Elevated cytokine and chemokine levels in the placenta are associated with in-utero HIV-1 mother-to-child transmission

Distinct cytokine profiles in late pregnancy in Ugandan people with HIV

During pregnancy, multiple immune regulatory mechanisms establish an immune-tolerant environment for the allogeneic fetus, including cellular signals called cytokines that modify immune responses. However, the impact of maternal HIV infection on these responses is incompletely characterized. We analyzed paired maternal and umbilical cord plasma collected during labor from 147 people with HIV taking antiretroviral therapy and 142 HIV-uninfected comparators. Though cytokine concentrations were overall similar between groups, using Partial Least Squares Discriminant Analysis we identified distinct cytokine profiles in each group, driven by higher IL-5 and lower IL-8 and MIP-1α levels in pregnant people with HIV and higher RANTES and E-selectin in HIV-unexposed umbilical cord plasma (P-value < 0.01). Furthermore, maternal RANTES, SDF-α, gro α -KC, IL-6, and IP-10 levels differed significantly by HIV serostatus (P < 0.01). Although global maternal and umbilical cord cytokine profiles differed significantly (P < 0.01), umbilical cord plasma profiles were similar by maternal HIV serostatus. We demonstrate that HIV infection is associated with a distinct maternal plasma cytokine profile which is not transferred across the placenta, indicating a placental role in coordinating local inflammatory response. Furthermore, maternal cytokine profiles in people with HIV suggest an incomplete shift from Th2 to Th1 immune phenotype at the end of pregnancy.

Crosstalk between inflammasomes, inflammation, and Nrf2: Implications for gestational diabetes mellitus pathogenesis and therapeutics

The role of inflammasomes in gestational diabetes mellitus (GDM) has emerged as a critical area of research in recent years. Inflammasomes, key components of the innate immune system, are now recognized for their involvement in the pathogenesis of GDM. Activation of inflammasomes in response to various triggers during pregnancy can produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-18 (IL-18), contributing to systemic inflammation and insulin resistance. This dysregulation not only impacts maternal health but also poses significant risks to fetal development and long-term health outcomes. Understanding the intricate interplay between inflammasomes and GDM holds promise for developing novel therapeutic strategies and interventions to mitigate the adverse effects of this condition on both mothers and their offspring. Researchers have elucidated that targeting inflammasomes using anti-inflammatory drugs and compounds can effectively reduce inflammation in GDM. Furthermore, the addition of nuclear factor erythroid 2-related factor 2 (Nrf2) to this complex mechanism opens novel avenues for therapeutics. The antioxidant properties of Nrf2 may potentially suppress inflammasome activation in GDM. This comprehensive review investigates the intricate relationship between inflammasomes and GDM, emphasizing the pivotal role of inflammation in its pathogenesis. It also sheds light on potential therapeutic strategies targeting inflammasome activation and explores the role of Nrf2 in mitigating inflammation in GDM.

Associations of circulation levels of cytokines with birthweight, preterm birth, spontaneous miscarriages, and stillbirth: A Mendelian randomization analysis

Background: The association between immune imbalances and adverse pregnancy outcomes has been extensive investigated by observational studies, but remain unclear. Thus, this study aimed to establish the causality of the circulation levels of cytokines on adverse pregnancy outcomes, such as offspring's birthweight (BW), preterm birth (PTB), spontaneous miscarriage (SM), and stillbirth (SB). Methods: Two-sample Mendelian randomization (MR) analysis was employed to investigate potential causal relations between 41 cytokines and pregnancy outcomes on the basis of previously published GWAS datasets. Multivariable MR (MVMR) analysis was implemented to investigate the effect of the composition of cytokine networks on the pregnancy outcomes. Potential risk factors were further estimated to explore the potential mediators. Results: Genetic correlation analysis based on large GWAS data sources revealed that genetically predicted MIP1b (β = -0.027, S.E. = 0.010, p = 0.009) and MCSF (β = -0.024, S.E. = 0.011, p = 0.029) were associated with reduced offspring's BW, MCP1 (OR: 0.90, 95% CI: 0.83-0.97, p = 0.007) was associated with reduced SM risk, SCF (β = -0.014, S.E. = 0.005, p = 0.012) associated with decreased number of SB in MVMR. The univariable MR showed that GROa (OR: 0.92, 95% CI: 0.87-0.97, p = 0.004) was associated with decreased PTB risk. Except for the MCSF-BW association, all above associations surpassed the Bonferroni corrected threshold. The MVMR results revealed that MIF, SDF1a, MIP1b, MCSF and IP10 composed cytokine networks, associated with offspring's BW. Risk factors analysis indicated that the above causal associations might be mediated by smoking behaviors. Conclusion: These findings suggest the causal associations of several cytokines with adverse pregnancy outcomes, which were potentially mediated by smoking and obesity. Some of the results did not been corrected through multiple tests and larger samples verification is required in further studies.

Pharmacological approaches to prevent vertical transmission of HIV and HBV

INTRODUCTION

Mother-to-child transmission (MTCT) is mainly responsible for the global pediatric HIV and HBV epidemic. Vertical transmission can be prevented and reduced through a series of interventions at the primary healthcare level, including extensive screening of pregnant women, administration of antivirals or immune-based treatments, counselling on type of delivery and breastfeeding.

AREAS COVERED

In this narrative review, approved therapeutic options for the treatment of pregnant women living with HIV or HBV are discussed with special focus on efficacy and safety profiles of each agent or drug class examined. The search was performed using Medline (via PubMed), Web of Science, and Google Scholar to identify studies assessing vertical transmission of both HIV and HBV.

EXPERT OPINION

Elimination of MTCT of both infections is firmly endorsed by major global commitments and the integration of tailored preventive interventions into maternal and newborn health services is of strategical importance to achieve this critical target. However, further research centered on antiviral-based and immunization trials among pregnant women is urgently needed to mitigate the risk of maternal and neonatal adverse outcomes, effectively prevent transmission to the offspring and finally eliminate the pediatric HIV and HBV epidemic, one of the key global health challenges of our time.

Anthropometry, body composition, early growth and chronic disease risk factors among Zambian adolescents exposed or not to perinatal maternal HIV

Early life exposures and growth patterns may affect long-term risk of chronic non-communicable diseases (NCD). We followed up in adolescence two Zambian cohorts (n 322) recruited in infancy to investigate how two early exposures - maternal HIV exposure without HIV infection (HEU) and early growth profile - were associated with later anthropometry, body composition, blood lipids, Hb and HbA1c, blood pressure and grip strength. Although in analyses controlled for age and sex, HEU children were thinner, but not shorter, than HIV-unexposed, uninfected (HUU) children, with further control for socio-demographic factors, these differences were not significant. HEU children had higher HDL-cholesterol than HUU children and marginally lower HbA1c but no other biochemical or clinical differences. We identified three early growth profiles - adequate growth, declining and malnourished - which tracked into adolescence when differences in anthropometry and body fat were still seen. In adolescence, the early malnourished group, compared with the adequate group, had lower blood TAG and higher HDL, lower grip strength (difference: -1·87 kg, 95 % CI -3·47, -0·27; P = 0·02) and higher HbA1c (difference: 0·5 %, 95 % CI 0·2, 0·9; P = 0·005). Lower grip strength and higher HbA1c suggest the early malnourished children could be at increased risk of NCD in later life. Including early growth profile in analyses of HIV exposure reduced the associations between HIV and outcomes. The results suggest that perinatal HIV exposure may have no long-term effects unless accompanied by poor early growth. Reducing the risk of young child malnutrition may lessen children's risk of later NCD.

Understanding Viral and Immune Interplay During Vertical Transmission of HIV: Implications for Cure

Despite the significant progress that has been made to eliminate vertical HIV infection, more than 150,000 children were infected with HIV in 2019, emphasizing the continued need for sustainable HIV treatment strategies and ideally a cure for children. Mother-to-child-transmission (MTCT) remains the most important route of pediatric HIV acquisition and, in absence of prevention measures, transmission rates range from 15% to 45% via three distinct routes: in utero, intrapartum, and in the postnatal period through breastfeeding. The exact mechanisms and biological basis of these different routes of transmission are not yet fully understood. Some infants escape infection despite significant virus exposure, while others do not, suggesting possible maternal or fetal immune protective factors including the presence of HIV-specific antibodies. Here we summarize the unique aspects of HIV MTCT including the immunopathogenesis of the different routes of transmission, and how transmission in the antenatal or postnatal periods may affect early life immune responses and HIV persistence. A more refined understanding of the complex interaction between viral, maternal, and fetal/infant factors may enhance the pursuit of strategies to achieve an HIV cure for pediatric populations.

The impact of the duration of HAART on cytokine profiles in pregnancy

OBJECTIVE

To determine the cytokine profile of HIV infected women treated with highly active anti-retroviral therapy (HAART) of variable duration in pregnancy.

METHODS

HIV infected women were enrolled at a large tertiary hospital in Durban, South Africa in their antenatal period and stratified into those that initiated HAART before pregnancy (pre-pregnancy HAART or PPH group) and those who initiated HAART during pregnancy (in-pregnancy HAART or IPH group). These were compared with HIV negative women (HN group), matched for gestational age at the time of enrolment. Serum was obtained and Th1 and Th2 cytokines expression determined using the Bio-Plex Pro™ Human Cytokine Treg Panels.

RESULTS

The overall cytokine profile of the cohort was pro-inflammatory as a result of significant IL-6 and TNF alpha expression. The anti-inflammatory markers (i.e. Th2 cytokines, namely IL4 and IL10) were poorly expressed by the whole cohort, with IL 4 seen almost exclusively in the IPH group, thus counter-balancing the predominantly pro-inflammatory milieu only in this group. PPH group had a pro-inflammatory milieu comparable to the HN control. IL 6 was the predominant cytokine in all groups, and as expected, it increased with advancing gestation in all the groups. This highly pro-inflammatory milieu was unexpected and needs further review CONCLUSION: Long use of HAART suppresses the anti-inflammatory markers previously reported to be conducive for the wellbeing of pregnancy. This effect needs further review as it was similarly observed in our HIV uninfected controls.

Impact of maternal HIV infection on pregnancy outcomes in southwestern China - a hospital registry based study

Globally, human immune deficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) continues to be a major public health issue. With improved survival, the number of people living with HIV/AIDS is increasing, with over 2 million among pregnant women. Investigating adverse pregnant outcomes of HIV-infected population and associated factors are of great importance to maternal and infant health. A cross-sectional data collected from hospital delivery records of 4397 mother-infant pairs in southwestern China were analysed. Adverse pregnant outcomes (including low birthweight/preterm delivery/low Apgar score) and maternal HIV status and other characteristics were measured. Two hundred thirteen (4.9%) mothers were HIV positive; maternal HIV infection, rural residence and pregnancy history were associated with all three indicators of adverse pregnancy outcomes. This research suggested that maternal population have high prevalence in HIV infection in this region. HIV-infected women had higher risks of experiencing adverse pregnancy outcomes. Rural residence predisposes adverse pregnancy outcomes. Findings of this study suggest social and medical support for maternal-infant care needed in this region, selectively towards rural areas and HIV-positive mothers.

Pregnancy favors circulating IL-21-secreting TFH -like cell recovery in ARV-treated HIV-1-infected women

PROBLEM

Pregnancy appears to favor maternal antibody production. In contrast, by damaging follicular helper T cells (T_FH ), HIV-1 infection compromises protective humoural immune response. Therefore, we aimed to investigate the frequency of different T_FH -like cells in HIV-infected pregnant women (PW) before and after antiretroviral (ARV) therapy.

METHOD OF STUDY

Peripheral blood mononuclear cells, CD4⁺ T and B cells, were obtained from asymptomatic HIV-1-infected non-PW and PW just before and after ARV therapy. In some experiments, healthy HIV-1-negative PW were also tested. The frequency of different T_FH -like cell subsets was determined by flow cytometry. The plasma titers of IgG anti-tetanus toxoid (TT), anti-HBsAg, and anti-gp41 were determined by ELISA. The in vitro production of total IgG, IL-21, and hormones (estrogen and progesterone) was quantified also by ELISA.

RESULTS

Our results demonstrate that antiretroviral (ARV) therapy was more efficient in elevating the percentage of circulating IL-21-secreting T_FH cells in HIV-1-infected pregnant women (PW) than in non-pregnant patients (nPW). Moreover, in co-culture systems, CD4⁺ T cells from ART-treated PW were more efficient in assisting B cells to produce IgG production. The in vivo anti-HBsAg IgG titers after ARV therapy were also significantly higher in PW, and their levels were directly associated with both IL-21⁺ T_FH frequency and plasma concentration of estrogen.

CONCLUSION

In summary, our results suggest that pregnancy favors the recovery of T_FH -like cells after ARV therapy in HIV-1-infected women, which could help these mothers to protect their newborns from infectious diseases by transferring IgG across the placenta.

HIV, Cytomegalovirus, and Malaria Infections during Pregnancy Lead to Inflammation and Shifts in Memory B Cell Subsets in Kenyan Neonates

Infections during pregnancy can expose the fetus to microbial Ags, leading to inflammation that affects B cell development. Prenatal fetal immune priming may have an important role in infant acquisition of pathogen-specific immunity. We examined plasma proinflammatory biomarkers, the proportions of various B cell subsets, and fetal priming to tetanus vaccination in cord blood from human United States and Kenyan neonates. United States neonates had no identified prenatal infectious exposures, whereas Kenyan neonates examined had congenital CMV or mothers with prenatal HIV or Plasmodium falciparum or no identified infectious exposures. Kenyan neonates had higher levels of IP-10, TNF-α, CRP, sCD14, and BAFF than United States neonates. Among the Kenyan groups, neonates with prenatal infections/infectious exposures had higher levels of cord blood IFN-γ, IL-7, sTNFR1, and sTNFR2 compared with neonates with no infectious exposures. Kenyan neonates had greater proportions of activated memory B cells (MBC) compared with United States neonates. Among the Kenyan groups, HIV-exposed neonates had greater proportions of atypical MBC compared with the other groups. Although HIV-exposed neonates had altered MBC subset distributions, detection of tetanus-specific MBC from cord blood, indicative of fetal priming with tetanus vaccine given to pregnant women, was comparable in HIV-exposed and non-HIV-exposed neonates. These results indicate that the presence of infections during pregnancy induces fetal immune activation with inflammation and increased activated MBC frequencies in neonates. The immunologic significance and long-term health consequences of these differences warrant further investigation.

Pediatric HIV-1 Acquisition and Lifelong Consequences of Infant Infection

Increased availability of antiretroviral therapy to pregnant and breastfeeding women in resource-limited areas has proven remarkably successful at reducing HIV vertical transmission rates over the past several decades. Yet, still more than 170,000 children are infected annually due to failures in therapy implementation, monitoring, and adherence. Mother-to-child transmission (MTCT) of HIV-1 can occur at one of several distinct stages of infant development - intrauterine, intrapartum, and postpartum. The heterogeneity of the maternal-fetal interface at each of these modes of transmission poses a challenge for the implementation of immune interventions to prevent all modes of HIV MTCT. However, using mother-infant human cohorts and nonhuman primate models of infant simian immunodeficiency virus (SIV) acquisition, investigators have made important observation about the biology of pediatric HIV infection and have identified unique protective immune factors for each mode of transmission. Knowledge of immune factors protective against HIV MTCT will be critical to the development of targeted immune therapies to prevent infant HIV acquisition and to bring an end to the pediatric AIDS epidemic.

IP-10 is highly involved in HIV infection

Interferon-γ (IFN-γ)-induced protein 10 (IP-10 or CXCL-10) is a chemokine involved in trafficking immune cells to inflammatory sites. Numerous studies have reported abnormally high plasma IP-10 levels in the context of human immunodeficiency virus (HIV) infection, and IP-10 is considered an important pro-inflammatory factor in the HIV disease process. The data regarding the roles of IP-10 in HIV infection required collation; this review summarizes the biological characteristics of IP-10, the positive association between plasma IP-10 levels and HIV disease progression, the effect of IP-10 on human immune cells, and potential related mechanisms. This review provides important insights into the role of IP-10 in HIV monitoring and treatment.

Marginal Effects of Systemic CCR5 Blockade with Maraviroc on Oral Simian Immunodeficiency Virus Transmission to Infant Macaques

Current approaches do not eliminate all human immunodeficiency virus type 1 (HIV-1) maternal-to-infant transmissions (MTIT); new prevention paradigms might help avert new infections. We administered maraviroc (MVC) to rhesus macaques (RMs) to block CCR5-mediated entry, followed by repeated oral exposure of a CCR5-dependent clone of simian immunodeficiency virus (SIV) mac251 (SIVmac766). MVC significantly blocked the CCR5 coreceptor in peripheral blood mononuclear cells and tissue cells. All control animals and 60% of MVC-treated infant RMs became infected by the 6th challenge, with no significant difference between the number of exposures (P = 0.15). At the time of viral exposures, MVC plasma and tissue (including tonsil) concentrations were within the range seen in humans receiving MVC as a therapeutic. Both treated and control RMs were infected with only a single transmitted/founder variant, consistent with the dose of virus typical of HIV-1 infection. The uninfected RMs expressed the lowest levels of CCR5 on the CD4+ T cells. Ramp-up viremia was significantly delayed (P = 0.05) in the MVC-treated RMs, yet peak and postpeak viral loads were similar in treated and control RMs. In conclusion, in spite of apparent effective CCR5 blockade in infant RMs, MVC had a marginal impact on acquisition and only a minimal impact on the postinfection delay of viremia following oral SIV infection. Newly developed, more effective CCR5 blockers may have a more dramatic impact on oral SIV transmission than MVC.IMPORTANCE We have previously suggested that the very low levels of simian immunodeficiency virus (SIV) maternal-to-infant transmissions (MTIT) in African nonhuman primates that are natural hosts of SIVs are due to a low availability of target cells (CCR5+ CD4+ T cells) in the oral mucosa of the infants, rather than maternal and milk factors. To confirm this new MTIT paradigm, we performed a proof-of-concept study in which we therapeutically blocked CCR5 with maraviroc (MVC) and orally exposed MVC-treated and naive infant rhesus macaques to SIV. MVC had only a marginal effect on oral SIV transmission. However, the observation that the infant RMs that remained uninfected at the completion of the study, after 6 repeated viral challenges, had the lowest CCR5 expression on the CD4+ T cells prior to the MVC treatment appears to confirm our hypothesis, also suggesting that the partial effect of MVC is due to a limited efficacy of the drug. New, more effective CCR5 inhibitors may have a better effect in preventing SIV and HIV transmission.

High Plasma Levels of sTNF-R1 and CCL11 Are Related to CD4+ T-Cells Fall in Human Immunodeficiency Virus Elite Controllers With a Sustained Virologic Control

Our aim was to analyze the relationship between plasma inflammatory biomarkers and CD4+ T-cells evolution in human immunodeficiency virus (HIV) elite controllers (HIV-ECs) with a suppressed viremia. We carried out a retrospective study in 30 HIV-ECs classified into two groups: those showing no significant loss of CD4+ T-cells during the observation period (stable CD4+, n = 19) and those showing a significant decrease of CD4+ T-cells (decline CD4+, n = 11). Baseline plasma biomarkers were measured using a multiplex immunoassay: sTNF-R1, TRAIL, sFas (APO), sFasL, TNF-α, TNF-β, IL-8, IL-18, IL-6, IL-10, IP-10, MCP-1, MIP-1α, MIP-1β, RANTES, SDF1α, GRO-α, and CCL11. Baseline levels of sTNF-R1 and CCL11 and sTNF-R1/TNF-α ratio correlated with the slope of CD4+ T-cells (cells/μl/year) during follow-up [r = -0.370 (p = 0.043), r = -0.314 (p = 0.091), and r = -0.381 (p = 0.038); respectively]. HIV-ECs with declining CD4+ T-cells had higher baseline plasma levels of sTNF-R1 [1,500.7 (555.7; 2,060.7) pg/ml vs. 450.8 (227.9; 1,263.9) pg/ml; p = 0.018] and CCL11 [29.8 (23.5; 54.9) vs. 19.2 (17.8; 29.9) pg/ml; p = 0.041], and sTNF-R1/TNF-α ratio [84.7 (33.2; 124.2) vs. 25.9 (16.3; 75.1); p = 0.012] than HIV-1 ECs with stable CD4+ T-cells. The area under the receiver operating characteristic (ROC) curve [area under ROC curve (AUROC)] were 0.758 ± 0.093 (sTNF-R1), 0.727 ± 0.096 (CCL11), and 0.777 ± 0.087 (sTNF-R1/TNF-α). The cut-off of 75th percentile (high values) for these biomarkers had 71.4% positive predictive value and 73.9% negative predictive value for anticipating the evolution of CD4+ T-cells. In conclusion, the loss of CD4+ T-cells in HIV-ECs was associated with higher levels of two plasma inflammatory biomarkers (sTNF-R1 and CCL11), which were also reasonably accurate for the prediction of the CD4+ T-cells loss.

Host Molecular Factors and Viral Genotypes in the Mother-to-Child HIV-1 Transmission in Sub-Saharan Africa

Maternal viral load and immune status, timing and route of delivery, viral subtype, and host genetics are known to influence the transmission, acquisition and disease progression of human immunodeficiency virus-1 (HIV-1) infection. This review summarizes the findings from published works on host molecular factors and virus genotypes affecting mother to child transmission (MTCT) in Africa and identifies the gaps that need to be addressed in future research. Articles in PubMed, Google and AIDSearch and relevant conference abstracts publications were searched. Accessible articles on host factors and viral genetics impacting the MTCT of HIV, done on African populations till 2015 were downloaded. Forty-six articles were found and accessed; 70% described host genes impacting the transmission. The most studied gene was the CCR5 promoter, followed by the CCR2-64I found to reduce MTCT; then SDF1-3’A shown to have no effect on MTCT and others like the DC-SIGNR, CD4, CCL3 and IP-10. The HLA class I was most studied and was generally linked to the protective effect on MTCT. Breast milk constituents were associated to protection against MTCT. However, existing studies in Sub Saharan Africa were done just in few countries and some done without control groups. Contradictory results obtained may be due to different genetic background, type of controls, different socio-cultural and economic environment and population size. More studies are thus needed to better understand the mechanism of transmission or prevention.

Maternal HIV infection alters the immune balance in the mother and fetus; implications for pregnancy outcome and infant health

PURPOSE OF REVIEW

With the rapid roll-out of combination antiretroviral therapy to prevent mother-to-child transmission of HIV, there is an annual increase in the number of uninfected infants born to HIV-infected women. Although the introduction of combination antiretroviral therapy has vastly improved pregnancy outcome and the health of infants born to HIV-infected women, concerns remain regarding the impact the maternal HIV infection on the pregnancy outcome and the health of HIV-exposed uninfected infants.

RECENT FINDINGS

Maternal HIV infection is associated with negative pregnancy outcomes such as low birth weight. In addition, an increased susceptibility to infections is reported in HIV-exposed uninfected infants compared with infants born to uninfected women. Studies have shown that HIV-exposure affects the maternal/fetal unit, with increase of proinflammatory cytokine produced by placental cells, as well as altered infant immune responses. These changes could provide the underlying conditions for negative pregnancy outcomes and facilitate mother-to-child transmission of HIV in the infant. Further studies are required to understand the underlying mechanisms and investigate whether these altered infant immune responses persist and have clinical consequences beyond childhood.

SUMMARY

HIV infection in pregnant women is associated with altered immune responses in HIV-infected women and their offspring with clinical consequences for pregnancy outcome and the HIV-exposed uninfected infant. Further studies are required to address the origin and long-term consequences of prenatal HIV-exposure and subsequent immune activation for infant health.

Impact of HIV-1 infection on the feto-maternal crosstalk and consequences for pregnancy outcome and infant health

Adaptation of the maternal immune system to establish maternal/fetal equilibrium is required for a successful pregnancy. Viral infections, including HIV-1 infection, can alter this maternal/fetal equilibrium, with significant consequences for pregnancy outcome, including miscarriages, impaired fetal growth, and premature delivery. Furthermore, maternal HIV-1 infection has been shown to have a long-term impact on the developing fetal immune system also when the infant is not infected with the virus. In this review, we discuss the consequences of maternal HIV-1 infection and antiretroviral therapy on pregnancy outcome and the health of the uninfected HIV-1-exposed infant.

Peripheral and placental biomarkers in women with placental malaria: a systematic review

Placental malaria (PM) causes significant morbidity in mothers and infants. Diagnosis of PM during pregnancy is however problematic due to placental sequestration of parasites. Host biomarkers may therefore be used as a diagnostic method. In this systematic review most studies focused on inflammatory markers. A trend was observed for increased IL-10 and TNF-α in PM positives. These markers are however unspecific, thus a combination of multiple biomarkers involved in different pathophysiological pathways of PM is indicated. Of interest are inflammatory markers (TNF-R2, CXCL-13), markers of lipid metabolism (APO-B), angiogenesis (sFlt-1) and hormones (estradiol). As the majority of published studies tested biomarker levels only at delivery, more longitudinal cohort studies will be necessary to detect biomarkers during pregnancy that can predict PM.

Development of a rectal sexually transmitted infection--HIV coinfection model utilizing Chlamydia trachomatis and SHIVSF162p3

BACKGROUND

Rectal sexually transmitted infections (STIs) may increase HIV susceptibility in men who have sex with men (MSM), and Chlamydia trachomatis is prevalent among HIV-positive MSM. To study STIs and HIV infection in MSM, we first evaluated whether cynomolgus macaques can sustain both C. trachomatis and SHIVSF162p3 infections.

METHODS

Four SHIVSF162p3 -positive male cynomolgus macaques were used (n = 3 rectally inoculated with 10(6) IFU; n = 1 control). Systemic and rectal SHIV RNA levels and cytokines were measured by real-time PCR and Luminex assays, respectively.

RESULTS

Macaques were successfully Chlamydia infected. Rectal SHIV shedding (P = 0.02 χ(2) ) and levels of G-CSF, IL-1ra, IL-6, IL-8, IFN-γ, and TNF-α (P ≤ 0.01, Mann-Whitney) in rectal secretions increased following infection.

CONCLUSIONS

These pilot data successfully demonstrate rectal C. trachomatis-SHIV coinfection in cynomolgus macaques and suggest the feasibility of a rectal C. trachomatis model for SHIV susceptibility and biomedical prevention studies in the context of rectal STIs.

Role of the placenta in adverse perinatal outcomes among HIV-1 seropositive women

Women seropositive for human immunodeficiency virus type 1 (HIV-1) are at an increased risk for a number of adverse perinatal outcomes. Although efforts to reduce mother-to-child transmission of HIV (MTCT) remain a priority in resource-limited countries, HIV testing and treatment have led to steep declines in MTCT in well-resourced countries. Even so, HIV seropositive pregnant women in the United States continue to deliver a disproportionately high number of preterm and low birth weight infants. In this mini-review, we address the role of the placenta in such HIV-related perinatal sequelae. We posit that adverse perinatal outcomes may result from two mutually non-exclusive routes: (1) HIV infection of the placenta proper, potentially leading to impaired maternal-fetal exchange; and (2) infection of the maternal decidual microenvironment, possibly disrupting normal placental implantation and development. Further research into the relationship between HIV-1 infection and placental pathology may lead to the development of novel strategies to improve birth outcomes among HIV-1 seropositive parturients.

Immunology of pediatric HIV infection

Most infants born to human immunodeficiency virus (HIV)-infected women escape HIV infection. Infants evade infection despite an immature immune system and, in the case of breastfeeding, prolonged repetitive exposure. If infants become infected, the course of their infection and response to treatment differs dramatically depending upon the timing (in utero, intrapartum, or during breastfeeding) and potentially the route of their infection. Perinatally acquired HIV infection occurs during a critical window of immune development. HIV's perturbation of this dynamic process may account for the striking age-dependent differences in HIV disease progression. HIV infection also profoundly disrupts the maternal immune system upon which infants rely for protection and immune instruction. Therefore, it is not surprising that infants who escape HIV infection still suffer adverse effects. In this review, we highlight the unique aspects of pediatric HIV transmission and pathogenesis with a focus on mechanisms by which HIV infection during immune ontogeny may allow discovery of key elements for protection and control from HIV.

The Significance of Interferon-γ in HIV-1 Pathogenesis, Therapy, and Prophylaxis

Interferon-γ (IFNγ) plays various roles in the pathogenesis of HIV/AIDS. In an HIV-1 infected individual, the production of IFNγ is detected as early as the acute phase and continually detected throughout the course of infection. Initially produced to clear the primary infection, IFNγ together with other inflammatory cytokines are involved in establishing a chronic immune activation that exacerbates clinical diseases associated with AIDS. Unlike Type 1 IFNs, IFNγ has no direct antiviral activity against HIV-1 in primary cultures, as supported by the in vivo findings of IFNγ therapy in infected subjects. Results from both in vitro and ex vivo studies show that IFNγ can instead enhance HIV-1 replication and its associated diseases, and therapies aimed at decreasing its production are under consideration. On the other hand, IFNγ has been shown to enhance cytotoxic T lymphocytes and NK cell activities against HIV-1 infected cells. These activities are important in controlling HIV-1 replication in an individual and will most likely play a role in the prophylaxis of an effective vaccine against HIV-1. Additionally, IFNγ has been used in combination with HIV-1 vaccine to augment antiviral immunity. Technological advancements have focused on using IFNγ as a biological marker to analyze the type(s) of immunity generated by candidate HIV vaccines and the levels of immunity restored by anti-retroviral drug therapies or novel immunotherapies. Hence, in addition to its valuable ancillary role as a biological marker for the development of effective HIV-1 prophylactic and therapeutic strategies, IFNγ has a vital role in promoting the pathogenesis of HIV.

Severity of maternal HIV-1 disease is associated with adverse birth outcomes in Malawian women: a cohort study

BACKGROUND

Compared with HIV-negative women, HIV-infected women have increased risk of low birthweight (LBW) and preterm delivery (PTD). We assessed whether severity of maternal HIV-1 disease was associated with LBW or PTD.

METHODS

Secondary analysis of The Malaria and HIV in Pregnancy prospective cohort, which enrolled HIV-positive, pregnant Malawian women from 2000 to 2004. Included participants (n = 809) were normotensive antiretroviral treatment-naive women who delivered a live singleton infant. Binomial regression models were used to assess the unadjusted and adjusted prevalence ratios (PRs) and 95% confidence intervals (CI) of the effect of severity of HIV-1 disease, defined by viral load and CD4 T-cell counts, on prevalence of LBW and PTD.

RESULTS

In unadjusted analyses, among those with malaria (n = 198), there was no association between severity of HIV-1 infection and LBW, whereas among women without malaria (n = 611), we observed a harmful association between both increasing peripheral viral load and LBW (PR: 1.44 per 1-log10 increase, 95% CI: 1.12 to 1.86) and placental viral load and LBW (PR: 1.24 per 1-log10 increase, 95% CI: 1.00 to 1.53). We observed a similar association between increasing placental viral load and PTD (PR: 1.33 per one-log10 increase, 95% CI: 1.04 to 1.69). These associations persisted in multivariate models adjusted for residence, maternal education, primigravid status, and maternal anemia.

CONCLUSIONS

In malaria-negative women, maternal HIV-1 disease severity was significantly associated with increased prevalence of LBW and PTD. Such an association was not found in the malaria-infected women.

Imbalance of placental regulatory T cell and Th17 cell population dynamics in the FIV-infected pregnant cat

BACKGROUND

An appropriate balance in placental regulatory T cells (Tregs), an immunosuppressive cell population, and Th17 cells, a pro-inflammatory cell population, is essential in allowing tolerance of the semi-allogeneic fetus. TGF-β and IL-6 are cytokines that promote differentiation of Tregs and Th17 cells from a common progenitor; aberrant expression of the cytokines may perturb the balance in the two cell populations. We previously reported a pro-inflammatory placental environment with decreased levels of FoxP3, a Treg marker, and increased levels of IL-6 in the placentas of FIV-infected cats at early pregnancy. Thus, we hypothesized that FIV infection in the pregnant cat causes altered placental Treg and Th17 cell populations, possibly resulting in placental inflammation.

METHODS

We examined the effect of FIV infection on Treg and Th17 populations in placentas at early pregnancy using quantitative confocal microscopy to measure FoxP3 or RORγ, a Th17 marker, and qPCR to quantify expression of the key cytokines TGF-β and IL-6.

RESULTS

FoxP3 and RORγ were positively correlated in FIV-infected placentas at early pregnancy, but not placentas from normal cats, indicating virus-induced alteration in the balance of these cell populations. In control cats the expression of IL-6 and RORγ was positively correlated as predicted, but this relationship was disrupted in infected animals. TGF-β was reduced in infected queens, an occurrence that could dysregulate both Treg and Th17 cell populations. Co-expression analyses revealed a highly significant positive correlation between IL-6 and TGF-β expression in control animals that did not occur in infected animals.

CONCLUSION

Collectively, these data point toward potential disruption in the balance of Treg and Th17 cell populations that may contribute to FIV-induced inflammation in the feline placenta.