Release of sICAM-1 in Oocytes and In Vitro Fertilized Human Embryos

Background: During the last years, several studies have reported the significant relationship between the production of soluble HLA-G molecules (sHLA-G) by 48–72 hours early embryos and an increased implantation rate in IVF protocols. As consequence, the detection of HLA-G modulation was suggested as a marker to identify the best embryos to be transferred. On the opposite, no suitable markers are available for the oocyte selection. Methodology/Principal Findings: The major finding of the present paper is that the release of ICAM-1 might be predictive of oocyte maturation. The results obtained are confirmed using three independent methodologies, such as ELISA, Bio-Plex assay and Western blotting. The sICAM-1 release is very high in immature oocytes, decrease in mature oocytes and become even lower in in vitro fertilized embryos. No significant differences were observed in the levels of sICAM-1 release between immature oocytes with different morphological characteristics. On the contrary, when the mature oocytes were subdivided accordingly to morphological criteria, the mean sICAM-I levels in grade 1 oocytes were significantly decreased when compared to grade 2 and 3 oocytes. Conclusions/Significance: The reduction of the number of fertilized oocytes and transferred embryos represents the main target of assisted reproductive medicine. We propose sICAM-1 as a biochemical marker for oocyte maturation and grading

HLA-G and inflammatory diseases.

HLA-G antigens are non classical HLA-class I molecules characterized by a low allelic polymorphism, a limited tissue distribution and the presence of membrane bound and soluble isoforms. The HLA-G antigens were firstly detected in cytotrophoblast cells at the feto-maternal interface where they maintain a tolerogenic status between the mother and the semiallogenic fetus. Recently a variable expression of HLA-G molecules has been documented in several autoimmune diseases, viral infections, cancer diseases and transplantation. Overall the presence of HLA-G molecules in both membranes bound and soluble isoforms was associated with tolerogenic functions against innate and adaptative cellular responses. HLA-G antigens are able to affect the cytotoxicity of natural killer and CD8+ T cells, CD4+ T lymphocyte functions and dendritic cell maturation. In addition to the allelic polymorphism the HLA-G gene shows a deletion/insertion polymorphism of a 14 base pairs sequence (14bp) in the exon 8 at the 3’ untranslated region. Several reports have associated the presence of the 14bp insertion allele (+14bp) to an unstable mRNA and a lower sHLA-G protein production, suggesting a different ability to counteract inflammation between genotypes. We reviewed the literature on the expression of HLA-G antigens in autoimmune and allergic diseases and the possible functional role of these molecules in counteracting inflammation

The possible role of HLA-G molecules in human oocyte/embryo secretome

Human leucocyte antigen-G (HLA-G) is a nonclassical HLA class I molecule observed for the first time in human cytotrophoblast. Several investigations have demonstrated the presence of soluble HLA-G in oocyte/embryo secretome. A focus on the possible role of HLA-G in oocyte/embryo context will be developed in this review. In addition, the possible use of HLA-G in assisted reproductive technology will be treated

In rheumatoid arthritis, a polymorphism in the HLA‐G gene concurs in the clinical response to methotrexate treatment

MTX can induce the in vitro production of circulating HLA-G molecules with interindividual differences. The highest production of sHLA-G molecules is associated with the presence of the deletion (-14/-14 bp) genotype. In rheumatoid arthritis it seems to be important to consider the concurrence of different genetic polymorphisms to help to predict the clinical respose toMTX treatment

HLA-G 14BP POLYMORPHISM REGULATES THE METHOTREXATE RESPONSE IN RHEUMATOID ARTHRITIS AND MAY BE PREDICTIVE OF RESPONSIVENESS

Background: Methotrexate (MTX) represents the most used anti-rheumatic drug in rheumatoid arthritis (RA). HLA-G antigens are inducible non classical MHC class Ib molecules important in maintaining anti-inflammatory conditions. HLA-G gene is characterized by a deletion/insertion polymorphism of 14 bp, that controls the specific mRNA stability and the protein levels. It has been reported that MTX therapy mediates an increase of Interleukin-10 (IL-10) producing cells. This cytokine up-regulates HLA-G expression. Objectives: To test the hypothesis of a MTX mediated HLA-G production and the possible relationship between the HLA-G 14 bp polymorphism and therapeutic responsiveness to MTX. Methods: Peripheral blood mononuclear cells (PBMCs) from 25 healthy subjects and 5 no-MTX-treated RA patients were activated with different MTX concentrations. sHLA-G and IL-10 production was investigated by specific immunoenzimatic assay (ELISA). HLA-G 14 bp polymorphism genotyping was also performed in 162 healthy subjects and in 156 RA patients, defined as "responders" (n=88) and "non responders" (n=68) to the MTX therapy after a 6 months therapeutic trial, on the basis of EULAR response criteria. Results: MTX activation induces the production of sHLA-G molecules. A significant association was observed between the highest sHLA-G concentrations and the -14/-14 bp genotype. The analysis of the HLA-G 14bp polymorphism in MTX treated RA patients confirmed an increase of the -14/-14 bp genotype in the responder group (p = 0.036; Fisher exact p test) (OR = 2.77 [95%CI 1.19 - 6.45] logistic regression model). Conclusion: Our results suggest that MTX induces the production of anti-inflammatory sHLA-G molecules that concur to the overall therapeutic response. Furthermore, the association between -14/-14 bp genotype and MTX responsiveness, indicates that HLA-G 14 bp polymorphism may be useful in the therapeutic decision during the early phases of the disease. A prospective study aimed to confirm these data is ongoing. References: Carosella ED, Moreau P, Aractingi S, Rouas-Freiss N. HLA-G: a shield against inflammatory aggression. Trends Immunol 2001; 10: 553-555. Hviid TV, Rizzo R, Christiansen OB, Melchiorri L, Lindhard A, Baricordi OR. HLA-G and IL-10 in serum in relation to HLA-G genotype and polymorphisms

HLA-G and IL-10 in serum in relation to HLA-G genotype and polymorhisms

The expression and importance of the non-classical human leukocyte antigen (HLA) class Ib gene, HLA-G, at the feto-maternal interface have been recognized. The HLA-G molecule is almost monomorphic and expressed in both membrane-bound and soluble isoforms. It has been shown to inhibit NK-mediated cell lysis and influence cytokine expression. Recently, a possible boarder immunoregulatory function of HLA-G also in adult life has been recognized. HLA-G gene polymorphism has been linked to differences in gene expression profile of alternatively spliced HLA-G transcripts and levels of specific HLA-G mRNA isoforms. On this background it is of general interest to further elucidate any associations between HLA-G polymorphism and protein expression. We have HLA-G genotyped 85 individuals attending IVF treatment, and further studied sHLA-G1/HLA-G5 and interleukin-10 (IL-10) in serum samples. In 21% of the serum samples sHLA-G1/HLA-G5 could be detected. There was no correlation between sHLA-G1/HLA-G5 and IL-10 concentrations in serum. Soluble HLA-G1/HLA-G5 was not detected in any samples homozygous for a 14-bp insertion polymorphism in exon 8 of the 3'-untranslated region (3'UTR) of the HLA-G gene ( P=0.03; Fisher's exact test). Polymorphisms in the 5'-upstream regulatory region (5'URR) of the HLA-G gene were also studied. In conclusion, this study indicates that polymorphisms in the 3'UTR and the 5'URR of the HLA-G gene may influence the expression of sHLA-G of possible importance in pathological pregnancies and also in organ transplantation

Can HLA-G predict disease course in rheumatoid arthritis patients?

Rheumatoid arthritis (RA) remains a major clinical problem with many patients having persistent systemic inflammatory disease resulting in progressive erosive joint damage and high levels of disability. The goal of RA therapy has shifted to initiate treatment early and aggressively to achieve remission or low disease activity as quickly as possible. To achieve this 'treat-to-target' concept it is necessary to identify new biomarkers for disease progression and treatment follow-up and of new therapeutic targets. The focus of this review is to up-date the scientific knowledge on the expression of HLA-G molecules in RA and the possible implication in the future management of the disease