Soluble human leucocyte antigen-G and interleukin-10 levels in isocyanate-induced asthma.

BACKGROUND: We previously reported that in moderate-to-severe asthma there is a deficit of IL-10 secretion that could prevent the production of soluble HLA-G (sHLA-G), a non-classical human leucocyte antigen class I molecule with tissue-protective properties in inflammatory responses. OBJECTIVE: Our objective was to investigate the production of sHLA-G and the secretion of IL-10 by peripheral blood mononuclear cells (PBMCs) in asthma induced by isocyanates and to compare the results with those obtained in non-occupational allergic asthma. METHOD: sHLA-G and IL-10 were measured by ELISA in the culture supernatants of unstimulated or lipopolysaccharide (LPS)-stimulated PBMCs obtained from 20 subjects with isocyanate asthma, 16 asymptomatic subjects exposed to isocyanates, 18 subjects with non-occupational allergic asthma, and 26 healthy control subjects. RESULTS: Occupational exposure to isocyanates was associated with high baseline levels of secretion of IL-10 by PBMCs, whether or not the exposed subjects had asthmatic symptoms. However, spontaneous production of sHLA-G by PBMC was significantly higher in subjects with isocyanate asthma compared with asymptomatic-exposed controls. In contrast, PBMCs from subjects with non-occupational allergic asthma produced sHLA-G only after LPS stimulation. CONCLUSIONS: sHLA-G production and IL-10 secretion are influenced by workplace exposure to isocyanates and by development of asthma. The different behaviour of both sHLA-G and IL-10 in asthma induced by isocyanates compared with non-occupational allergic asthma suggests a heterogeneous biological role for HLA-G molecules and for IL-10, a key cytokine of immune and inflammatory responses.

P2X7 gene polymorphisms do not appear to be a susceptibility gene locus in sporadic cases of systemic lupus erythematosus.

The P2X(7) receptor is a ligand-gated cation-selective channel that mediates ATP-induced apoptosis of cells of the immune system. A loss-of-function single nucleotide polymorphism (SNP) at position 1513 (1513 A-->C) of the P2X(7) gene has recently been identified in both healthy and chronic lymphocytic leukemia (CLL) B-cells, translating into a loss of P2X(7)-mediated apoptosis in these cells. This antiapoptotic effect results in increased B-cell numbers, thereby potentially contributing to the survival of B-CLL clones. It was hypothesized that prolonged cell survival may also predispose to induction of autoimmunity. The objective of this study is to analyze the role of the P2X(7) receptor and its loss-of-function 1513 A-->C polymorphism (SNP) in the development of systemic lupus erythematosus (SLE). DNA samples obtained from patients with sporadic SLE were analyzed for the presence of the 1513 A-->C polymorphism using polymerase chain reaction (PCR) amplification and then direct sequencing. No significant difference in allele frequencies (1513 A-->C polymorphism) between sporadic cases of SLE and controls was found. A loss-of-function SNP at position 1513 (1513 A-->C) of the P2X(7) gene does not appear to be a susceptibility gene locus for the development of sporadic SLE.

A functional role for soluble HLA-G antigens in immune modulation mediated by mesenchymal stromal cells.

BACKGROUND: It has been suggested that soluble factors produced by bone marrow (BM) mesenchymal stromal cells (MSC) play a fundamental role in mediating immune modulation. HLA-G antigens (Ag) are major histocompatibility complex (MHC) class Ib molecules characterized by a limited polymorphism and a splicing mechanism that regulates the production of membrane-bound and soluble isoforms. Interleukin-10 (IL-10) cytokine is one of the main up-modulators of soluble HLA-G Ag (sHLA-G) production by CD14+ peripheral blood monocyte cells and increased IL-10 levels are reported to be associated with MSC immune modulation. METHODS: We investigated, by specific enzyme-linked immunosorbent assay (ELISA), the possible role of sHLA-G molecules in the inhibition of the peripheral blood mononuclear cell (PBMC) response to phytohemagglutinin (PHA) mediated by MSC from different sources. RESULTS: There was a significant correlation between the presence of increased levels of sHLA-G and IL-10 in the MSC/PBMC/PHA culture supernatants and lymphoproliferative inhibition. Neutralizing experiments performed with monoclonal Ab directed against HLA-G and IL-10 molecules confirmed the inhibitory ability of sHLA-G Ag. Furthermore, exogenous IL-10 induced sHLA-G molecule secretion by MSC alone in a polymorphic way, while a longitudinal analysis confirmed the loss of MSC inhibitory functions in relation to in vitro MSC aging. DISCUSSION: Overall the results obtained suggest a functional role for sHLA-G molecules in inhibiting the PBMC response mediated by MSC. Moreover, the ability of IL-10 to induce sHLA-G Ag production by MSC alone could be proposed as a marker of MSC functional ability.

Soluble HLA-G molecules in follicular fluid: a tool for oocyte selection in IVF?

Currently, different approaches are used to select oocytes for in vitro fertilization (IVF) procedures, but they do not assure a significant association with the pregnancy outcome. Since several studies have proposed the expression of HLA-G antigens in early embryos to be a possible marker of elevated implantation rate, we have investigated the presence of soluble HLA-G molecules in 50 follicular fluids (FFs). The results have shown soluble HLA-G antigens (sHLA-G) in 19/50 (38%) FFs. Furthermore, we have related the presence of sHLA-G molecules in FFs to detection of the soluble antigens in culture supernatants of the corresponding fertilized oocyte, evidencing a significant relationship (p=1.3 x 10(-6); Fisher exact p-test). Specific ELISA and Western blot approaches identified both HLA-G5 and soluble HLA-G1 molecules in FFs while immunocytochemical analysis indicated polymorphonuclear-like and granulosa cells as responsible for production of sHLA-G1 and HLA-G5 molecules. In contrast, only sHLA-G1 antigens were detected in culture supernatants of fertilized oocytes. Overall, these results suggest a role for sHLA-G molecules in the ovulatory process and propose the FFs analysis for sHLA-G molecule presence as a useful tool for oocyte selection in IVF.

Cytolytic P2X purinoceptors.

Anecdoctal evidence accumulated over almost 20 years has shown that many different cell types are killed by sustained exposure to high concentrations of extracellular ATP. The plasma membrane receptors involved have been pharmacologically characterized and cloned during the last 3 years, and named purinergic P2X. P2X receptors share an intriguing structural relatedness with Caenorhabditis elegans degenerins and mammalian amiloride-sensitive Na channels (ENaCs). Depending on the ATP dose, length of stimulation and receptor subtype, P2X receptor stimulation may cause necrosis or apoptosis. The intracellular pathways activated are poorly known, but the perturbation in intracellular ion homeostasis clearly plays a major role. ICE proteases (caspases) are also triggered, nonetheless their activation is not requested for ATP-dependent cell death. The physiological meaning of P2X receptor-dependent cytotoxicity is not understood, but an involvement in immune-mediated reactions is postulated.

Behcet's disease associated with HLA-B51 and DRw52 antigens in Italians.

Thirty-eight Italian patients with Behcet's disease, all with ocular involvement, (28 complete type and ten incomplete) were typed for HLA A,B,DR, and DQ antigens. A significant increase of HLA-B51 (p less than 0.00001) and DRw52 (p = 0.045) with no significant difference between complete and incomplete syndrome was found. The involvement of B51 antigen as the main immunogenetic factor in the disease is suggested by the high value of relative risk (RR = 16.03). However, the association with the II class antigen DRw52 (RR = 2.77) cannot be easily explained as a secondary association due to linkage disequilibria with B51.

Failure to find a B51 IEF variant associated with Behçet's disease.

HLA B51 antigen from 8 Italian Behçet's disease (BD) patients and 8 healthy controls were analyzed by isoelectric focusing (IEF). No differences were found in the migration patterns.

Increased sensitivity of DMD lymphoblastoid cell to low doses of X-irradiation.

Several cell membrane abnormalities affecting various cell populations have been reported in Duchenne muscular dystrophy (DMD) by different investigators. In peripheral blood lymphocytes intrinsic cellular membrane defect evidentiated by impairment of capping capacities has been repeatedly obtained, suggesting that DMD product could act in such cellular phenotype at the cytoskeletal compartment. It has been previously reported that lymphoid cells are characterized by high radiosensitivity. On the assumption that DMD phenotypes could increase this susceptibility, we have compared the radiosensitivity of normal and DMD lymphoblastoid cell lines (LCLs) to small doses (0-2Gy) of x-irradiation. The results obtained suggest an increased sensitivity of DMD cells without Ca++ uptake or apoptotic phenomena, associated with an effect upon cell cycle length.

HLA B51 antigen associated with neutrophil hyper-reactivity.

HLA B51 specificity is strongly associated with Behcet's disease (BD) (for references see Baricordi et al., 1986), a multisystem vasculitis of unknown aetiology, for which an immunological pathogenesis has been proposed (O'Duffy et al., 1983; O'Duffy et al., 1990). Neutrophil abnormalities observed in BD patients even during clinical remission suggest prominent involvement of these phagocytic cells in the pathogenesis of the disease (Niwa et al., 1982). In order to clarify how HLA B51 antigen might confer susceptibility to BD, we have investigated neutrophil function in 13 B51-positive and 13 B51-negative healthy subjects. Lymphocyte spontaneous proliferation and circulating immune complexes were also evaluated. Whereas neutrophils from B51-positive subjects showed an increase in the chemotactic response toward casein (P = 0.003) and LPS (P = 0.033) and also in the PMA-induced superoxide production (P = 0.008) no evidence of enhanced lymphocyte activation emerged. These results suggest that the HLA region can exert a regulatory control on PMN functions.

Allogeneic gene-modified tumour cells in metastatic kidney cancer. Report II.

In a limited study, comprising only ten patients, we have previously reported that allogeneic irradiated RCC-cell-line cells, engineered to produce IL-2 (ACHN-IL-2), admixed with autologous metastatic formalin-treated tumour cells were used to vaccinate MRCC patients in progression of disease and also receiving IL-2 immunotherapy. The cells, admixed to autologous TC, were administered subcutaneously. We now report an extended study on thirty patients and one hundred thirty-one controls. Patients received 4-20 injections (mean 10 +/- 4), containing an average of 92 x 10(6) +/- 45 x 10(6) ACHN-IL-2 transfected cells (a minimum of 25 x 10(6), and a maximum of 200 x 10(6)). Autologous TC, admixed to allogeneic, were also administered by 4-16 s.c. injections (mean 7 +/- 3), i.e. a total of 12 x 10(6)-160 x 10(6) cells. Vaccination was administered during 73-1451 (307 +/- 316) days, and the follow-up continued for 1122 +/- 1240 days (106-5137). Throughout this period, the patients continued receiving the previously set immunotherapy treatment. No adverse side effects related to the treatment were noticed. One complete and four partial tumour responses were observed, as well as nine cases of stable disease. Thirteen patients died in the treated group (43%) and 63 (44%) in the control group. Responding patients resumed progression in 4-11 months and died 18 and 36 months after beginning the vaccine therapy. The Gehan Wilcoxon's test showed a significantly (P < 0.01) better survival in the vaccinated patients compared to that of the controls. Thus, we confirm, in an increased number of patients and an extensive follow-up, that our vaccination protocol is safe, devoid of adverse side effects, and promising.

The role of HLA--G 14-bp polymorphism in allo-HSCT after short-term course MTX for GvHD prophylaxis.

HLA-G molecules are HLA class Ib antigens characterized by tolerogenic and immunoinhibitory functions. The HLA-G 14-bp insertion/deletion (ins/del) polymorphism controls protein expression and seems to be implicated in both MTX treatment response and SCT outcome. The aim of our study is to evaluate the role of HLA-G 14 bp polymorphism in subjects affected by hematological malignancies undergoing allo-SCT and receiving MTX therapy for GvHD prophylaxis. We performed a retrospective analysis of HLA-G 14 bp polymorphism using a specific PCR in 47 recipients and in their respective donors, and evaluated the correlation with the incidence of aGvHD, OS and disease-free survival (DFS) after allo-SCT. We did not observe any correlation between this polymorphism and the risk of aGvHD occurrence. On the contrary, we found that the recipients with a 14 bp ins/14 bp ins genotype were characterized by a lower OS and DFS in univariate and multivariate analysis (OS=OR: 3.235; DFS=OR: 3.302). These data indicate a role for recipient HLA-G 14 bp polymorphism in allo-SCT immunotolerance status and follow-up.

Soluble human leukocyte antigen-g and its insertion/deletion polymorphism in papillary thyroid carcinoma: novel potential biomarkers of disease?

INTRODUCTION: Human leukocyte antigen-G (HLA-G), a nonclassical major histocompatibility complex class I antigen, plays a pivotal role in immune tolerance and a paradoxical role in cancers. AIMS: Our aims were to evaluate plasma soluble HLA-G (sHLA-G) concentrations and the 14-bp insertion/deletion polymorphism of the HLA-G gene in patients with papillary thyroid carcinoma (PTC) or Hashimoto's thyroiditis (HT) and to assess the possible association of these parameters with PTC aggressiveness. METHODS: Samples for the analysis of sHLA-G and +14/-14-bp HLA-G polymorphism were obtained from 121 patients with HT and 183 with PTC; 245 gender- and age-matched healthy subjects served as controls. PTC histopathological aggressiveness was defined according to the last American Thyroid Association guidelines. RESULTS: Positive serum antithyroid antibody titers were observed in 22% of PTC patients and lymphocyte infiltration of thyroid parenchyma at histological examination in 21%, whereas both circulating and histological autoimmunity was detectable in 12% of PTC patients. No differences in the +14/-14-bp polymorphism frequencies were observed between the study groups. The prevalence of detectable sHLA-G was lower in healthy controls (52%) as compared with both HT (57%) and PTC (62%) patients. By stratifying the study groups according to sHLA-G level of positive subjects, significantly higher plasma sHLA-G values in PTC (42.9 ± 3.3 ng/ml; P = 0.002) and HT patients (49.1 ± 2.6 ng/ml; P < 0.002) as compared with healthy controls (8.5 ± 1.8 ng/ml) were obtained. Moreover, PTC patients with detectable plasma sHLA-G levels showed a higher aggressive behavior (P < 0.04) than those without. CONCLUSIONS: Although confirming the frequent association between PTC and chronic autoimmune thyroiditis, these data suggest that elevated circulating sHLA-G levels, besides an important signal of alterations of immune homeostasis, may be considered a potential, novel marker of PTC histopathological aggressiveness at diagnosis. Additional studies are needed to confirm the actual role and clinical relevance of the HLA-G complex in PTC development and progression.

CSF levels of soluble HLA-G and Fas molecules are inversely associated to MRI evidence of disease activity in patients with relapsing-remitting multiple sclerosis.

Cerebrospinal fluid (CSF) concentrations of soluble human leukocyte antigen class I (HLA-I) (sHLA-I), HLA-G (sHLA-G) and anti-apoptotic Fas (sFas) molecules were measured by enzyme linked immunosorbent assay technique in 65 relapsing-remitting (RR) MS patients classified according to clinical and magnetic resonance imaging (MRI) evidence of disease activity. Sixty-four patients with other inflammatory neurological disorders (OIND) and 64 subjects with noninflammatory neurological disorders (NIND) served as controls. CSF concentrations were higher in RRMS and in OIND than in NIND patients for sHLA-I (P < 0.02), greater in RRMS than in OIND and in NIND for sHLA-G (P < 0.001 and P < 0.01, respectively) and lower in RRMS than in OIND and in NIND for sFas (P < 0.001 and P < 0.02, respectively). An increase in CSF levels was identified in MRI active RRMS for sHLA-I (P < 0.01) and in MRI stable RRMS for sHLA-G (P < 0.01), whereas CSF values of sFas were decreased in RRMS without Gd-enhancing lesions (P < 0.02). In MS patients with no evidence of MRI disease activity, a trend towards an inverse correlation was found between CSF concentrations of sHLA-G and sHLA-I and between CSF levels of sHLA-G and sFas. Our results indicate that enhanced CSF levels of sHLA-I antigens most likely represent an indirect manifestation of intrathecal immune activation taking place in neuroinflammation. Conversely, reciprocal fluctuations in CSF sHLA-G and sFas levels observed when MRI disease activity resolved suggest that sHLA-G could play an immunomodulatory role in MS through Fas/FasL-mediated mechanisms.

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.

Intrathecal synthesis of soluble HLA-G and HLA-I molecules are reciprocally associated to clinical and MRI activity in patients with multiple sclerosis.

The aim of this study was to provide further insight into the effective contribution of classical soluble HLA-A, B and C class Ia (sHLA-I) and non-classical soluble HLA-G class Ib (sHLA-G) molecules in immune dysregulation occurring in multiple sclerosis (MS). We evaluated by enzyme-linked immunosorbent assay (ELISA) technique intrathecal synthesis and cerebrospinal fluid (CSF) and serum levels of sHLA-I and sHLA-G in 69 relapsing-remitting (RR), 21 secondary progressive (SP) and 13 primary progressive (PP) MS patients stratified according to clinical and magnetic resonance imaging (MRI) evidence of disease activity. We also tested, as neurological controls, 91 patients with other inflammatory neurological disorders (OIND) and 92 with non-inflammatory neurological disorders (NIND). Eighty-two healthy volunteers served as further controls for sHLA-I and sHLA-G determinations. An intrathecal production of sHLA-I and sHLA-G detected by specific indexes was significantly more frequent in MS patients than in controls (P<0.01). An intrathecal synthesis of sHLA-I was prevalent in clinically (P<0.02) and MRI active (P<0.001) MS, whereas a CSF-restricted release of sHLA-G predominated in clinically (P<0.01) and MRI stable (P<0.001) MS. sHLA-I levels were low in the serum of clinically active (P<0.001) and high in the CSF of MRI active (P<0.01) MS. Conversely, sHLA-G concentrations were decreased in the serum of clinically stable MS (P<0.01) and increased in the CSF of MRI inactive MS (P<0.001). The trends towards a negative correlation observed between CSF and serum concentrations and intrathecal synthesis of sHLA-I and sHLA-G in patients without evidence of clinical and MRI activity confirmed that intrathecal production and fluctuations in CSF and serum concentrations of sHLA-I and sHLA-G were reciprocal in MS. Our results suggest that, in MS, a balance between classical sHLA-I and non-classical sHLA-G products modulating both MRI and clinical disease activity in opposite directions may exist.

Embryonic soluble HLA-G as a marker of developmental potential in embryos.

BACKGROUND: In human reproduction, embryo implantation is complex and poorly understood. At present, no single markers are used in routine treatment to assay biochemical functions of the human embryo. Soluble human leukocyte antigen-G (sHLA-G) could be considered a possible marker of embryo developmental potential. It is localized primarily on the extravillous trophoblast, making this antigen a potential mediator of immune interaction at the maternal-fetal interface during gestation. METHODS: Soluble-HLA-G levels were evaluated by an enzyme-linked immunosorbent assay (ELISA) employing monoclonal antibody MEM-G9. It was evaluated in 318 media of single embryo cultures. We correlated the presence of sHLA-G with embryo morphology and the pregnancy obtained in that treatment cycle. RESULTS: No correlation was found between embryo morphology and sHLA-G levels. Pregnancy was observed only when the medium of at least one transferred embryo contained sHLA-G. In 26 out of 66 patients, none of the obtained embryos showed any detectable sHLA-G molecules and no pregnancy occurred. CONCLUSIONS: From our results, we propose sHLA-G as a potential marker of embryo development: the sHLA-G ELISA can be a useful biochemical assay in addition to embryo morphology in embryo selection for transfer in IVF treatment if there are other embryos with the same morphology.

Enrichment of B lymphocytes from human peripheral blood by sedimentation of E rosette stabilized with dextran.

A simple method for the enrichment of B lymphocytes population from human peripheral blood by isolated of lymphocytes responsible for E rosette in presence of dextran is presented. Qualitative and quantitative results regarding the yield, the viability and the purity of the enriched population are discussed.

Transfer factor in chronic mucocutaneous candidiasis.

Fifteen patients suffering from chronic mucocutaneous candidiasis were treated with an in vitro produced TF specific for Candida albicans antigens and/or with TF extracted from pooled buffy coats of blood donors. CMI of the patients was assessed using the LMT and the LST in presence of candidine. The aim of the study was the clinical evaluation of TF treatment and the incidence of positive tests before, during, and after therapy. Immunological data were matched using the Chi square test. 87 LMT were performed for each antigen dose and at the dilution of 1/50, 58.9% (33/56) tests were positive during non-treatment or non-specific TF treatment. On the contrary 83.9% (26/31) were positive during specific TF treatment (P < 0.05). In the LST, a significant decrease of thymidine uptake in the control cultures in presence of autologous or AB serum was observed when patients were matched according to non-treatment, and both non specific (P < 0.05) and specific TF treatment (P < 0.01). Only during specific TF treatment was a significant increase of reactivity against the Candida antigen at the highest concentration noticed, when compared with the period of non specific treatment (P < 0.01). Clinical observations were encouraging: all but one patient experienced significant improvement during treatment with specific TF. These data confirm that orally administered specific TF, extracted from induced lymphoblastoid cell-lines, increases the incidence of reactivity against Candida antigens in the LMT. LST reactivity appeared not significantly increased with respect to the periods of non treatment, but was significantly increased when it was compared to the non-specific TF treatment periods. At the same time, a clinical improvement was noticed.

Hereditary hemorrhagic telangiectasy (HHT) and HLA.

Linkage between HHT and 10 genetic marker systems was investigated in a family with 7 affected members. The analysis supports the previously suggested linkage between HLA and HHT (theta = .17).

Inhibition of DNA synthesis in peripheral blood mononuclear cells treated with phosphatidylserines containing unsaturated acyl chains.

The immunosuppressive action of phosphatidylserine has been studied in mitogen-activated human peripheral blood mononuclear cells. The addition of phospholipid (10-60 nmol/10(6) cells) causes a dose-dependent inhibition of DNA synthesis induced by PHA, anti-CD3 mAb, allogeneic lymphocytes and tetradecanoylphorbol acetate plus ionomycin. In contrast, the interleukin-2-dependent DNA synthesis is less affected. Flow cytometric analysis and binding of radioiodinated interleukin-2 show that the phospholipid prevents the expression of interleukin-2 and transferrin receptors. Removal of monocytes by adherence does not change the action of phosphatidylserine. Furthermore, the phospholipid is equally effective in preparations depleted of CD4+ or CD8+ lymphocytes. Phosphatidylinositol partly reproduces the action of phosphatidylserine. Phosphatidic acid, phosphatidylglycerol and phosphatidylcholine are inactive. Also unsaturated phosphatidylserine analogues inhibit DNA synthesis whereas saturated phosphatidylserines do not. The data suggest that phosphatidylserine mainly affect the steps of T cell activation preceding the production of interleukin-2 and the expression of its receptor. The phosphorylserine headgroup and the unsaturated acyl chains contribute to this effect.