Variations in cytokine mRNA expression during normal human pregnancy

Human labour is associated with altered regulatory T cell function and maternal immune activation

During human pregnancy, regulatory T cell (T_reg ) function is enhanced and immune activation is repressed allowing the growth and development of the feto-placental unit. Here, we have investigated whether human labour is associated with a reversal of the pregnancy-induced changes in the maternal immune system. We tested the hypothesis that human labour is associated with a decline in T_reg function, specifically their ability to modulate Toll-like receptor (TLR)-induced immune responses. We studied the changes in cell number, activation status and functional behaviour of peripheral blood, myometrial (myoMC) and cord blood mononuclear cells (CBMC) with the onset of labour. We found that T_reg function declines and that T_reg cellular targets change with labour onset. The changes in T_reg function were associated with increased activation of myoMC, assessed by their expression of major histocompatibility complex (MHC) class II molecules and CBMC inflammatory cells. The innate immune system showed increased activation, as shown by altered monocyte and neutrophil cell phenotypes, possibly to be ready to respond to microbial invasion after birth or to contribute to tissue remodelling. Our results highlight changes in the function of the adaptive and innate immune systems that may have important roles in the onset of human labour.

The Role of Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

Gestational cytokine concentrations and neurocognitive development at 7 years

Gestational inflammation may contribute to brain abnormalities associated with childhood neuropsychiatric disorders. Limited knowledge exists regarding the associations of maternal cytokine levels during pregnancy with offspring neurocognitive development. We assayed the concentrations of five cytokines (interleukin (IL)-6, IL-1β, IL-8, tumor necrosis factor alpha (TNF-α), and IL-10) up to four times in the 2nd and 3rd trimesters of pregnancy using stored prenatal sera from 1366 participants in the New England Family Study (enrollment 1959-1966). Intelligence (IQ), academic achievement, and neuropsychological functioning of singleton offspring were assessed at age 7 years using standardized tests. We used linear mixed models with random effects to estimate the cumulative exposure to each cytokine during 2nd and 3rd trimesters, and then related cumulative cytokine exposure to a wide range of offspring neurocognitive outcomes. We found that children of women with higher levels of the pro-inflammatory cytokine, TNF-α, in the 2nd and 3rd trimesters had lower IQ (B = -2.51, 99% CI: -4.84,-0.18), higher problem scores in visual-motor maturity (B = 0.12, 99% CI: 0.001,0.24), and lower Draw-a-Person test scores (B = -1.28, 99% CI: -2.49,-0.07). Higher gestational levels of IL-8, another pro-inflammatory molecule, were associated with better Draw-a-Person test scores and tactile finger recognition scores. Other cytokines were not associated with our outcome of interest. The opposing directions of associations observed between TNF-α and IL-8 with childhood outcomes suggest pleiotropic effects of gestational inflammation across the domains of neurocognitive functioning. Although the path to psychopathological disturbances in children is no doubt multifactorial, our findings point to a potential role for immune processes in the neurocognitive development of children.

Assessment of the innate immune response in the periparturient cow

The transition period is the most critical phase in the life of high yielding dairy cows. Within a few weeks, cows are submitted to many challenges (physiological, nutritional, psychological, management) that require prompt and effective adaptive responses. The immune system is involved in this process, and many changes of the cow's immune system components have been observed around calving. Cows are considered to be immunosuppressed in late lactation, and available data suggest that the immune system is dysregulated around parturition. Significant attention has been focused on modification of cellular functions (e.g. the reduction of phagocytosis and diapedesis), but growing interest concerns the components of the innate immune system, which often exhibits increased responses such as susceptibility to inflammatory events and the related acute phase response (APR). Systemic inflammation plays a significant role in early lactation, affects many liver functions and has been associated with the impairment of cow performance (i.e. reduced feed intake, milk yield, fertility, welfare). The assessment of variations in immune-metabolic indices offers opportunities to predict the onset of the health troubles and to anticipate the proper therapies needed to guarantee health, good welfare and fertility in the following lactation. The frequency of diseases (metabolic and infectious) before calving is rare, but several clues suggest that various metabolic and immune variations can begin during the dry period. Interesting preliminary results encourage this perspective and possible candidates are suggested.

Changes in T Cell and Dendritic Cell Phenotype from Mid to Late Pregnancy Are Indicative of a Shift from Immune Tolerance to Immune Activation

During pregnancy, the mother allows the immunologically distinct fetoplacental unit to develop and grow. Opinions are divided as to whether this represents a state of fetal-specific tolerance or of a generalized suppression of the maternal immune system. We hypothesized that antigen-specific T cell responses are modulated by an inhibitory T cell phenotype and modified dendritic cell (DC) phenotype in a gestation-dependent manner. We analyzed changes in surface markers of peripheral blood T cells, ex vivo antigen-specific T cell responses, indoleamine 2,3-dioxygenase (IDO) activity (kynurenine/tryptophan ratio, KTR), plasma neopterin concentration, and the in vitro expression of progesterone-induced blocking factor (PIBF) in response to peripheral blood mononuclear cell culture with progesterone. We found that mid gestation is characterized by reduced antigen-specific T cell responses associated with (1) predominance of effector memory over other T cell subsets; (2) upregulation of inhibitory markers (programmed death ligand 1); (3) heightened response to progesterone (PIBF); and (4) reduced proportions of myeloid DC and concurrent IDO activity (KTR). Conversely, antigen-specific T cell responses normalized in late pregnancy and were associated with increased markers of T cell activation (CD38, neopterin). However, these changes occur with a simultaneous upregulation of immune suppressive mechanisms including apoptosis (CD95), coinhibition (TIM-3), and immune regulation (IL-10) through the course of pregnancy. Together, our data suggest that immune tolerance dominates in the second trimester and that it is gradually reversed in the third trimester in association with immune activation as the end of pregnancy approaches.

Quantitative IFN-γ and IL-2 Response Associated with Latent Tuberculosis Test Discordance in HIV-infected Pregnant Women

RATIONALE

Pregnant women with latent tuberculosis infection (LTBI) are at high risk for development of TB, especially if infected with HIV.

OBJECTIVES

To assess the performance of LTBI tests in pregnant and postpartum women infected with HIV, investigate the immunology behind discordance in pregnancy, and explore the implications for the development of postpartum TB.

METHODS

We screened pregnant women in their second/third trimester and at delivery for LTBI using the tuberculin skin test (TST) and IFN-γ release assay (IGRA) (QuantiFERON Gold). A subset of antepartum women had longitudinal testing, with repeat testing at delivery and postpartum and additional cytokines measured from the IGRA supernatant. The kappa statistic and Wilcoxon rank sum test were used to determine agreement and comparison of cytokine concentrations, respectively.

MEASUREMENTS AND MAIN RESULTS

Of 252 enrolled, 71 (28%) women had a positive IGRA but only 27 (10%) had a positive TST (P < 0.005). There was 75% agreement (kappa, 0.25). When stratified by pregnancy versus delivery, 20% had IGRA(+)/TST(-) discordance at each time point. A positive IGRA was associated with known TB contact (odds ratio, 3.6; confidence interval, 1.2-11.1; P = 0.02). Compared with IGRA(+)/TST(+), women with IGRA(+)/TST(-) discordance had significantly less IFN-γ (1.85 vs. 3.48 IU/ml; P = 0.02) and IL-2 (46.17 vs. 84.03 pg/ml; P = 0.01). Five developed postpartum TB, of which three had IGRA(+)/TST(-) discordance during pregnancy.

CONCLUSIONS

Choice of LTBI test in pregnant women infected with HIV affects results. Pregnant women with IGRA(+)/TST(-) discordance had less IFN-γ and IL-2 than those with concordant-positive results and may represent an especially high-risk subset for the development of active TB postpartum.

Estrous Cycle and Gestational Age-Dependent Expression of Members of the Interleukin-36 Subfamily in a Semi-Allogeneic Model of Infected and Non-Infected Murine Pregnancy

The IL-36 subfamily is a recently described group of cytokines with pro-inflammatory behavior, comprising three agonists (α, β, and γ), its receptor (R), and one antagonist (Ra). The expression and function of IL-36 subfamily members in the estrous cycle in healthy and infected pregnancy has not been described. We evaluated mRNA and protein expression of IL-36 family members during the estrous cycle, implantation, fetal development, and post-labor periods in a model of allogenic pregnancy in mice. We also explored the ability of Listeria monocytogenes to modulate the expression of IL-36 subfamily members during pregnancy. Expression of IL-36 subfamily members showed different expression during the estrous cycle and pregnancy but was induced at estrous, 16.5 days post coitum (dpc), 18.5 dpc, and labor. IL-36 subfamily members showed a characteristic distribution in the glandular epithelium, perimetrium, myometrium, and stratum vasculare. Infection with L. monocytogenes during pregnancy induced strong production of IL-36 subfamily members, an observation that correlated with an increasing prevalence of fetal loss. In conclusion, IL-36 agonists showed specific patterns of mRNA and protein expression that might suggest functional specialization or specific target cells. Infection with L. monocytogenes during pregnancy induced strong production of IL-36 subfamily members.

Effect of cytokine level variations in individuals on the progression and outcome of bacterial urogenital infections--a meta-analysis

Bacterial urogenital infections such as chlamydia, gonorrhoea and syphilis are widespread inflammatory diseases, which may be accompanied by severe complications. These complications can range from basic inflammation to tubal pathology, infertility and neurological dysfunction, though infections go unnoticed in the majority of cases. Cytokines in the host play a vital role in both the initial and long-term immune response and inflammation. However, levels of cytokine expression vary between individuals. A meta-analysis was performed to evaluate the effect of cytokine expression differences on severity of infections with these pathogens. Studies comparing expression of cytokines in humans with inflammation or inflammation-based complications were identified using NCBI, Google Scholar and Cochrane databases. Only studies into human cytokine expressions were included, and three articles per subject were required to be suitably analysed during meta-analysis. A total of 52 articles were included for meta-analysis. It was shown that differences in IL-1, IL-6, IL-8, IL-10, TNFα and IFNγ affect the clinical outcome of Chlamydia trachomatis infection significantly. Similarly, IL-1 and IL-8 expression during Neisseria gonorrhoeae infection significantly affects the outcome of the disease. For Treponema pallidum infection, it was shown that IFNγ variation in hosts could be linked to severity of disease. However, a lack of studies to use in the meta-analysis and fluctuation in the resulting data depending on the adjustments makes adequate evaluation difficult.

Modulation of Cytokine Production by the Dydrogesterone Metabolite Dihydrodydrogesterone

PROBLEM

Previous studies have shown that dydrogesterone, the orally administered progestogen, upregulates the production of Th2 cytokines and downregulates Th1 cytokine production. This study was designed to ascertain whether dihydrodydrogesterone (DHD), the major metabolite of dydrogesterone, is similarly capable of modulating cytokine production by peripheral blood mononuclear cells (PBMC) from women with a history of unexplained recurrent miscarriage.

METHOD OF STUDY

Mitogen-stimulated PBMC from women with unexplained recurrent miscarriage were exposed to progesterone or dydrogesterone or DHD, and the levels of pro-inflammatory (IFN-γ, TNF-α) and anti-inflammatory (IL-4, IL-10, IL-13) cytokines were estimated by ELISA. To ascertain whether DHD mediates its effects via the progesterone receptor, RU486, a progesterone agonist, was added to cultures along with mitogen and DHD.

RESULTS

The metabolite DHD, like its parent molecule dydrogesterone, suppresses the production of the pro-inflammatory cytokines IFN- γ and TNF-α and upregulates the production of the anti-inflammatory cytokine IL-4. The progesterone antagonist RU486 reverses the effect of DHD, suggesting that this molecule mediates its cytokine-modulating effect via the progesterone receptor.

CONCLUSION

Dihydrodydrogesterone retains the immunomodulatory effects of the progestogen dydrogesterone by bringing about a shift in cytokine production profiles that might be conducive to the success of pregnancy.

Understanding the behavioural phenotype of the precocial spiny mouse

The use of the spiny mouse (Acomys cahirinus) in experimental research is steadily increasing, due to the precocial nature of this species and the similarities in endocrinology to the human. The characterisation of normal behavioural traits throughout development has not been comprehensively measured in the spiny mouse. Therefore the aim of this study was to behaviourally phenotype the spiny mouse, with the use of behavioural paradigms commonly used to assess behaviour in rat and mouse models of human behavioural disorders such as autism, attention-deficit disorder, and schizophrenia. Male and female spiny mice were assessed at 1-5, 10-15, 20-25, 40-45 and 80-85 days of age using the open field test, novel object recognition test, rotarod, elevated plus maze, a social interaction test, and prepulse inhibition. Exploratory activity, motor coordination, fear, anxiety and social behaviours could be accurately measured from 1 day of age. Open field exploration and motor coordination on a modified rotarod were precociously developed by 10-15 and 20-25 days of age, respectively, when they were equivalent to the performance of conventional adult mice. Learning and memory (assessed by the novel object recognition test), and sensory gating (prepulse inhibition) could be reliably determined only after 20-25 days of age, and performance on these tests differed significantly between male and female spiny mice, particularly in adulthood. This study characterises the behavioural traits of spiny mice and provides important information about critical periods of behavioural development throughout postnatal life.

Perinatal stress, fatigue, depressive symptoms, and immune modulation in late pregnancy and one month postpartum

Stress and fatigue are common complaints of pregnant and postpartum women as is depression. These symptoms may be related to immunomodulation. However, few studies have examined these relationships. The aim of this study was to examine the relationships among stress, fatigue, depression, and cytokines as markers of immune modulation in prenatal and postpartum women. Women completed questionnaires and gave blood samples during late pregnancy and again at 4–6 weeks postpartum. Blood was analyzed for cytokines as measures of immune modulation. Stress, fatigue, and depression were experienced at moderately high levels, with higher levels of fatigue and depression in the postpartum but higher stress in the prenatal period. Levels of several cytokines were increased in the postpartum over the prenatal period. Stress and depression were related in the prenatal period and stress, depression, and fatigue were related in the postpartum. While various cytokines were related to each other in both periods, only stress was related to MIP-1β, a cytokine that may be important for childbirth processes. More studies, especially longitudinal and interventional studies, are needed to increase our knowledge about etiology, patterns, symptoms, factors, and management of maternal distress. The search for reliable biomarkers for at-risk mothers remains a priority.

Cytokines and the neurodevelopmental basis of mental illness

Epidemiological studies suggest that prenatal exposure to different types of viral or bacterial infections may be associated with similar outcomes; i.e., an increased risk of mental illness disorders in the offspring. Infections arising from various causes have similar debilitating effects in later life, suggesting that the exact pathogen may not be the critical factor in determining the neurological and cognitive outcome in the offspring. Instead, it is thought that response of the innate immune system, specifically the increased production of inflammatory cytokines, may be the critical mediator in altering fetal brain development pre-disposing the offspring to mental illness disorders later in life. Inflammatory cytokines are essential for normal brain development. Factors such as the site of cytokine production, a change in balance between anti- and pro- inflammatory cytokines, placental transfer of cytokines, the effects of cytokines on glial cells, and the effects of glucocorticoids are important when evaluating the impact of maternal infection on fetal brain development. Although it is clear that cytokines are altered in the fetal brain following maternal infection, further evidence is required to determine if cytokines are the critical factor that alters the trajectory of brain development, subsequently leading to postnatal behavioral and neurological abnormalities.

Mechanism of human chorionic gonadotrophin-mediated immunomodulation in pregnancy

Human chorionic gonadotrophin (hCG) is released within hours of fertilization and has a profound ability to downregulate maternal cellular immunity against trophoblastic paternal antigens. It also promotes angiogenic activity of the extravillous trophoblast, and impairment of this function may lead to inadequate placentation and an increased risk of preeclampsia. There is increasing evidence that hCG alters the activity of dendritic cells via an upregulation of indoleamine 2,3-dioxygenase activity. This reduces T-cell activation and cytokine production, as well as encouraging Treg cell recruitment to the fetal-maternal interface. These changes are critical in promoting maternal tolerance. hCG is also able to increase the proliferation of uterine natural killer cells, while reducing the activity of cytotoxic peripheral blood natural killer cells. There are rare reports of autoantibodies directed against hCG or the luteinizing hormone/hCG receptor in women with recurrent miscarriage. These autoantibodies are more frequent in women with thyroid autoimmunity. This may explain the association between thyroid autoimmunity and impaired fertility. Downregulating these anti-hCG and anti-luteinizing hormone/hCG receptor autoantibodies may be helpful in some women with early miscarriage or recurrent failed in vitro fertilization.

Interferon gamma release assay compared with the tuberculin skin test for latent tuberculosis detection in pregnancy

OBJECTIVE

To estimate agreement and correlation between the tuberculin skin test and an interferon gamma release assay for detecting latent tuberculosis (TB) infection in pregnant women.

METHODS

We conducted a cross-sectional study of pregnant women initiating prenatal care at a university-affiliated public hospital between January 5, 2009, and March 15, 2010. Eligible women received a questionnaire about TB history and risk factors as well as the tuberculin skin test and phlebotomy for the interferon gamma release assay. Agreement and correlation between tests were estimated, and different cutoffs for interferon gamma release assay positivity were used to assess effect on agreement. Furthermore, predictors of test positivity and test discordance were evaluated using multivariable analysis.

RESULTS

Of the 220 enrolled women, 199 (90.5%) returned for tuberculin skin test evaluation. Over 70% were Hispanic and 65% were born in a country with high TB prevalence. Agreement between the tuberculin skin test and interferon gamma release assay was 77.39 (κ=0.26). This agreement was not significantly changed using different cutoffs for the assay. Birth bacille Calmette-Guérin vaccination was associated with tuberculin skin test positivity (odds ratio [OR] 4.33, 95% confidence interval [CI] 1.4-13.48, P=.01), but not interferon gamma release assay positivity. There were no statistically significant predictors of the tuberculin skin test and interferon gamma release assay result discordance; however, birth in a high-prevalence country was marginally associated with tuberculin skin test-positive and interferon gamma release assay-negative results (OR 2.94, 95% CI 0.86-9.97 P=.08).

CONCLUSION

Comparing the tuberculin skin test and interferon gamma release assay results in pregnancy, concordance and agreement were poor. Given that much is still unknown about the performance of interferon gamma release assays in pregnancy, further research is necessary before the tuberculin skin test is abandoned for screening of latent TB infection in pregnancy.

LEVEL OF EVIDENCE

III.

The multi-faceted influences of estrogen on lymphocytes: toward novel immuno-interventions strategies for autoimmunity management

Early studies of the immune system disclosed that, generally, females exhibit stronger responses to a variety of antigens than males. Perhaps as a result of this response, women are more prone to developing autoimmune diseases than men. Yet, the precise cellular and molecular mechanisms remain under investigation. Recently, interferon-gamma and the related pro-inflammatory interleukin-12 were found to be under effects of sex steroid hormones, with potential implications in regulating immune cells and autoimmune responses. In B lymphocytes, functional binding sites for estrogen receptors were identified in the promoter of the gene encoding activation-induced deaminase, an enzyme required for somatic hypermutation, and class-switch recombination. The observation that estrogen exerts direct impacts on antibody affinity-maturation provides a potential mechanism that could account for generating pathogenic high-affinity auto-antibodies. Further deciphering the multi-faceted influences of sex hormones on the responsiveness of immune cells could lead to novel therapeutic interventions for autoimmunity management.

Is the modulatory effect of pregnancy in multiple sclerosis associated with changes in blood apoptotic molecules?

OBJECTIVE

We examined whether the modulatory effect of pregnancy on multiple sclerosis (MS) is associated with changes in the apoptotic molecules in sera.

SUBJECTS AND METHODS

The serum levels of tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL), sFas, Fas ligand (sFasL) and macrophage migration inhibitory factor were analyzed from 19 MS patients and 14 controls during late pregnancy and post-partum. The obtained results were related to disease activity and the progression of MS.

RESULTS

Disease activity decreased during pregnancy. The levels of sTRAIL and sFasL increased from late pregnancy to post-partum situation in both MS patients and controls, but in MS patients the changes in the levels of sTRAIL from late pregnancy to post-partum were smaller than in controls.

CONCLUSIONS

Post-partum upregulation of TRAIL and FasL seems to be caused by physiologic reactivation of the mother's immune system after pregnancy. An increased risk of relapses in MS post-partum may be associated with changes in the immunomodulatory potential of these apoptotic molecules.

The effect of high gravidity on the carcinogenesis of mammary gland in TA2 mice

PROBLEM

Spontaneous breast cancer in Tientsin Albinao 2 (TA2) mice, like human pregnancy-associated breast cancer (PABC), often occurs in pregnancy and puerperium, especially in mice with high gravidity. We hypothesized that the dysfunction of cellular immunity caused by the increase of 17beta-estradiol (E2) and progesterone (P) might be one of the reasons for carcinogenesis of mammary gland.

METHOD OF STUDY

We investigated the T lymphocyte subsets and the concentration of serum hormone and cytokines in cancer-bearing, pregnant or postpartum TA2 mice using flow cytometry, chemiluminescent immunoassay, and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

The number of T lymphocytes and the concentration of E2, P, interleukin-2 (IL-2), IL-4, and interferon-gamma (IFN-gamma) changed with the increase of pregnancy and puerperium. During four pregnancies, elevated E2 and P resulted in a decrease in the number of CD3(+), CD4(+) T lymphocytes, CD4(+)/CD8(+) ratio, and the concentration of IL-2, IL-4, and IFN-gamma. Data in the fourth pregnancy were the closest to those of cancer-bearing mice.

CONCLUSION

T lymphocyte subsets and concentration of IL-2, IL-4, and IFN-gamma are affected by E2 and P during multiple pregnancy and delivery to some degree, which may contribute to the genesis of spontaneous breast cancer in TA2 mice.

Progesterone-induced blocking factor (PIBF) modulates cytokine production by lymphocytes from women with recurrent miscarriage or preterm delivery

Spontaneous miscarriage and preterm delivery are common complications of pregnancy. Pro-inflammatory cytokines have been shown to be associated with recurrent spontaneous miscarriage (RSM) and preterm delivery (PTD) and these have led to exploration of ways to downregulate pro-inflammatory cytokines and/or to upregulate anti-inflammatory cytokines. Progesterone-induced blocking factor (PIBF) is a molecule with inhibitory effects on cell-mediated immune reactions. We have ascertained the effects of PIBF on secretion of selected type 1 and type 2 cytokines by peripheral blood mononuclear cells from healthy non-pregnant women, women undergoing normal pregnancy, women with unexplained RSM and women with PTD. Peripheral blood mononuclear cells from 30 women with a history of unexplained RSM, 18 women undergoing PTD, 11 women with normal pregnancy and 13 non-pregnant healthy women were stimulated with a mitogen in the absence and presence of PIBF after which the levels of cytokines released into culture supernatants were determined by ELISA. Production of the type 2 cytokines IL-4, IL-6 and IL-10 by lymphocytes from the RSM and PTD groups and of IL-4 and IL-10 by lymphocytes from healthy pregnant women was significantly increased upon exposure to PIBF, while the levels of type 1 cytokines were not affected. Ratios of type 1:type 2 cytokines were decreased, suggesting a shift towards Th2 bias. PIBF did not affect cytokine production by lymphocytes from non-pregnant women. Thus, PIBF acts on lymphocytes in pregnancy to induce a type 1 to type 2 cytokine shift by upregulating the production of type 2 cytokines.

Recurrent miscarriages: What is the role of cytokines?

Recurrent miscarriage is defined as three or more consecutive miscarriages before 20 weeks of gestation. This condition is a frequent reproductive problem worldwide, affecting up to 1% of couples. Immune effector cell dysfunction has been implicated in the pathogenesis of early pregnancy loss. This dysfunction may involve defects in cytokines, growth factors and immunosuppressive factors at the maternofetal interface. This is a growing research field, especially the role of cytokines in recurrent miscarriage.

Listeria monocytogenes infection in pregnant guinea pigs is associated with maternal liver necrosis, a decrease in maternal serum TNF-alpha concentrations, and an increase in placental apoptosis

Stillbirths and spontaneous abortions can result when pregnant women are exposed to the food borne pathogen, Listeria monocytogenes. Fetuses and neonates account for one-third of the 2500 cases annually. The objectives were to determine the dose dependent trends of immunological and pathological effects in pregnant guinea pigs after infection with L. monocytogenes. Timed pregnant guinea pigs were treated on gestation day (gd) 35 with doses of 10(4) to 10(8) colony forming units (CFUs) and sacrificed on gd 56. Hepatic lesions were found in dams treated with >or=10(5)CFUs. Apoptosis was detected in significantly more placentas from dams treated with >or=10(6)CFUs compared to controls. Maternal serum TNF-alpha concentrations were significantly decreased in all dose groups compared to controls. In conclusion, increases in premature delivery, maternal hepatic effects and placental apoptosis along with a decrease in TNF-alpha concentrations were associated with L. monocytogenes infection in pregnant guinea pigs.

Immunomodulatory effects of the intake of fermented milk with Lactobacillus casei DN114001 in lactating mothers and their children

The healthy action of probiotics is not only due to their nutritional properties and their influence on the gastrointestinal environment, but also to their action on the immune system. The aim of the present study was to determine if 6 weeks of probiotic intake would be able to modulate the immune system in women who had recently delivered and were breast-feeding. The design consisted of a randomised, controlled and double-blind nutritional intervention study with parallel groups with a sample size of 104 women. The main variable is the T helper type 1/T helper type 2 (Th1/Th2) profile determined by measuring interferon-gamma (Th1) and IL-4 (Th2) values in peripheral blood by flow cytometry. The modifications of cytokines were evaluated in maternal milk by cytometric bead array in a flow cytometer and ELISA at three stages of breast-feeding: colostrum, early milk (10 d) and mature milk (45 d). Additionally, the anthropometry and infectious and allergic episodes in the newborn were followed up throughout the first 6 months of life. After the consumption of milk fermented with Lactobacillus casei during the puerperium, we observed a nonsignificant increase in T and B lymphocytes and a significant increase in natural killer cells. A decrease in the pro-inflammatory cytokine TNF-alpha in maternal milk and fewer gastrointestinal disturbances were also observed in the breast-fed child of the mothers who consumed L. casei. The intake of milk fermented with L. casei during the lactation period modestly contributes to the modulation of the mother's immunological response after delivery and decreases the incidence of gastrointestinal episodes in the breast-fed child.

Immunoregulatory factors in multiple sclerosis patients during and after pregnancy: relevance of natural killer cells

Multiple sclerosis (MS) ameliorates typically during pregnancy but after the delivery the relapse rate often increases. Our study was conducted to understand the immunoregulatory mechanisms accompanying this phenomenon. MS patients were followed-up prospectively during pregnancy and 6 months postpartum, with immunological characterization of the peripheral blood. Groups of age- and parity-matched healthy pregnant women, and age- and sex-matched non-pregnant women and non-pregnant MS patients were studied as controls. In our patient cohort, the annualized relapse rate was 1.0 +/- 1.0 relapses/woman/year (mean +/- standard deviation) during the year before pregnancy, but dropped to 0.2 +/- 0.9 during the third trimester (P = 0.02). After the delivery the relapse rate increased again to 1.4 +/- 1.9 (1-3 months postpartum versus third trimester P = 0.003). While percentages of peripheral blood CD3, CD4, CD8 and CD19 immune cell subsets were unchanged over the observation period, reduced disease activity during the last trimester was associated with a significant increase in the percentage of circulating CD56(bright) natural killer (NK) cells. Simultaneously, the proportion of circulating CD56(dim) NK cells was clearly reduced. No alteration was noted in CD4+ CD25(high) forkhead box P3+ regulatory T cells. Production of interferon-gamma by peripheral blood lymphocytes was down-regulated significantly during pregnancy in comparison to the postpartum period, resulting in an increased T helper type 2 (Th2) : Th1 ratio during pregnancy. In conclusion, pregnant state in MS patients is characterized by an increase in the percentage of CD56(bright) NK cells and by enhanced Th2 type cytokine secretion. Our findings suggest a potential role for CD56(bright) regulatory NK cells in the control of autoimmune inflammation during pregnancy in MS.

Human chorionic gonadotropin is an immune modulator and can prevent autoimmune diabetes in NOD mice

AIMS/HYPOTHESIS

Expression of T helper (Th)1 cytokine mRNA in pregnant women is known to be inversely correlated with serum human chorionic gonadotropin (hCG). Type 1 diabetes is a Th1-mediated autoimmune disease, in which intervention at an early stage of the autoimmune process can prevent disease progression. We hypothesised that immune modulation by treating young NOD mice with hCG may prevent diabetes.

METHODS

Female NOD mice were treated with hCG or recombinant hCG from 3 to 15 weeks of age and the incidence of diabetes and development of insulitis was determined. CD4(+) and CD8(+) T cell populations, T cell proliferation, cytokine production and CD4(+)CD25(+) regulatory T cells were examined and adoptive transfer experiments were performed.

RESULTS

Both purified and recombinant hCG prevented development of diabetes in NOD mice. hCG decreased the proportion and number of CD4(+) and CD8(+) T cells and inhibited T cell proliferative responses against beta cell antigens. hCG treatment suppressed IFN-gamma production, but increased IL-10 and TGF-beta production in splenocytes stimulated with anti-CD3 antibody. hCG treatment also suppressed TNF-alpha production in splenocytes stimulated with lipopolysaccharide. Furthermore, hCG treatment increased the CD4(+)CD25(+)/CD4(+) T cell ratio in spleen and pancreatic lymph nodes. Depletion of CD4(+)CD25(+) T cells from splenocytes of hCG-treated NOD mice abolished their preventive effect on diabetes transfer.

CONCLUSIONS/INTERPRETATION

We conclude that hCG has an immunomodulatory effect by downregulating effector cells, including Th1 cells, CD8(+) T cells and macrophages, and increasing the CD4(+)CD25(+)/CD4(+) T cell ratio, thus preventing autoimmune diabetes in NOD mice.

Rheumatoid arthritis and reproduction

Additional research is needed to establish the safety of biologic agents in pregnancy and lactation. The practitioner should convey information regarding the natural history of rheumatoid arthritis during pregnancy and safety issues related to pharmacotherapies to every woman of childbearing age with RA, well before conception and pregnancy, to ensure optimal outcomes.

Clinical and immunologic evaluation of women with multiple sclerosis during and after pregnancy

BACKGROUND

Multiple sclerosis (MS) is a disabling autoimmune disease of the central nervous system, typically affecting women of childbearing years. Although the disease course of MS is highly unpredictable, disease activity is almost invariably halted during pregnancy. After delivery, however, the relapse rate increases. Despite early recognition of this pattern of disease activity, its explanation remains a mystery.

OBJECTIVE

The aim of this study was to elucidate the underlying mechanisms responsible for the amelioration of MS during pregnancy and for its reactivation after delivery.

METHODS

This Finnish prospective study included clinical and immunologic follow-up of patients with MS during pregnancy and 6 months into the postpartum period. Groups of patients with MS who were not pregnant, along with pregnant and nonpregnant healthy women, served as controls. Laboratory investigations included subtype analysis of T, B, and natural killer (NK) cells during and after pregnancy, using immunofluorescence staining and fluorescence-activated cell sorting analysis

RESULTS

The clinical and immunologic follow-up data from 42 pregnant patients with MS indicated that the percentage of circulating NK cells decreases during the last trimester of pregnancy and increases again soon after the delivery. This correlates with disease activity as measured by annualized relapse rate. Early postpartum treatment with interferon-0 was effective in preventing relapses, and good response to postpartum treatment coincided with a reduction in the circulating NK cell levels.

CONCLUSIONS

Our findings have implications for the treatment and follow-up of pregnant women with MS. To prevent postpartum relapses, disease-modifying treatment should be initiated as early as possible.

Psychosocial stress increases inflammatory markers and alters cytokine production across pregnancy

Previous work has shown that psychosocial stress is related to increases in serum levels of pro-inflammatory cytokines late in pregnancy, and a growing body of research suggests that increased inflammatory activity during pregnancy, generally, may have a negative impact on outcome. The present study further addressed these issues by assessing relationships between psychosocial stress, social support and serum cytokines in early, mid, and late pregnancy, and the effects of stress and social support on the production of cytokines by stimulated lymphocytes in late pregnancy. In addition, we examined relationships between stress, support, and serum C-reactive protein (CRP) during pregnancy. Elevated stress was not only related to higher serum IL-6 late in pregnancy as in our prior work, but this relationship was also evident during early pregnancy and elevated stress was also associated with lower IL-10 in early pregnancy. No relationships between stress and cytokines were apparent during the 2nd trimester of pregnancy. Elevated stress during the 2nd trimesters and low social support during the 3rd trimester were related to increased serum levels of CRP, further suggesting that psychosocial factors can contribute increased inflammation during pregnancy. Importantly, elevated stress levels across pregnancy were predictive of elevated production of the pro-inflammatory cytokines IL-1B and IL-6 by stimulated lymphocytes in the 3rd trimester, suggesting that stress during pregnancy affects the function of immune system cells. These findings further support the notion that prenatal stress alters maternal physiology and immune function in a manner consistent with increased risk of pregnancy complications such as preeclampsia and premature labor.

Differential expression of BDNF mRNA splice variants in mouse brain and immune cells

For the neurotrophin BDNF several splice variants were recently described. We analyzed the expression of mBDNF mRNA splice variants in cells of the immune system in comparison to the central nervous system (CNS). Whereas all splice variants are expressed in the CNS, only mBDNF 3 mRNA could be detected in primary and secondary lymphoid organs as well as in purified T cells and macrophages. After activation, only mBDNF 3 mRNA expression was upregulated in T cells without the additional appearance of other mBDNF splice variants. Therefore, mBDNF mRNA is differentially regulated in the CNS and the immune system opening the possibility of specific manipulation of mBDNF expression in immune cells without globally affecting mBDNF in the CNS.

Peroxisome proliferator-activated receptor alpha deficiency increases the risk of maternal abortion and neonatal mortality in murine pregnancy with or without diabetes mellitus: Modulation of T cell differentiation

We assessed the implication of peroxisome proliferator-activated receptor (PPAR) alpha deficiency in pregnancy outcome and neonatal survival and in the modulation of T cell differentiation in murine diabetic pregnancy and their offspring. Pregnant wild-type (WT) and PPAR alpha-null mice of C57BL/6J genetic background were rendered diabetic by five low doses of streptozotocin. We observed that, in the absence of diabetes, PPAR alpha deficiency resulted in an increase in abortion rate, i.e. 0% in WT mice vs. 20% in PPAR alpha-null mice [odds ratio (OR) = 14.33; P = 0.013]. Under diabetic conditions, the abortion rate was enhanced, i.e. 8.3% in WT mice vs. 50% in PPAR alpha-null mice (OR = 4.28; P = 0.011). In the pups born to diabetic dams, the offspring mortality, due to the absence of PPAR alpha, was enhanced, i.e. 27.7% in WT mice vs. 78.9% in PPAR alpha-null animals (OR = 11.48; P < 0.001). Moreover, we observed that T helper (Th) 1/Th2 balance was shifted to a pregnancy protecting Th2 phenotype in WT diabetic dams and to a noxious Th1 phenotype in PPAR alpha-null mice with diabetic pregnancy. Furthermore, offspring born to diabetic WT dams were hyperinsulinemic and hyperglycemic, and they exhibited up-regulated profile of Th2 cytokines, whereas those born to diabetic PPAR alpha-null dams were hypoinsulinemic and hyperglycemic, and they showed down-regulated profile of Th2 cytokines. However, IFN-gamma, a Th1 cytokine, was up-regulated in the offspring of both diabetic WT and PPAR alpha-null dams. Altogether, our results suggest that PPAR alpha deficiency in mice may be implicated in the increase in maternal abortion, neonatal mortality, and T cell differentiation.

Treatment with an estrogen receptor alpha ligand is neuroprotective in experimental autoimmune encephalomyelitis

Multiple sclerosis is an inflammatory, neurodegenerative disease for which experimental autoimmune encephalomyelitis (EAE) is a model. Treatments with estrogens have been shown to decrease the severity of EAE through anti-inflammatory mechanisms. Here we investigated whether treatment with an estrogen receptor alpha (ERalpha) ligand could recapitulate the estrogen-mediated protection in clinical EAE. We then went on to examine both anti-inflammatory and neuroprotective mechanisms. EAE was induced in wild-type, ERalpha-, or ERbeta-deficient mice, and each was treated with the highly selective ERalpha agonist, propyl pyrazole triol, to determine the effect on clinical outcomes, as well as on inflammatory and neurodegenerative changes. ERalpha ligand treatment ameliorated clinical disease in both wild-type and ERbeta knock-out mice, but not in ERalpha knock-out mice, thereby demonstrating that the ERalpha ligand maintained ERalpha selectivity in vivo during disease. ERalpha ligand treatment also induced favorable changes in autoantigen-specific cytokine production in the peripheral immune system [decreased TNFalpha, interferon-gamma, and interleukin-6, with increased interleukin-5] and decreased CNS white matter inflammation and demyelination. Interestingly, decreased neuronal staining [NeuN+ (neuronal-specific nuclear protein)/beta3-tubulin+/Nissl], accompanied by increased immunolabeling of microglial/monocyte (Mac 3+) cells surrounding these abnormal neurons, was observed in gray matter of spinal cords of EAE mice at the earliest stage of clinical disease, 1-2 d after the onset of clinical signs. Treatment with either estradiol or the ERalpha ligand significantly reduced this gray matter pathology. In conclusion, treatment with an ERalpha ligand is highly selective in vivo, mediating both anti-inflammatory and neuroprotective effects in EAE.

Interleukin-18 (IL-18) mRNA expression and localization of IL-18 mRNA-expressing cells in the mouse uterus

Interleukin-18 (IL-18) belongs to the interleukin-1 family and was identified as an interferon-gamma inducing factor. We investigated IL-18 mRNA-expressing cells in the mouse uterus. By RNase protection assay, IL-18 mRNA and alpha subunit of IL-18 receptor mRNA were detected in the uterus. In the uterus, IL-18 mRNA levels increased during sexual maturation. In situ hybridization analysis demonstrated IL-18 mRNA-expressing cells in the mouse uterus of different ages. At 21 days of age, IL-18 mRNA-expressing cells were detected in the luminal epithelial cells and stromal cells although the IL-18 mRNA signal was weak. At 42 days of age, IL-18 mRNA signal was mainly detected in the stromal cells located near the myometrium, and in some of the luminal and glandular epithelial cells. In the uterus of 63-day-old adult mice, a strong hybridization signal for IL-18 mRNA was detected at estrus, but was weak at diestrus. IL-18 mRNA was mainly detected in the glandular epithelial cells and stromal cells. The effect of estradiol-17beta (E(2)) on IL-18 mRNA-expressing cells in the uterus was examined in ovariectomized mice. In oil-treated mice IL-18 mRNA signal was localized in luminal epithelial cells and stromal cells, while in E(2)-treated mice IL-18 mRNA signal was localized in stromal cells alone. These results suggest that the mouse uterus has an IL-18 system, and IL-18 exerts a physiological role within the uterus in a paracrine manner, and that IL-18 gene expression is regulated by estrogen.

Interleukin-18 gene promoter polymorphisms and recurrent spontaneous abortion

BACKGROUND

IL-18 is a multifunctional cytokine capable of inducing either Th1 or Th2 polarization depending on the immunologic milieu. IL-18 is detected at the materno-fetal interface very soon in early pregnancy. Two polymorphisms in the promoter region of the IL-18 gene at positions of -607 and -137 appear to have functional impacts.

OBJECTIVE

This study attempts to evaluate the frequency of these two polymorphisms in the IL-18 gene promoter in patients with recurrent spontaneous abortion (RSA) and normal pregnant women.

SUBJECTS AND METHODS

One hundred and two RSA patients and 103 healthy pregnant women were enrolled in this study. Single nucleotide polymorphisms of the IL-18 gene at positions -607 (C/A) and -137 (G/C) were analyzed by the sequence-specific PCR method.

RESULTS

There was no significant association between the allele, genotype, and haplotype frequencies of the two single nucleotide polymorphisms (SNPs) in the IL-18 gene promoter and RSA.

CONCLUSION

The results of this study showed that IL-18 gene promoter polymorphisms at positions -607 and -137 did not confer susceptibility to RSA in southern Iranian patients.

Validation and comparison of luminex multiplex cytokine analysis kits with ELISA: determinations of a panel of nine cytokines in clinical sample culture supernatants

PROBLEM

Analyses of the expression pattern of multiple cytokines are frequently required for characterization of the status of the immune system as it pertains to Th type bias and intrinsic levels of inflammation. Classically, analysis of cytokine expression patterns has been performed by enzyme-linked immunosorbent assays (ELISA) for each separate analyte. A new technology, Luminex MAP, facilitates the simultaneous evaluation of multiple immune mediators with advantages of higher throughput, smaller sample volume, and lower cost. Validation of this technology has been limited to small sample sets, limited use of clinical study specimens, and use of non-commercial reagents.

METHODS

Ninety-six specimens from women over the course of their respective pregnancies were evaluated for cytokine concentrations using commercially available ELISA kits and commercially available Luminex MAP kits according to the manufacturers' directions. Correlations between data sets were evaluated using Pearson's correlation coefficient (r).

RESULTS

Excellent correlations were demonstrated for IL-1 beta, IL-4, IL-5, IL-6, IL-10, IFN gamma, and TNF alpha, in contrast to IL-12 p 70 and IL-13.

CONCLUSIONS

Luminex multiplex technology has distinct advantages and is a valid alternative method to ELISA for the evaluation of the majority of cytokines tested and for the characterization of immune system status.

Bovine IL-18 ELISA: detection of IL-18 in sera of pregnant cow and newborn calf, and in colostrum

In this study, we examined the concentration of bovine IL-18 in the sera of pregnant cows, their fetuses and newborn calves, and in colostrum in order to examine the role of IL-18 in bovine pregnancy and the neonatal period. A sandwich-ELISA to quantify bovine IL-18 was established using anti-porcine IL-18 monoclonal antibodies, which cross-reacted with bovine IL-18, and used it to measure the concentration of bovine IL-18 in the sera of pregnant cows, their fetuses and newborn calves, and in colostrum. Significant levels of IL-18 were detected in the sera of pregnant cows, but not in the sera obtained from the corresponding fetuses, umbilical arteries and veins. After birth, IL-18 levels in the sera of 1-day and 1-week old calves were low, and significantly increased in the sera of 1-month and 4-month old calves. IL-18 was also detected in colostrum, with the concentration of IL-18 in the first colostrum produced after delivery being the highest, and then decreasing depending on the number of milkings. Furthermore, the serum IL-18 concentration of newborn calves was increased after the oral administration of colostrum. These results suggest that IL-18 during bovine pregnancy and in the newborn period may play important roles in the maintenance of pregnancy and in the maturation of neonatal immunity.

Estrogen inhibits interleukin-18 mRNA expression in the mouse uterus

Interleukin-18 (IL-18) is a proinflammatory cytokine expressed in female reproductive organs in humans, rats and mice. The physiological roles of uterine IL-18 and the regulatory mechanisms of IL-18 gene expression are unclear. The present study aimed to clarify the effects of estradiol-17beta (E2) and progesterone (P4) on IL-18 mRNA expression in the mouse uterus. Distribution and expression levels of IL-18 mRNA were studied using an RNase protection assay. Expression of IL-18 mRNA was observed in all organs studied, including testes, ovaries and uteri. The uterine IL-18 mRNA level of estrous mice was higher than that of diestrous mice. E2 treatment (1, 5, 25 or 250 ng/mouse) decreased uterine IL-18 mRNA levels in ovariectomized mice dose-dependently. E2 treatment acutely decreased IL-18 mRNA levels 3 h after injection, but these levels returned to the initial level after 48 h. P4 treatment (1 mg/mouse) decreased uterine IL-18 mRNA levels after 12 h, but levels returned to the initial level after 48 h. Both uterine IL-18 and IL-18Ralpha mRNAs were detected in cultured endometrial epithelial and stromal cells. These results suggest that uterine IL-18 expression is reduced by sex steroid hormones and that IL-18 acts on endometrial cells in a paracrine or autocrine manner.

Prenatal stress alters cytokine levels in a manner that may endanger human pregnancy

OBJECTIVE

Recent data suggest that prenatal stress negatively affects pregnancy and infant outcome. Existing studies implicate dysregulation of the immune and endocrine systems in stress-related increases in premature labor and poor birth outcome, but no published studies have directly addressed the relationships among these variables during pregnancy. We sought to test the hypothesis that high levels of psychosocial stress and low levels of social support during pregnancy alter maternal cytokine profiles in a manner that contributes to poor birth outcomes.

METHODS

Psychosocial stress and social support were measured in 24 women with overtly normal pregnancies once during each trimester of pregnancy. Levels of interleukin-10 (IL-10), IL-6, and tumor necrosis factor-alpha (TNF-alpha) were assessed concurrently with stress and support measurements.

RESULTS

High social support was associated with low stress scores. Elevated stress scores were positively correlated with higher levels of the proinflammatory cytokines IL-6 and TNF-alpha, and with low levels of the antiinflammatory cytokine IL-10.

CONCLUSIONS

These findings provide initial support for our hypothesis that stress-related neural immune interactions may contribute to pregnancy complications and poor outcome, but require further study to determine the mechanism and significance of these effects.

An update in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is defined as three or more consecutive pregnancy losses prior to the 20th week of gestation. The etiology of recurrent spontaneous abortion is often unclear and may be multifactorial, with much controversy regarding diagnosis and treatment. Reasonably accepted etiologic causes include, genetics, anatomical, endocrine, placental anomalies, hormonal problems, infection, smoking and alcohol consumption, exposure to environmental factors, psychological trauma and stressful life event, certain coagulation and immunoregulatory protein defects. Detection of an abnormality in any of these areas may result into specific therapeutic measures, with varying degrees of success. However, the majority of cases of RSA remains unexplained and is found to be associated with certain autoimmune (APA, ANA, ACA, ATA, AECA) and alloimmune (APCA, Ab2, MLR-Bf) antibodies that may play major role in the immunologic failure of pregnancy and may lead to abortion. Alteration in the expression of HLA-G molecules, T-helper-1 (Th-1) pattern of cytokines and natural killer (NK) cells activity may also induce abortion. Various forms of treatment like antithrombotic therapies such as aspirin and heparin, intravenous immunoglobulin (IVIg) therapy, immunotherapy with paternal lymphocytes and vitamin D3 therapy are effective mode of treatment for unexplained cause of fetal loss in women with RSA.

Preliminary studies of cytokine secretion patterns associated with pregnancy in MS patients

Multiple sclerosis has a tendency to remit during pregnancy, followed by an increase in the risk for disease relapses in the postpartum period. In this communication, preliminary data are presented to indicate that activated peripheral blood mononuclear cells (PBMC) from the postpartum period secrete elevated levels of gamma-interferon (IFN-gamma) relative to those collected during the third trimester. In addition, myelin antigen-specific T cell lines established from the third trimester of pregnancy secrete elevated levels of interleukin-10. The data suggest that the study of the mechanisms underlying natural fluctuations in disease activity during pregnancy and the postpartum period holds promise for a better understanding of factors capable of initiating and regulating remission and exacerbation in MS.

Expression of IL-4, IL-8 and IL-18 messenger RNAs in maternal peripheral blood and relationships with the HbF-gamma chain mRNA in it

PROBLEM

This study was designed to examine immunological changes in maternal peripheral blood and the relationship of these changes with the amount of fetal cells in the blood.

METHOD OF STUDY

The expression of interleukin-4 (IL-4), IL-8, IL-18 and fetal hemoglobin gamma chain (HbF-gamma chain) messenger RNAs (mRNAs) in maternal peripheral blood was measured by a quantitative reverse transcription-polymerase chain reaction method.

RESULTS

In maternal peripheral blood, the expression of IL-4 mRNA was up-regulated from the second gestational month (GM) to delivery. The expression of IL-8 and IL-18 mRNAs was down-regulated from the third or fourth GM until the eighth or ninth GM, respectively, and both increased before the onset of labor, though IL-4 mRNA decreased. The expression of IL-8 and IL-18, but not IL-4, mRNAs was correlated with that of HbF-gamma chain mRNA.

CONCLUSIONS

Immunological interactions between maternal peripheral immune cells and fetal cells appear to be related to the onset of labor.

GM-CSF and Pregnancy: Evidence of Significantly Reduced Blood Concentrations in Unexplained Recurrent Abortion Efficiently Reverted by Intravenous Immunoglobulin Treatment

PROBLEM

Certain Th-2 cytokines and granulocyte-macrophage colony-stimulating factor (GM-CSF) are propitious for the success of pregnancy and recurrent spontaneous abortion (RSA) is often characterized by a failure of Th-2 type responses. These considerations as well as the use of intravenous immunoglobulin (IVIg) in RSA induced us to evaluate the levels of GM-CSF in normal pregnancies, in pregnant women affected with unexplained RSA and the effects of IVIg treatment.

METHOD OF STUDY

Peripheral blood free GM-CSF was measured by means of a sandwich enzyme immunoassay in 39 healthy women (13 non-pregnant, 26 pregnant) and in 53 RSA patients (11 non-pregnant, 42 pregnant). In 14 pregnant RSA patients GM-CSF was studied also after the very first IVIg infusion (0.5 g/kg body weight).

RESULTS

In healthy women we found a significant increase of GM-CSF during pregnancy, in pregnant RSA patients such an increase was not detected. After IVIg, GM-CSF concentrations were almost doubled.

CONCLUSIONS

GM-CSF is found increased in normal pregnancy and is very low during pregnancy in RSA. IVIg infusions are capable of increasing GM-CSF in pregnant recurrent aborters.

Plasma levels of the immunomodulatory cytokine interleukin-10 during normal human pregnancy: a longitudinal study

Pregnancy is proposed to be a Th2 phenomenon, where Th2 cytokines inhibit Th1 responses to improve foetal survival. The importance of interleukin-10 (IL-10), an immunomodulatory cytokine produced by Th2 cells, in the maintenance of normal pregnancy is becoming increasingly apparent. In a longitudinal case-control study, the physiological effect of pregnancy on plasma IL-10 was investigated. The plasma concentration of IL-10 was determined using an ELISA technique in 99 pregnant women sampled at 12, 20 and 35 weeks of gestation, 38 non-pregnant control subjects sampled in parallel and in a subgroup of women sampled at 3 days post-partum (n, pregnant 21, non-pregnant 21). Plasma IL-10 was significantly higher in pregnant women at 12, 20 and 35 weeks of gestation (p<0.05, p<0.01 and p<0.0001, respectively), and in mothers post-delivery (p<0.01) when compared to non-pregnant control subjects. Furthermore, there was no significant effect of gestational time on IL-10 concentration. Results from the current study suggest that elevated IL-10 is a physiological consequence of normal healthy pregnancy. These findings help clarify previous conflicting results and establish a range for plasma levels of IL-10 in normal healthy pregnancy.

Expression of nuclear factor of activated T cells mRNA in maternal peripheral blood cells

PROBLEM

In T lymphocytes, nuclear factor of activated T cells (NF-AT) regulates the induction of cytokine genes upon antigenic stimulation. This study was designed to analyse the relationship between NF-AT and pregnancy.

METHOD OF STUDY

With informed consent, peripheral blood cells (PBCs) were obtained from non-pregnant (n = 114), pregnant (n = 604), and puerperal women (n = 52). The expression of NF-AT2 and NF-AT3 mRNAs in PBCs was measured by a quantitative reverse transcriptase-polymerase chain reaction method.

RESULTS

In the early pregnancy period, in successful pregnancy, both NF-AT2 and NF-AT3 mRNAs increased significantly, whereas in cases of spontaneous abortion they did not change significantly. After peaking, they decreased gradually and were re-elevated in the ninth and tenth gestational month. In the puerperal period, NF-AT3 mRNAs decreased, but NF-AT2 mRNA showed a comparatively high expression level.

CONCLUSION

These findings suggested that in humans NF-AT signal transduction might be involved in alloantigenic recognition and tolerance and play important roles, especially in the early and late period of pregnancy.

PCR-based calibration curves for studies of quantitative gene expression in human monocytes: development and evaluation

BACKGROUND

Quantitative reverse transcription-PCR (RT-PCR) used to detect small changes in specific mRNA concentrations is often associated with poor reproducibility. Thus, there is a need for stringent quality control in each step of the protocol.

METHODS

Real-time PCR-based calibration curves for a target gene, tissue factor (TF), and a reference gene, beta-actin, generated from PCR amplicons were evaluated by running cDNA controls. In addition, the reverse transcription step was evaluated by running mRNA controls. Amplification efficiencies of calibrators and targets were determined. Variances within and between runs were estimated, and power statistics were applied to determine the concentration differences that could reliably be detected.

RESULTS

Within- and between-run variations (CVs) of cDNA controls (TF and beta-actin), extrapolated from reproducible calibration curves (CVs of slopes, 4.3% and 2.7%, respectively) were 4-10% (within) and 15-38% (between) using both daily and "grand mean" calibration curves. CVs for the beta-actin mRNA controls were 12% (within) and 19-28% (between). Estimates of each step's contribution to the total variation were as follows: CV(RT-PCR), 28%; CV(PCR), 15%; CV(RT), 23% (difference between CV(RT-PCR) and CV(PCR)). PCR efficiencies were as follows: beta-actin calibrator/target, 1.96/1.95; TF calibrator/target, 1.95/1.93. Duplicate measurements could detect a twofold concentration difference (power, 0.8).

CONCLUSIONS

Daily PCR calibration curves generated from PCR amplicons were reproducible, allowing the use of a grand mean calibration curve. The reverse transcription step contributes the most to the total variation. By determining a system's total variance, power analysis may be used to disclose differences that can be reliably detected at a specified power.

T(H)1/T(H)2 cytokine profile, metalloprotease-9 activity and hormonal status in pregnant rheumatoid arthritis and systemic lupus erythematosus patients

During the course of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), several immune and neuroendocrine changes associated with pregnancy may exert positive (amelioration) or negative (exacerbation) effects on the clinical outcome. In order to shed light on the mechanisms underlying these responses, we performed a prospective longitudinal study in RA and SLE pregnant women, including healthy pregnant women as a control group. Cytokine messenger RNA (mRNA) expression assessed by quantitative competitive polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC), cytokine levels and lymphocyte proliferation responses (LPR) following phytohaemagglutinin (PHA) stimulation of PBMC, plasma metalloprotease-9 activity (MMP-9) and hormonal status during pregnancy were determined. TNFa was the most abundant cytokine mRNA expressed in PBMC in all groups studied (healthy pregnant women, RA and SLE pregnant patients). However, a general TH2 response reflected by high IL-10 levels was found in RA, as well as SLE, patients. A significant change in IFN-gamma was observed in RA patients but only during the first trimester of pregnancy. This compared with a major TH1 response in healthy pregnant women. Interestingly, our study showed a homogeneous hormonal pattern in RA and SLE patients. Although decreased cortisol levels were observed in all patients studied, this is possibly related to the remission of disease activity status brought about by steroid treatment before and during pregnancy. In summary, we suggest that complex immune and hormonal networks are involved in pregnancy and that rheumatic diseases are very dynamic immune processes that cannot be described with a clear-cut cytokine profile. Furthermore, the observations in this study may reflect treatment-related immune effects more than those associated with disease.

In-situ detection of both inflammatory and anti-inflammatory cytokines in resting peripheral blood mononuclear cells during pregnancy

INTRODUCTION

Local and possibly systemic curtailment of the maternal immune response is important for a successful pregnancy. Although the local milieu at the utero-placental interface is likely to harbor the most prominent alterations, it is suggested, at least in mice, that systemic immunity is also tolerized during pregnancy. In the present study, we investigated mRNA expression of the key immunomodulatory cytokines; interleukin (IL)-4, IL-10, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma during normal pregnancy.

MATERIAL AND METHODS

In-situ hybridization (ISH) of cytokine mRNA in resting peripheral blood mononuclear cells (PBMCs) was used to detect the number of cells spontaneously expressing cytokines. Eleven women with normal gestations were followed during pregnancy as well as 8 weeks postpartum, and compared with 10 non-pregnant healthy controls.

RESULTS

The numbers of IFN-gamma and IL-4 mRNA expressing cells were found to be significantly increased during pregnancy and postpartum compared with non-pregnant controls. Pregnant women and non-pregnant controls did not differ in their expression of TNF-alpha and IL-10.

CONCLUSION

Our studies demonstrated increased numbers of both IFN-gamma and IL-4 mRNA expressing cells in blood suggesting that systemic immunomodulation, albeit partial, takes place during normal pregnancy. It is proposed that enhanced IL-4 expression, possibly in concert with other elevated anti-inflammatory immunomodulatory cytokines, curtail the potentially hazardous effects of IFN-gamma on systemic immunity during pregnancy.

Demonstration of the presence of IL-16, IL-17 and IL-18 at the murine fetomaternal interface during murine pregnancy

PROBLEM

To determine if interleukin-16 (IL-16), IL-17, and IL-18 are present at the murine fetomaternal interface during pregnancy as a first step towards investigating their roles in fetomaternal relationship.

METHODS

Expression of IL-16, IL-17, and IL-18, was assessed by immunohistochemistry (IHC) in the BALB/c x BALB/k (H2d x H2k), and the CBA/J x BALB/c non-abortion prone, and CBA/J x DBA/2 abortion prone matings. Enzyme-linked immunosorbent assay (ELISA) were performed for the two latter cytokines to compare local production in the abortion prone CBA/J x DBA/2 versus the non-abortion prone CBA/J x BALB/c matings.

RESULTS

Expression of IL-17 was borderline. The anti-IL-16 staining specifically localized in the uterine stroma and glandular epithelium and was rather low in the placenta. IL-18 staining started in the peri-implantation uterus in the basal proliferative stroma, and was also traced, although weaker, in the glandular epithelium. In the immediate post-implantation period, a weak stromal staining persisted but there was a strong labeling of the ectoplacental cone. Interestingly, when the ectoplacental cone differentiates into placenta having a major histocompatibility complex (MHC) class I + spongiotrophoblast and a (MHC class I-) labyrinth, a very strong transient labeling of uterine natural killer (u-NK) cells was found. Later in gestation, IL-18 was also produced by giant cell and spongiotrophoblast. Finally, we compared by ELISA the production of IL-17/-18 in CBA/J x DBA/2 and CBA/J x BALB/c matings. We detected significantly more IL-18 in the non-abortion prone combination decidua or placenta.

CONCLUSION

The three cytokines IL-16, IL-17, and IL-18 were detected at the fetomaternal interface with a tissue specific, stage-dependent distribution. The predominance of IL-18 secretion in the non-resorption prone matings lead us to question the general validity of the classical T-helper (Th)1/2 paradigm.

Modulation of cytokine mRNA expression by brain-derived neurotrophic factor and nerve growth factor in human immune cells

Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) exert various effects on immune cells. Here we studied, whether they influence the cytokine expression pattern in peripheral blood mononuclear cells (PBMCs) or antigen specific T-cells. In PBMCs BDNF and NGF had interindividually variable effects on T helper cell type (Th)1- and Th2-cytokines. However, there was a high correlation between the modulating properties of these neurotrophins (r=0.97) concerning the expression of interleukin (IL) 4, transforming growth factor-beta and tumour necrosis factor-alpha mRNA at a concentration of 100 ng/ml. In myelin basic protein-specific T-cell lines BDNF and NGF increased interferon -gamma mRNA to a moderate extent, but not IL4. No major effects were detected at the cytokine protein level. In conclusion, our results suggest a partial effect of neurotrophins on immune cells, which may be modified by other signals.

Human CD34(+) blood cells induce T-cell unresponsiveness to specific alloantigens only under costimulatory blockade

OBJECTIVES

The immunogenic role of human CD34(+) cells in allogeneic hematopoietic stem cell transplantation is controversial. In this study we tested the role of CD40 and CTLA4 ligands on CD34(+) cell costimulation of HLA-mismatched lymphocytes.

MATERIALS AND METHODS

An anti-CD40L monoclonal antibody (hu5C8) and/or CTLA4-Ig molecule were used in primary mixed lymphocyte culture (MLC) with irradiated CD34(+) blood cells and allogeneic responders. Then, secondary MLC, cytotoxic activity, and effector cytokine expression and production were measured.

RESULTS

Each reagent was able to reduce anti-CD34(+) cell alloreactivity, but only the combination of the anti-CD40L monoclonal antibody and CTLA4-Ig induced greater than 90% inhibition of T-cell response in primary MLC and prevented generation of cytotoxic T cells when priming with purified CD34(+) cells. Importantly, responder cells activated by allogeneic CD34(+) cells in the presence of anti-CD40L monoclonal antibody and CTLA4-Ig entered a state of antigen-specific unresponsiveness while responding to third party antigen, tetanus toxoid, or phytohemagglutinin, and showed suppression of interferon-gamma and increase of interleukin-10 expression and release. Interestingly, addition of interleukin-2 in secondary MLC did not reverse T-cell anergy.

CONCLUSIONS

The results demonstrate that human CD34(+) blood progenitors stimulate T-cell responses potently and can induce T-cell unresponsiveness only when both B7:CD28 and CD40:CD40L pathways are blocked, with an increase of interleukin-10-producing cells. Therefore, our data allow design of in vivo studies aimed at achieving T-cell tolerance across HLA barriers by using purified CD34(+) cells and costimulatory blockade.