ORCID Profile
0000-0002-7803-5364
Current Organisation
University of South Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 13-03-2022
DOI: 10.1111/IMCB.12539
Abstract: The ongoing coronavirus disease 2019 (COVID‐19) pandemic perpetuated by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants has highlighted the continued need for broadly protective vaccines that elicit robust and durable protection. Here, the vaccinia virus‐based, replication‐defective Sementis Copenhagen Vector (SCV) was used to develop a first‐generation COVID‐19 vaccine encoding the spike glycoprotein (SCV‐S). Vaccination of mice rapidly induced polyfunctional CD8 T cells with cytotoxic activity and robust type 1 T helper‐biased, spike‐specific antibodies, which are significantly increased following a second vaccination, and contained neutralizing activity against the alpha and beta variants of concern. Longitudinal studies indicated that neutralizing antibody activity was maintained up to 9 months after vaccination in both young and middle‐aged mice, with durable immune memory evident even in the presence of pre‐existing vector immunity. Therefore, SCV‐S vaccination has a positive immunogenicity profile, with potential to expand protection generated by current vaccines in a heterologous boost format and presents a solid basis for second‐generation SCV‐based COVID‐19 vaccine candidates incorporating additional SARS‐CoV‐2 immunogens.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.GHIR.2015.02.001
Abstract: Insulin-like growth factors (IGFs) are known to interact with the renin-angiotensin system (RAS). We previously demonstrated that administration of IGF1 to guinea pigs in early to mid pregnancy promotes placental function and fetal growth in mid to late gestation. Early administration of IGF2 had sustained, but not acute, effects on these parameters and also on placental structural differentiation. Here, we aimed to determine whether the IGFs interact with the placental RAS in early to mid gestation to modulate placental development and increase fetal growth and survival, and if IGF2 binding the IGF2R is implicated in the sustained effects of IGF2 treatment. At day 20 of pregnancy, guinea pigs were infused with 1m g/kg/day of IGF1, IGF2, (Leu27)IGF2 or vehicle for 18days and sacrificed on either day 62 (late pregnancy) or during the infusion period on day 35 (early-mid pregnancy). Placental structure at day 35 was analyzed using morphometric technique and expression of RAS genes in the placenta and placental and plasma renin activity were measured at both time points. Compared with vehicle at day 35 of gestation, IGF1 infusion reduced the total midsagittal cross-sectional area of the placenta (-17%, p = 0.02) and the labyrinth area (-22%, p = 0.014) but did not alter the labyrinth volume nor labyrinth:interlobium ratios. IGF2 treatment did not affect placental structure. IGF1 did not alter placental mRNA for any of the RAS genes quantified at day 35 (AGTR1, ACE, AGT, TGFB1) but increased TGFB1 expression by more than 16-fold (p = 0.005) at day 62. IGF2 increased placental expression of AGTR1 (+88%, p = 0.03) and decreased AGT (-73%, p = 0.01) compared with the vehicle-treated group at day 35, and both IGF2 and (Leu27)IGF2 increased expression of TGFB1 at day 62 by 9-fold (p = 0.016) and 6-fold (p = 0.019) respectively. Both IGFs increased the ratio of active:total placental renin protein (+22% p = 0.026 p = 0.038) compared to vehicle compared to vehicle at day 35 but not 62. At day 62, IGF2-treated mothers showed a marked increase in total plasma renin (+495%) and active renin (+359%) compared to vehicle but decreased the ratio of active to total renin by 41% (p = 0.042). (Leu27)IGF2-treated animals had higher levels of placental active renin (+73%, p = 0.001) and total renin (+71%, p = 0.001) compared with the vehicle control. The data obtained in the current study suggest the potential for alternate roles for the induction of the RAS after IGF treatment. IGF1 and 2 treatments increase the activation of prorenin to renin in the placenta, possibly due to increased protease activity. In addition, IGF2 treatment in early pregnancy may enhance the maternal adaptation to pregnancy through stimulation of renin in the kidney. The sustained effects on placental differentiation and function after IGF2 treatment suggest therapeutic potential for exogenous administration of IGFs in improving pregnancy outcomes.
Publisher: Wiley
Date: 10-2021
DOI: 10.1002/HSR2.410
Publisher: American Medical Association (AMA)
Date: 12-2011
DOI: 10.1001/ARCHPEDIATRICS.2011.796
Abstract: To examine whether single-nucleotide polymorphisms (SNPs) in VEGFA (-2578 C/A and +936 C/T) associate with small-for-gestational-age (SGA) pregnancies and to identify their effects on first-trimester placental VEGFA expression. Multicenter prospective cohort study. Adelaide, Australia, and Auckland, New Zealand. A total of 3234 nulliparous pregnant women, their partners, and their infants. The SNPs in the parent-infant trios and first-trimester placentae (n = 74) were genotyped. Placental VEGFA messenger RNA expression was determined by quantitative reverse transcription-polymerase chain reaction. Small for gestational age was defined as a birth weight less than the 10th customized birth weight percentile adjusted for maternal height, weight, parity, and ethnicity and for gestational age at delivery and infant sex. Uterine and umbilical artery Doppler was performed at 20 weeks' gestation, and resistance indices greater than the 90th percentile were considered abnormal. Of 2123 pregnancies, 1176 (55.4%) were uncomplicated and 216 (10.2%) had SGA infants. Neonatal VEGFA +936 C/T SNP associates with SGA (adjusted odds ratio [aOR], 1.6 95% CI, 1.0-2.3), SGA with abnormal Doppler findings (aOR, 3.5 95% CI, 1.8-7.1), lower birth weight (P = .006), customized birth weight percentile (P = .049), and abnormal uterine artery Doppler findings (OR, 2.5 95% CI, 1.2-5.4). Maternal VEGFA +936 C/T associates with abnormal umbilical artery Doppler findings (OR, 1.5 95% CI, 1.1-2.2). VEGFA +936 CT+TT first-trimester placentae have 36% lower VEGFA messenger RNA expression compared with CC (P = .045). Neonatal VEGFA +936 C/T associates with SGA, and the association is stronger for SGA with abnormal uterine or umbilical artery Doppler findings. The SNP also associates with reduced first-trimester placental VEGFA expression, suggesting that it may have a role in the pathogenesis of SGA. Trial Registration clinicaltrials.gov Identifier: ACTRN12607000551493.
Publisher: Bioscientifica
Date: 09-2014
DOI: 10.1530/EC-14-0068
Abstract: Circulating IGFs are important regulators of prenatal and postnatal growth, and of metabolism and pregnancy, and change with sex, age and pregnancy. Single-nucleotide polymorphisms (SNPs) in genes coding for these hormones associate with circulating abundance of IGF1 and IGF2 in non-pregnant adults and children, but whether this occurs in pregnancy is unknown. We therefore investigated associations of plasma IGF1 and IGF2 with age and genotype at candidate SNPs previously associated with circulating IGF1, IGF2 or methylation of the INS – IGF2 – H19 locus in men ( n =134), non-pregnant women ( n =74) and women at 15 weeks of gestation ( n =98). Plasma IGF1 concentrations decreased with age ( P .001) and plasma IGF1 and IGF2 concentrations were lower in pregnant women than in non-pregnant women or men (each P .001). SNP genotypes in the INS – IGF2 – H19 locus were associated with plasma IGF1 ( IGF2 rs680, IGF2 rs1004446 and IGF2 rs3741204) and IGF2 ( IGF2 rs1004446, IGF2 rs3741204 and H19 rs217727). In single SNP models, effects of IGF2 rs680 were similar between groups, with higher plasma IGF1 concentrations in in iduals with the GG genotype when compared with GA ( P =0.016), or combined GA and AA genotypes ( P =0.003). SNPs in the IGF2 gene associated with IGF1 or IGF2 were in linkage disequilibrium, hence these associations could reflect other genotype variations within this region or be due to changes in INS – IGF2 – H19 methylation previously associated with some of these variants. As IGF1 in early pregnancy promotes placental differentiation and function, lower IGF1 concentrations in pregnant women carrying IGF2 rs680 A alleles may affect placental development and/or risk of pregnancy complications.
No related grants have been discovered for Jamie Zhang.