Induction of phagocyte-stimulating cytokines by in vitro stimulation of human peripheral blood mononuclear cells with Haemophilus influenzae

The aim of this study was to analyse the in vitro response of human peripheral blood mononuclear cells to stimulation with killed Haemophilus influenzae strains of different capsular types, isolation sites and from cases with different forms of infections. The mean stimulatory index using 10(6) bacteria/well was 10, and 80 when 10(8) bacteria/well were used for stimulation. The mean+/-SD level was 13+/-4 ng/ml for interleukin (IL)-1beta, 128+/-73 ng/ml for IL-6, 203+/-122 ng/ml for IL-8, 3160+/-1220 pg/ml for IL-10, 29+/-40 pg/ml for IL-12, 2800+/-1790 pg/ml for tumour necrosis factor (TNF)-alpha and 4+/-7 ng/ml for interferon (IFN)-gamma, when stimulating cells with the lower dose of 10(6) bacteria/well. Using the higher bacterial dose, the levels of IL-1beta, TNF-alpha and IL-12 remained similar, whereas the IL-6, IL-8 and IL-10 levels were significantly lower, and IFN-gamma levels were significantly higher. Strains isolated from the bronchial tree induced significantly higher levels of IFN-gamma and significantly lower levels of IL-6, IL-8 and IL-10 than strains from other isolation sites. In conclusion, H. influenzae generated phagocyte-activating cytokines and an IL-10/IL-12 ratio that was 1090 times that described previously for Streptococcus pneumoniae.     

EIAV减毒疫苗诱导马外周血单个核细胞Th1型细胞因子的转录

目的：探讨马传染性贫血病毒驴白细胞减毒疫苗免疫马后,外周血单个核细胞中Th1型细胞因子转录水平与免疫保护应答的关系,揭示DLV的免疫保护机制。方法：应用分子克隆及实时定量RT-PCR技术,建立了马PBMC中IFNγ-、IL-2、IL-12 mRNA转录水平的定量检测方法,定期观察4组（疫苗免疫组、阴性对照组、强毒株阳性对照组、自然感染组）12匹马外周血PBMC中细胞因子的转录水平及分布特征,同时监测体温变化等指标。疫苗株免疫动物8个月后,用EIAV强毒株攻击,观察攻击前后细胞因子转录水平的变化。结果：DLV免疫马,在免疫后3周外周血PBMC中IFN-γ、IL-2转录量显著高于阴性对照组及自然感染组（P〈0.01）;免疫后用EIAV强毒株攻击,IFNγ-、IL-2和IL-12转录的量明显升高,免疫马获得完全保护;强毒株攻击阳性对照马IFN-γ、IL-2转录量随疾病进展波动,发热期下降。结论：本研究首次证明EIAV减毒疫苗可诱导马外周血PBMC中IFN-γ、IL-2、IL-12基因高效转录,其转录水平与DLV的免疫保护密切相关,此结果在分子水平为阐明DLV的免疫保护机制提供了新的实验依据。     

Kinetics of cytokine release and expression of lymphocyte cell-surface activation markers after in vitro stimulation of human peripheral blood mononuclear cells with Streptococcus pneumoniae

The aim of this study was to describe the kinetics of the cytokine release and the expression of activation markers on lymphocytes after stimulation of peripheral blood mononuclear cells (PBMC) with whole killed Streptococcus pneumoniae. The cytokine release and the expression of CD25 and HLA-DR on T cells, and CD69 on T cells, B cells and NK cells, were measured at different times. Our results show that tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-10 and IL-12 reached maximal levels at 24 h, while IL-6, IL-8, TNF-beta and interferon (IFN)-gamma increased throughout the 1-week test period. The strains tested gave an increased expression of CD69 on all cell types, as well as an increase of CD25 and HLA-DR expression on T cells. The maximal CD69 expression was seen after 24 h on T cells and NK cells, while the B-cell expression of CD69 reached a plateau at the same time. All the cells still expressed CD69 on their surfaces after 1 week. In conclusion the results indicate that there was probably an early activation of monocytes leading to a polyclonal activation of lymphocytes.     

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.     

In vitro production of cytokines by peripheral blood mononuclear cells from hydatid patients.

The role of cytokines in human hydatidosis (Echinococcus granulosus infection) was evaluated in immunoassays determining production of IL-4, IL-10 and interferon-gamma (IFN-gamma) in peripheral blood mononuclear cell (PBMC) cultures from 30 hydatid patients and 14 uninfected controls. In cell cultures from hydatid patients parasite and non-parasite antigen stimulation significantly increased IL-4 production (P < or 0.005). Spontaneous and mitogen-driven IL-4 production was similar in patients and controls. IL-10 and IFN-gamma production did not differ statistically in the two groups, even though some hydatid patients produced these cytokines in large amounts. Notably, antigen-driven IFN-gamma concentrations were invariably higher in patients than in uninfected controls. Data analysis showed a relationship between IgE and IgG4 responses and parasite-driven cytokine production. High IgE and IgG4 responders produced high IL-4 and IL-10 concentrations. High IgE responders showed decreased IFN-gamma production, but high IgG4 responders had IFN-gamma levels slightly higher than those of low responders. Cytokine response patterns did not relate to the clinical stage of disease. The significantly increased IL-4 and the high IL-10 concentrations found in PBMC from many hydatid patients in this study are consistent with Th2 cell activation in human hydatidosis. The presence of antigen-driven IFN-gamma production in patients with E. granulosus infection implies concurrent intervention of the Th1 or Th0 cell subset.     

喘可治注射液对人外周血单个核细胞Th1/Th2细胞因子谱的影响

目的：通过研究喘可治注射液对人外周血单个核细胞（PBMCs）Th1／Th2细胞因子谱的影响，探讨喘可治注射液的免疫调节作用机制。方法：以流式微球分析（CBA）法检测不同处理情况下，人外周血单个核细胞分泌Th1（IFN-γTNF-α、IL-2）和Th2（IL4、IL-6、IL-10）细胞因子水平。结果：健康人PBMCs体外培养12小时后，上清中细胞因子主要为TNF-α和IL-6，喘可治使Th1和Th2细胞因子全面升高；喘可治对PDB加离子霉素诱导的PBMCs分泌Th1和Th2细胞因子具有抑制作用，并能抑制流感病人异常升高的INF-γ、TNF-α、IL-6和IL-10分泌。结论：喘可治注射液上调健康人PBMCs分泌TH1和Th2细胞因子，对异常活化的PBMCs分泌的Th1和Th2细胞因子则具有下调作用。     

Inhibition of varicella-zoster virus in vitro by human peripheral blood mononuclear cells.

A functional in vitro assay of cell-mediated immunity to varicella-zoster virus (VZV) is described. This procedure uses an enzyme-linked immunosorbent assay (ELISA) to measure the inhibitory effect of human peripheral blood mononuclear cells on VZV antigen production by VZV-infected cell monolayers. When mononuclear cells from VZV-immune, tetanus-immune donors were stimulated with either VZV antigen or tetanus toxoid they reduced VZV antigen production. In contrast, mononuclear cells from VZV-nonimmune, tetanus-immune donors reduced VZV antigen only when stimulated with tetanus toxoid, but not when stimulated with VZV antigen. Cell-free supernatants recovered from the VZV inhibition assays contained the anti-VZV activity. The magnitude of the anti-VZV activity of the supernatants equalled the inhibition observed when the stimulated mononuclear cells were added to the VZV-infected monolayers. Treatment of either mononuclear cells or supernatants with anti-interferon gamma antibody indicated that their VZV inhibitory capability was largely due to the production of interferon gamma by stimulated mononuclear cells.     

Comparative analysis of spontaneous and mycobacterial antigen-induced secretion of Th1, Th2 and pro-inflammatory cytokines by peripheral blood mononuclear cells of tuberculosis patients

The cytokines produced by T helper (Th)1 cells (IFN‐γ, IL‐2 and TNF‐β) correlate with protection, whereas the cytokines released by Th2 cells (IL‐4, IL‐5) and the anti‐inflammatory cytokine IL‐10 correlate with pathogenesis of tuberculosis (TB). However, the pro‐inflammatory cytokines (IL‐1β, IL‐6, IL‐8, TNF‐α and IL‐12p70) are responsible for both protection and pathogenesis of TB. The aim of this work was to carry out a comparative analysis of cytokines present in early (day 2) and late (day 6) cultures of peripheral blood mononuclear cells (PBMCs) obtained from pulmonary tuberculosis patients. PBMCs were cultured in vitro in the absence and presence of exogenously added complex mycobacterial antigens and RD1 peptide pool. The supernatants were collected on day 2 and day 6 of culture and assayed for secreted cytokines using the flow cytomix assay. All of the cytokines, except for IL‐12p70, were spontaneously secreted by PBMCs of 27–100% TB patients, but only TNF‐α concentration was significantly higher on day 2 than day 6 (P < 0.05). Two days following antigenic stimulation, only IL‐1β, IL‐6, TNF‐α and IL‐10 were secreted in response to some mycobacterial antigens. However, 6 days later, all of the cytokines, except for IL‐2, IL‐4, IL‐5 and IL‐8, were secreted significantly in response to all complex antigens and RD1 peptides, compared with the non‐stimulated cultures (P < 0.05). In conclusion, the study shows that the longer in vitro stimulation time (6 days) was necessary for the optimal induction of IFN‐γ and TNF‐β, and practically convenient for the detection of IL‐10, IL‐1 β, TNF‐α and IL‐6.     

Seasonal variation of IgE synthesis in vitro by human peripheral blood mononuclear cells

Seasonal variations in IgE antibody synthesis in vitro were studied in cultures of blood mononuclear cells (MNC) from 11 pollen allergic individuals. The IgE levels were significantly higher in two summer seasons than in the winter and spring between them. Net synthesis was confined to the summer in all but one of the patients. All the IgE in the cultures outside the pollen season represented preformed IgE which was present mainly (59%) in the monocyte fraction. Thus, preformed IgE seems to persist in monocytes at times when there is little de novo synthesis of IgE.     

Induction of nitric oxide in bovine peripheral blood mononuclear cells by bovine herpesvirus 1

Bovine peripheral blood mononuclear cells (PBMCs) and monocytes were stimulated with bovine herpesvirus 1 (BHV-1), LPS and concanavalin A (Con A) to produce L-arginine-dependent nitric oxide (NO) in vitro. NO was detected as early as 12 hrs and up to 72 hrs post stimulation (p.s.). The NO from lipopolysacharide (LPS)-stimulated PBMCs and monocytes was found to exhibit antiviral effect against BHV-1. The anti-BHV-1 effect was inhibited with N(omega)-methyl L-arginine indicating involvement of inducible NO synthase (iNOS) in NO production.     

Interleukin-25 reduces Th17 cells and inflammatory responses in human peripheral blood mononuclear cells

Background

The absence of interleukin-25 (IL-25) favors the induction of Th1 and Th17 immune responses in mice. Th1 immune responses have been associated with the pathology of atherosclerosis, a lipid and inflammation driven disease of the arterial wall.

Induction of in vitro antigen-specific antibody production against NIP-KLH in nonadherent cells derived from human peripheral blood mononuclear cells

A primary in vitro antibody response to 4-hydroxy-3-iodo-5-nitrophenylacetyl keyhole limpet hemocyanin (NIP-KLH) by plastic dish nonadherent human peripheral blood mononuclear cells (PBMC) was examined. Nonadherent cells of most donors produced an anti-NIP antibody when they were cultured with the antigen at a cell density of 2.5 X 10(6)/ml in the presence of Staphylococcus aureus Cowan I (SAC) at a concentration of 0.003% for 5 days, washed and further cultured in the absence of the antigen and SAC for an additional 5 or 6 days. Nonadherent cells of 'low-responders' responded to NIP-KLH plus SAC and produced anti-NIP antibody when they were cultured with not only NIP-KLH plus SAC but also with the culture supernatant obtained on phytohemagglutinin (PHA) stimulation of a mixture of PBMC from 2 donors. Furthermore, it was found that the PHA supernatants could be very effectively substituted for by human recombinant interleukin-2.     

T regulatory cells and Th1/Th2 cytokines in peripheral blood from tuberculosis patients

About 10% of people infected with Mycobacterium tuberculosis develop active tuberculosis (TB), and Th1 effector cells and Th1 cytokines play key roles in controlling M. tuberculosis infection. Here, we hypothesise that this susceptibility to M. tuberculosis infection is linked to increased T regulatory (Treg) cells and Th2 cytokines in TB patients. To test this, we recruited 101 participants (71 TB patients, 12 non-TB pulmonary diseases and 18 healthy subjects) and investigated Treg cells and Th1/Th2 cytokines in peripheral blood. CD4⁺CD25⁺ T cells and CD4⁺CD25⁺FoxP3⁺ T cells significantly increased and IL-5 dramatically decreased in TB patients relative to healthy subjects. CD8⁺CD28⁻ T cells, IFN-γ, TNF-α, IL-10 and IL-4 significantly increased in patients with culture and sputum smear-positive pulmonary TB (PTB(+)) compared with healthy subjects. CD4⁺CD25⁺FoxP3⁺ and CD8⁺CD28⁻ T cells significantly decreased in PTB(+) after one month of chemotherapy. CD4⁺, CD4⁺CD25⁺ and CD8⁺CD28⁺ T cells significantly increased in extra-pulmonary TB patients after one month of chemotherapy. These findings suggest that M. tuberculosis infection induces circulating CD4⁺CD25⁺FoxP3⁺ and CD8⁺CD28⁻ T cell expansion, which may be related to the progression of M. tuberculosis infection, and that the balance between effector immune responses and suppression immune responses is essential to control M. tuberculosis infection.     

OK-432-induced cytokines production by peripheral blood mononuclear cells]

Cytokines production by OK-432-stimulated peripheral blood mononuclear cells (PBMC) were measured to investigate the in vitro function of macrophages (M phi) and lymphocytes. PBMC (1 x 10(6) cells/ml) were cultured with OK-432 (0.05 KE/ml) for 72 hr at 37 degrees C under 5% CO2, then interleukin 1 beta (IL-1 beta), interleukin 2 (IL-2) and soluble IL-2 receptor (sIL-2R) levels in the culture supernatants were measured by ELISA. While there was no significant differences of IL-1 beta production between patients with chronic active hepatitis type B (CAH-B) and controls, sIL-2R production (335 +/- 219 U/ml, mean +/- SD) was significantly decreased (p < 0.001) in patients with CAH-B. On the other hand, in pregnant women, production of both IL-1 beta (6.3 +/- 3.9 ng/ml, p < 0.01) and sIL-2R (300 +/- 169 U/ml, p < 0.001) were significantly lower than those in controls (13.5 +/- 3.8 ng/ml, 969 +/- 154 U/ml). These results suggest that the expression of IL-2R alpha on lymphocytes membrane is suppressed in patients with CAH-B, and that decreased M phi function is present in pregnant women.     

MHC-unrestricted lysis of MUC1-expressing cells by human peripheral blood mononuclear cells

Many human adenocarcinomas can be killed in vitro by targeted cytotoxic T-lymphocytes (CTL); however, major histocompatibility complex (MHC)-restrictions are typically required. The MUC1 antigen is common in many human adenocarcinomas, and is associated with a variable number of tandem repeats. It has been proposed that antigens with such repeated epitopes may be vulnerable to cytotoxic T-lymphocyte killing without MHC-restriction. Therefore, it is possible that MUC1-expressing malignant cells may be killed by targeted cytotoxic T-lymphocyte in the absence of MHC-restriction. In this study, a human MUC1-expressing murine mammary carcinoma cell line was used to determine if cytotoxic T-lymphocyte killing of MUC1-expressing adenocarcinoma cells requires MHC-restriction. Specifically, MUC1-stimulated human mononuclear cells (M1SMC) were observed to kill human MUC1-transfected, MUC1-expressing murine mammary carcinoma cells, but not the mock-transfected, non-MUC1-expressing murine mammary carcinoma cells. Furthermore, the killing was blocked by antibody to MUC1, indicating MUC1-specific killing. In conclusion, cytotoxic T-lymphocyte killing of MUC1-expressing adenocarcinoma cells can be MHC-unrestricted.     

Chlamydia pneumoniae enhances the Th2 profile of stimulated peripheral blood mononuclear cells from asthmatic patients

Chlamydia pneumoniae is a cause of respiratory infection in adults and children. There is evidence for an association between atypical bacterial respiratory pathogens and the pathogenesis of asthma. We compared T helper (Th) responses in C. pneumoniae – infected peripheral blood mononuclear cells (PBMC) in patients with or without asthma. PBMC (1 × 10⁶/mL) from asthmatic patients (N = 11) and non-asthmatic controls (N = 12) were infected or mock-infected for 1 h +/− C. pneumoniae TW-183 at a multiplicity of infection (MOI) = 1 and MOI = 0.1, or cultured for 24 h +/− Lactobacillus rhamnosus GG (LGG). Interleukin (IL)-4, IL-10, IL-12, Interferon (IFN)-gamma and total IgE levels were measured in supernatants (ELISA). C. pneumoniae infection led to an increase (>50%) of IgE levels in PBMC from asthmatics, compared with mock-infected on day 10; IgE wasn’t detected in non-asthmatics. C. pneumoniae – infected PBMC from asthmatics increased levels of IL-4 and IFN-gamma after 24 h, compared with PBMC alone; levels of IL-10 and IL-12 were low. When uninfected-PBMC from asthmatics were LGG-stimulated, after 24 h, IL-4 was undetectable, but IL-10, IL-12, and IFN-gamma increased, compared with PBMC alone. Thus, C. pneumoniae infection has the ability to induce allergic responses in PBMC of asthmatics, as evidenced by production of Th2 responses and IgE.     

Induction of suppressor cells after activation of human peripheral blood mononuclear cells with sodium periodate.

Pretreatment of normal human peripheral blood mononuclear cells (MN) with sodium periodate (NaIO4) resulted in the induction of suppressor cells. The mitogenic response of fresh allogeneic and autologous cells to phytohaemagglutinin (PHA), Concanavalin A (Con A), pokeweed mitogen (PWM), various antigens and in mixed lymphocyte culture was suppressed when NaIO4 pretreated cells were present. PWM-induced plaque-forming-cell responses were also suppressed by NaIO4-pretreated cells. Treatment of cells with mitomycin C before the NaIO4 treatment abolished the suppressive activity. A ratio of 1 : combination that resulted in the strongest suppression. Supernatants from NaIO4-pretreated cell cultures were not inhibitory.     

Apoptotic cells selectively suppress the Th1 cytokine interferon gamma in stimulated human peripheral blood mononuclear cells and shift the Th1/Th2 balance towards Th2

Apoptotic cells are readily recognized and engulfed by phagocytes and usually do not induce inflammation or tissue damage. Furthermore, they can actively suppress a pro-inflammatory response in phagocytes: In the presence of apoptotic cells, activated monocytes/macrophages produce more of the anti-inflammatory and immunoregulatory cytokines IL-10 and TGF-beta, but less of the pro-inflammatory cytokines TNFalpha, IL-1beta and IL-12. This immunoregulatory effect is most likely mediated by several receptors on monocytes/macrophages including the thrombospondin receptor (CD36). In addition to the modulation of cytokine secretion, apoptotic cell material inhibited the expression of MHC class II molecules on the surface of monocytes/macrophages. Decreased MHC II expression appeared to be mediated predominantly by increased IL-10 secretion in a para-/autocrine manner. Here, we show that the functional modulation of antigen-presenting monocytes/macrophages by apoptotic cells also influences T cell activation and function. When human peripheral blood mononuclear cells were stimulated with recall antigens in the presence of apoptotic cells, interferon gamma (IFN gamma) secretion was markedly suppressed, whereas secretion of the Th2 cytokine IL-4 was not significantly altered. Hence, apoptotic cells shift the T cell cytokine secretion pattern towards a Th2-like response. This Th2 shift can largely be prevented by neutralizing IL-10, indicating an important role of this cytokine for modulating T cell cytokine secretion patterns.