Home About us Contact
|
Home About us Contact | ||
|
|
||
HLA-G Molecule (hla-g + molecule)
Selected AbstractsA decreased positivity for CD90 on human mesenchymal stromal cells (MSCs) is associated with a loss of immunosuppressive activity by MSCs,CYTOMETRY, Issue 3 2009Diana Campioni Abstract Biologic and clinical interest in human mesenchymal stromal cells (hMSC) has risen over the last years, mainly due to their immunosuppressive properties. In this study, we investigated the basis of immunomodulant possible variability using hMSC from different sources (amniotic membrane, chorion, and bone marrow from either healthy subjects or patients with hematological malignancies, HM) and having discordant positivity for several immunological markers. The CD90+ hMSC reduced lymphoproliferative response in phytohemagglutinin (PHA) activated peripheral blood mononuclear cells (PBMC) via sHLA-G and IL-10 up-modulation. On the contrary, hMSC showing a significantly lower expression for CD90 antigen, elicited a lymphoproliferative allogeneic response in PHA/PBMCs without any increase in soluble HLA-G and IL-10 levels. These data seems to suggest that CD90 molecule may be considered a novel predictive marker for hMSC inhibitory ability, and might cooperate with HLA-G molecule in regulating suppressive versus stimulatory properties of hMSC. These results may have clinical implication in either transplantation or in regenerative medicine fields. © 2008 Clinical Cytometry Society [source] ORIGINAL ARTICLE: Soluble Human Leukocyte Antigen-G Isoforms in Maternal Plasma in Early and Late PregnancyAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2009Roberta Rizzo Problem Human Leukocyte Antigen (HLA)-G is a class Ib gene located in the human major histocompatibility complex (MHC). Several lines of investigation indicate that the HLA-G molecule is involved in the maternal acceptance of the semi-allogenic fetus during pregnancy and in the development of tolerance. Expression of soluble HLA-G (sHLA-G) is positively correlated with successful in vitro fertilization (IVF) treatments, and aberrant expression of HLA-G in certain complications of pregnancy, such as pre-eclampsia and spontaneous abortion, has been reported. The main purpose of this study was to investigate the levels of different soluble HLA-G isoforms in maternal plasma in early and late pregnancy. Method of study Soluble HLA-G (sHLA-G) can be detected in maternal blood, and in this study, two different isoforms of sHLA-G, namely sHLA-G1 generated by shedding of membrane-bound HLA-G1 and HLA-G generated by specific HLA-G transcripts, have been investigated early [median of 16.4 weeks of gestation (GW)] and late (median: 38.9 GW) in pregnancy in an original cohort of 580 pregnant Caucasian women. Results Lower concentrations of sHLA-G1 were found late in pregnancy (>32 GW) in a group of women with severe pre-eclampsia compared with controls with uncomplicated pregnancies (P = 0.029, PC = 0.09; Mann,Whitney; Logistic regression analysis: P = 0.024, OR = 0.920, 95% CI: 0.855,0.989). However, this was not the case with HLA-G5, and significantly more of the cases with severe pre-eclampsia had detectable plasma HLA-G5 compared with that of the control group (P = 0.013, PC = 0.04; Mann,Whitney). Similar findings were not observed in women with gestational hypertension or existing hypertension continuing into pregnancy. Furthermore, there was a trend toward lower maternal plasma sHLA-G1 in a group of women with premature birth (<37 GW) compared with that of the control group (P = 0.028, PC = 0.17; Mann,Whitney). On the contrary, HLA-G5 was lower in the control group compared with that in the premature group (P = 0.004, PC = 0.02; Mann,Whitney). Conclusion This study shows in line with other published studies that a high, detectable soluble HLA-G concentration in maternal plasma or serum is not mandatory for a successful pregnancy. However, complications during pregnancy, such as (severe) pre-eclampsia, spontaneous abortion, IUGR, and premature birth, are associated with a low or undetectable level of soluble HLA-G in the maternal blood circulation. Also, this study indicates that sHLA-G1 is the interesting soluble HLA-G isoform in pre-eclampsia, and that low or undetectable levels of HLA-G5 at the end of pregnancy seem to be associated with an uncomplicated normal pregnancy, whereas in severe pre-eclampsia and possibly other pregnancy complications, such as preterm birth and IUGR, the level of HLA-G5 is higher. [source] Expression of human leucocyte antigen-G primarily targets affected skin of patients with psoriasisBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2010R.N. Cardili Summary Background, The nonclassical human leucocyte antigen (HLA)-G molecule has been well recognized as a tolerogenic molecule and few studies have evaluated the role of the molecule in inflammatory cutaneous autoimmune diseases. Objectives, To evaluate the expression of HLA-G in skin specimens of patients with psoriasis and to analyse its correlation with epidemiological and clinical variables. Methods, Thirty untreated patients with psoriasis and 32 healthy individuals were enrolled. Immunohistochemistry was applied to identify HLA-G expression in formalin-fixed paraffin-embedded cutaneous skin biopsies. Results, Soluble and membrane-bound HLA-G expression was detected in 30 (90%) of the skin specimens from patients presenting clinical and histopathological features of psoriasis. Although infiltrating lymphomononuclear cells of the dermis exhibited HLA-G expression, the epidermis was primarily targeted. HLA-G expression was also observed in 27% (three of 11) of the specimens that exhibited no clinical and histopathological features of psoriasis (nonaffected areas). In contrast, skin specimens obtained from healthy individuals exhibited no HLA-G expression (P < 0·0001). The intensity of HLA-G expression was not associated with type I/II psoriasis, Psoriasis Area and Severity Index score or clinical forms. Conclusions, As the HLA-G molecule was consistently expressed in affected and, to a lesser extent, in nonaffected areas of untreated patients with psoriasis, irrespective of the severity of the clinical variants, one may hypothesize that the presence of HLA-G may be responsible, at least in part, for the regulation of autoimmune effector cells. [source] Aberrant expression of HLA-G antigen in interferon ,-stimulated acute myelogenous leukaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2000Shinichi Mizuno We have analysed the expression of HLA-G in 40 leukaemia samples of various subtypes [seven cases of acute lymphoblastic leukaemia (ALL), 28 cases of acute myelogenous leukaemia (AML), three cases of chronic myelogenous leukaemia (CML) and two cases of chronic lymphocytic leukaemia (CLL)] by flow cytometry using HLA-G-specific monoclonal antibody. No leukaemia samples expressed HLA-G without incubation with interferon (IFN)-,. However, six out of 28 (21%) AML samples expressed HLA-G upon incubation with IFN-,. These six samples derived from one out of seven M2, two out of eight M4 and three out of five M5. The results indicated that AML cells, especially myelomonocytic leukaemia samples, are capable of expressing the HLA-G molecule. [source] REVIEW ARTICLE: Anti-phospholipid Antibodies and Other Immunological Causes of Recurrent Foetal Loss , A Review of Literature of Various Therapeutic ProtocolsAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2009Shrimati Shetty Problem, An immune-based aetiology is one of the several accepted causes for recurrent foetal loss (RFL). However, most of the immunological theories have not fulfilled the criteria for causality. This is a review of the various immunological causes of RFL and the outcome of different treatment protocols. Method of study, Both auto- and alloimmune maternal immunological abnormalities have been proposed to account for foetal loss. Among the autoimmune factors, anti-phospholipid antibodies (APAs) have been demonstrated to be the strongest risk factors for foetal loss, the prevalence of which is as high as 40% in women with RFL. Other autoimmune antibodies implicated in RFL are anti-nuclear antibodies (ANAs), anti-thyroid antibodies and anti-endothelial cell antibodies. The alloimmune factors implicated in pregnancy loss of unknown aetiology include abnormal natural killer (NK) cell activity, alteration in T helper 1 (Th1) and T helper 2 (Th2) ratios, presence of alloimmune antibodies like anti-paternal cytotoxic antibodies, anti-idiotypic antibodies, mixed lymphocyte reaction blocking antibodies and abnormal expression of HLA-G molecules. Management of patients with RFL is mainly based on immunomodulatory (prednisolone, intravenous immunoglobulins, plasma exchange, paternal lymphocyte therapy), anti-aggregation (aspirin) or anti-coagulation (unfractionated or low molecular weight heparin) agents. Results, Low-molecular-weight heparin with low-dose aspirin has been found to be the most effective treatment for women with APAs and RFL. Differences in dosage, timing of treatment, inclusion criteria, outcome assessment parameters etc. are some of the factors which have resulted in discrepancies in various reports. Conclusion, Identification of the immunological mechanisms involved in pregnancy loss and the action of different therapeutic reagents is important so that effective therapies can be designed and investigated. [source] The human leucocyte antigen-G 14-basepair polymorphism correlates with graft-versus-host disease in unrelated bone marrow transplantation for thalassaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2007Giorgio La Nasa Summary The presence of the 14-bp insertion polymorphism of the human leucocyte antigen (HLA)-G gene (HLA-G) promotes immune tolerance through increased synthesis of HLA-G molecules. We investigated this polymorphism in a large cohort of 53 thalassaemia patients transplanted from an unrelated donor. Sixteen patients (30·2%) homozygous for the 14-bp deletion had a higher risk of developing acute graft-versus-host disease (aGvHD) than patients homozygous for the 14-bp insertion (,14-bp/,14-bp vs +14-bp/+14-bp: Relative Risk = 15·0; 95% confidence interval 1·59,141·24; P = 0·008). Therefore, the 14-bp polymorphism could be an important predictive factor for aGvHD following bone marrow transplantation. [source] | ||||||||||