脆弱类杆菌脂多糖对正常人外周血单个核细胞分泌白细胞介素的影响

目的　通过研究脆弱类杆菌脂多糖 (LPS)对正常人外周血单个核细胞 (PBMC)分泌白细胞介素 2 (IL 2 )和白细胞介 4素 (IL 4 )的影响 ,探讨脆弱类杆菌感染的机制。　方法　采用脆弱类杆菌临床分离菌和标准菌株 (NCTC9343)提取的LPS ,以不同浓度作用于PBMC ,2 4h后收集培养细胞上清 ,运用ELISA法检测其IL 2和IL 4的含量变化。　结果　脆弱类杆菌LPS对正常人PBMC分泌IL 2有显著抑制作用 ,并呈明显的浓度依赖关系 (r=0 .80 2 4 ,P <0 .0 1)。脆弱类杆菌LPS对正常人PB MC分泌IL 4有显著刺激作用 (P <0 .0 5 ) ,但无浓度依赖关系。脆弱类杆菌临床分离菌与标准菌株LPS对正常人PBMC分泌IL 2和IL 4具有相同效应 ,两组之间无明显差异 (r =0 .10 95 ,P >0 .0 5 )。　结论　脆弱类杆菌LPS对正常人PBMC分泌IL 2有抑制作用 ,而对IL 4的分泌有刺激作用     

In vitro effects of monophthalates on cytokine expression in the monocytic cell line THP-1 and in peripheral blood mononuclear cells from allergic and non-allergic donors

It has recently been shown that plasticizers are present in indoor air dust, which may lead to human exposure via the inhalation route. Moreover, studies have indicated that plasticizers may possess adjuvant effects increasing the health damaging potential of allergens. The aim of this study was to investigate the in vitro effect of metabolites of phthalate plastisizers, such as whether an adjuvant effect is paralleled by changes of the cytokine expression in the monocytic cell line THP-1 and in peripheral blood mononuclear cells (PBMCs) from allergics and non-allergics. The toxicity monitored by cell viability was determined by incubating THP-1 cells with a 10-fold dilution series of monophthalates for 24 h. At different points in time cytokine expression (IL-1β, IL-6, IL-12 (p35)) in THP-1 cells incubated with non-toxic concentrations of monophthalate (2–20 μg/ml)±LPS (1 μg/ml) were determined using Quantitative Competitive RT-PCR. PBMCs from allergics and non-allergics were incubated with monophthalate 220 μg/ml) for up to 48 h and cytokine expression (IL-4, IL-5, IFN-γ) was measured using real-time PCR. The cytotoxic level of monophthalates is 20–200 μg/ml, depending on the individual monophthalate. There seems to be a correlation between increasing side-chain length and toxicity. Monophthalates did not induce changes in cytokine expression in THP-1 cells, though there is an increase when co-incubating with LPS. Cytokine expression in PBMC seems virtually unchanged when co-incubated with monophthalate, though mono-n-butyl phthalate (MBUP) tends to increase the level of IL-4 in PBMCs from allergic individuals. The two cellular models demonstrated the dynamics of regulated cytokine mRNA and are applicable for in vitro immunotoxicological investigations. The results regarding monophthalates suggest these to have a limited effect on cytokine expression in the monocytic cell line THP-1 and weak effect on cytokine expression in PBMCs from allergic and non-allergic individuals.     

Influence of immunosuppressive drugs on the CD30 molecule in kidney transplanted patients

Background

Soluble CD30 (sCD30) is a suggested marker for kidney transplantation outcomes. We investigated whether sCD30 serum levels are influenced by immunosuppression and whether they correlate with findings in protocol biopsies and with CD30 gene expression in peripheral blood mononuclear cells (PBMC).

Biomarkers of immune tolerance in liver transplantation

The liver exhibits intrinsic immune tolerogenic properties that contribute to a unique propensity toward spontaneous acceptance when transplanted, both in animal models and in humans. Thus, in contrast to what happens after transplantation of other solid organs, several years following liver transplantation a significant subset of patients are capable of maintaining normal allograft function with histological integrity in the absence of immunosuppressive drug treatment. Significant efforts have been put into identifying sensitive and specific biomarkers of tolerance in order to stratify liver transplant recipients according to their need for immunosuppressive medication and their likelihood of being able to completely discontinue it. These biomarkers are currently being validated in prospective clinical trials of immunosuppression withdrawal both in Europe and in the United States. These studies have the potential to transform the clinical management of liver transplant recipients by mitigating, at least in part, the burden of lifelong immunosuppression.     

Increased T cell immunosenescence and accelerated maturation phenotypes in older kidney transplant recipients

Older kidney transplant recipients experience increased rates of infection and death, and less rejection, compared with younger patients. However, little is known about immune dysfunction in older compared with younger kidney transplant recipients and whether it is associated with infection. We evaluated T cell phenotypes including maturation, immune senescence, and exhaustion in a novel investigation into differences in older compared with younger patients receiving identical immune suppression regimens.We evaluated PBMC from 60 kidney transplant recipients (23 older and 37 matched younger patients) by multiparameter immune phenotyping. Older kidney transplant recipients demonstrated decreased frequency of naïve CD4+ and CD8+ T cells, and increased frequency of terminally differentiated, immune senescent, and NK T cells expressing KLRG1. There was a trend towards increased frequency of T cell immune senescence in patients experiencing infection in the first year after transplantation, which reached statistical significance in a multivariate analysis.This pilot study reveals immune dysfunction in older compared with younger transplant recipients, and suggests a likely mechanism for increased vulnerability to infection. The ability to assess T cell maturation and immune senescence in transplant recipients offers the potential for risk stratification and customization of immune suppression to prevent infection and rejection after transplantation.     

Regulatory T cell abundance and activation status before and after priming with HIVIS-DNA and boosting with MVA-HIV/rgp140/GLA-AF may impact the magnitude of the vaccine-induced immune responses

Background

Little is known about regulatory CD4 T cells (Tregs) in the context of HIV vaccines. Tregs can be differentiated into resting (FoxP3⁺CD45RA⁺ – rTregs), activated (FoxP3^HighCD45RA^? – aTregs) and memory (FoxP3^LowCD45RA^? – mTregs). Tregs, as CD4 T cells, are also frequent targets for HIV infection. We studied how the abundance and phenotypes of Tregs in terms of activation status and expression of HIV-1 binding molecules would have changed during vaccination in healthy volunteers participating in a phase IIa HIV vaccine clinical trial. Subjects were primed three times with HIVIS-DNA and boosted twice with MVA-CMDR-HIV alone (n?=?12) or MVA-CMDR combined with protein CN54rgp140 (n?=?13). The proportions of β7 integrin in all CD4 T cells and in the Tregs subset decreased moderately after the final vaccination (p?=?0.001 and p?=?0.033, respectively) and the rTregs proportion within the total Tregs were also decreased after the final vaccination (p?=?0.038). All these proportions returned to normal values within the three months after the final vaccination. The magnitude of HIV-Envelope-specific IFNγ?+?T cells after vaccination (r?=?0.66; p?=?0.021) correlated directly with the proportion of Tregs, and correlated inversely correlated with ratios of Th17/Tregs (r?=??0.75; p?=?0.0057) and Th17/mTregs (r?=??0.78; p?=?0.0065). Higher titers of IgG gp140 antibodies were observed in subjects with higher mTregs proportions (r?=?0.52; p?=?0.022). Interestingly, pre-vaccination levels of mTregs correlated with vaccine-induced Env-binding antibodies (r?=?0.57; p?=?0.01) and presence of neutralizing antibodies (r?=?0.61; p?=?0.01), while the pre-vaccination Th17/mTregs ratio correlated inversely with the magnitude of cellular IFN-γ ELISpot responses (r?=??0.9; p?=?0.002). Taken together, these results suggest that pre- and post-vaccination Tregs, their activation status, the Th17/Tregs ratio and other host factors affecting Treg abundance, have an impact on the magnitude of HIV vaccine-induced immune responses. Moreover, the DNA-HIVIS/MVA-HIV regimen, alone or in combination with CN54rgp140 induced moderate and temporary alterations of the Tregs activation status. We also show a decrease in expression of the HIV-1 ligand β7 integrin on Tregs and all CD4 T cells.     

The effects of systemic treatment with aminobisphosphonates and statins on circulating Vγ9Vδ2-T cells in patients with advanced cancer

Aminobisphosphonates (NBP) are used for treatment of metastatic bone disease. Frequently, patients undergoing NBP-treatment experience side-effects, known as acute phase response (APR), resulting from cytokine production by Vγ9Vδ2-T cells. As opposed to NBP, statins reduce intracellular phosphoantigen levels and prevent NBP-induced Vγ9Vδ2-T cell activation in vitro. We conducted a pilot study in patients with (bone-)metastasized malignancies receiving NBP-treatment and evaluated the phenotype and function of circulating Vγ9Vδ2-T cells in vivo and the effects of statins on Vγ9Vδ2-T cell responses and the associated APR. We observed reduced expression of perforin, granzyme B and HLA-DR on Vγ9Vδ2-T cells in patients treated with NBP and statins. However, statins could not prevent NBP-induced changes in circulating Vγ9Vδ2-T cell numbers or production of IFNγ and TNFα. Consistent with this, simvastatin could not prevent the occurrence of APR upon NBP-infusion. These observations call for the exploration of alternative strategies to prevent collateral APR upon NBP treatment.     

Macrophages from disease resistant B2 haplotype chickens activate T lymphocytes more effectively than macrophages from disease susceptible B19 birds

Resistance to respiratory pathogens, including coronavirus-induced infection and clinical illness in chickens has been correlated with the B (MHC) complex and differential ex vivo macrophage responses. In the current study, in vitro T lymphocyte activation measured by IFNγ release was significantly higher in B2 versus B19 haplotypes. AIV infection of macrophages was required to activate T lymphocytes and prior in vivo exposure of chickens to NP AIV plasmid enhanced responses to infected macrophages. This study suggests that the demonstrated T lymphocyte activation is in part due to antigen presentation by the macrophages as well as cytokine release by the infected macrophages, with B2 haplotypes showing stronger activation. These responses were present both in CD4 and CD8 T lymphocytes. In contrast, T lymphocytes stimulated by ConA showed greater IFNγ release of B19 haplotype cells, further indicating the greater responses in B2 haplotypes to infection is due to macrophages, but not T cells. In summary, resistance of B2 haplotype chickens appears to be directly linked to a more vigorous innate immune response and the role macrophages play in activating adaptive immunity.     

Immunoassay and molecular methods to investigate DNA methylation changes in peripheral blood mononuclear cells in HIV infected patients on cART

This study aimed to investigate the influence of antiretroviral therapy on methylation markers, in a group of HIV infected, heavily treated patients. Immune and molecular methods were used to investigate potential changes in methylation profile in DNA isolated from peripheral blood mononuclear cells collected from antiretroviral-experienced HIV infected patients and healthy controls. The percentage of 5-methylcytosine was inversely correlated with proviral DNA and active replication while DNMT1 (p = 0.01) and DNMT3A (p = 0.004) independently correlated with active viral replication. DNMT3A expression increased with total treatment duration (p = 0.03), number of antiretroviral drugs ever used (p = 0.003), and cumulative exposure to protease inhibitors (p = 0.02) even in currently HIV undetectable patients.