Imbalance between CD205 and CD80/CD86 in dendritic cells in patients with immune thrombocytopenia. Thromb Res. 2015;135:352-361. [PMID: 25554498 DOI: 10.1016/j.thromres.2014.11.042]

Assessing the causal relationship between circulating immune cells and abdominal aortic aneurysm by bi-directional Mendelian randomization analysis

Although there is an association between abdominal aortic aneurysm (AAA) and circulating immune cell phenotypes, the exact causal relationship remains unclear. This study aimed to explore the causal relationships between immune cell phenotypes and AAA risk using a bidirectional two-sample Mendelian randomization approach. Data from genome-wide association studies pertaining to 731 immune cell traits and AAA were systematically analyzed. Using strict selection criteria, we identified 339 immune traits that are associated with at least 3 single nucleotide polymorphisms. A comprehensive MR analysis was conducted using several methods including Inverse Variance Weighted, Weighted Median Estimator, MR-Egger regression, Weighted Mode, and Simple Median methods. CD24 on switched memory cells (OR = 0.922, 95% CI 0.914-0.929, P = 2.62e-79) at the median fluorescence intensities level, and SSC-A on HLA-DR + natural killer cells (OR = 0.873, 95% CI 0.861-0.885, P = 8.96e-81) at the morphological parameter level, exhibited the strongest causal associations with AAA. In the reverse analysis, no significant causal effects of AAA on immune traits were found. The study elucidates the causal involvement of multiple circulating immune cell phenotypes in AAA development, signifying their potential as diagnostic markers or therapeutic targets. These identified immune traits may be crucial in modulating AAA-related inflammatory pathways.

Decreased levels of immune-regulatory cytokines in patients with immune thrombocytopenia and long-lasting overexpression of these cytokines in the splenectomized patients

Immune thrombocytopenia (ITP) is an autoimmune-mediated disease characterized by decreased platelet counts. Cytokines play important roles in modulating the immune response and are involved in the pathogenesis of many autoimmune diseases. This study aimed at exploring the serum levels of a core set of cytokines that exert immune-regulatory functions in newly diagnosed ITP patients (both before and after treatment) and splenectomized ITP patients. Using the Bio-Plex suspension array system and ELISA, the serum levels of IL-10, IL-21, IL-27, IL-33, IL-35, IL-37, and TGF-β₁ were detected. The data showed that the serum levels of the immune regulatory cytokines IL-10, IL-35, and TGF-β₁ were significantly lower in newly diagnosed ITP patients. Decreased cytokine levels could be improved in patients with a complete response or a response after steroid-based treatment(s). The serum concentrations of TGF-β₁ were positively correlated with the platelet counts both before and after treatment. All the detected immune-regulatory cytokines, except IL-37, showed significantly higher levels in splenectomized ITP patients than pretreatment ITP patients and healthy controls. In conclusion, these data suggest that lower levels of immune-regulatory cytokines are involved in the pathogenesis of ITP and that there is a long-lasting overexpression of immune-regulatory cytokines in ITP patients with splenectomy.

Regulation of Th1/Th2 and Th17/Treg by pDC/mDC imbalance in primary immune thrombocytopenia

This study investigates the regulatory effect of plasmacytoid dendritic cells (pDC)/myeloid dendritic cells (mDC) imbalance on balance of Th1/Th2 and Th17/Treg in primary immune thrombocytopenia (ITP). A total of 30 untreated ITP patients and 20 healthy controls were recruited. Compared with healthy control, the pDC proportion of ITP patients was significantly reduced (P = 0.004), while the mDC proportion was not significantly changed (P = 0.681), resulting in a decrease in the pDC/mDC ratio (P = 0.001). Additionally, compared with controls, serum levels of interleukin (IL)-6, IL-12, and IL-23 were increased in ITP patients (P < 0.001), and mRNA levels of IL-12p40, IL-12p35, and IL-23p19 were also increased (P =0.014, P = 0.043, P < 0.001). Compared with the healthy control, the proportion of Th1 and Th17 cells in ITP patients increased (P = 0.001, P = 0.031). Serum levels of interferon gamma (IFN-γ) and IL-17 in ITP patients also increased (P = 0.025, P = 0.005). Furthermore, T-bet and RORγt mRNA levels were increased in peripheral blood of ITP patients (P = 0.018, P < 0.001). Correspondingly, the proportion of Th2 and Treg cells decreased (P = 0.007, P < 0.001), along with a decrease in serum IL-4 and transforming growth factor beta (TGF-β) (P = 0.028, P = 0.042), and an increase in GATA-3 mRNA (P < 0.001). However, there was no significant difference in Foxp3 mRNA levels (P = 0.587). Pearson correlation analysis showed that the proportion of total dendritic cells (DCs) was positively correlated with IL-12 (r = 0.526, P = 0.003) and IL-23 (r = 0.501, P = 0.005) in ITP patients. Th1/Th2 ratio, IFN-γ, and IL-12 levels were negatively correlated with platelet counts (r = -0.494, P = 0.009; r = -0.415, P = 0.028; r = -0.492, P = 0.032). However, IL-23 was positively correlated with IL-17 (r = 0.489, P = 0.006) and negatively correlated with platelet count (r = -0.564, P = 0.001). The ratio of IL-6 and Th17 cells was negatively correlated with platelet count (r = -0.443, P = 0.014; r = -0.471, P = 0.011). The imbalance of pDC/mDC and the increase of IL-6, IL-12, and IL-23 lead to the increased differentiation of CD4+ T cells into Th1 and Th17 cells, which might be the important mechanisms underlying the imbalance of Th1/Th2 and Th17/Treg in ITP patients.

Distinct Signatures in the Receptor Repertoire Discriminate CD56bright and CD56dim Natural Killer Cells

NK cells are phenotypically and functionally diverse lymphocytes due to variegated expression of a large array of receptors. NK-cell activity is tightly regulated through integration of receptor-derived inhibitory and activating signals. Thus, the receptor profile of each NK cell ultimately determines its ability to sense aberrant cells and subsequently mediate anti-viral or anti-tumor responses. However, an in-depth understanding of how different receptor repertoires enable distinct immune functions of NK cells is lacking. Therefore, we investigated the phenotypic diversity of primary human NK cells by performing extensive phenotypic characterization of 338 surface molecules using flow cytometry (n = 18). Our results showed that NK cells express at least 146 receptors on their surface. Of those, 136 (>90%) exhibited considerable inter-donor variability. Moreover, comparative analysis of CD56bright and CD56dim NK cells identified 70 molecules with differential expression between the two major NK-cell subsets and allowed discrimination of these subsets via unsupervised hierarchical clustering. These receptors were associated with a broad range of NK-cell functions and multiple molecules were not previously associated with predominant expression on either subset (e.g. CD82 and CD147). Altogether, our study contributes to an improved understanding of the phenotypic diversity of NK cells and its potential functional implications on a cellular and population level. While the identified distinct signatures in the receptor repertoires provide a molecular basis for the differential immune functions exerted by CD56bright and CD56dim NK cells, the observed inter-individual differences in the receptor repertoire of NK cells may contribute to a diverging ability to control certain diseases.

Cellular immune dysregulation in the pathogenesis of immune thrombocytopenia

: Immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease characterized by immune-mediated increased platelet destruction and decreased platelet production, resulting from immune intolerance to autoantigen. The pathogenesis of ITP remains unclear, although dysfunction of T and B lymphocytes has been shown to be involved in the pathogenesis of ITP. More recently, it is found that dendritic cells, natural killer, and myeloid-derived suppressor cells also play an important role in ITP. Elucidating its pathogenesis is expected to provide novel channels for the targeted therapy of ITP. This article will review the role of different immune cells in ITP.

Laparoscopic splenectomy for primary immune thrombocytopenia: Current status and challenges

Primary immune thrombocytopenia (ITP) is an immune-mediated disorder affecting both adults and children, characterised by bleeding complications and low platelet counts. Corticosteroids are the first-line therapy for ITP, but only 20%-40% of cases achieve a stable response. Splenectomy is the main therapy for patients failing to respond to corticosteroids for decades, and about two-thirds of patients achieve a long-lasting response. Although some new drugs are developed to treat ITP as second-line therapies in recent years, splenectomy is still the better choice with less cost and more efficiency. Laparoscopic splenectomy (LS) for ITP proves to be a safe technique associated with lower morbidity and faster recovery and similar hematological response when compared to traditional open splenectomy. Based on the unified hematological outcome criteria by current international consensus, the response rate of splenectomy should be reassessed. So far, there are not widely accepted preoperative clinical indicators predicting favorable response to LS. Since the patients undergoing surgery take the risk of complications and poor hematological outcome, the great challenge facing the doctors is to identify a reliable biomarker for predicting long-term outcome of splenectomy which can help make the decision of operation.

Enhancement of anti-tumor immune responses induced by ligand-mediated biomimetic Texosomes

In order to overcome the immune tolerance and awake the tumor patients’ self immune response, hTERT-HSP70 as a universal tumor antigen is specifically transferred to dendritic cells by DEC205McAb Texosomes as the carriers of a tumor vaccine.