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[Display omitted] • Malaria C3H1 zinc finger proteins PfCZIF1 and 2 have similar stage expression. • Both C3H1s could be truncated individually and partially in tandem. • Inability to knock-out both shows asexual parasite growth requires at least one. • Loss of PfCZIF2 led to changes in gene expression for exported proteins. Plasmodium falciparum exerts strong temporal control of gene expression across its lifecycle. Proteins expressed exclusively during late schizogony of blood stages, for example, often have a role in facilitating merozoite invasion of the host red blood cell (RBC), through merozoite development, egress, invasion or early establishment of infection in the RBC. Here, we characterise P. falciparum C3H1 zinc finger 1 (Pf CZIF1, Pf 3D7_1468400) and P. falciparum C3H1 zinc finger 2 (Pf CZIF2, Pf3D7_0818100) which we identified as the only C3H1-type zinc finger proteins with peak expression at schizogony. Previous studies reported that antibodies against Pf CZIF1 inhibit merozoite invasion, suggesting this protein may have a potential role during RBC invasion. We show using C-terminal truncations and gene knockouts of each of Pfczif1 and Pfczif2 that neither are essential for blood stage growth. However, they could not both be knocked out simultaneously, suggesting that at least one is needed for parasite growth in vitro. Immunofluorescence localisation of Pf CZIF1 and Pf CZIF2 indicated that both proteins occur in discrete foci on the periphery of the parasite's cytosol and biochemical assays suggest they are peripherally associated to a membrane. Transcriptomic analyses for the C-terminal truncation mutants reveal no significant expression perturbations with Pf CZIF1 truncation. However, modification of Pf CZIF2 appears to modify the expression for some exported proteins including Pf KAHRP. This study does not support a role for Pf CZIF1 or Pf CZIF2 in merozoite invasion of the RBC and suggests that these proteins may help regulate the expression of proteins exported into the RBC cytosol after merozoite invasion. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Merozoite invasion of host red blood cells (RBCs) is essential for survival of the human malaria parasite Plasmodium falciparum. Proteins involved with RBC binding and invasion are secreted from dual-club shaped organelles at the apical tip of the merozoite called the rhoptries. Here we characterise P. falciparum Cytosolically Exposed Rhoptry Leaflet Interacting protein 2 (PfCERLI2), as a rhoptry bulb protein that is essential for merozoite invasion. Phylogenetic analyses show that cerli2 arose through an ancestral gene duplication of cerli1. We show that PfCERLI2 is essential for blood-stage growth and localises to the cytosolic face of the rhoptry bulb. Inducible knockdown of PfCERLI2 led to a proportion of merozoites failing to invade and was associated with elongation of the rhoptry organelle during merozoite development and inhibition of rhoptry antigen processing. These findings identify PfCERLI2 as a protein that has key roles in rhoptry biology during merozoite invasion. Benjamin Liffner and Miguel Balbin et al. report that the Plasmodium falciparum protein, PfCERLI2, localises to the cytosolic face of the parasite's rhoptry bulb and is essential for invasion and growth within human red blood cells. [ABSTRACT FROM AUTHOR]

Perinatal exposures are associated with altered risks of childhood allergy. Human studies and our previous work suggest that restricted growth in utero (IUGR) is protective against allergic disease. The mechanisms are not clearly defined, but reduced fetal abundance and altered metabolism of methyl donors are hypothesized as possible underlying mechanisms. Therefore, we examined whether late-gestation maternal dietary methyl donor and cofactor supplementation of the placentally restricted (PR) sheep pregnancy would reverse allergic protection in progeny. Allergic outcomes were compared between progeny from control pregnancies (CON; n = 49), from PR pregnancies without intervention (PR; n = 28), and from PR pregnancies where the dam was fed a methyl donor plus cofactor supplement from day 120 of pregnancy until delivery (PR = Methyl; n = 25). Both PR and PR + Methyl progeny were smaller than CON; supplementation did not alter birth size. PR was protective against cutaneous hypersensitivity responses to ovalbumin (OVA; P = 0.01 in singletons). Cutaneous hypersensitivity responses to OVA in PR = Methyl progeny were intermediate to and not different from the responses of CON and PR sheep. Cutaneous hypersensitivity responses to house dust mites did not differ between treatments. In singleton progeny, upper dermal mast cell density was greater in PR + Methyl than in PR or CON (each P = 0.05). The differences in the cutaneous allergic response were not explained by treatment effects on circulating immune cells or antibodies. Our results suggest that mechanisms underlying in utero programming of allergic susceptibility by IUGR and methyl donor availability may differ and imply that late-gestation methyl donor supplementation may increase allergy risk. [ABSTRACT FROM AUTHOR]

Intrauterine growth restriction (IUGR) increases the risk of adult type 2 diabetes (T2D) and obesity. Neonatal exendin-4 treatment can prevent diabetes in the IUGR rat, but whether this will be effective in a species where the pancreas is more mature at birth is unknown. Therefore, we evaluated the effects of neonatal exendin-4 administration after experimental restriction of placental and fetal growth on growth and adult metabolic outcomes in sheep. Body composition, glucose tolerance, and insulin secretion and sensitivity were assessed in singletonborn adult sheep from control (CON; n = 6 females and 4 males) and placentally restricted pregnancies (PR; n = 13 females and 7 males) and in sheep from PR pregnancies that were treated with exendin-4 as neonates (daily sc injections of 1 nmol/kg exendin-4; PR + exendin- 4; n = 11 females and 7 males). Placental restriction reduced birth weight (by 29%) and impaired glucose tolerance in the adult but did not affect adult adiposity, insulin secretion, or insulin sensitivity. Neonatal exendin-4 suppressed growth during treatment, followed by delayed catchup growth and unchanged adult adiposity. Neonatal exendin-4 partially restored glucose tolerance in PR progeny but did not affect insulin secretion or sensitivity. Although the effects on glucose tolerance are promising, the lack of effects on adult body composition, insulin secretion, and insulin sensitivity suggest that the neonatal period may be too late to fully reprogram the metabolic consequences of IUGR in species that are more mature at birth than rodents. [ABSTRACT FROM AUTHOR]

Prenatal and early childhood exposures are implicated as causes of allergy, but the effects of intrauterine growth restriction on immune function and allergy are poorly defined. We therefore evaluated effects of experimental restriction of fetal growth on immune function and allergic sensitization in adolescent sheep. Immune function (circulating total red and white blood cells, neutrophils, lymphocytes, monocytes, eosinophils, and basophils, and the antibody response to Clostridial vaccination) and responses to house dust mite (HDM) allergen and ovalbumin (OVA) antigen sensitization (specific total Ig, IgG1, and IgE antibodies, and cutaneous hypersensitivity) were investigated in adolescent sheep from placentally restricted (PR, n = 23) and control (n = 40) pregnancies. Increases in circulating HDM-specific IgE (P = 0.007) and OVA-specific IgE (P = 0.038) were greater in PR than control progeny. PR did not alter total Ig, IgG1, or IgM responses to either antigen. PR increased OVA-specific but not HDM-specific IgA responses in females only (P = 0.023). Multiple birth increased Ig responses to OVA in a sex-specific manner. PR decreased the proportion of positive cutaneous hypersensitivity responders to OVA at 24 h (P = 0.030) but had no effect on cutaneous responses to HDM. Acute wheal responses to intradermal histamine correlated positively with birth weight in singletons (P = 0.023). Intrauterine growth restriction may suppress inflammatory responses in skin downstream of IgE induction, without impairment in antibody responses to a nonpolysaccharide vaccine. Discord between cutaneous and IgE responses following sensitization suggests new mechanisms for prenatal allergy programming. [ABSTRACT FROM AUTHOR]

Appropriate partitioning of nutrients between the mother and conceptus is a major determinant of pregnancy success, with placental transfer playing a key role. Insulin- like growth factors (IGFs) increase in the maternal circulation during early pregnancy and are predictive of fetal and placental growth. We have previously shown in the guinea pig that increasing maternal IGF abundance in early to mid-pregnancy enhances fetal growth and viability near term. We now show that this treatment promotes placental transport to the fetus, fetal substrate utilization, and nutrient partitioning near term. Pregnant guinea pigs were infused with IGF-I, IGF-II (both 1 mg·kg-1·day-1) or vehicle subcutaneously from days 20-38 of pregnancy (term = 69 days). Tissue uptake and placental transfer of the nonmetabolizable radio analogs [³H]methyl-D-glucose (MG) and [14C]aminoisobutyric acid (AIB) in vivo was measured on day 62. Early pregnancy exposure to elevated maternal IGF-1 in- creased placental MG uptake by >70% (P = 0.004), whereas each IGF increased fetal plasma MG concentrations by 40-50% (P < 0.012). Both IGFs increased fetal tissue MG uptake (P < 0.048), whereas IGF-l also increased AIB uptake by visceral organs (P = 0.046). In the mother, earlier exposure to either IGF increased AIB uptake by visceral organs (P < 0.014), whereas IGF-l also enhanced uptake of AIB by muscle (P = 0.044) and MG uptake by visceral organs (P = 0.016) and muscle (P = 0.046). In conclusion, exogenous maternal IGFs in early pregnancy sustainedly increase maternal substrate utilization, placental transport of MG to the fetus, and fetal utilization of substrates near term. This was consistent with the previously observed increase in fetal growth and survival following IGF treatment. [ABSTRACT FROM AUTHOR]

CDK8 regulates transcription either by phosphorylation of transcription factors or, as part of a four-subunit kinase module, through a reversible association of the kinase module with the Mediator complex, a highly conserved transcriptional coactivator. Deregulation of CDK8 has been found in various types of human cancer, while the role of CDK8 in supressing anti-cancer response of natural killer cells is being understood. Currently, CDK8-targeting cancer drugs are highly sought-after. Herein we detail the discovery of a series of novel pyridine-derived CDK8 inhibitors. Medicinal chemistry optimisation gave rise to 38 (AU1-100), a potent CDK8 inhibitor with oral bioavailability. The compound inhibited the proliferation of MV4-11 acute myeloid leukaemia cells with the kinase activity of cellular CDK8 dampened. No systemic toxicology was observed in the mice treated with 38. These results warrant further pre-clinical studies of 38 as an anti-cancer agent. Image 1 • Novel 3,4,5-trisubstituted pyridines were discovered as potent CDK8 inhibitors. • 38 selectively inhibited proliferation of MV4-11 over 18 human cancer cell lines. • 38 was orally bioavailable in rats and mice. • Administration of 38 did not induce systemic toxicity in mice. [ABSTRACT FROM AUTHOR]