The synergic effects of CTLA-4/Foxp3-related genotypes and chromosomal aberrations on the risk of recurrent spontaneous abortion among a Chinese Han population

Association of cytotoxic T-lymphocyte-associated protein 4 polymorphisms with recurrent pregnancy loss: A case-control study

Background

A large proportion of cases of recurrent pregnancy loss (RPL) are associated with immunological factors.

Objective

This study investigated the association between single nucleotide polymorphisms of cytotoxic T-lymphocyte-associated protein (CTLA)-4 gene in women with a history of RPL compared to healthy women.

Materials and Methods

A case-control study was performed on 2 groups consisting of 120 healthy women with no history of abortion and at least one delivery (control) and 120 women with a history of 2 or more primary RPLs (case). In addition, 5 mL of peripheral blood sample was taken from all subjects. The frequencies of CTLA-4 rs3087243 and rs231775 polymorphisms were assayed by restriction fragment length polymorphism polymerase chain reaction and rs5742909 using the high-resolution melting real-time polymerase chain reaction method.

Results

The mean age of the women in the control and RPL groups were 30.03 ± 4.23 (range 21-37), and 28.64 ± 3.61 yr (range 20-35), respectively. Pregnancy loss numbers ranged between 2-6 in women with a history of RPL, and between 1 and 4 in the successful pregnancy group. Statistical analysis showed a significant difference between the genotypes of GG and AG in the 2 groups in rs3087243 polymorphism (OR 1.00 for GG genotype and OR 2.87 for AG genotype, p = 0.0043). No significant difference was observed in the genotype frequencies of rs231775 and rs5742909 polymorphisms, of the 2 groups (p = 0.37, and p = 0.095), respectively.

Conclusion

Our findings indicated that CTLA-4 polymorphism, rs3087243, might be associated with a risk of RPL in Iranian women.

Role of polymorphisms on the Recurrent Pregnancy Loss: A systematic review, Meta-analysis and bioinformatic analysis

Recurrent miscarriage (RM) is a major reproductive health issue. RM is a multi-factorial disease, and is affected by environmental, genetic, and epigenetic factors. Genetics has a common role in recurrent miscarriage occurrence. It seems that molecular genetics has a great role in RSA incidence. So, in these years, RM has become for a major subject of genetics research. There are many genes that are involved in each phase for successful reproduction. This research aimed to evaluate the effect of all studied polymorphisms in studies on RSA that have not been included in any meta-analysis. PubMed, Scopus, and Web of Science databases were recruited to investigate the related articles. The systematic review results identified 143 studies worldwide. Thirteen genes have been included in assessing the case-control studies. Sixty-four SNPs were recruited to assess the association between genetic factors and RSA susceptibility. Ninety-two studies containing twenty two SNPs (from 10 genes) were included in the quantitative analysis. Bioinformatic analysis indicated that rs12722482 showed "Damaging Status" by double servers, and rs315952 and rs854560 had "Possibly damaging" status in the PolyPhen-2 server. MethPrimer server indicated that there is "CpG Island" in the rs10895068, rs1130355, and rs41557518 variants, and rs10895068-G allele makes a CpG dinucleotide which can change the gene methylation and result in altering the gene expression. So, further studies on rs12722482 and rs10895068 can demonstrate valuable results. To the best of our knowledge, this systematic review has covered the all studied polymorphisms of HLA-C, HLA-G, PON1, AGTR1, TAFI, FAS, FAS-L, ESR1, PGR, CTLA-4, MMP-2, MMP-3, MMP-9, and IL1RN for the first time. Also, we did a novel meta-analysis for AGTR1 rs5186, TAFI rs1926447, rs3742264, HLA-G rs1063320, rs1233334, rs1736936, rs2249863, PON1 rs662, rs854560, FAS rs2234767, rs1800682, FAS-L rs763110, ESR1, rs9340799, rs3798759, PGR rs1042838, CTLA4 rs4553808, rs5742909, rs231775, rs3087243, and MMP-2 rs243865 and updated statistical finding for rs2234693 and rs371194629. Rs2234693, rs9340799, rs231775, and rs371194629 demonstrated a significant association with RSA risk. Some variations showed significant association, while further studies are suggested to confirm the results. Finally, Rs4553808 and rs5742909 revealed no significant deviation in the results. It is suggested that these SNPs may be excluded from subsequent case-control studies or other analyses.

Human forkhead box protein 3 gene variants associated with altered susceptibility to idiopathic recurrent pregnancy loss: A retrospective case-control study

BACKGROUND

The pathogenesis of recurrent pregnancy loss (RPL) is multifactorial and not completely elucidated. Dysregulated immunity was implicated with RPL, in which regulatory T cells (Tregs) are key. As Tregs development and function are regulated by forkhead box P3 (FOXP3) transcription factor, and as FOXP3 expression is genetically determined, a role for FOXP3 polymorphisms in RPL pathogenesis was suggested.

AIM

To investigate the association of rs2294021, rs2232365, rs3761548, and rs141704699 FOXP3 variants with idiopathic RPL in Lebanese women.

METHODS

This retrospective case-control study included 386 RPL cases and 398 age-matched control women. Logistic odds ratios (OR) were estimated with 95% confidence interval after adjustment; a significance value of P<.05 was set.

RESULTS

Significantly lower rs22944021 and rs2232365 minor allele frequency (MAF) was found in patients with idiopathic RPL in comparison with the control group. Furthermore, statistically significantly lower frequency of heterozygous and homozygous rs2294021 and rs2232365 genotypes was seen in controls, while significantly lower rs3761548 heterozygous genotype frequencies were found in the patient group. Obesity, antihypertension treatment, smoking, positive RPL family history, abortion state, and infertility treatment correlated negatively with rs2294021, while rs2232365 negatively correlated with obesity, and rs3761548 negatively correlated with infertility treatment. Marked linkage disequilibrium (LD) was noted among FOXP3 SNPs, with TGCC and CGAC haplotypes being positive, while CAAC, CACC, and TGAC haplotypes being negatively associated with RPL risk. Except for CGAC, the association of these haplotypes with RPL persisted after adjustment.

CONCLUSION

FOXP3 gene variants and haplotypes are associated with altered incidence of RPL, proposing the role of Treg in RPL pathogenesis.

Frequency of an X-Linked Maternal Variant of the Bovine FOXP3 Gene Associated with Infertility in Different Cattle Breeds: A Pilot Study

Immune adaptation plays an essential role in determining pregnancy, which has been shown to be dependent on sufficient immunological tolerance mediated by FOXP3+ regulatory T cells. Recently, an X-linked maternal single-nucleotide polymorphism (SNP), located 2175 base pairs upstream of the start codon in the bovine FOXP3 gene (NC_037357.1: g.87298881A>G, rs135720414), was identified in Japanese Black (JB: Bos taurus) cows in association with recurrent infertility. However, with the exception of JB cows, the frequency of this SNP has yet to be studied in other cow populations. In this study, we thus aimed to evaluate the frequency of this SNP in different cow breeds. Between 2018 and 2021, a total of 809 DNA samples were obtained from 581 JB, 73 Holstein Friesian (HF: B. taurus), 125 Korean Hanwoo (KH: B. taurus coreanae), and 30 Indonesian Madura (IM: a crossbreed between B. indicus and B. javanicus) cows, which were genotyped using a TaqMan probe-based real-time polymerase chain reaction assay designed in this study. The frequency of the G allele was found to be relatively high in local IM (0.700), moderate in dairy HF (0.466), and low in beef JB (0.250) and KH (0.112) cows, with differences in the frequencies between each group being shown to be statistically significant (p < 0.005) using Fisher’s exact test. The results obtained in this study indicate that the G allele frequencies of the identified the SNP differ markedly in different breeds of taurine and indicine cattle. Given these findings, it would thus be important to evaluate the relationships between high frequencies of the G allele and infertility in different breeds.

Next generation of immune checkpoint molecules in maternal-fetal immunity

Successful pregnancy is a unique situation requires the maternal immune system to recognize and tolerate a semi-identical fetus and allow normal invasion of trophoblast cells. Although efforts have been made, the deep mechanisms of the maternal-fetal crosstalk have not yet been fully deciphered. Immune checkpoint molecules (ICMs) are a group of negative modulators of the immune response that avoid immune damage. They have been extensively studied in the fields of oncology and transplantation, while the latest evidence suggests that they are closely associated with pregnancy outcomes via multiple inhibitory mechanisms. Although studies have mostly demonstrated the regulatory role of the well-known PD-1, CTLA-4 at the maternal-fetal interface, what is unique about the newly discovered multiple ICMs remains a mystery. Here, we review the latest knowledge on ICMs, focusing on the first generation of checkpoints (PD-1, CTLA-4) and the next generation (Tim-3, Tigit, Lag-3, VISTA) highlighting their immunoregulatory roles in maternal-fetal tolerance and decidual vascular remodeling, and their involvement in pathological pregnancies. The content covers three aspects: the characteristics they possess, the dynamic expression profile of their expression at the maternal-fetal interface, and their involvement in pathological pregnancy. In immunotherapy strategies for pregnancy complications, upregulation of immune checkpoints may play a role. Meanwhile, the impact on pregnancy outcomes when using ICMs in clinical cancer treatment during pregnancy is a topic worth exploring. These may serve as a guide for future basic research and clinical applications of maternal-fetal immunity.

Polymorphisms Within DNA Double-Strand Breaks Repair-Related Genes Contribute to Structural Chromosome Abnormality in Recurrent Pregnancy Loss

Background: Structural chromosome abnormality (SCA) is an important cause of human diseases, including recurrent pregnancy loss (RPL). DNA double-strand breaks (DSBs) repair-related genes play critical roles in SCA. The present study aims to investigate the potential contribution of DSBs repair-related gene polymorphisms to SCA.

Methods: Fifty-four affected RPL individuals with SCA, 88 affected RPL individuals without SCA, and 84 controls were analyzed. Targeted whole-exome sequencing (WES) was used for screening single nucleotide polymorphisms in six DSBs repair-related genes (EP300, XRCC6, LIG4, XRCC4, PRKDC, and DCLRE1C), and validation was performed by Sanger sequencing. Finally, we detected the frequency of radiation-induced chromosome translocations in no SCA samples with significant polymorphisms by fluorescence in situ hybridization (FISH).

Results: A total of 35 polymorphisms have been identified and confirmed. Frequencies of EP300 rs20551, XRCC6 rs132788, and LIG4 rs1805388 were significantly different between SCA RPL and no SCA RPL (p = 0.030, 0.031, and 0.040 respectively). Frequencies of those three gene polymorphisms between SCA RPL and controls also were significantly different (p = 0.017, 0.028, and 0.029 respectively). Moreover, the frequency of the G allele at rs20551 locus, the T allele at rs132788 locus and the A allele at rs1805388 locus was significantly higher in SCA RPL than no SCA RPL (OR = 3.227, p = 0.005; OR = 1.978, p = 0.008 and OR = 1.769, p = 0.036 respectively) and controls (OR = 7.130, p = 0.000; OR = 2.157, p = 0.004; OR = 2.397, p = 0.003 respectively). Additionally, the frequency of radiation-induced translocation in no SCA samples with rs20551, rs132788 or rs1805388 was significantly higher compared with the wild type samples (p = 0.015, 0.012, and 0.007 respectively).

Conclusion: Our results suggest that rs20551, rs132788, and rs1805388 might be associated with the risk of SCA. Larger scales of genetic variations studies and functional experiments are necessary to further confirm these findings.

Immune checkpoints and reproductive immunology: Pioneers in the future therapy of infertility related Disorders?

As co-stimulatory receptors, immune checkpoint molecules are found on the surface of various immune cells and transduce inhibitory signals following ligand binding. The most studied members in this regard include PD-1, TIM-3, and CTLA-4. The physiological part immune checkpoints possess is the prevention of dangerous immune attacks towards self-antigens throughout an immune response, which takes place through the negative regulation of the effector immune cells, through the induction of T-cell exhaustion, for instance. It has recently been suggested that each checkpoint reduces immunoactivation via distinct intracellular mechanisms of signaling. Regulators of immune checkpoints are supposed to participate actively in immune defense mechanisms against infections, preventing autoimmunity, transplantation, and tumor immune evasion. In pregnancy, as an active immunotolerance mechanism which is also natural, the maternal immune system encounters two simultaneous challenges; in addition to accepting the semi-allogeneic fetus, the maternal immune system should also prevent infections. In this regard, the part immune checkpoint molecules possess is particularly interesting. Herein, the current understanding of such part in reproductive immunology is described.

Association of Human forkhead box protein 3 (FOXP3) gene polymorphisms with idiopathic recurrent pregnancy loss among Kazakhstani women

BACKGROUND

Recurrent pregnancy loss (RPL) is major pregnancy complication, with poorly defined cause.Forkhead Box P3 (FOXP3) is a transcription factor that supports Treg activation and development and attenuates immune responses. As FOXP3 production is genetically determined, we tested the association of FOXP3 gene variants with RPL.

METHODS

A retrospective case-control study, performed between April 2019 and February 2020. Study subjects comprised 62 RPL cases and 60 control women. Genotyping of the four FOXP3 variants rs2294021 (T > C), rs2232365 (G > A), rs3761548 (C > A), and rs141704699 (C > T) was done by real-time PCR, with defined clusters. Logistic odds ratios (ORs) of RPL risk were estimated with 95% confidence interval (CI) after adjustment; statistical significance set at P < 0.05.

RESULTS

Minor allele frequency (MAF) of rs2294021 was significantly lower [P < 0.001; OR(95% CI) = 0.25(0.11-0.55)], while rs2232365 MAF was significantly higher [P = 0.045; OR(95% CI) = 1.85(1.05-3.28)] in cases, hence assigning RPL-protection and -susceptibility to these variants, respectively. Increased RPL risk was seen in rs2232365 homozygous minor allele carrying genotype [OR(95% CI) = 5.14(1.01-26.15)], while reduced RPL risk was noted in rs2294021 heterozygous [OR(95% CI) = 0.30(0.11-0.80)], and homozygous minor allele [OR(95% CI) = 0.10(0.01-0.83)] genotype carriers. Moderate linkage disequilibrium analysis was seen between the tested variants. Increased frequency of TACC, and reduced frequency of CGAC haplotypes were seen in RPL cases when compared to controls, thereby assigning RPL susceptibility and protection to these haplotypes, respectively.

CONCLUSION

These results suggest that FOXP3 variants and haplotypes are associated with idiopathic RPL, suggesting the likely contribution of Treg to RPL.

A sequencing study of CTLA4 in Pakistani rheumatoid arthritis cases

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease. The interaction of genetic and environmental factors is likely necessary for RA. Among potential genetic factors, many major histocompatibility complex (MHC) and non-MHC variants may be involved in RA susceptibility. CTLA4 is involved in the regulation of T-cell response during an immune reaction, and multiple CTLA4 single nucleotide polymorphisms (SNPs) have been associated with numerous autoimmune diseases, including RA. To our knowledge, the genetic association of CTLA4 with RA risk has not been examined previously in the Pakistani population. In this study, we sequenced the entire CTLA4 gene and flanking regions in 95 Pakistani RA cases followed the screening of identified variants in Study 1 sample consisting of 350 RA cases and controls. Four common significant variants identified in Study 1 sample were further examined in a larger Study 2 replication sample comprising 1,678 independent RA cases and controls. We report significant associations of three variants from the combined analysis: rs3087243 (OR = 1.26, p = 4.47E-03), rs5742909 (OR = 1.78, p = 4.60E-03), and rs11571319 (OR = 1.48, p = 6.64E-03); the latter is a novel association in the Pakistani sample.

Immune Checkpoint Molecules in Reproductive Immunology

Immune checkpoint molecules, like CTLA-4, TIM-3, PD-1, are negative regulators of immune responses to avoid immune injury. Checkpoint regulators are thought to actively participate in the immune defense of infections, prevention of autoimmunity, transplantation, and tumor immune evasion. Maternal-fetal immunotolerance represents a real immunological challenge for the immune system of the mother: beside acceptance of the semiallogeneic fetus, the maternal immune system has to be prepared for immune defense mostly against infections. In this particular situation, the role of immune checkpoint molecules could be of special interest. In this review, we describe current knowledge on the role of immune checkpoint molecules in reproductive immunology.

Association among cytotoxic T-lymphocyte antigen 4 gene, rs231775 polymorphism, and recurrent pregnancy loss risk

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is expressed constitutively on regulatory T cells. So far, several studies have focused on association between CTLA-4 gene polymorphisms and recurrent pregnancy loss (RPL). However, above association between the CTLA-4 gene polymorphism and RPL susceptibility is uncertain. Therefore, we performed a timely meta-analysis of all current publications to clarify this relationship. We located articles from the PubMed and Chinese language (WanFang) databases that were published up until July 25, 2018. Finally, we obtained six case–control studies, containing 2405 total cases and 2607 total controls, based on search criteria for abortion susceptibility related to the CTLA-4 +49 G/A polymorphism. The odds ratios (OR) and 95% confidence intervals (CIs) revealed association strengths. There was significantly decreased association between this polymorphism and whole population risk (e.g. AA vs. GG: OR = 0.56, 95% CI = 0.38–0.81, P=0.002). Additionally, in ethnicity subgroups, similar association was found both in China (e.g. AA vs. GG: OR = 0.49, 95% CI = 0.39–0.63, P=0.002) and non-China (e.g. AG vs. GG: OR = 0.46, 95% CI = 0.34–0.63, P<0.001). Current analysis suggested CTLA-4 +49 G/A polymorphism may weakly decrease RPL risk for women of childbearing age.