Effects of interleukin-4 and interferon-γ on the secretion of IgG4 from human peripheral blood mononuclear cells

Whereas IgE antibodies are linked with allergy, IgG4 antibodies may reflect the state of immunity and protection against a particular antigen. It has been shown that interleukin (IL)-4 is required for induction of IgE synthesis. In order to elucidate the role of IL-4 in the production of IgG4 and to compare IgG4 and IgE regulatory processes, we quantified these immunoglobulin isotypes after in vitro culture of peripheral blood mononuclear cells (PBMC) in the presence of IL-4. The production of IgG4 was increased by IL-4 under the same conditions which are optimal for IgE production but not among PBMC from all donors, depending on the magnitude of spontaneous IgG4 secretion: IL-4 was effective only when the spontaneous secretion of IgG4 was < 7% of the total IgG secretion; it had no effect when spontaneous IgG4 production was >7% of total IgG. The IL-4-induced IgE response was consistently obtained when IgG4 was < 7% of total IgG but was markedly diminished or absent when IgG4 was > 7% of total IgG. If Staphylococcus aureus strain Cowan 1 (SAC) was present during the 48-h preincubation step, spontaneous IgG4 production was increased, but the stimulatory effect of this mitogen on immunoglobulin production, including IgG4, was markedly blocked by the addition of IL-4. In contrast, IL-4-induced IgE synthesis was strongly blocked by the presence of SAC. Finally, secretion of IgG4 (spontaneous and IL-4-induced) was suppressed among cells from most donors by interferon-γ (IFN-γ). These results suggest that IL-4 has opposite effects on in vitro IgG4 production and that the in vitro synthesis of both IgG4 and IgE appears to be regulated similarly by IL-4 and IFN-γ, whereas additional signals promote the production of one isotype in preference to the other. It is possible that activated B cells respond to IL-4 less well than do nonactivated cells.     

Allergen-Specific increase in interleukin (IL)-4 and IL-5 secretion from peripheral blood mononuclear cells during birch-pollen immunotherapy

The mechanisms behind the effects of immunotherapy (IT) with birch-pollen extract are largely unknown. In this pilot study, we measured the cytokine secretion in vitro from peripheral blood mononuclear cells (PBMC) obtained from birch-pollen-allergic patients undergoing IT treatment ( n =4) or placebo administration (n=4), collected before treatment, 1 and 4 weeks after start of treatment, and during and just after the pollen season (12–14 weeks after start of treatment). The PBMC were stimulated with birch-pollen extract in vitro for 7 days, followed by restimulation with the mitogens phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) for 24 h, to enhance the production of cytokines. The supernatants were analyzed with ELISA and radioimmunoassay for interferon-gamma (IFN-y), interleukin (IL)-4, and IL-5. In the therapy group, we noted an increased secretion of IL-4 and IL-5 from PBMC collected at 4 weeks after the start of treatment (IL-4: 29±21 pg/ml [day 0] to 3741448 pg/ml [week 4], mean± SD; IL-5: 95+48 pg/ml to 11471697 pg/ml). No increase was seen in the placebo group. During the pollen season, we noted a trend toward increased IL-4 and IL-5 secretion in both groups. We conclude that the temporary increase in serum IgE observed in many IT studies may be a consequence of increased IL-4 production due to the allergen exposure.     

Peripheral blood mononuclear cells stimulate progesterone production by luteal cells derived from pregnant and non-pregnant women: possible involvement of interleukin-4 and interleukin-10 in corpus luteum function and differentiation

Human luteal cells have been reported to express human leukocyteantigen-DR and lymphocyte functional antigen-3 on the cell surface,suggesting physiological interaction between luteal cells andT-lymphocytes through the menstrual cycle into early pregnancy.To elucidate the role of peripheral lymphocytes on corpus luteumdifferentiation, the effect of peripheral blood mononuclearcells (PBMC) on steroidogenesis by luteal cells was investigated.The production of Th-2 cytokines such as interleukin (IL)-4and IL-10 by the co-cultured cells was also examined, and theeffects of these cytokines on progesterone production by lutealcells were investigated. Corpora lutea were obtained from eightnon-pregnant women in the luteal phase and five women in earlypregnancy for luteal cell culture. PBMC were isolated from unrelatedwomen in the follicular phase, secretory phase, and early pregnancy.After co-culture with allogenic PBMC for 48 h, progesteroneproduction was significantly enhanced by PBMC from the secretoryphase and early pregnancy in the non-pregnant luteal cell culture.In the pregnant luteal cell culture, a significant increasein progesterone production was also observed by the co-culturewith PBMC from women in early pregnancy, showing that PBMC havea luteotrophic effect. The stimulatory effects of PBMC werealso observed in co-culture conditions which prevented directcell-to-cell interaction with luteal cells, showing the minorinfluence of mixed lymphocyte reaction. By co-culture with PBMC,the production of IL-10, but not IL-4, was significantly augmentedin luteal cell culture derived from non-pregnant women, whereasthe production of both IL-4 and IL-10 was significantly enhancedin the luteal cell culture derived from pregnant women. Moreover,IL-4 and IL-10 promoted progesterone production by culturedluteal cells, especially in the luteal cell culture derivedfrom corpora lutea of early pregnancy. These findings indicatethat PBMC stimulate progesterone production by luteal cellsand suggest the involvement of PBMC in corpus luteum functionand differentiation probably via the Th-2-type lymphocytes.     

Peripheral blood mononuclear cells from IgE- and non-IgE-associated allergic atopic eczema/dermatitis syndrome (AEDS) demonstrate increased capacity of generating interleukin-13 but differ in their potential of synthesizing interferon-gamma

BACKGROUND: A subgroup of patients with allergic atopic eczema/dermatitis syndrome (AEDS) are known to have normal total and specific IgE levels and negative skin prick tests towards common environmental allergens. This form of the disease has been termed non-IgE-associated allergic AEDS. Although allergic mechanisms appear to be important, the pathogenesis of both IgE- and non-IgE-associated forms of the disease is unknown. METHODS: We have compared the cytokine production pattern of peripheral blood mononuclear cells (PBMC) from IgE-associated AEDS, non-IgE-associated AEDS, and normal control individuals. PBMC were stimulated with anti-CD3 and/or anti-CD28 monoclonal antibodies (mAb) and cytokine production was measured by immunoassays in supernatants of 24-h cultures. RESULTS: Compared to healthy subjects and non-IgE-associated AEDS patients, stimulated PBMC from IgE-associated AEDS patients produced less interferon (IFN)-gamma. However, stimulated PBMC from both IgE-associated AEDS and non-IgE-associated AEDS patients produced more interleukin (IL)-13 than PBMC from control individuals. Moreover, IL-5 production was significantly increased in non-IgE-associated AEDS but not in IgE-associated AEDS patients. CONCLUSIONS: The underlying mechanism leading to increased differentiation of T helper (Th) 2 cells may involve a deficient capacity in producing IFN-gamma in IgE-associated AEDS but not in non-IgE-associated AEDS patients. IL-13 may be a key cytokine in the pathogenesis of both allergic forms of AEDS.     

Effect of seasonal exposure to pollen on nonspecific interleukin-4, interleukin-5, and interferon-gamma in vitro release by peripheral blood mononuclear cells from subjects with pollinosis

The immune response to environmental allergens depends on both genetic and environmental factors. Allergen exposure triggers the activation of allergen-specific Th2 cells in allergic patients, as well as increased Th2-type cytokine mRNA expression and eosinophil recruitment. Nevertheless, different patterns of release of cytokines could explain the heterogeneity of atopic response. In our study, 25 patients with pollinosis and 15 healthy donors were selected to characterize their release of Th2 (interleukin [IL]-4 and IL-5) and Thi (interferon-gamma [IFN-y]) cytokines, both during and outside the pollen season. Peripheral blood mononuclear cells from patients and controls were isolated, cultured in the presence of phorbol-12-myristate-13- acetate plus ionomycine, and phytohemagglutinin (PHA), and cytokine release was assessed by titration in the supernatants. Both IL-4 and IL-5 showed higher levels during than outside the pollen season in pollinic patients (P<0.05) after nonspecific stimuli, whereas IFN-y levels were significantly lower during than outside the pollen season only after culture with PHA. Significant differences were not observed in the control group. Our results are consistent with the hypothesis that release of cytokines by peripheral blood mononuclear cells from patients with pollinosis depends on environmental exposure to sensitizing pollens, and that influence can be revealed by in vitro nonspecific stimulation. Nevertheless, the heterogeneity in results suggests that the use of mitogens to assess Thl/Th2 dominance may need careful evaluation.     

Allergen-specific production of interferon-γ by peripheral blood mononuclear cells and CD8 T cells in allergic disease and following immunotherapy

BACKGROUND: CD8 T cells are important immunoregulatory cells in animal models of allergic disease, but their role in human allergic immune responses has not been defined. With the development of novel immunotherapeutic reagents, it is clearly important to ascertain whether CD8 T-cell responses are altered following conventional allergen-specific immunotherapy (SIT) and hence targets for future developments/strategies. OBJECTIVE: To study the allergen-specific cytokine release of freshly isolated CD8 T cells from the blood of separate groups of house dust mite- (HDM) allergic patients, patients post-SIT and control nonatopic donors. METHODS: CD8 T cells were isolated by positive selection with immunomagnetic beads and cultured with the affinity purified major mite allergen Der p 1 or with different mitogens, using irradiated autologous peripheral blood mononuclear cells as antigen-presenting cells (APCs). Supernatants were collected at a number of time points and assayed by ELISA for the cytokines interleukin (IL) -4, IL-5 and interferon-gamma (IFNgamma). RESULTS: CD8 T cells stimulated with Der p 1 produced significant quantities of IFNgamma with cells from HDM-allergic subjects releasing considerably more IFNgamma than cells from nonatopic subjects, an average of 804 +/- 283 pg/mL of supernatant compared with 30.2 +/- 18.8 pg/mL (P = 0.006). The cytokine was detected in cultures of 16/17 of the allergic subjects and 4/7 of the nonatopic. CD8 T cells from 6/10 patients who had received HDM-SIT released IFNgamma at an average of 363 +/- 202 pg/mL, which was less than the allergic group but still higher than the nonatopic (P = 0.05). Equivalent levels of IFNgamma were detected when the cells were stimulated with the mitogen PHA and this was the same in all groups. Reliable allergen-specific release of significant quantities of IL-4 or IL-5 was not detected from CD8 T cells. CONCLUSION: Allergen-specific IFNgamma is produced at far greater levels from CD8 T cells of HDM-sensitive allergic patients than from nonatopic control individuals and this level is reduced following SIT.     

Cytokine production of in vitro stimulated peripheral lymphocytes during the course of pregnancy and pseudopregnancy in the rat

Problem Does maternal lymphocyte cytokine production after in vitro stimulation vary with the stage of pregnancy in the rat? Method of study Blood samples were taken during the estrus cycle in rats (n = 11). Thereafter, rats were rendered pregnant (n = 6) or pseudopregnant (n = 5) and blood samples were taken at days 4, 8, 11, 15, and 20 of pregnancy and pseudopregnancy. White blood cell (WBC) count was measured and whole blood was stimulated with phorbol 12‐myristate 13‐acetate and calcium ionophore; interferon‐γ (IFNγ) and interleukin‐4 (IL‐4) production as well as (sub)populations of lymphocytes were measured using flow cytometry. Results We observed an increase of WBC in the second week of pregnancy and a slowly decreasing percentage of lymphocytes during the course of pregnancy. The percentage IFNγ producing T‐lymphocytes after in vitro stimulation was increased during pregnancy (for Th‐lymphocytes only in the second week of pregnancy, for Tc‐lymphocytes at all days). This increased IFNγ production in pregnant T‐lymphocytes was accompanied by an increase during pseudopregnancy, and therefore may result from increased sex hormone concentrations. The percentage IFNγ producing natural killer (NK) cells after in vitro stimulation was decreased on day 20 of pregnancy. No effect of pregnancy or pseudopregnancy was seen on percentage IL‐4 producing lymphocytes after in vitro stimulation. Conclusion In the rat the IFNγ production after in vitro stimulation varies during pregnancy and is increased, rather than decreased, during pregnancy.     

The lymphocyte transformation test in the diagnosis of drug hypersensitivity

Diagnosis of drug hypersensitivity is difficult, as an enormous amount of different drugs can elicit various immune-mediated diseases with distinct pathomechanism. The lymphocyte transformation test (LTT) measures the proliferation of T cells to a drug in vitro--from which one concludes to a previous in vivo reaction due to a sensitization. This concept of the LTT has been confirmed by the generation of drug-specific T-cell clones and the finding that drugs can directly interact with the T-cell receptor, without previous metabolism or need to bind to proteins. In this review, technical aspects and usefulness of this test for the diagnosis of drug hypersensitivity are discussed. The main advantage of this test is its applicability with many different drugs in different immune reactions, as drug-specific T cell are almost always involved in drug hypersensitivity reactions. Its main disadvantages are that an in vitro proliferation of T cells to a drug is difficult to transfer to the clinical situation and that the test per se is rather cumbersome and technically demanding. In addition, its sensitivity is limited (for beta-lactam allergy it is in the range of 60-70%), - although at least in our hands - it is higher than of other tests for drug hypersensitivity diagnosis. Consequently, drug hypersensitivity diagnosis needs to rely on a combination of history and different tests, as none of the single tests available has per se a sufficiently good sensitivity. Within this setting, the LTT has proven to be a useful test for the diagnosis of drug hypersensitivity reactions and helped to better understand these reactions. Further work on the simplification of this test and systematic evaluation of its sensitivity and specificity in some main groups of drugs are necessary to make this test more widely available.     

CD69 upregulation on T cells as an in vitro marker for delayed-type drug hypersensitivity

Background:  T cells play a key role in delayed-type drug hypersensitivity reactions. Their reactivity can be assessed by their proliferation in response to the drug in the lymphocyte transformation test (LTT). However, the LTT imposes limitations in terms of practicability, and an alternative method that is easier to implement than the LTT would be desirable.
Methods:  Four months to 12 years after acute drug hypersensitivity reactions, CD69 upregulation on T cells of 15 patients and five healthy controls was analyzed by flow cytometry.
Results:  All 15 LTT-positive patients showed a significant increase of CD69 expression on T cells after 48 h of drug-stimulation exclusively with the drugs incriminated in drug-hypersensitivities. A stimulation index of 2 as cut-off value allowed discrimination between nonreactive and reactive T cells in LTT and CD69 upregulation. T cells (0.5–3%) showed CD69 up-regulation. The reactive cell population consisted of a minority of truly drug reactive T cells secreting cytokines and a higher number of bystander T cells activated by IL-2 and possibly other cytokines.
Conclusions:  CD69 upregulation was observed after 2 days in all patients with a positive LTT after 6 days, thus appearing to be a promising tool to identify drug-reactive T cells in the peripheral blood of patients with drug-hypersensitivity reactions.     

Increased expression of allergen-induced in vitro interleukin-10 and interleukin-18 mRNA in peripheral blood mononuclear cells of allergic rhinitis patients after specific immunotherapy

BACKGROUND: During specific pollen immunotherapy (SIT) there is a local mucosal shift from Th2- to Th1- type cytokine predominance, with IL-12 having a major role in this shift. IL-10-induced tolerance is supposed to be a key phenomenon in venom immunotherapy (VIT). However, the role of Th1-promoting cytokines, on the one hand, and the role of regulatory cytokines, on the other hand, have not been studied in parallel during SIT. OBJECTIVE: This study was undertaken to analyse the allergen-induced in vitro mRNA expression of Th1-type effector cytokine IL-18 and regulatory cytokines IL-10 and TGF-beta during SIT in peripheral blood mononuclear cells (PBMC) of allergic rhinitis (AR) patients. METHODS: Thirty patients with AR undergoing pollen SIT and 10 patients with AR who were not treated with SIT were included in the study. The symptoms and medications were registered post-seasonally before the beginning of SIT and after 1 year of therapy. PBMC samples were collected and stimulated with pollen allergen extract prior to the treatment, at the maintenance phase in 12 patients and after 1 year of the treatment. The cytokine mRNA expression was assessed using kinetic real-time RT-PCR (TaqMan). RESULTS: There was a clear increase in the treated AR patients, in comparison with untreated AR patients, in the expression of both IL-10 (mean change from baseline (SEM): 3.1 (0.8) vs. -0.3 (0.3), P<0.002, Mann-Whitney U-test) and IL-18 (2.7 (0.9) vs. -0.2 (0.6), P<0.03) mRNA after 1 year. The clearest increase in IL-10 mRNA expression was seen in patients who did not benefit at all (6.0 (2.3), P<0.001 vs. untreated) and the least increase in patients that had the greatest reduction of symptoms (0.8 (0.6), n.s. vs. untreated) at 1 year. The clearest increase in IL-18 mRNA expression was seen in patients with moderate outcome (3.4 (1.6), P<0.04 vs. untreated). In intermediate samples, taken when the maintenance dose was reached, the peak expression of allergen-induced IL-10 mRNA was associated with the most favourable outcome of SIT (P=0.01, Fisher exact test). A similar trend was seen in IL-18 mRNA expression. CONCLUSIONS: The results suggest that an early and transient increase in allergen-specific IL-10 and IL-18 mRNA expression in PBMC is essential for the therapeutic outcome after 1 year of SIT.     

Immune complex-stimulated production of interleukin-12 in peripheral blood mononuclear cells is regulated by the complement system

Immune complexes (IC) can induce cytokine production in vitro. While immune aggregates (IA) consisting of heat-aggregated gamma globulin (HAGG) as model IC increased interleukin (IL)-10 levels in cell cultures with native human serum, IL-12p40/p70 production was inhibited. Three series of experiments suggested that the effects of IA on IL-12 production depended on a functionally intact complement system: (1) heat-inactivation of serum inverted the inhibitory effect of IA on IL-12p40/p70 production; (2) IA-induced IL-12p40 production in a C4 deficient serum was lowered by addition of C4; and (3) addition of the peptide compstatin, which blocks C3 activation, mimicked the effects of heat inactivation on IL-12p40 levels. Neutralization of IL-12 resulted in modestly increased IL-10 levels, while neutralization of IL-10 had no effects on IL-12p40 production. IA-induced production of IL-10 was partially blocked by anti-Fcgamma RII antibodies, whereas Fcgamma R or CR blockade had no effect on IL-12p40 production. IC and local or systemic complement activation characterize rheumatoid arthritis, systemic lupus erythematosus and many malignancies. Different and complement-dependent effects on the production of IL-10 and IL-12 can be of importance in these diseases, where control of the complement system might be a way to direct IC-induced cytokine production in either a type 1 or type 2 direction.     

原核表达、体外折叠的HLA-G5促进人外周血单核细胞产生TNF

通过原核表达获得HLA-G5重链和轻链(β2m),经初步纯化后,利用稀释法与人工合成的九肽(KGPPAALTL)一起进行体外复性折叠,形成HLA-G5-抗原肽复合物,经非变性PAGE/Western blot和夹心ELISA法鉴定,证实复性后成功获得天然构象的HLA-G5。利用PBMC受LPS刺激后产生TNF的特点,观察原核表达、体外折叠的HLA-G5对人PBMC分泌TNF的影响。TNF分泌量采用TNF敏感的L929细胞进行生物法测定,结果显示原核表达、体外折叠的HLA-G5促进人PBMC分泌TNF-α。     

Determination of optimal incubation time for the production of acute phase cytokines ex vivo by peripheral blood mononuclear cells from renal transplant recipients

Levels of acute phase cytokines secreted ex vivo by peripheral blood mononuclear cells (PBMCs) have been shown to be associated with clinical conditions or histologic lesions in renal transplant recipients. One of the limiting factors for the potential use of this assay as a diagnostic tool is the incubation time needed to measure adequate cytokine levels. Here, we validated that shorter time periods than the usual 48 h are sufficient for the production of acute phase cytokines. Cytokine levels were measured with the Luminex platform. We observed that, in contrast to cytokines associated with adaptive immunity, cytokines such as IL-1β, IL-6 and TNF-α are measurable as early as 2 h following incubation at a concentration of 1.5 million PBMC/150 μL. Levels obtained in the 2 h cultures have good correlations with the levels obtained after 48 h of culture for IL-1β and TNF-α (R=0.79, P=0.004 and R=0.92, P<0.001 respectively). We conclude that same-day incubation of PBMCs and measurement of these cytokines following blood collection in transplant recipients is feasible. It provides a rationale for further studies using shorter incubation times for ex vivo cellular assay measuring acute phase cytokine levels.     

Effect of recombinant interleukin-4 on immunoglobulin synthesis in a culture of mononuclear cells isolated from human peripheral blood

The effect of recombinant interleukin-4 on the synthesis of immunoglobulins is studied in a culture of mononuclear cells isolated from peripheral blood of healthy donors and patients with hay fever. It is shown that interleukin-4 stimulates production of IgE in cells of healthy donors, but not of hay fever patients, and does not affect the synthesis of other isotypes in either group. At the same time, increased cell proliferation under the influence of interleukin-4 was observed in cultured cells of both healthy donors and patients. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 10, pp. 426–428, October, 1994 Institute of Pulmonology, Ministry of Health, Moscow. (Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences)     

Analysis of the spontaneous in vitro anti-HIV-1 antibody secretion by peripheral blood mononuclear cells in HIV-1 infection.

We studied the spontaneous in vitro secretion of anti-HIV-1 antibodies by peripheral blood mononuclear cells (PBMC) from HIV-1-infected patients. Specific antibody production was detected in supernatants of PBMC cultures using an ELISA; HIV-1 specificity was confirmed by antigen adsorption and Western blotting. This antibody secretion was found to be an active phenomenon and was not due to a release of plasma antibodies passively adsorbed onto the cell membranes. In all positive supernatants, anti-HIV-1-secreted antibodies were directed against env-encoded antigens and many supernatants also contained antibodies to pol- and gag-encoded antigens. PBMC from all HIV-1-infected patients tested (140 adults and 18 infants) secreted anti-HIV-1 antibodies. This production was found during all the clinical stages of HIV-1 infection. Our results suggest that this spontaneous HIV-1-specific antibody secretion represents a marker of HIV-1 infection. Detection of these antibodies could be a valuable tool for early confirmation of HIV-1 infection in neonates born to HIV-1-seropositive mothers.     

Interleukin-10 prevents the generation of dendritic cells from human peripheral blood mononuclear cells cultured with interleukin-4 and granulocyte/ macrophage-colony-stimulating factor

We evaluated the effects of interleukin (IL)-10 on the differentiation of dendritic cells (DC) obtained by culturing plastic-adherent peripheral blood mononuclear cells for 7 days in presence of granulocyte/macrophage-colony-stimulating factor (GM-CSF)+IL-4. The addition of IL-10 at the initiation of culture resulted in the generation of macrophage-like cells with expressing high levels of CD14 and decreased levels of CD1a and CD1c. Furthermore, cells generated in presence of IL-10 secreted lower levels of IL-12, but higher levels of IL-8 compared with DC generated in absence of IL-10, both spontaneously and after CD40 engagement. Finally, cells generated in presence of IL-10 were less efficient than DC in stimulating the production of IL-2, interferon-γ, and IL-4 by allogeneic T cells. We conclude that IL-10 prevents the generation of DC induced by GM-CSF+IL-4 and favors the development of macrophages with a lower T cell stimulatory potential, but secreting higher levels of IL-8 than DC.     

IL-4 is more effective than IL-13 for in vitro differentiation of dendritic cells from peripheral blood mononuclear cells

Dendritic cells (DCs) are the most potent professional antigen-presenting cells which can activate T cells to induce the primary immune response. For clinical studies, DCs are often differentiated in vitro from peripheral blood mononuclear cells (PBMCs) through treatment with granulocyte macrophage colony-stimulating factor (GM-CSF) and IL-4. However, IL-13, a cytokine closely related to IL-4, has also been reported to induce differentiation equally or more efficiently when used with GM-CSF. For the present study, we compared the DC characteristics exhibited by iDCs and LPS-matured DCs differentiated from PBMCs using GM-CSF and IL-4 or IL-13. Physical characteristics examined include cellular morphology and surface phenotype. Functional traits investigated include FITC-dextran uptake, IL-10 and IL-12 production, allostimulation and cytokine production by stimulated T cells and antigen-specific T cell stimulation. Compared with IL-13-derived DCs, IL-4 treatment yielded more differentiated DCs, with extensive dendrites and higher expression of DC-SIGN, DEC-205, CD86 and HLA-DR. In addition, IL-4 DCs were more efficient at inducing allogeneic T cell proliferation and immature IL-4 DCs had higher endocytic activity at low FITC-dextran concentrations (1 microg ml(-1)). Although IL-13 was capable of generating DCs from PBMCs, it was not as effective as IL-4 in generating DC phenotype and functionality. Thus, the use of GM-CSF and IL-4 is the more efficient treatment for inducing DC differentiation from PBMCs.     

Human leukocyte antigen-G-expressing cells differently modulate the release of cytokines from mononuclear cells present in the decidua versus peripheral blood

PROBLEM: To better understand the role of human leukocyte antigen (HLA)-G in regulating the T helper (Th)1/Th2 cytokine balance, one of key conditions in determining the fate of pregnancy, we asked whether the presence of HLA-G protein altered the release of cytokines from both decidual mononuclear cells and peripheral blood mononuclear cells (PBMCs). METHOD OF STUDY: The amounts of cytokines released from decidual mononuclear cells and PBMCs were compared in the presence or absence of HLA-G-expressing cells. RESULTS: When cocultured with HLA-G-expressing cells, the amounts of tumor necrosis factor-alpha and interferon-gamma released from decidual mononuclear cells and PBMCs were decreased, while the amounts of interleukin (IL)-4 from PBMCs was increased, with IL-4 release from decidual mononuclear cells being unchanged. CONCLUSIONS: Upon contact with HLA-G, decidual mononuclear cells, and PBMCs as well, modulate their ability to release cytokines in a way that may shift the Th1/Th2 balance towards relative Th2 dominance, suggesting a role for HLA-G in maintaining pregnancy.