The prognostic impact of soluble and vesicular HLA-G and its relationship to circulating tumor cells in neoadjuvant treated breast cancer patients

The non-classical human leukocyte antigen G (HLA-G) molecule and its soluble forms exert multiple immune suppressive regulatory functions in malignancy and in stem cells contributing to immune escape mechanisms. HLA-G can be secreted as free soluble HLA-G molecules or via extracellular vesicles (EVs). Here we evaluated these soluble HLA-G forms as prognostic marker for prediction of the clinical outcome of neoadjuvant chemotherapy (NACT) treated breast cancer (BC) patients. Plasma samples of BC patients procured before (n = 142) and after (n = 154) NACT were quantified for total soluble HLA-G (sHLA-G_tot) and HLA-G levels in ExoQuick™ derived EV fractions (sHLA-G_EV) by ELISA. The corresponding increments were specified as free sHLA-G (sHLA-G_free). Total and free sHLA-G were significantly increased in NACT treated BC patients compared to healthy controls (n = 16). High sHLA-G_free levels were exclusively associated to estrogen receptor expression before NACT. Importantly, high sHLA-G_EV levels before NACT were related to disease progression and the detection of stem cell-like circulating tumor cells, but high sHLA-G_free levels indicated an improved clinical outcome. Thus, this study demonstrates for the first time that the different sHLA-G subcomponents represent dissimilar qualitative prognostic impacts on the clinical outcome of NACT treated BC patients, whereas the total sHLA-G levels without separating into subcomponents are not related to clinical outcome.     

HLA-G haplotype structure shows good conservation between different populations and good correlation with high,normal and low soluble HLA-G expression

HLA-G molecule has considerable impact in various clinical fields, therefore many studies attempted to predict its expression based on HLA-G genotype. These studies have focused on polymorphisms in either the coding region or in one of the two untranslated regions (UTR) of the gene. The aim of our study was to determine if HLA-G haplotype defined based on SNPs 5′ and 3′UTR could be used to predict soluble HLA-G expression in unstimulated individuals. Our findings showed that HLA-G haplotype structure was well conserved between distant populations and that the defined haplotypes were correlated with high, normal and low HLA-G soluble secretors. In conclusion, we showed that this genotyping strategy based on the use of a few selected SNPs rather than isolated SNP analysis allows reliable HLA-G expression in all populations. This strategy could be useful in a number of clinical settings, e.g., predicting graft compatibility immunogenetic laboratories.     

Total expression of HLA-G and TLR-9 in chronic lymphocytic leukemia patients

Suppressed immune status facilitates immune escape mechanisms that allow chronic lymphocytic leukemia cells to proliferate and expand. The expression of HLA-G could effectively inhibit the immune response. In immune response inhibitory signals follow activation of immune system which might be occur during bacterial or viral infection in CLL patients. In the current study we characterized two components of immune system, inhibitory molecule HLA-G with its receptor – CD85j and Toll-like receptor 9.     

Embryo selection criteria based on morphology VERSUS the expression of a biochemical marker (sHLA-G) and a graduated embryo score: prediction of pregnancy outcome

Purpose  

To compare pregnancy and implantation rates when embryos are selected based on a single Day 3 (D 3) morphology score vs. a GES score plus sHLA-G expression.     

Implications of uterine NK cells and regulatory T cells in the endometrium of infertile women

A range of studies have shown that the complex process of implantation and an establishment of a pregnancy also involves immune factors. Disturbances in these underlying immune mechanisms might lead to implantation and pregnancy failure and may be involved in the pathogenesis of unexplained infertility. Several studies have reported that imbalances in uterine NK (uNK) cell abundance are associated with infertility; however, controversies exist. An increased amount of CD56⁺ uNK cells along with a decrease in CD16⁺ uNK cells have been associated with normal fertility in some studies. Very few studies of FoxP3⁺ regulatory T cells (Tregs) in the pre-implantation endometrium have been performed. Results are sparse and controversial, studies reporting both increased and decreased numbers of Tregs, respectively, in women suffering from infertility. In conclusion, studies imply that uNK cells, Tregs and HLA-G carry pivotal roles regarding the establishment of a healthy pregnancy, and that abnormal immune mechanisms involving these parameters may be associated with infertility. However, more research in early phases of the reproductive cycle, such as investigating the conditions in the endometrium before implantation, is needed to further clarify the underlying mechanisms.     

Overexpression of immunomodulatory mediators in oral precancerous lesions

Human leukocyte antigen (HLA) G and E, programmed cell death 1 ligand 1 (PD-L1), IL-10 and TGF-β are proteins involved in failure of the antitumor immune response. We investigated the expression of these immunomodulatory mediators in oral precancerous lesions (oral leukoplakia-OL; n = 80) and whether these molecules were related to the risk of malignant transformation. Samples of normal mucosa (n = 20) and oral squamous cells carcinoma (OSCC, n = 20) were included as controls. Tissue and saliva samples were analyzed by immunohistochemistry and ELISA respectively. Fifteen OL samples showed severe dysplasia (18.7%) and 40 samples (50%) presented combined high Ki-67/p53. Irrespective of the degree of epithelial dysplasia and the proliferation/apoptosis index of OL, the expression of HLA-G, -E, PD-L1, IL-10, TGF-β2 and -β3 was higher to control (P < 0.05) and similar to OSCC (P > 0.05). The number of granzyme B⁺ cells in OL was similar to control (P = 0.28) and lower compared to OSCC (P < 0.01). Salivary concentrations of sHLA-G, IL-10 and TGF-β did not allow for a distinction between OL and healthy individuals. Overexpression of immunosuppressive mediators in the OL reflects the immune evasion potential of this lesion, which is apparently independent of at cytological and proliferation/apoptosis status.     

Human leukocyte antigen (HLA)-G during pregnancy part I: Correlations between maternal soluble HLA-G at midterm,at term,and umbilical cord blood soluble HLA-G at term

Human leukocyte antigen (HLA)-G is a class Ib molecule with restricted tissue distribution expressed on trophoblast cells and has been proposed to have immunomodulatory functions during pregnancy. Soluble HLA-G1 (sHLA-G1) can be generated by the shedding of membrane-bound HLA-G molecules; however, three soluble isoforms also exist (HLA-G5 to -G6). During pregnancy, it is unknown whether there is a correlation between sHLA-G levels in maternal and fetal blood. In 246 pregnancies, we have measured the levels of sHLA-G1/-G5 in maternal blood plasma samples from gestational week 20 (GW20) and at term, as well as in umbilical cord blood samples. Soluble HLA-G levels declined by 38.4% in maternal blood from GW20 to term, and sHLA-G levels were significantly lower in maternal blood at term than in GW20 (P < 0.001). At term, the sHLA-G levels were significantly higher in maternal blood than in umbilical blood (P < 0.001). HLA-G levels in maternal blood in GW20 and at term, and in maternal blood at term and umbilical cord blood, were correlated (P < 0.001 and P < 0.01, respectively). This is the first large study simultaneously measuring sHLA-G in both maternal and umbilical cord blood. The finding that sHLA-G levels are significantly lower in fetal compared with maternal blood at term documents for the first time that sHLA-G is not freely transferred over the placental barrier. Soluble HLA-G levels in maternal and fetal blood were found to be correlated, which may be due to shared genetic factors of importance for production of sHLA-G in the mother and child, or it may support the theory that sHLA-G in the pregnant woman and the fetus is partly derived from a “shared organ”, the placenta.     

Human leukocyte antigen (HLA)-G during pregnancy part II: Associations between maternal and fetal HLA-G genotypes and soluble HLA-G

Human leukocyte antigen (HLA)-G is a class Ib molecule with restricted tissue distribution expressed on the extra-villous trophoblast and seems to have immunomodulatory functions during pregnancy. Studies have linked HLA-G polymorphisms to pregnancy complications such as preeclampsia and recurrent miscarriage. Levels of soluble HLA-G (sHLA-G) in blood plasma from non-pregnant donors seem to be associated with these polymorphisms. In the current study, we have genotyped 246 mothers and their offspring for HLA-G polymorphisms in the 3′-untranslated region (3′UTR) and measured sHLA-G in maternal blood plasma samples from gestational week 20 and at term, as well as in fetal umbilical cord blood samples. This is the first large study simultaneously performing HLA-G genotyping of mother and offspring and measuring sHLA-G in both maternal and umbilical cord blood. The results showed that increasing numbers of 14 bp ins (rs66554220) alleles in the mother–child genotype combinations were associated with higher maternal sHLA-G levels at term when restricting the analysis to 14 bp ins/del heterozygous mothers (p = 0.015). Furthermore, increasing numbers of 14InsG haplotypes (14 bp ins/del and +3142C/G (rs1063320) polymorphism) in mother–child genotype combinations were associated with higher levels of sHLA-G at term in heterozygous 14DelC/14InsG mothers (p = 0.005). In conclusion, the results indicate that there is an association between combined feto-maternal HLA-G genotypes and sHLA-G levels in maternal blood plasma.     

Soluble human leucocyte antigen-G molecules in peripheral blood haematopoietic stem cell transplantation: a specific role to prevent acute graft-versus-host disease and a link with regulatory T cells

Haematopoietic stem cell transplantation is often complicated by the life-threatening graft-versus-host disease (GVHD) which consists of an allogeneic reaction of the graft cells against the host organs. The aim of this study was to investigate the putative involvement of soluble human leucocyte antigen (sHLA) class I molecules, and particularly sHLA-G molecules, in the occurrence and/or prevention of acute GVHD (aGVHD) in allogeneic peripheral blood stem cell (PSC) transplantation. Whole sHLA class I molecules seem to be involved in aGVHD pathogenesis because detection of a high concentration of these molecules in the first month post allograft is correlated with aGVHD occurrence. Conversely, a high level of sHLA-G molecules before and after allograft could indicate good prognosis in PSC allograft transplantation. sHLA-G molecules seem to be involved in aGVHD prevention, not only because they are enriched in plasma of patients without aGVHD, but also because: (i) a positive correlation has been found between sHLA-G level and CD4+ CD25+ CD152+ natural regulatory T cell (T(reg)) frequency in the blood of transplanted patients; and (ii) the presence of CD4+ CD25+ CD152+ natural T(reg) is correlated with increased sHLA-G expression in in vitro mixed leucocyte reaction cultures. Altogether, these results support the immunomodulatory function of sHLA-G molecules that might create a regulatory network together with the natural T(reg) to foster the induction of a tolerogenic environment and improve PSC transplantation favourable outcome.     

噬血细胞综合征患者血清sHLA-G表达及其临床意义

本研究旨在探讨血清可溶性人类白细胞抗原G(sHLA-G)在噬血细胞综合征(HPS)患者中的表达水平及临床意义。收集2008年9月至2010年7月经首都医科大学附属北京友谊医院确诊的HPS患者23例,根据不同病因分为感染相关性HPS、肿瘤相关性HPS和风湿免疫病相关性HPS,同时收集25例健康人血清,分别采用酶联免疫吸附(ELISA)法检测患者及健康人血清sHLA-G水平,并与各实验室检查指标进行相关性分析。结果表明,HPS患者组血清sHLA-G水平高于健康对照者,差异有显著统计学意义(p=0.003),对HPS患者组中不同病因人群进行单因素方差分析,差异无统计学意义(p=0.233)。检测HPS患者血清sHLA-G水平与采血当日WBC、Hb、Plt、ALT、AST、LDH、ALB、TBil、DBil、IBil、Cr、BUN、TG、纤维蛋白原、铁蛋白的相关性发现,其与血小板水平呈正相关关系,与其他各项实验室指标均无相关性。结论:血清sHLA-G水平在HPS患者中升高可能有多种原因,包括感染、肿瘤、T淋巴细胞过度活化以及一些细胞因子的刺激等,sHLA-G还可以抑制NK细胞活性,导致异常免疫风暴形成,在HPS的发病...