Genetic regulation of cervical antiinflammatory cytokine concentrations during pregnancy

Spontaneous preterm birth: Involvement of multiple feto-maternal tissues and organ systems, differing mechanisms, and pathways

Survivors of preterm birth struggle with multitudes of disabilities due to improper in utero programming of various tissues and organ systems contributing to adult-onset diseases at a very early stage of their lives. Therefore, the persistent rates of low birth weight (birth weight < 2,500 grams), as well as rates of neonatal and maternal morbidities and mortalities, need to be addressed. Active research throughout the years has provided us with multiple theories regarding the risk factors, initiators, biomarkers, and clinical manifestations of spontaneous preterm birth. Fetal organs, like the placenta and fetal membranes, and maternal tissues and organs, like the decidua, myometrium, and cervix, have all been shown to uniquely respond to specific exogenous or endogenous risk factors. These uniquely contribute to dynamic changes at the molecular and cellular levels to effect preterm labor pathways leading to delivery. Multiple intervention targets in these different tissues and organs have been successfully tested in preclinical trials to reduce the individual impacts on promoting preterm birth. However, these preclinical trial data have not been effectively translated into developing biomarkers of high-risk individuals for an early diagnosis of the disease. This becomes more evident when examining the current global rate of preterm birth, which remains staggeringly high despite years of research. We postulate that studying each tissue and organ in silos, as how the majority of research has been conducted in the past years, is unlikely to address the network interaction between various systems leading to a synchronized activity during either term or preterm labor and delivery. To address current limitations, this review proposes an integrated approach to studying various tissues and organs involved in the maintenance of normal pregnancy, promotion of normal parturition, and more importantly, contributions towards preterm birth. We also stress the need for biological models that allows for concomitant observation and analysis of interactions, rather than focusing on these tissues and organ in silos.

Cytokines and pregnancy: Potential regulation by histone deacetylases

Cytokines are important regulators of pregnancy and parturition. Aberrant expression of proinflammatory cytokines during pregnancy contributes towards preterm labor, pre-eclampsia, and gestational diabetes mellitus. The regulation of cytokine expression in human cells is highly complex, involving interactions between environment, transcription factors, and feedback mechanisms. Recent developments in epigenetic research have made tremendous advancements in exploring histone modifications as a key epigenetic regulator of cytokine expression and the effect of their signaling molecules on various organ systems in the human body. Histone acetylation and subsequent deacetylation by histone deacetylases (HDACs) are major epigenetic regulators of protein expression in the human body. The expression of various proinflammatory cytokines, their role in normal and abnormal pregnancy, and their epigenetic regulation via HDACs will be discussed in this review.

Nucleotide variation in IL-10 and IL-12 and their receptors and cervical and vulvar cancer risk: a hybrid case-parent triad and case-control study

Given the important role of cell mediated immunity in viral clearance and control of premalignant lesions, we hypothesize that variation in the IL-12/IL-10 cytokine and cytokine receptor genes may influence cervical and vulvar cancer risk. We evaluated 76 tagSNPs from seven candidate genes (IL-10, IL-12A, IL-12B, IL-10RA, IL-10RB, IL-12RB1, and IL12RB2) in case-parent sets (n=43 cervical squamous cell carcinoma (SCC), n=96 cervical adenocarcinoma, n=53 vulvar SCC), additional cases (n=356 cervical SCC, n=406 cervical adenocarcinoma, and n=473 vulvar SCC) and population based controls (1,111). We calculated log-additive odds ratios (ORs) and 95% confidence intervals (CIs) for the association between tagSNP and cancer risk using a pseudo-likelihood based method which combined genotype information on cases, parents, and population controls. After correction for multiple comparisons, we identified several statistically significant SNP associations. Cervical SCC risk was associated with the minor alleles of the IL10RA rs9610 3' UTR SNP (OR=1.76, 95% CI=1.15-2.68) and two synonymous IL12RB2 SNPs (rs4297265, OR=0.46, 95% CI=0.26-0.82; rs2229546, OR=0.43, 95% CI=0.21-0.87). Cervical adenocarcinoma risk was associated with the minor alleles of the IL10RA rs4252314 intronic SNP (OR=2.23, 95% CI=1.26-3.96) and IL12RB1 rs11575934 non-synonymous SNP (OR=1.51, 95% CI=1.12-2.05). Finally, the minor allele of the IL12B rs3181224 3' UTR SNP was associated with a reduced risk of vulvar SCC (OR=0.30, 95% CI=0.12-0.74). These results raise the possibility that a shift in the balance of the immune response due to genetic variants in key cytokine genes could influence the development of cervical and vulvar cancer.

Trophoblast cells induce a tolerogenic profile in dendritic cells

BACKGROUND

Dendritic cells (DCs), which are biased toward a tolerogenic profile, play a pivotal role in tissue-remodeling processes and angiogenesis at the maternal-fetal interface. Here, we analyzed the effect of trophoblast cells on the functional profile of DCs to gain insight on the tolerogenic mechanisms underlying the human placental-maternal dialog at early stages of gestation.

METHODS

DCs were differentiated from peripheral blood monocytes obtained from fertile women (n = 21), in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor during 5 days in culture. Then, DCs were cultured with trophoblast cells (Swan-71 cell line obtained from normal cytotrophoblast, at 7 weeks) for 24 h and for an additional 24 h in the absence or presence of lipopolysaccharide (LPS) from Escherichia coli. DCs were recovered and used for flow cytometry, enzyme-linked immunosorbent assay, RT-PCR and suppression and migration assays.

RESULTS

Trophoblast cells significantly prevented the increase in CD83 expression induced by LPS without affecting the expression of CD86, CD40 and human leukocyte antigen-DR (P < 0.05). Trophoblast cells significantly decreased the production of IL-12p70 and tumor necrosis factor-α, while it increased the production of IL-10 (P < 0.05). No changes were observed in the production of IL-6 and monocyte chemotactic protein-1. The culture of DCs with trophoblast cells, also suppressed the stimulation of the allogeneic response triggered by LPS (P < 0.05). Conditioned DCs were able to increase the frequency of CD4 + CD25 + Foxp3 cells and this effect was accompanied by an increase in indoleamine 2, 3-dioxygenase expression in DCs (P < 0.05).

CONCLUSIONS

The interaction of DCs with trophoblast cells promotes the differentiation of DCs into cells with a predominantly tolerogenic profile that could contribute to a tolerogenic microenvironment at the maternal-fetal interface.

Baseline variation and associations between subject characteristics and five cytokine biomarkers of vaginal safety among healthy non-pregnant women in microbicide trials

Interleukins (IL)-8, IL-1α, IL-1β, and IL-1 receptor antagonist (IL-1RA) have emerged as indicators of vaginal inflammation and HIV-1 transmission risk. We provide values and factors of normal variation of these immune mediators in premenopausal women to allow their wider clinical application as biomarkers of vaginal health. Cross-sectional analyzes (Kruskal-Wallis and Wilcoxon exact tests) of cytokine concentrations in relation to sociodemographic variables and Nugent score were performed on baseline (prior to product) cervicovaginal lavage from two Phase I randomized microbicide trials. All women in the analysis had regular menstrual cycles, 72 h abstinence, normal blood and Pap tests, and absence of genitourinary infections, study-relevant allergies, antibiotics use and history of substance abuse. Cytokine norms were defined as the values among those with Nugent score <4. Among women with normal Nugent score (n=92), IL-8 and IL-1β were lowest in those using abstinence as compared to hormonal contraceptives or male/female sterilization as their primary method for birth control. No difference was found by age, prior pregnancy, or education, and also by race after controlling for contraceptive method. Women with abnormal (>7) and borderline (4-6) Nugent scores had elevated IL-1α and/or IL-1β although their IL-1RA-to-IL(α+β) ratio remained within the normal range due to higher IL-1RA. Women with borderline Nugent scores had IL-8 levels above the normal range. IL-8 and the IL-1RA-to-IL-1 ratio can be used as independent biomarkers of vaginal immune balance. More studies must determine the role of sexual activity, contraceptive method, and borderline Nugent scores, which normally are not exclusion criteria for enrollment in microbicide trials but may affect product tolerability and HIV-1 risk due to the aberrant cytokine levels.

Association between genes encoding components of the IL-10/IL-0 receptor pathway and asthma in children

BACKGROUND

Asthma is a chronic inflammation of the airways associated with recurrent symptoms that range from mild to debilitating. Interleukin-10 (IL-10) is a cytokine that displays pleiotropic effects in asthma and allergy.

OBJECTIVE

To determine whether polymorphisms of IL-10/IL-10R pathway contribute to asthma susceptibility in Egyptian children.

METHODS

The IL-10 (-1082G/A), IL-10R1 (G330R), and signal transducer and activator of transcription 3 (STAT3) rs2293452 single-nucleotide polymorphism (SNP) were genotyped in 110 atopic children with asthma, 110 non-atopic children with asthma, and 110 healthy children. Serum IL-10 and immunoglobulin E (IgE) levels were determined by enzyme-linked immunosorbent assay.

RESULTS

A significant association was observed between the IL-10 polymorphism and asthma in both atopic (P = .03) and non-atopic asthma groups (P = .04). The genotype frequencies of IL-10R1 polymorphisms did not differ between all groups. We identified a significant association between STAT3 polymorphism and asthma susceptibility in atopic asthma (P < .001), whereas no such association was observed in the non-atopic asthma group (P = .9). No evidence of gene interactions was found.

CONCLUSION

Polymorphisms of IL-10 and STAT3 may be useful as a new DNA-based diagnostic biomarker for identifying high-risk children susceptible to asthma.

Polymorphisms in the gene encoding bovine interleukin-10 receptor alpha are associated with Mycobacterium avium ssp. paratuberculosis infection status

Background

Johne's disease is a chronic inflammatory bowel disease (IBD) of ruminants caused by Mycobacterium avium ssp. paratuberculosis (MAP). Since this pathogen has been implicated in the pathogenesis of human IBDs, the goal of this study was to assess whether single nucleotide polymorphism (SNPs) in several well-known candidate genes for human IBD are associated with susceptibility to MAP infection in dairy cattle.

Methods

The bovine candidate genes, interleukin-10 (IL10), IL10 receptor alpha/beta (IL10RA/B), transforming growth factor beta 1 (TGFB1), TGFB receptor class I/II (TGFBR1/2), and natural resistance-associated macrophage protein 1 (SLC11A1) were sequenced for SNP discovery using pooled DNA samples, and the identified SNPs were genotyped in a case-control association study comprised of 242 MAP negative and 204 MAP positive Holstein dairy cattle. Logistic regression was used to determine the association of SNPs and reconstructed haplotypes with MAP infection status.

Results

A total of 13 SNPs were identified. Four SNPs in IL10RA (984G > A, 1098C > T, 1269T > C, and 1302A > G) were tightly linked, and showed a strong additive and dominance relationship with MAP infection status. Haplotypes AGC and AAT, containing the SNPs IL10RA 633C > A, 984G > A and 1185C > T, were associated with an elevated and reduced likelihood of positive diagnosis by serum ELISA, respectively.

Conclusions

SNPs in IL10RA are associated with MAP infection status in dairy cattle. The functional significance of these SNPs warrants further investigation.

Genetic association of Toll-like receptor 4 with cervical cytokine concentrations during pregnancy

Toll-like receptors (TLRs) are critical components of innate immunity, recognizing bacterial microorganisms and initiating local inflammatory responses. In this study, we assessed the impact of genetic variation in TLR genes on cervical concentrations of pro- and anti-inflammatory cytokines, and determined whether this relationship is influenced by bacterial vaginosis (BV). A total of 4 single nucleotide polymorphisms (SNPs) in TLR2 and 12 in TLR4 were examined for associations with 10 cervical pro- and anti-inflammatory cytokine concentrations in 91 African-American (AA) and 97 European-American (EA) women in the first trimester of pregnancy. In EAs, individuals with the TT genotype at rs1554973 (TLR4) had higher cervical concentrations of interleukin-1 beta (IL-1b) compared with those with the CT or TT genotypes (P=1.5 x 10(-5)), which remains significant after correction for multiple testing. This association was more significant in women with BV (P=5 x 10(-3)) than those without BV (P=0.02). This SNP was also associated with cervical concentrations of IL-1a, IL-6, IL-8 and IP10 (interferon-gamma-inducible protein 10) (P=6 x 10(-3), 0.03, 0.05, 6 x 10(-3), respectively). Our study demonstrates that TLR4 is an important mediator of pro-inflammatory cervical immune responses, particularly in EA women and especially in those with microbial disorders such as BV.

First-trimester cervical inflammatory milieu and subsequent early preterm birth

OBJECTIVE

Our objective was to explore the relation between the pro- and antiinflammatory cervical cytokine balance in early pregnancy and subsequent early preterm birth.

STUDY DESIGN

In this prospective cohort of 218 pregnant women who were enrolled in the first trimester, we assayed cervical concentrations of interleukin-1alpha, -1beta, -6, -4, -10, and -13. Based on these cytokines, we categorized subjects into 1 of 3 strata: high proinflammatory/low antiinflammatory, high antiinflammatory/low proinflammatory, or balanced. The primary outcome of interest was preterm birth at < 34 weeks' gestation.

RESULTS

Women in the high antiinflammatory/low proinflammatory stratum had a subsequent odds ratio for preterm birth < 34 weeks' gestation of 7.7 (95% CI, 4.9-9.1; P = .01), after adjustment for marital status, smoking, bacterial vaginosis, maternal race, and less than high school education.

CONCLUSION

Women with a relatively hyporesponsive cervical inflammatory milieu in early pregnancy are at higher risk of subsequent early spontaneous preterm birth.