Does maternal vitamin D status influence placental weight or vascular and inflammatory pathology? Secondary analysis from the Kellogg Pregnancy Study.

INTRODUCTION: Positive effects of vitamin D (vitD) supplementation on comorbidities of pregnancy (COP) have been explored; however, few studies have elucidated the pathophysiology behind the development of these COP and the potential relationship with derangements in placental development and morphology. Additionally, it is known that placentas weighing 10th-90th % for gestational age are associated with better outcomes. Therefore, the objective of this study was to assess the impact of resulting circulating serum 25(OH)D concentrations associated with intake of high or low doses of supplementary vitD on placental development and morphology in women who participated in a randomized double blind, placebo-controlled trial of vitD supplementation. We hypothesized that if maternal serum 25(OH)D concentration (vitD status marker) is insufficient/deficient, then placental weight and % for gestational age (GA) will be smaller and will correlate with increased vascular and inflammatory placental pathologic findings. METHODS: The findings of the present study are a secondary analysis of data generated from a previously reported randomized controlled trial (RCT), the Kellogg Vitamin D Pregnancy Study. Pregnant women (n = 297) in this RCT (January 2013 - April 2018) were randomly assigned to 400 IU vs. 4400 IU vitD/day (10-14 weeks' gestational age) and followed to delivery. 132 placentas were analyzed by pathologists blinded to treatment, and the 2016 Amsterdam Consensus Criteria were used to categorize grouping/grading of placental pathology and weight. Total [25(OH)D] was measured using radioimmunoassay (ng/mL). Chi-square and Student's t-test were used to show the difference in maternal characteristics by treatment group and by placental weight. Chi-square analysis was used to determine differences between the percent pathology findings by treatment group. Students t-test was used to determine the differences in vitD status and the frequency of placental lesions. Association between [25(OH)D] area under the curve (AUC) and placental morphology were determined in a regression model that included maternal BMI ≥ 30 kg/m2, race/ethnicity, and vitD treatment group allocation. Data were analyzed using SAS v9.4 (Cary, NC) and statistical significance was indicated by p < 0.05. RESULTS: The percent pathology findings by treatment group were not significantly different for each of the placental pathology categories as defined by the 2016 Amsterdam Consensus Criteria including placental weight. However, when using 25(OH)D as a biomarker for vitD status, linear regression model showed maternal serum [25(OH)D] AUC was significantly associated with greater placental weight (p = 0.023). Logistic regression models showed mothers with BMI ≥ 30 kg/m2 had larger placental weight (p = 0.046), and Hispanic and white/Caucasian mothers had greater placental weights than Black American mothers (p = 0.025). When placentas ≥ 90th % for GA, n = 7, were removed from the placental pool, Pearson correlation still showed a positive association between maternal serum 25(OH)D AUC and placental weight (p = 0.011). In a second linear regression model of placentas ≥ 90th % for GA (n = 7) vs. placentas < 90th % (n = 108), maternal serum 25(OH)D AUC was significantly greater in those placentas ≥ 90th % (p = 0.03); however, this was not associated with increased perinatal mortality. CONCLUSION FINDINGS: suggest increasing maternal serum [25(OH)D] via vitamin D supplementation during pregnancy did not adversely affect placental morphology; trends showed those in the treatment group had fewer placental lesions. Placental weight was found to be significantly associated with [25(OH)D] AUC, which represents maternal vitamin D status over the course of pregnancy; 7 placentas ≥ 90th % for GA were not associated with perinatal mortality.

Investigation of peanut oral immunotherapy with CpG/peanut nanoparticles in a murine model of peanut allergy.

BACKGROUND: Treatments to reverse peanut allergy remain elusive. Current clinical approaches using peanut oral/sublingual immunotherapy are promising, but concerns about safety and long-term benefit remain a barrier to wide use. Improved methods of delivering peanut-specific immunotherapy are needed. OBJECTIVE: We sought to investigate the efficacy and safety of peanut oral immunotherapy using CpG-coated poly(lactic-co-glycolic acid) nanoparticles containing peanut extract (CpG/PN-NPs) in a murine model of peanut allergy. METHODS: C3H/HeJ mice were rendered peanut allergic by means of oral sensitization with peanut and cholera toxin. Mice were then subjected to 4 weekly gavages with CpG/PN-NPs, vehicle (PBS), nanoparticles alone, peanut alone, CpG nanoparticles, or peanut nanoparticles. Untreated mice served as naive controls. After completing therapy, mice underwent 5 monthly oral peanut challenges. Anaphylaxis was evaluated by means of visual assessment of symptom scores and measurement of body temperature and plasma histamine levels. Peanut-specific serum IgE, IgG1, and IgG2a levels were measured by using ELISA, as were cytokine recall responses in splenocyte cultures. RESULTS: Mice with peanut allergy treated with CpG/PN-NPs but not vehicle or other treatment components were significantly protected from anaphylaxis to all 5 oral peanut challenges, as indicated by lower symptom scores, less change in body temperature, and a lower increase of plasma histamine levels. Importantly, CpG/PN-NP treatment did not cause anaphylactic reactions. Treatment was associated with a sustained and significant decrease in peanut-specific IgE/IgG1 levels and an increase in peanut-specific IgG2a levels. Compared with vehicle control animals, peanut recall responses in splenocyte cultures from nanoparticle-treated mice showed significantly decreased levels of TH2 cytokines (IL-4, IL-5, and IL-13) but increased IFN-γ levels in cell supernatants. CONCLUSIONS: Preclinical findings indicate that peanut oral immunotherapy with CpG/PN-NPs might be a valuable strategy for peanut-specific immunotherapy in human subjects.

TLR9-targeted biodegradable nanoparticles as immunization vectors protect against West Nile encephalitis.

Vaccines that activate humoral and cell-mediated immune responses are urgently needed for many infectious agents, including the flaviviruses dengue and West Nile (WN) virus. Vaccine development would be greatly facilitated by a new approach, in which nanoscale modules (Ag, adjuvant, and carrier) are assembled into units that are optimized for stimulating immune responses to a specific pathogen. Toward that goal, we formulated biodegradable nanoparticles loaded with Ag and surface modified with the pathogen-associated molecular pattern CpG oligodeoxynucleotides. We chose to evaluate our construct using a recombinant envelope protein Ag from the WN virus and tested the efficiency of this system in eliciting humoral and cellular responses and providing protection against the live virus. Animals immunized with this system showed robust humoral responses polarized toward Th1 immune responses compared with predominately Th2-biased responses with the adjuvant aluminum hydroxide. Immunization with CpG oligodeoxynucleotide-modified nanoparticles resulted in a greater number of circulating effector T cells and greater activity of Ag-specific lymphocytes than unmodified nanoparticles or aluminum hydroxide. Ultimately, compared with alum, this system offered superior protection in a mouse model of WN virus encephalitis.