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Biomedical subjects

Thomas Vauvert F Hviid

Publications and source records attributed to Thomas Vauvert F Hviid.

13 recordsLinked to original sources

HLA class I expression and tumor immune infiltration together shape colon cancer immune contexture.

BACKGROUND: The relative contribution of HLA class I molecules-including classical HLA class Ia (HLA-A, -B, -C) and non-classical HLA class Ib (HLA-E, -F, -G)-to shaping the tumor immune microenvironment in colon cancer remains insufficiently defined. We investigated how their expression patterns relate to immune infiltration and clinical outcome. METHODS: In a retrospective cohort of 280 colon cancers, we assessed HLA class Ia and class Ib expression and quantified CD45-positive immune cell infiltration by immunohistochemistry. These features were correlated with clinicopathological variables, microsatellite instability (MSI) status, and previously established genomic immune signatures. RESULTS: High HLA class Ia expression and increased CD45-positive cell infiltration were each associated with improved overall, disease-specific, and progression-free survival. CD45-positive density correlated strongly with Immunologic Constant of Rejection scores. HLA class Ia loss was more frequent in advanced stages and in MSI-H tumors. Among HLA class Ib molecules, only HLA-E expression was associated with favorable disease-specific and progression-free survival. Integrative analysis identified three immune phenotypes with distinct prognostic profiles; tumors characterized by high HLA class Ia expression, low HLA class Ib expression, and high CD45-positive infiltration had the best outcomes. CONCLUSION: Colon cancer immunogenicity is shaped by coordinated patterns of HLA class I expression and immune infiltration. Integrating HLA class Ia/Ib expression with immune cell density provides a refined stratification of tumor immune phenotypes and may support personalized immunotherapeutic decision-making.

Antigen presentation↗

Investigations of HLA-F and HLA-G 3'UTR Polymorphisms in Preeclampsia and Fetal Growth Restriction Indicate a Possible Role of HLA-F-HLA-G Haplotypes and Diplotypes.

HLA-F and HLA-G may be involved in the pathogeneses of preeclampsia and fetal growth restriction (FGR). However, the functions of HLA-F and HLA-G in placental dysfunction remain unclear. The aim was to investigate differences in the prevalence of specific HLA-F and HLA-G gene allelic polymorphisms, genotypes, haplotypes, and diplotypes between controls and cases with preeclampsia or FGR. In total, blood samples from 365 pregnant females (controls, n = 192; preeclampsia, n = 164; FGR, n = 19) in their second and third trimester, and corresponding cordial blood samples (reflecting newborns, n = 160) were obtained after delivery. Genomic DNA was sequenced with a focus on the specific gene polymorphisms in the HLA-F gene locus, especially the single nucleotide polymorphisms (SNPs) rs1362126 (G/A), rs2523405 (T/G) and rs2523393 (A/G), as well as the rs371194629 (14-bp ins/del) in the 3'UTR of HLA-G. Haplotype and diplotype distributions were obtained using PHASE v2.1, and linkage disequilibrium analyses were performed. SNPs in the HLA-F gene locus and the 3'UTR of HLA-G were not associated with the risk of preeclampsia or FGR. The SNPs did not correlate with fetal-placental weight ratio, deviation of birth weight at gestational age, and placental weight. However, a trend towards an absence of certain HLA-F-HLA-G extended diplotypes in preeclampsia was observed. The current study does not support associations of the investigated HLA-F SNPs with preeclampsia or FGR. However, further studies are needed to evaluate the possible role of certain fetal HLA-F-HLA-G extended haplotypes and diplotypes in preeclampsia.

Humans↗

Polymorphism in the 5' upstream regulatory and 3' untranslated regions of the HLA-G gene in relation to soluble HLA-G and IL-10 expression.

The nonclassical human leukocyte antigen (HLA) class Ib gene HLA-G may be important for the induction and maintenance of immune tolerance between the mother and the semi-allogeneic fetus during pregnancy. Expression of HLA-G can influence cytokine and cytotoxic T-lymphocyte responses. Different HLA-G mRNA isoform expression patterns have been associated with HLA-G polymorphism, especially with a 14-bp insertion deletion polymorphism in the 3' untranslated region (3'UTR) of the HLA-G gene. A significantly high level of interleukin-10 (IL-10) secretion is observed in homozygous +14/+14-bp HLA-G peripheral blood mononuclear cells after lipopolysaccharide (LPS) stimulation. This study finds that polymorphism in the 5' upstream regulatory region (5'URR) of the HLA-G gene may also be implicated in differences in IL-10 secretion. However, this may also be due to linkage disequilibrium with the 14-bp polymorphism. A single-nucleotide polymorphism located -477 bp from the start site of exon 1 had a significant association with IL-10 concentrations but not after correction (p=0.011; pc=0.154). This polymorphism is located next to a heat shock element. Eighteen 5'-URR/3'-UTR HLA-G haplotypes were defined; one common homozygous genotype based on these haplotypes was significantly associated with a high IL-10 level after LPS stimulation compared to certain other genotypes. This study indicates that polymorphism in the 5'-URR of the HLA-G gene may have functional significance, although a new line of investigations is needed to elucidate these findings.

3' Untranslated Regions↗

[Non-classical human leukocyte antigen (HLA) tissue types--from implantation to transplantation].

The classical and extremely polymorphic human leukocyte antigens (HLA) classes Ia and II have been studied in great detail and have significant importance in organ transplantation, autoimmune diseases and presentation of antigen peptides. However, in the human major histocompatibility complex (MHC), other functional HLA genes have been detected, the so-called non-classical HLA class Ib genes: HLA-E, -G and -F. They resemble the HLA class Ia antigens in many ways, but several major differences have been described. They are almost monomorphic and generally have a restricted pattern of expression. One function of HLA-E is to inhibit and modulate natural killer (NK) activity. HLA-G seems to be important in the modulation of the maternal immune system during pregnancy and thereby the maternal acceptance of the semi-allogenic foetus. HLA-G can already be detected in at least some blastocysts and probably has a role in implantation. A very strong expression of HLA-G is observed in the invasive trophoblast cells in the placenta. HLA-G may be involved in certain complications of pregnancy and the genetic predisposition to these. Finally, HLA-G expression has been associated with a reduced risk of rejection episodes in heart and kidney/liver transplants.

Autoimmune Diseases↗

CARD15 single nucleotide polymorphisms 8, 12 and 13 are not increased in ethnic Danes with sarcoidosis.

BACKGROUND: Mutations of the caspase-activating recruitment domain 15 (CARD15) gene on chromosome 16 are associated with chronic inflammatory granulomatous bowel disease (Crohn's disease). Sarcoidosis is a systemic granulomatous disease with unknown etiology, which shares histological features with Crohn's disease. OBJECTIVES: To evaluate whether ethnic Danes with sarcoidosis have an increased frequency of CARD15 mutations compared to healthy control subjects. METHODS: Genotyping for CARD15 mutations R702W, G908R, and L1007fsinsC, also designated single nucleotide polymorphism (SNP) SNP8, SNP12 and SNP13, respectively, were performed by capillary electrophoresis single-strand confirmation polymorphism in 53 patients with histologically verified sarcoidosis and in 103 healthy controls. RESULTS: The frequencies of CARD15 mutations in sarcoidosis patients were: SNP8, 4/106 chromosomes (3.8%); SNP12, 2/106 chromosomes (1.9%); SNP13, 2/106 chromosomes (1.9%); SNP8+SNP12+SNP13, 8/106 chromosomes (7.6%). All 8 patients were heterozygous. The frequencies in controls were: SNP8, 9/206 chromosomes (4.4%); SNP12, 2/206 chromosomes (1.0%); SNP13, 4/206 chromosomes (1.9%); SNP8+SNP12+SNP13, 15/206 chromosomes (7.3%). All controls were heterozygous. The differences were not statistically significant (p>0.05). Furthermore, the course of disease was not significantly different in the 8 patients with CARD15 mutations and the 45 patients without mutations. CONCLUSION: The frequency of CARD15 mutations is not increased in ethnic Danish patients with sarcoidosis, and heterozygosity for such mutations apparently has no influence on the course of disease.

Adult↗

HLA-G polymorphisms and HLA-G expression in sarcoidosis.

BACKGROUND: The MHC class Ib molecule Human Leukocyte Antigen (HLA)-G may be important in induction and maintenance of immunological tolerance, and HLA-G expression may have a role in different cancers, in certain diseases with associations to HLA, and in organ transplantation. Sarcoidosis is a systemic granulomatous disease with unknown etiology but at the molecular level several studies have shown HLA associations. METHODS: In the present study, HLA-G alleles/polymorphisms were studied in sarcoidosis patients (n = 47) and controls (n = 129) by PCR techniques and HLA-G protein expression was investigated in granulomas from sarcoidosis patients with the use of immunohistochemistry. RESULTS: The HLA-G*010102/-G*0106 alleles were observed more often in sarcoidosis patients (39.4%) than in controls (26.4%), p = 0.025 (Fisher's exact test); however, not significant after correction (p(c) = 0.15). When HLA-G expression was investigated by immunohistochemistry in granulomas from sarcoidosis patients, weak HLA-G expression was observed in only one patient. CONCLUSIONS: HLA-G alleles that include a 14-bp sequence polymorphism in exon 8 of the HLA-G gene are observed more often in sarcoidosis patients than in controls. The sequence variation may influence HLA-G mRNA stability and influence the expression of soluble isoforms of HLA-G. Only rare and weak expression of HLA-G was observed in granulomas from sarcoidosis patients. More studies are needed to further elucidate the possible role for HLA-G in sarcoidosis.

Adult↗

HLA-G in human reproduction: aspects of genetics, function and pregnancy complications.

The non-classical human leukocyte antigen (HLA) class Ib genes, HLA-E, -G and -F, are located on chromosome 6 in the human major histocompatibility complex (MHC). HLA class Ib antigens resemble the HLA class Ia antigens in many ways, but several major differences have been described. This review will, in particular, discuss HLA-G and its role in human reproduction and in the human MHC. HLA-G seems to be important in the modulation of the maternal immune system during pregnancy and thereby the maternal acceptance of the semiallogenic fetus. Recent findings regarding aspects of HLA-G polymorphism, the possible significance of this polymorphism in respect to HLA-G function and certain complications of pregnancy (such as pre-eclampsia and recurrent spontaneous abortions (RSA)) are discussed together with possible importance to IVF. Finally, aspects of a possible role of HLA-G in organ transplantation and in inflammatory or autoimmune disease, and of HLA-G in an evolutionary context, are also briefly examined.

Female↗

The HLA-G genotype is associated with IL-10 levels in activated PBMCs.

Human leukocyte antigen (HLA)-G is an MHC class Ib molecule that is expressed at the feto-maternal interface during pregnancy. However, recent results have also shown that it may have important functions as an immuno-modulatory factor in adult life. Differences in the pattern of alternative splicing and in the stability of HLA-G mRNA transcripts have been associated with HLA-G polymorphisms, especially a 14 bp deletion/insertion polymorphism in the 3' untranslated region of the HLA-G gene. We have investigated the secretion of HLA-G5/soluble HLA-G1 and interleukin-10 (IL-10) in lipopolysaccharide (LPS)-activated peripheral blood mononuclear lymphocytes (PBMCs) in relation to the HLA-G 14 bp genotype. No HLA-G5/sHLA-G1 could be detected in the non-activated control PBMC culture media, and there were no significant differences among the three HLA-G 14 bp genotypes regarding IL-10 concentrations. In LPS-activated PBMC cultures, no significant differences among the three HLA-G 14 bp genotypes regarding HLA-G5/sHLA-G1 concentrations were observed. However, this was in contrast to the IL-10 levels (P=0.0004, Kruskal-Wallis test). The +14/+14 bp PBMC samples expressed higher levels of IL-10 when compared to the -14/+14 bp genotype and the -14/-14 bp genotype. Interestingly, the IL-10 G/G polymorphism at position -1082 was more frequent in the +14/+14 bp genotype (P=0.024, chi2 test). These results support an autocrine loop between HLA-G5/sHLA-G1 and IL-10 expression in activated PBMCs, which may result in higher IL-10 levels in +14/+14 bp HLA-G genotypes.

3' Untranslated Regions↗

Linkage disequilibrium between human leukocyte antigen (HLA) class II and HLA-G--possible implications for human reproduction and autoimmune disease.

A line of investigation indicates that one or several genes in the human major histocompatibility complex (MHC) influences reproductive success. Studies have revealed associations between human leukocyte antigen (HLA) class II genes and risk of recurrent spontaneous abortion (RSA) and pre-eclampsia. However, these genes are not expressed at the feto-maternal interface. Furthermore, associations between polymorphisms in the nonclassical HLA class Ib gene, HLA-G, and reproductive outcome have been demonstrated. HLA-G is expressed by extravillous trophoblast during pregnancy, making it a more obvious candidate gene for a possible influence on pregnancy outcome. HLA-G has immunomodulatory functions. We have studied linkage disequilibrium between HLA class II genes, primarily HLA-DRB1 alleles, and HLA-G alleles in women with RSA and their partners (n = 103) and in control women and their partners (n = 92). We found a significant linkage disequilibrium between HLA-DR3 and HLA-G*010102 in both the RSA and control populations. For all four studied HLA loci, the alleles in the haplotype HLA-DRB1*03.DQA1*05.DQB1*02.G*010102 was in clear linkage disequilibrium. This HLA haplotype has repeatedly been associated with different autoimmune diseases but also with RSA. The G*010102 allele includes a 14-bp sequence polymorphism in the 3' untranslated region of the gene, which has been associated with differences in HLA-G mRNA alternative splicing and stability. This 14-bp polymorphism has also been associated with RSA, pre-eclampsia, and outcome of in vitro fertilization. Implications of HLA polymorphism--and other polymorphic genes in the MHC for pregnancy outcome--and for autoimmune diseases during pregnancy are discussed.

Abortion, Habitual↗

HLA-G and IL-10 in serum in relation to HLA-G genotype and polymorphisms.

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.

3' Untranslated Regions↗

Association between HLA-G genotype and risk of pre-eclampsia: a case-control study using family triads.

Pre-eclampsia affects 2-7% of all pregnancies with varying severity and is a leading cause of maternal and fetal mortality and morbidity. The aetiology involves almost certainly a combination of genetic predisposition with maternal and fetal contributions and environmental factors. Research points towards pathologies in the placenta as the triggering factor which leads to systemic endothelial dysfunction in the mother, probably as the result of interaction with released placental factors circulating in the maternal blood. One prominent hypothesis regarding the aetiology of pre-eclampsia suggests that it is caused by immune- maladaptation. The MHC class Ib gene, HLA-G, is expressed in the placenta and seems to have immunomodulatory functions. Aberrant HLA-G mRNA and protein expression in pre-eclamptic placentas have been reported. Here, we have investigated detailed HLA-G genotypes in a case-control study of 155 family triads of mother, father and newborn. Among primiparas, an overrepresentation of a homozygous HLA-G genotype was detected in the 40 pre-eclamptic offspring compared to the 70 controls [P = 0.002, Fisher's exact test; odds ratio 5.57 (95% CI 1.79-17.31)]. Further analyses suggested that the differences between pre-eclamptic cases and controls primarily were accomplished by a different transmission from the father of a 14 bp deletion/insertion polymorphism in exon 8 (P = 0.006, Fisher's exact test), which previously has been linked to differences in the levels of HLA-G expression and in HLA-G mRNA splicing. The results may also indicate that combined mother-child HLA-G genotypes could influence the risk of developing pre-eclampsia. Overall, the study suggests that HLA-G genotypes and expression might have a significant influence on development of pre-eclampsia.

Case-Control Studies↗

HLA-G expression in placenta in relation to HLA-G genotype and polymorphisms.

PROBLEM: The expression of the non-classical human leukocyte antigen (HLA) class Ib gene, HLA-G, seems to be important at the feto-maternal interface. The HLA-G molecule is almost monomorphic and expressed in both membrane-bound and soluble isoforms. It has been shown to inhibit natural killer cell -mediated lysis and influence cytokine expression. 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 messenger RNA (mRNA) isoforms. Furthermore, aberrant HLA-G expression has been reported in preeclamptic placentas. On this background it is of general interest to further elucidate any associations between HLA-G polymorphism and protein expression. METHODS: We have investigated HLA-G protein expression by immunohistochemistry in HLA-G genotyped placentas from term. HLA-G mRNA expression in preeclamptic placentas and in control placentas was also studied by microarray technology. RESULTS AND CONCLUSIONS: The studies of HLA-G protein expression in term placentas by immunohistochemical analysis showed no clear associations with HLA-G genotypes although this could be because of the very semi-quantitative nature of this technique. However, we found a tendency towards reduction of HLA-G mRNA expression in placentas from preeclamptic cases compared to matched controls with the use of microarray technology.

Biopsy↗

HLA-G allelic variants are associated with differences in the HLA-G mRNA isoform profile and HLA-G mRNA levels.

During pregnancy, the human extra-villous trophoblast in the contact zone between maternal and fetal tissue in the placenta does not express the classical MHC class I and II molecules. Instead, HLA-G and -C, and possibly HLA-E, are expressed. HLA-G may modulate the immunological relationship between mother and fetus in several ways. Finally, the expression of membrane-bound HLA-G and soluble HLA-G has been proposed to influence the outcome of pregnancy, and an aberrant HLA-G expression in pre-eclamptic placentas and spontaneous abortions has been reported. Here, an association between certain HLA-G polymorphisms and the mRNA levels of the different alternatively spliced HLA-G isoforms in first trimester trophoblast cell populations is reported. Several alternatively spliced HLA-G mRNA isoforms, including a 14-bp polymorphism in the 3'UTR end (exon 8) of the HLA-G gene, are expressed at a significantly lower level than the corresponding HLA-G mRNA isoforms with the 14-bp sequence deleted. Furthermore, characteristic HLA-G mRNA isoform expression patterns were associated with specific HLA-G genotypes and alleles. In the HLA-G*01012 and - G*01013 alleles that include the 14-bp sequence, an additional alternative splicing was observed, with the first 92-bp of exon 8 spliced out. This was most pronounced in HLA-G genotypes with G*01013. These findings may have functional implications for the recent reports of aberrant HLA-G expression and reproductive success.

Alternative Splicing↗