Postpartum-activation of multiple sclerosis is associated with down-regulation of tolerogenic HLA-G

Prominent epigenetic and transcriptomic changes in CD4+ and CD8+ T cells during and after pregnancy in women with multiple sclerosis and controls

BACKGROUND

Multiple sclerosis (MS) is a neuroinflammatory disease in which pregnancy leads to a temporary amelioration in disease activity as indicated by the profound decrease in relapses rate during the 3rd trimester of pregnancy. CD4⁺ and CD8⁺ T cells are implicated in MS pathogenesis as being key regulators of inflammation and brain lesion formation. Although Tcells are prime candidates for the pregnancy-associated improvement of MS, the precise mechanisms are yet unclear, and in particular, a deep characterization of the epigenetic and transcriptomic events that occur in peripheral T cells during pregnancy in MS is lacking.

METHODS

Women with MS and healthy controls were longitudinally sampled before, during (1st, 2nd and 3rd trimesters) and after pregnancy. DNA methylation array and RNA sequencing were performed on paired CD4⁺ and CD8⁺ T cells samples. Differential analysis and network-based approaches were used to analyze the global dynamics of epigenetic and transcriptomic changes.

RESULTS

Both DNA methylation and RNA sequencing revealed a prominent regulation, mostly peaking in the 3rd trimester and reversing post-partum, thus mirroring the clinical course with improvement followed by a worsening in disease activity. This rebound pattern was found to represent a general adaptation of the maternal immune system, with only minor differences between MS and controls. By using a network-based approach, we highlighted several genes at the core of this pregnancy-induced regulation, which were found to be enriched for genes and pathways previously reported to be involved in MS. Moreover, these pathways were enriched for in vitro stimulated genes and pregnancy hormones targets.

CONCLUSION

This study represents, to our knowledge, the first in-depth investigation of the methylation and expression changes in peripheral CD4⁺ and CD8⁺ T cells during pregnancy in MS. Our findings indicate that pregnancy induces profound changes in peripheral T cells, in both MS and healthy controls, which are associated with the modulation of inflammation and MS activity.

The HLA-G Immune Checkpoint Plays a Pivotal Role in the Regulation of Immune Response in Autoimmune Diseases

The human G-leukocyte antigen (HLA-G) molecule is a non-classical major histocompatibility complex (MHC) class I molecule. The pertinence of HLA-G has been investigated in numerous studies which have sought to elucidate the relevance of HLA-G in pathologic conditions, such as autoimmune diseases, cancers, and hematologic malignancies. One of the main goals of the current research on HLA-G is to use this molecule in clinical practice, either in diagnostics or as a therapeutic target. Since HLA-G antigens are currently considered as immunomodulatory molecules that are involved in reducing inflammatory and immune responses, in this review, we decided to focus on this group of antigens as potential determinants of progression in autoimmune diseases. This article highlights what we consider as recent pivotal findings on the immunomodulatory function of HLA-G, not only to establish the role of HLA-G in the human body, but also to explain how these proteins mediate the immune response.

Pregnancy-Induced Changes in microRNA Expression in Multiple Sclerosis

Pregnancy affects the disease course in multiple sclerosis (MS), particularly in the third trimester, where the relapse rate is reduced by as much as two thirds. This study aimed at identifying changes in microRNA (miRNA) and immune cell phenotypes in pregnant MS patients. Discovery and validation studies to detect differentially expressed miRNAs were performed with quantitative real-time PCR on peripheral blood mononuclear cells (PBMC). Flow cytometry analysis was performed on PBMC stained with antibodies directed against surface markers of antigen presenting cells (APCs), NK-cells, NKT cells, CD4+ and CD8+ T cells and subsets of these cell types, including PDL1 and PDL2 expressing subsets. RNA was extracted from whole blood, monocytes, and NK-cells to investigate expression and correlation between regulated miRNAs and mRNAs. In total, 15 miRNAs were validated to be differentially expressed between third trimester pregnant and postpartum MS patients (Benjamini-Hochberg false discovery rate from p = 0.03–0.00004). Of these, 12 miRNAs were downregulated in pregnancy and 6 of the 15 miRNAs were altered by more than ±2-fold (+2.99- to -6.38-fold). Pregnant MS patients had a highly significant increase in the percentage of monocytes and a decrease of NK-cells and myeloid dendritic cells compared to non-pregnant MS patients. We confirm previous reports of a relative increase in CD56-bright NK-cells and a decrease in CD56-dim NK-cells in third trimester of pregnancy and report an increase in non-committed follicular helper cells. PDL1 and PDL2 expression was increased in pregnant patients together with IL10. Also, in monocytes IL10, PDL1, and PDL2 were upregulated whereas miR-1, miR-20a, miR-28, miR-95, miR-146a, miR-335, and miR-625 were downregulated between pregnant and untreated MS patients. IL10, PDL1, and PDL2 were predicted targets of MS pregnancy-changed miRNAs, further supported by their negative correlations. Additionally, previously identified pregnancy-regulated mRNAs were identified as predicted targets of the miRNAs. PDL1 and PDL2 bind PD-1 expressed on T cells with an inhibitory effect on T-cell proliferation and increase in IL10 production. These results indicate that some of the effects behind the disease-ameliorating third trimester of pregnancy might be caused by changed expression of miRNAs and immunoregulatory molecules in monocytes.

Caring for Women with Multiple Sclerosis Across the Lifespan

PURPOSE OF REVIEW

Caring for women with multiple sclerosis (MS), whose first symptoms typically begin during the childbearing years, requires a comprehensive approach to management across a range of reproductive exposures, and beyond through menopause.

RECENT FINDINGS

This article summarizes what is known about the disease course in women with MS, how it differs from men, and the current state of knowledge regarding effects of reproductive exposures (menarche, childbearing, menopause) on MS-related inflammation and neurodegeneration. Recent findings regarding pregnancy-associated relapses in the treatment era, protective effects of breastfeeding, and care for women during the menopausal transition are reviewed. Then, updated recommendations to guiding women during childbearing-including pre-conception counseling, discontinuation of MS therapies, and management of postpartum relapses-are provided. Whenever possible, areas of uncertainty and avenues for future research are highlighted. From childhood through the postreproductive life stages, gender and hormonal exposures appear to shape an individual's risk for MS, as well as the experience of living with MS.

Why monkeys do not get multiple sclerosis (spontaneously): An evolutionary approach

The goal of this review is to apply an evolutionary lens to understanding the origins of multiple sclerosis (MS), integrating three broad observations. First, only humans are known to develop MS spontaneously. Second, humans have evolved large brains, with characteristically large amounts of metabolically costly myelin. This myelin is generated over long periods of neurologic development—and peak MS onset coincides with the end of myelination. Third, over the past century there has been a disproportionate increase in the rate of MS in young women of childbearing age, paralleling increasing westernization and urbanization, indicating sexually specific susceptibility in response to changing exposures. From these three observations about MS, a life history approach leads us to hypothesize that MS arises in humans from disruption of the normal homeostatic mechanisms of myelin production and maintenance, during our uniquely long myelination period. This review will highlight under-explored areas of homeostasis in brain development, that are likely to shed new light on the origins of MS and to raise further questions about the interactions between our ancestral genes and modern environments.

Hormones and MS: Risk factors, biomarkers, and therapeutic targets

Sex differences in epidemiological, clinical, and pathological features of multiple sclerosis (MS) have been observed for decades, establishing a foundation for more recent progress in our understanding of their overall impact on the disease. In the ACTRIMS session on Hormones, Sex Chromosomes, and MS: Risk Factors, Biomarkers, and Therapeutic Targets, this progress was summarized in three presentations by pioneers in the field, revealing evidence that sex chromosomes, epigenetic factors, and sex hormones function as interactive determinants of disease risk and phenotype in a fashion dependent upon life stage, from prenatal development, childhood, and adolescence to adulthood and aging. Implications for the effects of puberty, pregnancy, menopause, and andropause on autoimmune and neurodegenerative mechanisms were discussed, along with potential applications of exogenous hormones. Although several limitations in current approaches and concepts were noted, current insights pave the way for future progress in our understanding of this enigmatic disease

Hormonal and gender-related immune changes in multiple sclerosis

Similarly to many other autoimmune diseases, multiple sclerosis (MS) is more common among women than men, and its incidence among women is rising. There are also qualitative differences in the disease course between men and women, with male patients experiencing increased disease progression, brain atrophy, and cognitive impairment. During pregnancy, women with MS typically have a greatly reduced relapse rate, whereas very soon after the delivery, the disease activity returns, often even at a higher level than seen in the prepregnancy year. The reasons for the increased postpartum activity are not entirely clear, but factors such as the abrupt decrease in estrogen levels immediately after the delivery and the loss of the immunosuppressive state of pregnancy are likely of importance. There is compelling evidence that estrogen, progesterone, and testosterone control MS pathology by influencing immune responses and by contributing to repair mechanisms in the nervous system. Hormones may thus offer important insights into MS disease prevention and treatment. In this review, the possible reasons for the sex bias in autoimmune diseases will be discussed. The pregnancy-related alterations in MS, including the effect of pregnancy on disease activity, long-term disability accumulation, and prevalence will be reviewed, as well as the hormonal and immunological mechanisms potentially underlying these changes. Finally, the present thinking on the effect of hormones on the changing incidence of MS will be elucidated.

Management of multiple sclerosis during pregnancy and the reproductive years: a systematic review

OBJECTIVE

To examine the evidence guiding management of multiple sclerosis (MS) in reproductive-aged women.

DATA SOURCES

We conducted an electronic literature search using PubMed, ClinicalTrials.gov, and other available resources. The following keywords were used: "multiple sclerosis" and "pregnancy." We manually searched the reference lists of identified studies.

METHODS OF STUDY SELECTION

Two reviewers categorized all studies identified in the search by management topic, including effect of pregnancy on MS course, fetal risks associated with disease-modifying treatments during pregnancy, and management of patients off disease-modifying treatment. We categorized studies by strength of evidence and included prior meta-analyses and systematic studies. These studies were then summarized and discussed by an expert multidisciplinary team.

TABULATION, INTEGRATION, AND RESULTS

The risk of MS relapses is decreased during pregnancy and increased postpartum. Data are lacking regarding the risks of disease-modifying treatments during pregnancy. There may be an increased risk of MS relapses after use of assisted reproductive techniques. There does not appear to be a major increase in adverse outcomes in newborns of mothers with MS.

CONCLUSION

Although there are many unmet research needs, the reviewed data support the conclusion that in the majority of cases, women with MS can safely choose to become pregnant, give birth, and breastfeed children. Clinical management should be individualized to optimize both the mother's reproductive outcomes and MS course.

HLA-G Molecules in Autoimmune Diseases and Infections

Human leukocyte antigen (HLA)-G molecule, a non-classical HLA-Ib molecule, is less polymorphic when compared to classical HLA class I molecules. Human leukocyte antigen-G (HLA-G) was first detected on cytotrophoblast cells at the feto-maternal interface but its expression is prevalent during viral infections and several autoimmune diseases. HLA-G gene is characterized by polymorphisms at the 3' un-translated region and 5' upstream regulatory region that regulate its expression and are associated with autoimmune diseases and viral infection susceptibility, creating an unbalanced and pathologic environment. This review focuses on the role of HLA-G genetic polymorphisms, mRNA, and protein expression in autoimmune conditions and viral infections.

Elevated concentration of C-reactive protein is associated with pregnancy-related co-morbidities but not with relapse activity in multiple sclerosis

During pregnancy, alterations take place in mother's immune system with the goal of maintaining a successful pregnancy, and delivering healthy offspring. Immune alterations include activation of the innate immune system and dampening of cell-mediated adaptive immunity. Due to these alterations, cell-mediated autoimmune diseases typically ameliorate during pregnancy. The objectives of this study were to evaluate whether C-reactive protein (CRP) concentration, a sensitive marker of systemic inflammation (1) is increased during MS pregnancy (2) predicts pregnancy-related co-morbidities associated with MS (3) predicts MS disease activity after delivery. CRP concentration was measured using a high sensitivity assay from seven prospectively collected serum samples of 41 MS patients and 19 controls during pregnancy and 6 months after delivery. Annualized relapse rates, EDSS, fatigue scores and obstetric details of the patients were recorded. Delivery-related CRP levels were significantly elevated both among MS patients and in controls. CRP levels were higher during pregnancy than during the postpartum period in both study groups. Delivery-related elevated CRP levels did not correlate with postpartum disease activity. MS patients with eventual gestational diabetes had a significantly higher median CRP in the beginning of pregnancy compared to non-diabetic MS patients (9.28 vs. 2.98 mg/l, p = 0.0025). MS patients reporting fatigue had a significantly higher CRP throughout pregnancy compared to patients without fatigue. Higher CRP values were associated with pregnancy-related co-morbidities but not with MS disease activity.

The role of postpartum intravenous corticosteroids in the prevention of relapses in multiple sclerosis

Multiple sclerosis (MS) is most prevalent in women of childbearing age. It is well established that the relapse rate decreases during pregnancy but increases significantly during the first postpartum trimester. The objective of this retrospective study was to evaluate the effectiveness of the administration of 1 g of intravenous methylprednisolone (IVMP) after delivery in the prevention of MS relapses. The study involved 47 women with one or more documented pregnancies; each pregnancy was treated as a separate case. There were 50 cases with relapsing-remitting MS and 2 with secondary progressive MS. The cases were divided into two groups: the IVMP group (those who received 1 g of IVMP after delivery) and the no-IVMP group (those who did not receive IVMP after delivery). There were 39 cases in the IVMP group and 13 in the no-IVMP group. During the first postpartum trimester, relapses occurred in 17.9% of the IVMP group, compared with 46.2% of the no-IVMP group (P = .0448). The difference in relapse percentage between the two groups during the second and third postpartum trimesters was not statistically significant. Our study shows a statistically significant benefit of postpartum IVMP administration in reducing MS relapses.

CD8(+) T cells in multiple sclerosis

INTRODUCTION

CD8(+) T cells were originally considered to exert a suppressive role in demyelinating disease because of bias toward the CD4(+) T cell-mediated experimental autoimmune encephalomyelitis, the most common multiple sclerosis (MS) model. However, recent studies of human MS lesion samples and cerebrospinal fluid (CSF) provided compelling evidence about the pathogenic role of CD8(+) T cells. In this article, we discuss the theoretical roles of different CD8(+) T-cell subsets in MS.

AREAS COVERED

A revised focus from CD4(+) to CD8(+) T cell-mediated demyelinating disease is summarized. Clonal expansion of CD8(+) T cells in MS lesions and in vitro evidence that CD8(+) T cells injure every central nervous system (CNS) cell type and transect axons are discussed. The role of CD8(+) T cells in two animal models of MS and of regulatory, interleukin (IL)-17-secreting CD8(+) T cells is reviewed. Lastly, an overview about the pathogenic and/or beneficial role of various CD8(+) T-cell subsets is offered.

EXPERT OPINION

Growing evidence supports the pathogenic role of CD8(+) T cells. Clonally expanded CD8(+) T cells within MS lesions may damage the nervous system. Revealing the specific antigen is critical to design novel efficient treatments with minimal adverse effects. Increasing evidence exists for the role of regulatory, IL-17-secreting CD8(+) T cells in MS.

The expression of human leukocyte antigen G (HLA-G) is associated with sacroiliitis stages of ankylosing spondylitis

Recent studies have demonstrated that human leukocyte antigen G (HLA-G) may play an important role in autoimmune diseases. The present study is to investigate whether or not HLA-G is associated with sacroiliitis stages of ankylosing spondylitis (AS), a systemic autoimmune disease. Plasma levels of soluble HLA-G (sHLA-G) and HLA-G expression on the surface of peripheral blood mononuclear cells (PBMCs) were measured in 55 AS patients and 49 healthy controls by using a specific HLA-G ELISA and flow cytometric (FCM) analysis, respectively. Association of HLA-G expression with sacroiliitis stages of the patients was statistically analyzed. The plasma sHLA-G concentrations were noticeably lower in the AS patients when compared to the healthy controls while the mean fluorescence intensity (MFI) of the HLA-G expression on the surface of PBMCs was significantly higher in the AS patients than in the healthy controls (both P<0.0001). The HLA-G expression on the surface of PBMCs, plasma sHLA-G levels and HLA-B27 expression were significantly correlated to each other. Moreover, the plasma sHLA-G was inversely associated with the sacroiliitis stages (P=0.008), while the HLA-G expression on the surface of PBMCs increased from stage 0 to II but decreased in stage III (P=0.001). The significant association of HLA-G expressions with AS sacroiliitis stages suggests that HLA-G is possibly involved in the pathology of the disease. The detection of HLA-G expression may therefore be a useful laboratory test to reveal disease process in AS patients.

Genome-wide comparison of two RNA-stabilizing reagents for transcriptional profiling of peripheral blood

Peripheral whole blood is relatively easily obtained for monitoring gene expression for biomarker discovery using transcriptomic platforms such as genome-wide microarrays. However, whole blood provides challenges caused by sensitivity for ex vivo incubation and overrepresentation of globin mRNAs. We compared the performance of 2 commercial whole blood preservation methods, TEMPUS (Applied Biosystems, Foster City, CA) and PAXgene (PreAnalytiX, Qiagen BD, Valencia, CA), using 2 RNA amplification protocols and high-density microarrays. Performance of commercial globin mRNA reduction protocol also was studied. Human peripheral blood samples collected with TEMPUS and PAXgene Blood RNA tubes were amplified with the RiboAmp OA 1 Round RNA Amplification Kit (Arcturus; Applied Biosystems) and the Affymetrix (Santa Clara, CA) small sample protocol. Affymetrix globin reduction protocol was applied for total RNA samples. Samples amplified with RiboAmp were hybridized on Illumina Sentrix HumanRef-8 Expression BeadChips (Illumina Inc, San Diego, CA) and subjected to statistical analyses. RiboAmp mRNA amplification did not notably amplify globin mRNA that is overrepresented in RNA isolated by both TEMPUS and PAXgene preservation. Enzymatic depletion of globin transcript reduced the quality of total RNA and is thus not recommendable. Microarray analysis showed acceptable correlation within and between the RNA preservation methods, but altogether 443 transcripts were differentially expressed between RNA samples preserved in TEMPUS and PAXgene tubes. We demonstrated that the 2 tested blood RNA-preservation methods combined with RiboAmp mRNA amplification may be used for microarray experiments without the need for a prior globin RNA reduction. However, because genes involved in immune cell functions and gene regulatory pathways were differentially expressed as a result of the technical bias between the preservation methods, they should not be used in the same analytic setting.

Multiple sclerosis and pregnancy: maternal considerations

Multiple sclerosis (MS) is the most commonly acquired neurological disorder affecting young adults of reproductive age with approximately a 3:1 female-to-male ratio. Pregnancy is not contraindicated in MS but remains to be an issue that raises many questions. Although relapse rates tend to increase in the first 3 months postpartum, pregnancy does not seem to be a detriment to the long-term progression of MS and has a protective effect on reducing relapses, especially during the third trimester. MS does not appear to affect fertility or increase the risk of congenital anomalies or pregnancy complications. There has been some evidence that maternal treatment with β interferons, the most commonly used disease-modifying therapies in MS, may cause adverse reproductive outcomes, prompting the US FDA to issue warnings about their use at conception and during pregnancy.

Female reproductive issues in multiple sclerosis

Multiple sclerosis (MS) is more common in females than males and frequently affects women during their reproductive years. Thus, issues surrounding pregnancy and reproduction are of concern to women with MS. This review documents studies that shed light on reproductive issues in women with MS. The available literature was searched for papers relating to pregnancy and MS. Pregnancy is protective in MS in the short term, perhaps due to modulation of the immune system in pregnancy. It also possible that changes in the brain in pregnancy could protect against the effects of inflammation. The long-term effects of pregnancy also seem to be beneficial to MS, perhaps due to long-term epigenetic changes or possibly due to the effects of fetal microchimerism. Obstetric outcomes in women with MS are similar to those in the general population. In addition, there have been no reports of severe fetal abnormalities in babies exposed to first-line MS therapies. There is no good evidence that breast-feeding is protective in MS. There is no evidence that oral contraceptive pill use predisposes to MS, nor influences the clinical course of MS. After menopause, there is possible deterioration of MS, but it’s difficult to disentangle this from the effects of aging and the natural progressive history of MS. The strong biological effect of pregnancy on MS deserves further study, so that these mechanisms can possibly be replicated as therapies for MS.

Role of CD8 T cell subsets in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system leading to demyelination and axonal/neuronal loss. Cumulating evidence points to a key role for CD8 T cells in this disabling disease. Oligoclonal CD8 T cells reside in demyelinating plaques where they are likely to contribute to tissue destruction. Histopathological analyses and compelling observations from animal models indicate that cytotoxic CD8 T cells target neural cell populations with the potential of causing lesions reminiscent of MS. However, CD8 T cell differentiation results in several subsets of effector CD8 T cells that could be differentially implicated in the mechanisms contributing to tissue damage. Moreover CD8 regulatory T cells arise as important populations involved in restoring immune homoeostasis and in maintaining immune privileged sites. Here we examine the current literature pertaining to the role of CD8 effector and regulatory T cell subsets in the pathogenesis of MS.

Systematic review of genome-wide expression studies in multiple sclerosis

Background Although recent genome-wide association studies have identified several genetic variants contributing to the complex aetiology of multiple sclerosis (MS), expression and functional studies are required to further understand its molecular basis. Objectives To identify genes and pathways with differential expression in MS. Design The authors conducted a systematic review of seven microarray studies, in which expression in immune cells was compared between MS patients and controls. These studies include a previously unpublished study, which is described here in detail. Results and conclusion Although in general the overlap between studies was poor, 229 genes were found to be differentially expressed in MS in at least two studies, of which 11 were in three studies and HSPA1A in four studies. After excluding the authors' unpublished experiment which may have been affected by certain confounding factors and inclusion of treated subjects, 135 genes were identified in at least two studies. The differentially expressed genes were significantly associated with several immunological pathways, including interleukin (IL)-4, IL-6, IL-17 and glucocorticoid receptor signalling pathways. 15 of the 229 loci have shown some association with MS in published genome-wide association studies (p<0.0001), including three loci with confirmed MS risk variants.

Janus head: the dual role of HLA-G in CNS immunity

The central nervous system (CNS) is considered an immune-privileged organ that maintains an adaptable immune surveillance system. Dysregulated immune function within the CNS contributes to the development of brain tumor growth, and robust immune activation results in excessive inflammation. Human lymphocyte antigen-G (HLA-G) proteins with tolerogenic immunoreactivity have been implicated in various pathophysiological processes including immune surveillance, governing homeostasis and immune regulation. In this review, we describe the wealth of evidence for the involvement of HLA-G in the CNS under physiological and pathological conditions. Further, we review regulatory functions that may be applicable as beneficial strategies in the therapeutic manipulation of immune-mediated CNS immune responses. Additionally, we try to understand how this molecule cooperates with other CNS-resident cells to maintain normal immune homeostasis, while still facilitating the development of the appropriate immune responses.

Pregnancy outcome in women with multiple sclerosis: results from a prospective nationwide study in Finland

The majority of individuals obtaining the diagnosis of multiple sclerosis are women of childbearing age. They are naturally concerned as to how multiple sclerosis affects the course of pregnancy and the developing foetus. The objective of this study was to prospectively evaluate the incidence of pregnancy complications and delivery risks, and to follow the natural course of multiple sclerosis during and after pregnancy in a cohort of Finnish patients with multiple sclerosis. Sixty-one patients with multiple sclerosis who became pregnant during the years 2003-2005 were prospectively followed-up from early pregnancy until 6 months postpartum. Multiple sclerosis relapses, Expanded Disability Status Scale rates and obstetric details were recorded. The results were compared with the statistics obtained from Finnish Medical Birth Register from the year 2004. We found that patients with multiple sclerosis were no more likely to experience pregnancy complications than Finnish pregnant women generally, but they had a greater likelihood for a need of artificial insemination (4.9% vs. 0.9%; p = 0.0009). Subjects with multiple sclerosis were more likely to undergo assisted vaginal delivery than the at-large cohort (16.4% vs. 6.5%; p = 0.0017). We conclude that pregnancy does not seem to pose a woman with multiple sclerosis to a greater risk for pregnancy complications when compared with women in general. The potential need for instrumental delivery should, however, be taken into account when planning the delivery of a mother with multiple sclerosis.

Amniotic fluid soluble human leukocyte antigen-G in term and preterm parturition, and intra-amniotic infection/inflammation

OBJECTIVE

Circulating soluble human leukocyte antigen-G (sHLA-G) has been associated with pregnancy complications, and determination of sHLA-G concentrations in amniotic fluid (AF) has been reported in normal pregnancies. Our aim was to determine if the AF concentrations of sHLA-G change with advancing gestation, spontaneous labor at term, and in patients with spontaneous preterm labor (PTL) with intact membranes, as well as in those with preterm prelabor rupture of membranes (PROM), in the presence or absence of intra-amniotic infection/inflammation (IAI).

STUDY DESIGN

This cross-sectional study included the following groups: (1) mid-trimester (n = 55); (2) normal pregnancy at term with (n = 50) and without (n = 50) labor; (3) spontaneous PTL with intact membranes divided into: (a) PTL who delivered at term (n = 153); (b) PTL who delivered preterm without IAI (n = 108); and (c) PTL with IAI (n = 84); and (4) preterm PROM with (n = 46) and without (n = 44) IAI. sHLA-G concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

(1) Among patients with PTL, the median AF sHLA-G concentration was higher in patients with IAI than in those without IAI or women that delivered at term (p < 0.001 for both comparisons); (2) Similarly, patients with preterm PROM and IAI had higher median AF sHLA-G concentrations than those without IAI (p = 0.004); (3) Among patients with PTL and delivery, those with histologic chorioamnionitis and/or funisitis had a higher median AF sHLA-G concentration than those without histologic inflammation (p < 0.001); and (4) The median AF sHLA-G concentration did not change with advancing gestational age.

CONCLUSIONS

AF sHLA-G concentrations are elevated in preterm parturition associated to IAI as well as in histologic chorioamnionitis. We propose that sHLA-G may participate in the regulation of the host immune response against intra-amniotic infection.

T-bet, pSTAT1 and pSTAT3 expression in peripheral blood mononuclear cells during pregnancy correlates with post-partum activation of multiple sclerosis

In pregnant women affected by multiple sclerosis (MS) we observed increased percentages of CD4(+)CD25(+)Foxp3(+) T regulatory cells at the 1st and the 2nd trimester of gestation that was associated with a decreased T-bet expression in CD4(+) T cells. In women showing clinical relapse and/or new lesions at MRI after delivery we found, a higher expression of T-bet, pSTAT1 and pSTAT3 in CD4(+), CD8(+) T cells and CD14(+) cells, associated with an increase of IFNgamma and IL17 production by PBMC at the 3rd trimester of gestation and after delivery. Our data suggest that the expansion of circulating CD4(+)CD25(+)Foxp3(+) regulatory T cells and the lower expression of T-bet in CD4(+) T cells may account for the decreased MS activity during pregnancy. The expression of T-bet, pSTAT1 and pSTAT3 in peripheral blood CD4(+) and CD8(+) T cells and monocytes could be useful to identify MS patients who will develop a relapse after delivery.

The role of CD8 suppressors versus destructors in autoimmune central nervous system inflammation

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) of putative autoimmune origin. Recent evidence indicates that MS autoimmunity is linked to defects in regulatory T-cell function, which normally regulates immune responses to self-antigens and prevents autoimmune diseases. MS and its animal model, experimental autoimmune encephalomyelitis (EAE), have long been regarded as a CD4(+) T-cell-mediated autoimmune disease. Studies addressing the role of CD8(+) T cells, however, have only recently begun to emerge. Pathogenic function was attributed to CD8(+) T cells because of their abundant presence or oligoclonal repertoire within MS lesions. However, CD8(+) T cells appeared to have important regulatory functions, as demonstrated in EAE or human MS studies. We here review the contribution of CD8(+) T cells to inflammation and immune regulation in CNS autoimmunity. The knowledge of distinct CD8(+) T-cell populations exerting destructive versus beneficial functions is summarized. The long-term goal is to delineate the exact phenotypic and functional characteristics of regulatory CD8(+) T-cell populations (natural as well as inducible) in humans. This knowledge may help to further develop concepts of reconstituting or enhancing endogenous mechanisms of immune tolerance in future therapeutic concepts for MS.

The role of regulatory T cells in multiple sclerosis

The dysregulation of inflammatory responses and of immune self-tolerance is considered to be a key element in the autoreactive immune response in multiple sclerosis (MS). Regulatory T (T(REG)) cells have emerged as crucial players in the pathogenetic scenario of CNS autoimmune inflammation. Targeted deletion of T(REG) cells causes spontaneous autoimmune disease in mice, whereas augmentation of T(REG)-cell function can prevent the development of or alleviate variants of experimental autoimmune encephalomyelitis, the animal model of MS. Recent findings indicate that MS itself is also accompanied by dysfunction or impaired maturation of T(REG) cells. The development and function of T(REG) cells is closely linked to dendritic cells (DCs), which have a central role in the activation and reactivation of encephalitogenic cells in the CNS. DCs and T(REG) cells have an intimate bidirectional relationship, and, in combination with other factors and cell types, certain types of DCs are capable of inducing T(REG) cells. Consequently, T(REG) cells and DCs have been recognized as potential therapeutic targets in MS. This Review compiles the current knowledge on the role and function of various subsets of T(REG) cells in MS and experimental autoimmune encephalomyelitis. We also highlight the role of tolerogenic DCs and their bidirectional interaction with T(REG) cells during CNS autoimmunity.

From fish to man: understanding endogenous remyelination in central nervous system demyelinating diseases

In the central nervous system (CNS) of man, evolutionary pressure has preserved some capability for remyelination while axonal regeneration is very limited. In contrast, two efficient programmes of regeneration exist in the adult fish CNS, neurite regrowth and remyelination. The rapidity of CNS remyelination is critical since it not only restores fast conduction of nerve impulses but also maintains axon integrity. If myelin repair fails, axons degenerate, leading to increased disability. In the human CNS demyelinating disease multiple sclerosis (MS), remyelination often takes place in the midst of inflammation. Here, we discuss recent studies that address the innate repair capabilities of the axon-glia unit from fish to man. We propose that expansion of this research field will help find ways to maintain or enhance spontaneous remyelination in man.

HLA-G: from biology to clinical benefits

The relevance of the nonclassical human leukocyte antigen (HLA) class I molecule HLA-G in human physiological and pathological contexts has been the center of intense investigation. In light of the recent advances, we report here the clinical implications of HLA-G as a tolerogenic molecule promoting uterine implantation of the embryo or acceptance of solid allografts while allowing the evasion of tumors or viruses from the immune response. These recent findings are important in terms of clinical benefits at both diagnostic and therapeutic levels.