Association of serum soluble human leukocyte antigen-G levels with chronic hepatitis B virus infection

Human leukocyte antigen-G is involved in immunotolerogenic, inflammatory and carcinogenic process. This study investigated serum soluble HLA-G (sHLA-G) levels in patients with chronic hepatitis B virus (HBV) infection according to the infection phases and clinical diagnoses. The study included 223 patients with chronic HBV infection [phases: 38 immune-tolerant (IT), 83 immune clearance (IC), 30 non/low-replicative (LR) and 72 HBeAg negative hepatitis (ENH); diagnoses: 38 asymptomatic HBV carriers (ASC), 98 chronic hepatitis (CH), 46 cirrhosis (LC) and 41 hepatocellular carcinoma (HCC)], 62 HBV infection resolvers and 66 healthy controls. The sHLA-G levels in patients were elevated compared with resolvers and healthy controls (P < 0.001). According to phases, sHLA-G levels were higher in IC and ENH than in IT (P = 0.017 and P = 0.001, respectively). Serum sHLA-G levels were also higher in ENH than in LR (P = 0.008). According to diagnoses, sHLA-G levels in HCC were significantly increased compared with LC, CH and ASC (P = 0.010, P < 0.001 and P < 0.001, respectively). Serum sHLA-G levels were higher in CH than in ASC (P = 0.039). The sHLA-G levels in IC, ENH and CH were correlated with alanine aminotransferase levels (P = 0.011, P = 0.010 and P < 0.001, respectively). It is concluded that sHLA-G is involved in the pathogenesis of chronic HBV infection and correlates with infection phases and clinical diseases, suggesting the value in evaluating disease activity and defining clinical diagnosis.     

可溶性HLA-G1与NK-92细胞表面ILT2及KIR2DL4受体相互作用的研究

 目的 探讨可溶性 HLA-G1（sHLA-G1）对人 NK-92 细胞杀伤活性的抑制与细胞表面免疫球蛋白样转录分子 2（ILT2）和杀伤细胞免疫球蛋白样受体 2DL4（KIR2DL4）受体的关系。 方法 ①通过原核表达技术获得 sHLA-G1 重组蛋白（重组蛋白），并采用蛋白质印迹法进行鉴定。②取 NK-92 细胞，加入终浓度 20 μg/ml 的重组蛋白分别培养 10、30 min，再分别加入抗 HLA-G1/G5、抗ILT2 和抗 KIR2DL4 抗体，采用流式细胞术检测各组 NK-92 细胞表面 sHLA-G1 和 ILT2、KIR2DL4 受体表达阳性率；以 NK-92 细胞单独培养作为对照组。③以人白血病 K562 细胞为靶细胞，以经不同方式处理的 NK-92 细胞为效应细胞，效靶比为5:1，共同培养 2 h，采用流式细胞术检测 NK-92 细胞对 K562 细胞的杀伤率。NK-92 细胞处理方式为单纯重组蛋白处理（分别加入终浓度为 0、10、20 μg/ml 的重组蛋白培养 30 min）和表面受体封闭 + 重组蛋白处理（分别加入抗 ILT2、抗 KIR2DL4、抗 LT2 + 抗 KIR2DL4 抗体培养 30 min，再分别加入终浓度为 0、10、20 μg/ml 的重组蛋白培养 30 min）。 结果 ①蛋白质印迹分析表明所获重组蛋白为带有组氨酸标签的特异蛋白。②NK-92 细胞与 20 μg/ml 重组蛋白共培养 30 min 后，sHLA-G1 表达阳性率明显高于而 ILT2、KIR2DL4 受体表达阳性率均明显低于对照组（均 P < 0.05）。③以终浓度 0、10、20 μg/ml 的重组蛋白处理的 NK-92 细胞对 K562 细胞的杀伤率分别为 39.79% ± 2.00%、27.79% ± 0.75%、21.36% ± 0.67%（两两比较，均 P < 0.01）；单独封闭 ILT2 受体，杀伤率分别为 23.09% ± 1.63%、21.13% ± 0.38%、18.42% ± 0.47%（两两比较，均 P < 0.01）；单独封闭 KIR2DL4 受体，杀伤率分别为 30.74% ± 0.44%、26.03% ± 0.38%、21.15% ± 0.35%（两两比较，均 P < 0.01）。 结论 sHLA-G1 通过与 NK-92 细胞表面 ILT2 和 KIR2DL4 受体直接结合而抑制 NK-92 细胞的杀伤活性。     

HCMV感染对人THP-1细胞HLA-G及其受体表达的影响

目的:研究人巨细胞病毒(HCMV)感染对人THP-1细胞人类白细胞抗原G(HLA-G)异构体及其受体表达的影响探讨HLA-G在HCMV逃逸宿主免疫应答中的作用。方法:HCMV Towne株感染THP-1细胞后,采用RT-PCR和Western blot检测HLA-G异构体mRNA和蛋白水平,流式细胞术检测THP-1细胞HLA-G及其表面受体ILT2、ILT4的表达,ELISA检测细胞培养上清中IL-10及可溶性HLA-G(sHLA-G)水平,同时检测细胞存活率。结果:HCMV感染后细胞未出现明显凋亡,细胞存活率高。HCMV感染THP-1细胞1 d后HLA-G1、-G3、-G4和-G5的mRNA表达明显上调,HLA-G1和HLA-G5的蛋白表达明显上调。THP-1细胞HLA-G、ILT2和ILT4的表达在感染1 d后明显上调。sHLA-G水平在感染1 d后显著升高,与对照组比较差异有统计学意义(P0.01)。THP-1细胞培养上清液IL-10水平在感染1 d后明显上调,与对照组比较,差异有统计学意义(P0.05)。结论:HCMV感染THP-1细胞能诱导HLA-G异构体的差异表达,以HLA-G1和HLA-G5为主,且上调其表面受体ILT2/ILT4的表达。同时,HCMV感染能诱导THP-1细胞分泌IL-10。该研究为进一步探讨HCMV逃避机体免疫应答的机制提供实验依据。     

Elevation of HLA-G-expressing DC-10 cells in patients with gastric cancer

DC-10 is a distinct subset of human tolerogenic dendritic cells (DCs) which express high levels of human leukocyte antigen-G (HLA-G). DC-10 could induce adaptive type 1 regulatory T cells through the IL-10 dependent ILT4/HLA-G signaling pathway. However, the significance of DC-10 in malignancies remains unclear. In this study, the frequency and mean fluorescence intensity (MFI) of HLA-G+ DC-10 in the peripheral blood of 124 patients with gastric cancer (GC) and 130 normal controls was analyzed with flow cytometry. Plasma sHLA-G was analyzed with ELISA. Results showed both the percentages of peripheral HLA-G+ DC-10 (median: 0.13% vs 0.01%; p < 0.01) and MFI of HLA-G on these cells (median: 310.0 vs 91.5; p < 0.01) were dramatically increased in GC patients than in normal controls. The frequency of HLA-G+ DC-10 in GC patients was strongly relative to the tumor grade (p = 0.021). sHLA-G levels in GC patients were significantly higher than in healthy controls (median: 85.80 U/ml vs 61.20 U/ml; p < 0.01). There was no significant correlation between the percentage of DC-10 and plasma sHLA-G (p > 0.05). However, the increased HLA-G+ DC-10, HLA-G MFI and plasma sHLA-G in patients with gastric cancer could be a diagnostic factor with the area under the ROC curve with 0.947 (p < 0.01), 0.882 (p < 0.01) and 0.700 (p < 0.01) respectively. Given the immune tolerant function of DC-10 could play, the increased DC-10 might play an important role in immune suppression for patients with gastric cancer, while more studies are necessary to illustrate the clinical relevance of DC-10 in cancer patients.     

Elevation of human leukocyte antigen-G expression is associated with the severe encephalitis associated with neurogenic pulmonary edema caused by Enterovirus 71

Enterovirus 71 (EV71) infection can develop devastating clinical outcomes such as brain stem encephalitis (BE) and pulmonary edema (PE). Alteration of human leukocyte antigen-G (HLA-G) expression or cytokine production was considered playing important roles in virus-related pathogenesis. However, clinical relevance of HLA-G in EV71 infection remains unknown. In the current study, patients were stratified by disease severity as BE (n = 107) and PE (n = 18). HLA-G expression on peripheral blood monocytes from patients with BE (n = 15), patients with PE (n = 15) and control subjects (n = 31) was analyzed with flow cytometry. Plasma soluble HLA-G (sHLA-G) (in 67 BE, 18 PE and 120 control subjects), IL-6 and IL-10 (in 50 patients with BE, 18 patients with PE and 45 control subjects) were determined with enzyme-linked immunosorbent assay. Data showed that the percentage of HLA-G-positive monocytes (mean 7.76 vs 3.68 %, p < 0.001), levels for sHLA-G (median 129.2 vs 70.6 U/ml, p < 0.001), IL-10 (median 160.5 vs 29.5 pg/ml, p < 0.001) and IL-6 (median 20.50 vs 5.21 pg/ml, p = 0.002) was significantly higher in patients with PE than in patients with BE. Taken together, our findings indicated that elevation of HLA-G expression on monocytes, plasma sHLA-G, IL-10 and IL-6 levels was associated with PE in patients infected with EV71.     

Human leukocyte antigen G is associated with esophageal squamous cell carcinoma progression and poor prognosis

Human leukocyte antigen G (HLA-G) is a non-classical HLA class I molecule thought to play a key role in maternal-fetal tolerance and cancer immune evasion. This study aimed to investigate the HLA-G expression in lesion sections and plasma sHLA-G levels of primary esophageal squamous cell carcinoma (ESCC) patients and its clinical significance in diagnosis and prognosis of ESCC. 60 ESCC patients and 28 healthy controls were recruited, and the positive expression of HLA-G in ESCC lesions and adjacent normal tissues were 70% (42/60) and 8.6% (5/60) (P < 0.05), respectively, while no expression was found in normal controls. HLA-G1 and HLA-G5 were determined to be dominating isoforms measured by RT-PCR. There was a significant difference in plasma sHLA-G levels between patients with ESCC (15.04 U/ml, range 4.33–250.00 U/ml) and healthy controls (6.81 U/ml, range 0–29.27 U/ml) (P < 0.01). The plasma IL-10 level was higher in ESCC patients than the controls (23.86 pg/ml vs. 12.81 pg/ml, P < 0.01). HLA-G expression in lesion tissues was correlated with cancer cell differentiation (P = 0.033), lymph node metastasis (P = 0.035) of ESCC. However, no obvious correlations were demonstrated between the plasma sHLA-G levels and the clinicopathological parameters. There was a significant correlation between sHLA-G and IL-10 expression (r = 0.353, P = 0.006) in patients with Esophageal squamous cell carcinoma. HLA-G positive expression showed poorer prognosis of ESCC. HLA-G positive expression might serve as a potential marker in the diagnosis or prediction of ESCC.     

Involvement of (IgG and IgM)-secreting B lymphocytes in severity of autoimmune hepatitis type 1

Autoimmune hepatitis type 1 (AIH1) is an autoimmune disease attacks the liver and characterized by periportal inflammation, elevated immunoglobulins, and autoantibodies. The central role of B lymphocyte in pathogenicity of AIH1 is unclear. Here, the effect of antibody-secreting cells activity in terms of number of plaque-forming cells (PFC) on severity of AIH1 was evaluated. The high number of PFC-(IgG and IgM) in peripheral blood of patients with AIH1 was observed and this was concomitant with increase in the number of CD4⁺ T lymphocyte, immunoglobulin (Ig) (IgG and IgM) concentrations, and levels of liver function tests (LFTs). However, the negative correlation (r < ?0.5, P < 0.05) between the numbers of PFC-(IgG and IgM) and CD8⁺ T lymphocytes was reported here. The present study showed the positive relationship between the concentrations of Ig (IgG and IgM) and levels of LFTs (r > +0.5, P < 0.05). The high expression of IL-10 mRNA was found in the tissue culture of peripheral blood lymphocytes obtained from patients with AIH1 as compared with that isolated from control group (P < 0.05). The current study proved the direct role of (IgG and IgM)-secreting cells in severity of AIH1. This was associated with CD4⁺ cell numbers and IL-10 mRNA expression, and mediated by IgG and IgM.     

Report of the Wet Workshop for Quantification of Soluble HLA-G in Essen, 2004

Membrane-anchored and soluble human leukocyte antigen HLA-G (sHLA-G) molecules exert strong inhibiting signals after interaction with their cognate receptors ILT2 (CD85j), ILT4 (CD85d), and KIR2DL4 (CD158d) that are differentially expressed by natural killer cells, T cells, and antigen-presenting cells. These inhibitory functions can become operative in conditions in which such immune cells try to attack viral infected or tumor cells. Recently, clinical studies showed that sHLA-G molecules are also relevant in the prediction of allograft acceptance after heart transplantation, liver-kidney cotransplantation, and the successful implantation and development of embryos after in vitro fertilization. In view of this diagnostic potential, reliable methods for the measurement of sHLA-G molecules in various body fluids are of interest. Thus, the aims of the Wet Workshop for measurement of sHLA-G held in Essen, Germany (at the Institute of Immunology October 18-20, 2004) were to select and validate HLA-G-specific enzyme-linked immunosorbent assay (ELISA) formats and purified standard HLA-G proteins, which can be easily generated and used as consensual references. To this end, the antibody combinations monoclonal antibody (mAb) MEM-G/9 (capture) + anti-beta2m (detection) and the mAb 5A6G7 (capture) + mAb W6/32 (detection) were chosen in an ELISA format for the simultaneous determination of shed HLA-G1 + soluble HLA-G5 (sHLA-G1 + HLA-G5) and for the exclusive detection of HLA-G5 molecules, respectively. As standard, protein HLA-G5 molecules were purified from insect SF9 cells coinfected by HLA-G5 + human beta2m and characterized for their antigenic determinants. A total of 24 members in 13 teams participated in the 3-day sHLA-G Wet Workshop. All workshop materials, protocols, standard reagents, and samples were provided to each team by the organizers. The Wet-Workshop results clearly demonstrated that (1) the HLA-G5 standard reagent was equally detected by both ELISA formats; (2) sHLA-G1 + G5 and HLA-G5 molecules, respectively, were specifically detected by the two ELISA formats; and (3) both ELISA formats measure reproducibly the amounts of sHLA-G. The comparison of the two ELISA results obtained evidenced that in healthy donors sHLA-G1 molecules can exist in body fluids besides HLA-G5. Moreover, a novel soluble HLA-G structure can be predicted that is recognized by the mAb 5A6G7 + mAb W6/32 antibody combination, but not by the one of mAb MEM-G/9 + anti-beta2m.     

Plasma soluble human leukocyte antigen-G expression is a potential clinical biomarker in patients with hepatitis B virus infection

The significance of upregulated soluble human leukocyte antigen-G (sHLA-G) expression under various pathologic conditions has been discussed. In this study, we evaluated the potential significance of plasma sHLA-G expression in patients with hepatitis B virus (HBV) infection. The study included 90 acute hepatitis B patients (AHB), 131 chronic hepatitis B patients (CHB), 152 resolved hepatitis B individuals (RHB), and 129 normal controls. sHLA-G were determined using enzyme-linked immunosorbent assay. A receiver operating characteristic (ROC) curve was used to evaluate the feasibility of plasma sHLA-G as a biomarker for distinguishing patients with HBV infection. sHLA-G levels in AHB (median, 193.1 U/mL; p < 0.001), CHB (median, 324.6 U/mL; p < 0.001), and RHB (median, 14.8 U/mL; p = 0.006) patients was much higher than that in normal controls (median, 9.0 U/mL). A significant difference for sHLA-G levels was also observed between patients with HBV infection (AHB vs CHB, AHB vs RHB, and CHB vs RHB; all p < 0.001). The area under the ROC curve for sHLA-G levels was 1.000 (p < 0.001) for AHB, 0.993 (p < 0.001) for CHB, and 0.604 (p = 0.003) for RHB patients versus normal controls, respectively. Data also indicated that the percentage of CD4⁺CD25⁺FoxP3⁺ T regulatory cells and HLA-G⁺CD14⁺ monocytes was significantly increased in AHB and CHB patients compared with normal controls (all p < 0.001). Our findings indicated that induction of HLA-G expression may play a role in HBV immune evasion and sHLA-G levels could be a useful biomarker in HBV infection.     

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.     

The influence of exercise training status on antigen-stimulated IL-10 production in whole blood culture and numbers of circulating regulatory T cells

Highly trained athletes are associated with high resting antigen-stimulated whole blood culture interleukin (IL)-10 production. The purpose of the present study was to examine the effects of training status on resting circulating T regulatory (T_reg) cell counts and antigen-stimulated IL-10 production and the effect of acute bout of exercise on the T_reg response. Forty participants volunteered to participate and were assigned to one of the four groups: sedentary (SED), recreationally active (REC), sprint-trained athletes and endurance-trained athletes (END). From the resting blood sample, CD4⁺CD25⁺CD127^low/? T_reg cells and in vitro antigen-stimulated IL-10 production were assessed. Ten REC subjects performed 60 min cycling at 70 % of maximal oxygen uptake and blood samples for T_reg analysis were collected post- and 1 h post-exercise. IL-10 production was greater in END compared with the other groups (P < 0.05). END had a higher T_reg percentage of total lymphocyte count compared with SED (P < 0.05). A smaller proportion of T_reg CD4⁺ cells were observed in SED compared with all other groups (P < 0.05). IL-10 production significantly correlated with the proportion of T_regs within the total lymphocyte population (r _s  = 0.51, P = 0.001). No effect of acute exercise was evident for T_reg cell counts in the REC subjects (P > 0.05). Our results demonstrate that high training loads in END are associated with greater resting IL-10 production and T_reg cell count and suggest a possible mechanism for depression of immunity commonly reported in athletes engaged in high training loads.     

Regulatory role of CCL5 (rs2280789) and CXCL10 (rs56061981) gene polymorphisms on intracellular CCL5 and CXCL10 expression in pulmonary tuberculosis

Genetic variations in chemokine genes influence the chemoattractive properties of T cells which may be associated with outcome of infections. In present study, we have investigated the regulatory role played by In1.1T/C (rs2280789) polymorphism of CCL5 and ?135G/A (rs56061981) polymorphism of CXCL10 gene on intracellular CCL5 and CXCL10 expression in T cells. Whole blood cell cultures were stimulated with culture filtrate antigen (CFA) and infected with live M. tuberculosis were used for intracellular CCL5 and CXCL10 expression using flow cytometry. Genotyping was performed using polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP). Significantly higher expression of CCL5 expressing CD3+ and CD3+ CD8+ T cells were observed in HCs with In1.1TT genotype compared to C allele carrier (TT + TC) under unstimulated and CFA induced cultures (p < 0.05). In ?135G/A (rs56061981) polymorphism, PTB patients with GG genotype showed a significantly decreased expression of CD3+ CXCL10+ and CD3+ CD4+ CXCL10+ T cells compared to A allele carrier (GA + AA) under unstimulated, CFA induced and M. tuberculosis infected cultures (P < 0.05). The present study suggest that TT genotype of CCL5 In1.1T/C (rs2280789) polymorphism play an important role to increased CCL5 expression in T cell which may enhanced Th1 immunity and help in protection against tuberculosis. The study also suggests GG genotype of CXCL10 ?135G/A (rs56061981) polymorphism decreased CXCL10 expression in T cells which may have defective recruitment of mononuclear cells at the site of infection as well granuloma formation and in turn contribute to progression of TB.     

Cytometry-based analysis of HLA-G functions according to ILT2 expression

HLA-G was described as a molecule inhibiting NK and T cells functions through its receptor, ILT2. However, most functional studies of HLA-G were so far performed on heterogeneous immune populations and regardless of ILT2 expression. This may lead to an underestimation of the effect of HLA-G. Thus, considering the immune subpopulations sensitive to HLA-G remained an important issue in the field. Here we present a new cytometry assay to evaluate HLA-G effects on both NK and CD8⁺ T cell cytotoxic functions.Using flow cytometry allows for the comparison of HLA-G function on multiple subsets and multiple functions in the same time. In particular, we sharpen the analysis by specifically studying the immune subpopulations expressing HLA-G receptor ILT2. We focused our work on: IFN-gamma production and cytotoxicity (CD107a expression) by CD8⁺ T cells and NK cells expressing or not ILT2. We compared the expression of these markers in presence of target cells, expressing or not HLA-G1, and added a blocking antibody to reverse HLA-G inhibition.This new method allows for the discrimination of cell subsets responding and non-responding to HLA-G1 in one tube. We confirm that HLA-G-specifically inhibits the ILT2⁺ CD8⁺ T cell and ILT2⁺ NK cell subsets but not ILT2-negative ones. By blocking HLA-G/ILT2 interaction using an anti-ILT2 antibody we restored the cytotoxicity level, corroborating the specific inhibition of HLA-G1. We believe that our methodology enables to investigate HLA-G immune functions easily and finely towards other immune cell lineages or expressing other receptors, and might be applied in several pathological contexts, such as cancer and transplantation.     

HLA-G genotype and HLA-G expression in systemic lupus erythematosus: HLA-G as a putative susceptibility gene in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease mainly mediated by the deposit of immune complexes and defects in T lymphocytes and antigen-presenting cells along with a high production of T-helper 2 cytokines. A tolerance-inducible function of nonclassical class Ib human leukocyte antigen (HLA)-G molecule in innate and adaptive cellular responses has been reported, suggesting a role in inflammatory diseases. A 14 bp sequence insertion/deletion polymorphism (rs16375) in the 3'-untranslated region of the HLA-G gene has been associated to the stability of HLA-G messenger RNA. The insertion of the 14 bp sequence seems to be associated with lower levels of soluble HLA-G (sHLA-G). The aim of this study was to evaluate the possible association of the presence of the 14 bp sequence (+14 bp) with SLE. We have HLA-G genotyped 200 SLE patients and 451 healthy control subjects (HS; Italian) and analyzed the plasma levels of sHLA-G and interleukin-10 (IL-10) in a subset of SLE patients and healthy subjects (Italian and Danish). A significant increase of the +14 bp HLA-G allele was detected in the Italian SLE patients compared with HS [P = 0.003, OR 1.44 (95% CI 1.13-1.82)]. A significant increased frequency of HLA-G +14/+14 bp and a decreased frequency of HLA-G -14/-14 bp were observed in SLE patients. There median concentration of sHLA-G was significantly lower in the plasma of SLE patients compared with that in the plasma of healthy controls (P < 0.0001). Furthermore, the results confirmed higher concentrations of IL-10-positive plasma in SLE patients. These results support a potential role for HLA-G in the susceptibility of SLE.     

Role of HLA-G 14bp deletion/insertion and +3142C>G polymorphisms in the production of sHLA-G molecules in relapsing-remitting multiple sclerosis

HLA-G is believed to act as an anti-inflammatory molecule in Multiple Sclerosis (MS). The 3′ untranslated region of the HLA-G gene is characterized by two polymorphisms, DEL/INS14bp and +3142C>G, which control soluble HLA-G (sHLA-G) production. The influence of these two HLA-G variants on sHLA-G serum and cerebrospinal fluid (CSF) levels was investigated in 69 Relapsing-Remitting MS patients grouped in magnetic resonance imaging (MRI) inactive and active disease. Serum and CSF sHLA-G levels were more elevated in high than in low DEL/INS 14bp and +3142C>G sHLA-G producers and were different among the various combined HLA-G genotypes in both MRI inactive and active diseases. The highest and the lowest sHLA-G values were identified in MS patients with C/C,DEL/DEL and G/G,INS/INS genotypes, respectively. Our preliminary findings suggest that serum and CSF sHLA-G levels in MS could be influenced by HLA-G polymorphisms irrespective of the inflammatory microenvironment.     

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.     

Relevance of HLA-G,HLA-E and IL-10 expression in lip carcinogenesis

HLA-G, HLA-E and IL-10 are molecules which can provide tumor immunosuppression as well as the capacity of evasion to the immune system host. This study set out to evaluate HLA-G, HLA-E and IL-10 expression in lip squamous cell carcinoma (LSCC) and in a potentially malignant disorder (actinic cheilitis – AC), correlating the expression of these proteins with the degree of epithelial dysplasia. Immunohistochemistry was undertaken to identify HLA-G, HLA-E and IL-10 in samples from patients with LSCC (n = 20), AC (n = 30) and healthy lip mucosa (control) (n = 10). A semiquantitative scoring system was used for analysis. Differences between the groups were evaluated using the Pearson Chi-Squared test. The percentage of LSCC samples showing high immunoreactivity (IRS > 2) for HLA-G, HLA-E and IL-10 (neoplastic/epithelial cells) and HLA-E (stroma/connective tissue) was significantly higher that of the control (P < 0.05). A tendency for a progressive increase in the proteins analyzed was observed from the control to AC and to LSCC. The degree of dysplasia in the AC samples was not significantly associated with the proteins evaluated (P > 0.05). The high expression of HLA-G, HLA-E and IL-10 in AC and LSCC reflects the capacity that these pathologies have for evasion and progression.