine-producing cells and the levels of secreted cytokines were analysed by ELISpot (IL-4, IL-13 and IFN-gamma) and ELISA (IL-10, IL-13 and IFN-gamma), respectively. The Ni-induced response was further assessed in the presence of recombinant IL-10 (rIL-10) or neutralizing antibody to IL-10 and the phenotype of the Ni-specific cytokine-producing cells regulated by IL-10 was determined by cell depletion experiments. Ni induced IL-10 production in Ni-PBMC (mean, (range); 33.1 pg/ml (0-93.4 pg/ml)) but not control PBMC (2.2 pg/ml (0-14.9 pg/ml)) (P = 0.002). Ni also induced significant production of IL-4, IL-13 and IFN-gamma that correlated with the IL-10 response. Addition of rIL-10 down-regulated the Ni-induced production of all cytokines but with a more pronounced effect on IFN-gamma. However, neutralization of Ni-induced IL-10 enhanced the levels of IFN-gamma induced by Ni (P = 0.004) but did not affect the number of IFN-gamma-producing cells or the production of other cytokines. Cell depletion experiments suggested that the Ni-specific IFN-gamma (and Th2-type cytokine) producing cells were CD4(+) T cells. The impact of IL-10 on Ni-induced IFN-gamma responses by CD4(+) T cells suggests that an important role of IL-10 in vivo is to counteract the allergic reactions mediated by Th1-type cytokines.     

Effect of glutamine on Th1 and Th2 cytokine responses of human peripheral blood mononuclear cells

Decreased glutamine concentrations are found in patients with catabolic stress and are related to susceptibility to infections. In this study, we evaluated the role of glutamine in Th1/Th2 cytokine responses. Peripheral blood mononuclear cells were stimulated with phytohemagglutinin (PHA), live attenuated bacillus Calmette-Guérin (BCG), or measles virus in the presence of different glutamine concentrations. We found that glutamine at an optimal concentration (0.6 mM) significantly enhanced PHA-stimulated lymphocyte proliferation as well as Th1 [interferon-gamma (IFN-gamma) and interleukin-2 (IL-2)] and Th2 cytokine (IL-4 and IL-10) production. In the absence of glutamine, BCG and measles virus elicited minimal lymphocyte proliferation, whereas BCG enhanced Th1 cytokine response and measles virus promoted Th2 cytokine response. Interestingly, addition of glutamine promoted the BCG-elicited Th1 cytokine response (IFN-gamma), but suppressed the measles-induced Th2 cytokine response (IL-10). These results suggest that appropriate glutamine levels may influence host responses to different antigens and microorganisms. Furthermore, predominately Th1, but not Th2, cytokine responses required the presence of optimal concentrations of glutamine.     

Distribution of Th1, Th2, and Th0 and the Th1/Th2 cell ratios in human peripheral and endometrial T cells

PROBLEM: To examine whether normal pregnancy involves type 2 T-helper (Th2) immune condition or not. METHOD OF STUDY: We measured the percentage of Th0, Th1, and Th2 and the Th1/Th2 cell ratios of human peripheral blood and endometrial T cells using flow cytometry, which can analyze both the surface marker CD3, and intracellular cytokines, interleukin 4 (IL-4) and interferon gamma (IFNgamma). RESULTS: No significant differences were found in the percentages of Th1, Th2, and Th0 and the Th1/Th2 cell ratios in the peripheral blood T cells of nonpregnant women and women in early pregnancy. On the other hand, the percentage of Th1 cells was highest during the proliferative phase of the endometrium, followed by the secretory phase and early pregnancy decidua. The percentage of Th2 cells was highest in early pregnancy decidua and lowest during the proliferative phase of the endometrium. The Th1/Th2 ratio was 147.48+/-96.68 during the proliferative phase of the endometrium, 37.74+/-21.33 during the secretory phase, and 1.31+/-0.48 in the early pregnancy decidua. CONCLUSIONS: These data indicate that Th1 cells predominate in the nonpregnant endometrium, especially during the proliferative phase, while Th2 cells predominate in early pregnancy decidua.     

Circulating cytokines and CD30 in normal human pregnancy and recurrent spontaneous abortions

Concentrations of the T-helper (Th) 1 cytokines interleukin (IL)-2, tumour necrosis factor (TNF) -alpha, TNF-beta and interferon-gamma, Th2 cytokines IL-4, IL-5, IL-6, IL-10 as well as those of soluble CD30 in sera have been examined during the three trimesters of gestation, at delivery in normal pregnancy, and at the time of spontaneous abortion in women with a history of unexplained recurrent spontaneous abortion (RSA). Significantly higher concentrations of the Th2 cytokines IL-6 and IL-10 were found at normal delivery than in women with RSA, and conversely significantly increased concentrations of the Th1-type cytokine TNF-alpha were found in RSA as compared with successful pregnancy. In abortion-prone women who had a successful pregnancy, significantly higher concentrations of IL-6 and significantly lower concentrations of TNF-alpha were found as compared with abortion-prone women who had another abortion, supporting the notion that Th2- and Th1-bias are associated with successful and unsuccessful pregnancy respectively. Serum CD30 concentrations did not correlate with the outcome of pregnancy. These findings support observations drawn from experiments on the cytokine secretion profiles of peripheral blood mononuclear cells and decidual lymphocytes which suggest that normal pregnancy is Th2-biased and that unexplained RSA is associated with Th1-type reactivity.     

Evaluation of Th1/Th2 ratio and cytokine production profile during acute exacerbation and convalescence in asthmatic children.

BACKGROUND: Th2-type cytokines, such as IL-4 and IL-5, are generally believed to play an important role in the pathogenesis of allergic asthma. In contrast, Th1-type cytokine, especially interferon (IFN)-gamma, is thought to have a downregulatory effect on Th2 immune response cells. Thus, the imbalance of Th1 and Th2 cells may be a key factor in relation to disease severity. OBJECTIVE: The aim of this study is to examine the changes in the Th1/Th2 ratios and cytokine production profiles of asthmatic children at acute attacks and convalescent stages. METHODS: Twelve asthmatic patients were included in this study. The percentages of IFN-gamma- or IL-4-producing cells were determined with a flow-cytometric method of intracellular protein detection. Fresh whole blood obtained from normal controls and patients at two stages was stimulated with brefeldin A, phorbol myristate acetate, and ionomycin for 4 hours. Cells were fixed and stained intracellularly with fluorescein isothiocyanate- or phycoerythrin-conjugated antibody specific to each cytokine in combination with anti-CD4. ELISA assays were applied to measure cytokine concentrations of supernatant from peripheral blood mononuclear cells (PBMC) activated with phorbol myristate acetate and ionomycin for 24 hours. RESULTS: Among CD4+ cells, the percentage of IL-4+ cells decreased significantly from 8.18 +/- 4.77% at acute attacks to 4.18 +/- 1.26% (P < .020) at convalescence. The percentage of IFN-gamma+ cells also decreased from 13.49 +/- 4.21% to 9.03 +/- 5.42% (P < .052). The Th1/Th2 ratios of patients at the two stages were similar, and both were lower than the normal controls. Significantly higher IL-5 and lower IFN-gamma production were detected from activated PBMC of asthmatic patients than normal controls. CONCLUSIONS: The decrease of IFN-gamma+ and IL-4+ cells detected at the single-cell level may explain the potential mechanism of convalescence from acute asthma attacks. High Th1/Th2 ratio and low IL-5 production from the PBMC of normal controls support the idea of a biased Th2 immune response in asthmatic patients.     

Questioning the Th1/Th2 paradigm in reproduction: peripheral levels of IL-12 are down-regulated in miscarriage patients

PROBLEM: It has been postulated that a T helper (Th)1 response is associated with pregnancy failure, whereas a Th2 response contributes to pregnancy maintenance. However, this Thl/Th2 dichotomy has recently been hypothesized to be an oversimplification. To prove this novel hypothesis, we investigated the levels of the Th1-inducer cytokine interleukin (IL)-12 in immunocompetent cells of patients with normal pregnancies (NP) and spontaneous abortion (SA). METHODS: Presence of intracellular IL-12 was evaluated in CD8+ and CD56-blood and decidual lymphocytes as well as in monocytes and granulocytes by flow cytometry from NP and SA individuals. IL-12 serum levels were measured by enzyme-linked immunosorbent assay (ELISA). We further investigated the effect of recombinant human (rh) IL-12 on the production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha in peripheral leukocytes ex vivo. RESULTS: In patients suffering from SA we observed lower percentages of IL-12 in lymphocytes, monocytes and granulocytes derived from peripheral blood and decidua, compared with women with normally progressing pregnancies. No differences could be observed when evaluating the levels of IL-12 in the granulocyte population. The IL-12 serum levels were below the ELISA sensitivity limit. Ex vivo stimulation of the peripheral blood cells with increasing doses of IL-12 resulted in a significant decrease of IFN-gamma+, whereas levels of TNF-alpha+ in lymphocytes were unaffected. CONCLUSIONS: The classical Th1/Th2 paradigm appears to be insufficient to exclusively explain the causes of pregnancy loss. Our current results render us to requestion the role of Th1 cytokines during pregnancy and suggest some protective function of the Th1-inducer cytokine IL-12.     

Balance of Th1/Th2 Cytokines Associated with the Preventive Effect of Incomplete Freund's Adjuvant on the Development of Adjuvant Arthritis in LEW Rats

Complete Freund's adjuvant (CFA) could induce adjuvant arthritis (AA) in LEW rats and incomplete Freund's adjuvant (IFA) could induce oil induced arthritis (OIA) in DA but not in LEW rats. Lymph node cells (LNCs) from these AA and OIA rats showed increased mRNA expression of IFN-gamma, IL-2 and TNF-alpha but not IL-4. LNCs from IFA immunized LEW rats showed increased expression of IL-4, reduced expression of IFN-gamma and TNF-alpha and no IL-2, in contrast to IFA immunized DA rats. The pretreatment of IFA before CFA challenge could completely prevent AA in LEW rats and their LNCs showed increased expression of IL-4 and IFN-gamma but not IL-2 and TNF-alpha. In F1 (LEW x DA) rats, IFA could not induce OIA but the pretreatment of IFA before CFA challenge could induce very mild AA with 80% incidence, LNCs showing an elevated expression of all the above cytokines. These findings suggest that increased Th1 cytokine expression is associated with disease development and that increased IL-4 expression or the balance of Th2 over Th1 cytokine expression plays an important regulatory role in disease development.     

Intracytoplasmic Th1 and Th2 cytokines in rheumatoid arthritis blood and synovial tissue

In rheumatoid arthritis (RA), T cells have been proposed either as a main actor or as an epiphenomenon in such a primarily synoviocyte-driven disease. A major issue remains the remarkable paradox between the T cell infiltrate and the relative failure to detect definite markers of their activity. To determine the Th1/Th2 cytokine profile in RA synovium, we used a single cell flow cytometric assay for interleukin-2 (IL-2), interferon-gamma (IFN-gamma), IL-4 and IL-10 in paired peripheral blood (PB) and synovial tissue (ST) lymphocytes from RA and osteoarthritis (OA) patients and PB lymphocytes from healthy controls. Cytokines were undetectable in unstimulated PB and ST lymphocytes. More stimulated PB and ST CD4(+)lymphocytes produced IFN-gamma than IL-4, for all individuals tested. RA PB CD4(+)lymphocytes showed the same Th1 cytokine pattern as normal controls. No increase of such a Th1 profile was observed for ST lymphocytes. A specific recruitment of T CD4(+)lymphocytes in the rheumatoid inflamed synovium could not be concluded on the basis of these results.     

Intracellular cytokine production by Th1/Th2 lymphocytes and monocytes of children with symptomatic transient hypogammaglobulinaemia of infancy (THI) and selective IgA deficiency (SIgAD)

Intracellular expression of several cytokines was assessed in lymphocytes and monocytes of children with transient hypogammaglobulinaemia of infancy (THI) and selective IgA deficiency (SIgAD). THI was characterized by an increased frequency of CD3+/CD4+ lymphocytes expressing tumour necrosis factor alpha (TNF-alpha), TNF-beta and interleukin 10 (IL-10), while in SIgAD elevated numbers of these cells containing TNF-alpha and interferon gamma (IFN-gamma) were observed. No changes in the number of CD4+ T cells expressing IL-4 in both diseases were noted. The proportion of CD33+ monocytes containing TNF-alpha both in THI and SIgAD was unchanged. The secretion of IL-12 by peripheral blood mononuclear cells (PBMCs) of patients with THI and SIgAD was significantly elevated and associated with an increased frequency of IL-12 expressing monocytes in THI but not in SIgAD. IL-18 secretion was slightly, but not significantly, elevated in both diseases. Intracellular Th1 and Th2 type cytokines within CD3+/CD4+ lymphocytes were also determined in the normal blood donors that showed high or low production of IgG and IgA in vitro. In low producers of IgG an increased proportion of CD3+/CD4+ cells expressing TNF-alpha and IFN-gamma was found, while in low IgA responders only elevated TNF-alpha positive CD3+/CD4+ cells were observed. These results suggest that THI and SIgAD may represent diseases with an excessive Th1 type response that is associated with an up-regulation of IL-12 secretion and, at least in THI, elevated numbers of monocytes expressing intracellular IL-12. Up-regulation of IL-12 may be the essential factor in the patomechanism(s) of these diseases as already described in common variable immunodeficiency (CVID).     

Monocytes are primed to produce the Th1 type cytokine IL-12 in normal human pregnancy: an intracellular flow cytometric analysis of peripheral blood mononuclear cells

This paper considers both monocytes and peripheral blood lymphocytes as potential targets for maternal immunological modulation in pregnancy. Peripheral blood mononuclear cells (PBMCs) from non-pregnant and normal pregnant donors were stimulated in vitro, and cytokine production detected intracellularly by flow cytometry. It was found that monocyte production of TNF-alpha was unaltered in pregnancy, while production of IL-12 was significantly enhanced. In contrast, production of the Th1 type cytokine IFN-gamma was suppressed in the lymphocyte subsets: CD4+ T helper cells and CD56+ NK cells. Production of the Th2 type cytokine IL-4 in CD4+ cells was not significantly altered in pregnancy. These data suggest that the concept that pregnancy is a 'Th2 phenomenon' cannot be generalized to the function of all aspects of maternal cellular immunity as, paradoxically, circulating monocytes are 'primed' to produce the Th1 cytokine IL-12. Furthermore, these data support the hypothesis that components of maternal innate immunity are activated in normal pregnancy.     

Reduced Th1, but not Th2, cytokine production by lymphocytes after in vivo exposure of healthy subjects to endotoxin

Endotoxin (lipopolysaccharide [LPS]) tolerance is characterized by a reduced capacity of monocytes to produce proinflammatory cytokines upon restimulation in vitro. To determine whether LPS exposure induces a change in lymphocyte cytokine production and whether this results in a shift in the T-helper 1 (Th1)/Th2 balance, whole blood obtained from seven healthy subjects before and after an intravenous injection of LPS (4 ng/kg) was stimulated in vitro with the T-cell stimulus anti-CD3/CD28 or staphylococcal enterotoxin B. Whole-blood production of the Th1 cytokines gamma interferon (IFN-gamma) and interleukin-2 (IL-2) was markedly reduced at 3 and 6 h, while the production of the Th2 cytokines IL-4 and IL-5 was not influenced or was slightly increased. The IFN-gamma/IL-4 ratio was strongly decreased at 6 h. Serum obtained after LPS exposure could slightly inhibit the release of IFN-gamma but increased IL-4 production during stimulation of blood drawn from subjects not previously exposed to LPS. Normal serum also inhibited IFN-gamma production, albeit to a lesser extent. LPS exposure influences lymphocyte cytokine production, resulting in a shift toward a Th2 cytokine response, an effect that may be mediated in part by soluble factors present in serum after LPS administration in vivo.