Assessment of efficacy and safety of dose-dense doxorubicin and cyclophosphamide (ddAC) in combination with immunotherapy in early-stage triple-negative breast cancer.

PURPOSE: This study aimed to assess safety and efficacy of a modified KEYNOTE 522 protocol, which incorporated pembrolizumab every 6 weeks, allowing for concomitant dose-dense (14 day) doxorubicin and cyclophosphamide (ddAC). By optimizing this dosing, the intention of this modified protocol was to improve pathologic complete response (pCR) rates in a population associated with a poorer prognosis. METHODS: This was a retrospective, single-center, cohort study. Patients were included if they had early stage, triple-negative breast cancer, and received at least one dose of AC. The entire cohort received neoadjuvant chemotherapy including weekly carboplatin and paclitaxel with pembrolizumab every 3 weeks for 12 weeks (4 cycles). The group then received either ddAC with pembrolizumab 400 mg every 6 weeks, or AC with pembrolizumab 200 mg every 3 weeks. The primary objective was pCR rate at time of surgery. RESULTS: This study assessed outcomes in 25 patients over 34 months. The pCR rate in the pembrolizumab, AC 3-week cohort was 64.3% versus 81.8% in the ddAC and 6-week pembrolizumab group. No pembrolizumab-associated grade 3-4 adverse events occurred in the either cohort. Despite seeing an increased incidence of grade 3-4 toxicities in the ddAC arm, this did not result in additional chemotherapy delays or dose reductions. CONCLUSION: This study demonstrated tolerability and a potential for favorable outcomes with this patient population, making this modified KEYNOTE 522 protocol a reasonable treatment approach. Larger, prospective studies are warranted to assess the feasibility of this dosing and true optimization of patient outcomes given the small sample size of this study.

Comparison of avoidance assay techniques to determine the response to 1-octanol in C. elegans.

In C. elegans , avoidance behaviors are vital for the nematode's ability to respond to noxious environmental stimuli, including the odorant 1-octanol. To test avoidance to 1-octanol, researchers expose C. elegans to this odorant and determine the time taken to initiate backward locomotion. However, the 1-octanol avoidance assay is sensitive to sensory adaptation, where the avoidance response is reduced due to overexposure to the odorant. Here, we examined two methods to expose nematodes to 1-octanol, using an eyelash hair or a p10 pipette tip, to compare their susceptibility to cause sensory adaptation.

Protection against APOE4 -associated aging phenotypes with the longevity-promoting intervention 17α-estradiol in male mice.

The apolipoprotein ε4 allele ( APOE4 ) is associated with decreased longevity, increased vulnerability to age-related declines, and disorders across multiple systems. Interventions that promote healthspan and lifespan represent a promising strategy to attenuate the development of APOE4 -associated aging phenotypes. Here we studied the ability of the longevity-promoting intervention 17α-estradiol (17αE2) to protect against age-related impairments in APOE4 versus the predominant APOE3 genotype using early middle-aged mice with knock-in of human APOE alleles. Beginning at age 10 months, male APOE3 or APOE4 mice were treated for 20 weeks with 17αE2 or vehicle then compared for indices of aging phenotypes body-wide. Across peripheral and neural measures, APOE4 was associated with poorer outcomes. Notably, 17αE2 treatment improved outcomes in a genotype-dependent manner favoring APOE4 mice. These data demonstrate a positive APOE4 bias in 17αE2-mediated healthspan actions, suggesting that longevity-promoting interventions may be useful in mitigating deleterious age-related risks associated with APOE4 genotype.

Glial KCNQ K+ channels control neuronal output by regulating GABA release from glia in C. elegans.

KCNQs are voltage-gated K+ channels that control neuronal excitability and are mutated in epilepsy and autism spectrum disorder (ASD). KCNQs have been extensively studied in neurons, but their function in glia is unknown. Using voltage, calcium, and GABA imaging, optogenetics, and behavioral assays, we show here for the first time in Caenorhabditis elegans (C. elegans) that glial KCNQ channels control neuronal excitability by mediating GABA release from glia via regulation of the function of L-type voltage-gated Ca2+ channels. Further, we show that human KCNQ channels have the same role when expressed in nematode glia, underscoring conservation of function across species. Finally, we show that pathogenic loss-of-function and gain-of-function human KCNQ2 mutations alter glia-to-neuron GABA signaling in distinct ways and that the KCNQ channel opener retigabine exerts rescuing effects. This work identifies glial KCNQ channels as key regulators of neuronal excitability via control of GABA release from glia.

Metabolism-focused CRISPR screen unveils mitochondrial pyruvate carrier 1 as a critical driver for PARP inhibitor resistance in lung cancer.

Homologous recombination (HR) and poly ADP-ribosylation are partially redundant pathways for the repair of DNA damage in normal and cancer cells. In cell lines that are deficient in HR, inhibition of poly (ADP-ribose) polymerase (poly (ADP-ribose) polymerase [PARP]1/2) is a proven target with several PARP inhibitors (PARPis) currently in clinical use. Resistance to PARPi often develops, usually involving genetic alterations in DNA repair signaling cascades, but also metabolic rewiring particularly in HR-proficient cells. We surmised that alterations in metabolic pathways by cancer drugs such as Olaparib might be involved in the development of resistance to drug therapy. To test this hypothesis, we conducted a metabolism-focused clustered regularly interspaced short palindromic repeats knockout screen to identify genes that undergo alterations during the treatment of tumor cells with PARPis. Of about 3000 genes in the screen, our data revealed that mitochondrial pyruvate carrier 1 (MPC1) is an essential factor in desensitizing nonsmall cell lung cancer (NSCLC) lung cancer lines to PARP inhibition. In contrast to NSCLC lung cancer cells, triple-negative breast cancer cells do not exhibit such desensitization following MPC1 loss and reprogram the tricarboxylic acid cycle and oxidative phosphorylation pathways to overcome PARPi treatment. Our findings unveil a previously unknown synergistic response between MPC1 loss and PARP inhibition in lung cancer cells.

Traumatic brain injury screening and neuropsychological functioning in women who experience intimate partner violence.

Objective: The potential for traumatic brain injury (TBI) to occur as the result of intimate partner violence (IPV) has received increased interest in recent years. This study sought to investigate the possible occurrence of TBI in a group of women who survived IPV and to measure the specific profile of cognitive deficits using standardized neuropsychological measures. Method: A comprehensive questionnaire about abuse history; neuropsychological measures of attention, memory and executive functioning; and measures of depression, anxiety and post-traumatic stress disorder were given to women who were IPV survivors, women who were sexual assault (SA) survivors, and a comparison group of women who did not experience IPV or SA. Results: Overall, rates of potential TBI, as measured by the HELPS brain injury screening tool, were high and consistent with previous studies. Consistent with potential TBI, lower scores were demonstrated on measures of memory and executive functioning compared to survivors of SA or those not exposed to violence. Importantly, significant differences on measures of memory and executive functioning remained, after controlling for measures of emotion. Of note, cognitive changes were highest among women who experienced non-fatal strangulation (NFS) compared to IPV survivors who did not. Conclusions: Rates of TBI may be high in women who survive IPV, especially those who survive strangulation. Better screening measures and appropriate interventions are needed as well as larger studies that look at social factors associated with IPV.

Rectal temperature after hypoxia-ischemia predicts white matter and cortical pathology in the near-term ferret.

BACKGROUND: Neonatal encephalopathy (NE) remains a common cause of infant morbidity and mortality. Neuropathological corollaries of NE associated with acute hypoxia-ischemia include a central injury pattern involving the basal ganglia and thalamus, which may interfere with thermoregulatory circuits. Spontaneous hypothermia (SH) occurs in both preclinical models and clinical hypoxic-ischemic NE and may provide an early biomarker of injury severity. To determine whether SH predicts the degree of injury in a ferret model of hypoxic-ischemic NE, we investigated whether rectal temperature (RT) 1 h after insult correlated with long-term outcomes. METHODS: Postnatal day (P)17 ferrets were presensitized with Escherichia coli lipopolysaccharide before undergoing hypoxia-ischemia/hyperoxia (HIH): bilateral carotid artery ligation, hypoxia-hyperoxia-hypoxia, and right ligation reversal. One hour later, nesting RTs were measured. RESULTS: Animals exposed to HIH were separated into normothermic (NT; ≥34.4 °C) or spontaneously hypothermic (SH; <34.4 °C) groups. At P42, cortical development, ex vivo MRI, and neuropathology were quantitated. Whole-brain volume and fractional anisotropy in SH brains were significantly decreased compared to control and NT animals. SH brains also had significantly altered gyrification, greater cortical pathology, and increased corpus callosum GFAP staining relative to NT and control brains. CONCLUSION: In near-term-equivalent ferrets, nesting RT 1 h after HIH may predict long-term neuropathological outcomes. IMPACT: High-throughput methods to determine injury severity prior to treatment in animal studies of neonatal brain injury are lacking. In a gyrified animal model of neonatal inflammation-sensitized hypoxic-ischemic brain injury in the ferret, rectal temperature 1 h after hypoxia predicts animals who will have increased cortical pathology and white matter changes on MRI. These changes parallel similar responses in rodents and humans but have not previously been correlated with long-term neuropathological outcomes in gyrified animal models. Endogenous thermoregulatory responses to injury may provide a translational marker of injury severity to help stratify animals to treatment groups or predict outcome in preclinical studies.

Harnessing large language models (LLMs) for candidate gene prioritization and selection.

BACKGROUND: Feature selection is a critical step for translating advances afforded by systems-scale molecular profiling into actionable clinical insights. While data-driven methods are commonly utilized for selecting candidate genes, knowledge-driven methods must contend with the challenge of efficiently sifting through extensive volumes of biomedical information. This work aimed to assess the utility of large language models (LLMs) for knowledge-driven gene prioritization and selection. METHODS: In this proof of concept, we focused on 11 blood transcriptional modules associated with an Erythroid cells signature. We evaluated four leading LLMs across multiple tasks. Next, we established a workflow leveraging LLMs. The steps consisted of: (1) Selecting one of the 11 modules; (2) Identifying functional convergences among constituent genes using the LLMs; (3) Scoring candidate genes across six criteria capturing the gene's biological and clinical relevance; (4) Prioritizing candidate genes and summarizing justifications; (5) Fact-checking justifications and identifying supporting references; (6) Selecting a top candidate gene based on validated scoring justifications; and (7) Factoring in transcriptome profiling data to finalize the selection of the top candidate gene. RESULTS: Of the four LLMs evaluated, OpenAI's GPT-4 and Anthropic's Claude demonstrated the best performance and were chosen for the implementation of the candidate gene prioritization and selection workflow. This workflow was run in parallel for each of the 11 erythroid cell modules by participants in a data mining workshop. Module M9.2 served as an illustrative use case. The 30 candidate genes forming this module were assessed, and the top five scoring genes were identified as BCL2L1, ALAS2, SLC4A1, CA1, and FECH. Researchers carefully fact-checked the summarized scoring justifications, after which the LLMs were prompted to select a top candidate based on this information. GPT-4 initially chose BCL2L1, while Claude selected ALAS2. When transcriptional profiling data from three reference datasets were provided for additional context, GPT-4 revised its initial choice to ALAS2, whereas Claude reaffirmed its original selection for this module. CONCLUSIONS: Taken together, our findings highlight the ability of LLMs to prioritize candidate genes with minimal human intervention. This suggests the potential of this technology to boost productivity, especially for tasks that require leveraging extensive biomedical knowledge.

FABP5 is important for cognitive function and is an important regulator of the physiological effects and pharmacokinetics of acute Δ9 tetrahydrocannabinol inhalation in mice.

Fatty acid binding protein 5 (FABP5) interacts with the endocannabinoid system in the brain via intracellular transport of anandamide, as well as Δ9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis. Previous work has established the behavioral effects of genetic deletion of FABP5, but not in the presence of THC. The present study sought to further elucidate the role of FABP5 on the pharmacokinetic and behavioral response to THC through global deletion. Adult FABP5+/+ and FABP5-/- mice were tested for behavioral response to THC using Open Field (OF), Novel Object Recognition (NOR), T-Maze, Morris Water Maze (MWM), and Elevated Plus Maze (EPM). An additional cohort of mice was used to harvest blood, brains, and liver samples to measure THC and metabolites after acute administration of THC. Behavioral tests showed that some cognitive deficits from FABP5 deletion, particularly in MWM, were blocked by THC administration, while this was not observed in other measures of memory and anxiety (such as T-Maze and EPM). Measurement of THC and metabolites in blood serum and brain tissue through UPLC-MS/MS analysis showed that the pharmacokinetics of THC was altered by FABP5. The present study shows further evidence of the importance of FABP5 in cognitive function. Additionally, results showed that FABP5 is an important regulator of the physiological effects and pharmacokinetics of THC.

Isavuconazonium or posaconazole for antifungal prophylaxis in patients with acute myeloid leukemia.

BACKGROUND: Invasive fungal infection (IFI) prophylaxis is recommended in patients with acute myeloid leukemia (AML) during induction chemotherapy. Posaconazole (POSA) is the recommended agent of choice; however, this medication can be associated with QTc prolongation, hepatotoxicity, and drug-drug interactions. Furthermore, there is conflicting evidence for the role of isavuconazole (ISAV) in this setting as an alternative to POSA. OBJECTIVE: The primary objective of this study was to evaluate the use of ISAV prophylaxis for primary IFI prevention in patients with AML undergoing induction. Additionally, the study investigated the use of ISAV trough concentration monitoring and compared these results to the efficacy of POSA therapeutic drug monitoring (TDM). Other secondary objectives included assessing the rates of toxicities associated with either prophylactic agent. This study analyzed the impact these toxicities had on patient outcomes by examining the need to hold or discontinue therapy. The final endpoint considered the efficacy associated with multiple dosing strategies employed at the study institution. Specifically, this included the use of loading doses or foregoing these when initiating prophylaxis. METHODS: This was a retrospective, single-center, cohort study. Patients included in this study were adults with AML admitted to Duke University Hospital between June 30, 2016 and June 30, 2021, who received induction chemotherapy and primary IFI prophylaxis for at least 7 days. Exclusion criteria included patients who received concomitant antifungal agents and patients who received antifungal agents as secondary prophylaxis. RESULTS: 241 patients met inclusion criteria with 12 (4.98%) participants in the ISAV group and 229 (95.02%) participants in the POSA group. The IFI incidence in the POSA group was 14.5%, while the ISAV group did not have any occurrences of IFI. No significant difference was found in the rate of IFI occurrence between the two treatment groups (p = 0.3805). Furthermore, it was demonstrated that the use of a loading dose when initiating prophylaxis could impact rates of IFI for this patient population. CONCLUSION: Due to no difference in incidence, patient specific factors such as concomitant medications and baseline QTc should influence the choice between prophylactic agent.

Fatty Acid-Binding Protein 5 Gene Deletion Enhances Nicotine-Conditioned Place Preference: Illuminating the Putative Gateway Mechanisms.

Emerging evidence indicates that the endogenous cannabinoid system modulates the behavioral and physiological effects of nicotine. Fatty acid-binding proteins (FABPs) are among the primary intracellular trafficking mechanisms of endogenous cannabinoids, such as anandamide. To this end, changes in FABP expression may similarly impact the behavioral manifestations associated with nicotine, particularly its addictive properties. FABP5 +/+ and FABP5 -/- mice were tested for nicotine-conditioned place preference (CPP) at two different doses (0.1 or 0.5 mg/kg). The nicotine-paired chamber was assigned as their least preferred chamber during preconditioning. Following 8 days of conditioning, the mice were injected with either nicotine or saline. The mice were allowed to access to all the chambers on the test day, and their times spent in the drug chamber on the preconditioning versus the test days were used to examine the drug preference score. The CPP results showed that the FABP5 -/- mice displayed a higher place preference for 0.1 mg/kg nicotine than the FABP5 +/+ mice, while no CPP difference was observed for 0.5 mg/kg nicotine between the genotypes. In conclusion, FABP5 plays an important role in regulating nicotine place preference. Further research is warranted to identify the precise mechanisms. The results suggest that dysregulated cannabinoid signaling may impact nicotine-seeking behavior.

Chemoselective Oxidation of Thiols with Oxoammonium Cations.

The oxidation of various aryl and aliphatic thiols with the commercially available and environmentally benign reagent Bobbitt's salt (1) has been investigated. The reaction affords the corresponding disulfide products in good to excellent yields (71-99%) and can be accomplished in water, methanol, or acetonitrile solvent. Moreover, the process is highly chemoselective, tolerating traditionally oxidation-labile groups such as free amines and alcohols. Combined experimental and computational studies reveal that the oxidation takes place via a polar two-electron process with concomitant and unexpected deoxygenation of the oxoammonium cation through homolysis of the weak N-O bond, differing from prototypical radical-based thiol couplings. This unusual consumption of the oxidant has significant implications for the development of new nitroxide-based radical traps for probing S-centered radicals, the advancement of new electrochemical or catalytic processes involving nitroxide/oxoammonium salt redox couples, and applications to biological systems.

Prenatal Effects of Nicotine on Obesity Risks: A Narrative Review.

Nicotine usage by mothers throughout pregnancy has been observed to relate to numerous deleterious effects in children, especially relating to obesity. Children who have prenatally been exposed to nicotine tend to have lower birth weights, with an elevated risk of becoming overweight throughout development and into their adolescent and adult life. There are numerous theories as to how this occurs: catch-up growth theory, thrifty phenotype theory, neurotransmitter or endocrine imbalances theory, and a more recent examination on the genetic factors relating to obesity risk. In addition to the negative effect on bodyweight and BMI, individuals with obesity may also suffer from numerous comorbidities involving metabolic disease. These may include type 1 and 2 diabetes, high cholesterol levels, and liver disease. Predisposition for obesity with nicotine usage may also be associated with genetic risk alleles for obesity, such as the DRD2 A1 variant. This is important for prenatally nicotine-exposed individuals as an opportunity to provide early prevention and intervention of obesity-related risks.

Vitamin E Decreases Cytotoxicity and Mitigates Inflammatory and Oxidative Stress Responses in a Ferret Organotypic Brain Slice Model of Neonatal Hypoxia-Ischemia.

The gyrencephalic ferret brain is an excellent model in which to study hypoxia-ischemia (HI), a significant contributor to neurological injury in neonates. Vitamin E, an essential fat-soluble antioxidant, reduces oxidative stress and inflammation in both animal models and human infants. The aim of this study was to assess the effects of vitamin E after oxygen-glucose deprivation (OGD) in an organotypic ferret brain slice model of neonatal HI. We hypothesized that vitamin E would decrease cytotoxicity, inflammation, and oxidative stress in OGD-exposed brain slices. Term-equivalent ferrets were sacrificed at postnatal (P) day 21-23 and 300 µM whole-hemisphere brain slices were obtained. During a 24-h rest period, slices were cultured in either nontreated control conditions or with erastin, a promotor of oxidative stress. Slices were then exposed to 2 h of OGD followed by vitamin E (25-100 IU/kg), erastin (10 µM), or ferrostatin (1 µM), an inhibitor of ferroptosis. Relative cytotoxicity was determined using a lactate dehydrogenase assay, cell death was quantified via nuclear propidium iodide staining, oxidative stress was quantified via cellular glutathione (GSH) levels, and target genes responsive to oxidative stress and inflammation were evaluated by qRT-PCR. OGD increased cytotoxicity, which was significantly reduced by treatment with vitamin E. Vitamin E also preserved GSH after OGD and decreased amplification of certain markers of oxidative stress (CHAC1, SLC7A11) and inflammation (TNF-alpha, IL-8). Vitamin E remained protective after pretreatment with erastin and was more protective than ferrostatin, presumably due to its added anti-inflammatory properties. Results from the ferret whole-hemisphere OGD model support the premise that vitamin E neuroprotection is mediated by restoring GSH and acutely decreasing inflammation and oxidative stress after neonatal HI.

Evaluating Neuroprotective Effects of Uridine, Erythropoietin, and Therapeutic Hypothermia in a Ferret Model of Inflammation-Sensitized Hypoxic-Ischemic Encephalopathy.

Perinatal hypoxic-ischemic (HI) brain injury, often in conjunction with an inflammatory insult, is the most common cause of death or disability in neonates. Therapeutic hypothermia (TH) is the standard of care for HI encephalopathy in term and near-term infants. However, TH may not always be available or efficacious, creating a need for novel or adjunctive neurotherapeutics. Using a near-term model of inflammation-sensitized HI brain injury in postnatal day (P) 17 ferrets, animals were randomized to either the control group (n = 43) or the HI-exposed groups: saline vehicle (Veh; n = 42), Ur (uridine monophosphate, n = 23), Epo (erythropoietin, n = 26), or TH (n = 24) to test their respective therapeutic effects. Motor development was assessed from P21 to P42 followed by analysis of cortical anatomy, ex vivo MRI, and neuropathology. HI animals took longer to complete the motor assessments compared to controls, which was exacerbated in the Ur group. Injury resulted in thinned white matter tracts and narrowed cortical sulci and gyri, which was mitigated in Epo-treated animals in addition to normalization of cortical neuropathology scores to control levels. TH and Epo treatment also resulted in region-specific improvements in diffusion parameters on ex vivo MRI; however, TH was not robustly neuroprotective in any behavioral or neuropathological outcome measures. Overall, Ur and TH did not provide meaningful neuroprotection after inflammation-sensitized HI brain injury in the ferret, and Ur appeared to worsen outcomes. By comparison, Epo appears to provide significant, though not complete, neuroprotection in this model.

Rheological Properties of Coordinated Physical Gelation and Chemical Crosslinking in Gelatin Methacryloyl (GelMA) Hydrogels.

Synthetically modified proteins, such as gelatin methacryloyl (GelMA), are growing in popularity for bioprinting and biofabrication. GelMA is a photocurable macromer that can rapidly form hydrogels, while also presenting bioactive peptide sequences for cellular adhesion and proliferation. The mechanical properties of GelMA are highly tunable by modifying the degree of substitution via synthesis conditions, though the effects of source material and thermal gelation have not been comprehensively characterized for lower concentration gels. Herein, the effects of animal source and processing sequence are investigated on scaffold mechanical properties. Hydrogels of 4-6 wt% are characterized. Depending on the temperature at crosslinking, the storage moduli for GelMA derived from pigs, cows, and cold-water fish range from 723 to 7340 Pa, 516 to 3484 Pa, and 294 to 464 Pa, respectively. The maximum storage moduli are achieved only by coordinated physical gelation and chemical crosslinking. In this method, the classic thermo-reversible gelation of gelatin occurs when GelMA is cooled below a thermal transition temperature, which is subsequently "locked in" by chemical crosslinking via photocuring. The effects of coordinated physical gelation and chemical crosslinking are demonstrated by precise photopatterning of cell-laden microstructures, inducing different cellular behavior depending on the selected mechanical properties of GelMA.

Everything Is Science: A Free City-Wide Science Festival.

A week-long, city-wide science festival called Everything is Science (EiS) was developed to educate the community in an informal manner. The festival serves as a platform for presenters from diverse professions to give engaging talks (without PowerPoint slides) to the public, free of charge, in restaurants and bars around town. Over 350 people attended the events over 5 days with 33 presenters. Surveys completed by attendees and session coordinators indicate strong support for this festival. Altogether, the EiS festival serves as a no-cost method to engage with the community and improve science literacy with potential for adoption in other cities.

A Ferret Model of Inflammation-sensitized Late Preterm Hypoxic-ischemic Brain Injury.

There is an ongoing need for clinically relevant models of perinatal infection and hypoxia-ischemia (HI) in which to test therapeutic interventions for infants with the neurological sequela of prematurity. Ferrets are ideal candidates for modeling the preterm human brain, as they are born lissencephalic and develop gyrencephalic brains postnatally. At birth, ferret brain development is similar to a 13 week human fetus, with postnatal-day (P) 17 kits considered to be equivalent to an infant at 32-36 weeks' gestation. We describe an injury model in the P17 ferret, where lipopolysaccharide administration is followed by bilateral cerebral ischemia, hypoxia, and hyperoxia. This simulates the complex interaction of prolonged inflammation, ischemia, hypoxia, and oxidative stress experienced in a number of neonates who develop brain injury. Injured animals display a range of gross injury severity, with morphological changes in the brain including narrowing of multiple cortical gyri and associated sulci. Injured animals also show slowed reflex development, slower and more variable speed of locomotion in an automated catwalk, and decreased exploration in an open field. This model provides a platform in which to test putative therapies for infants with neonatal encephalopathy associated with inflammation and HI, study mechanisms of injury that affect cortical development, and investigate pathways that provide resilience in unaffected animals.

Transiently increased IgE responses in infants and pre-schoolers receiving only acellular Diphtheria-Pertussis-Tetanus (DTaP) vaccines compared to those initially receiving at least one dose of cellular vaccine (DTwP) - Immunological curiosity or canary in the mine?

BACKGROUND: Several previous studies have highlighted the strong Th2-polarising and IgE-promoting activity of the DTaP vaccine, but there is no evidence that this has pathological consequences and accordingly there is no current interest amongst vaccine developers in reformulating DTaP to attenuate these properties. In light of an apparent resurgence in pertussis in many countries, and emerging evidence from other areas of paediatric immunology of IgE-mediated interference with host defence mechanisms, this issue requires more detailed clarification. METHODS: We have re-evaluated the impact of DTaP-only versus mixed DTwP/DTaP vaccination on Th2-dependent "bystander" IgE responses in three cohorts of children under different priming conditions, encompassing both vaccine-targeted and unrelated antigens including food allergens. RESULTS: We confirm the generalised IgE-trophic activity of the DTaP vaccine in pre-schoolers and demonstrate similar (albeit transient) effects in infants. We additionally demonstrate that use of an alternative mixed infant priming schedule encompassing an initial dose of DTwP significantly attenuates this property. INTERPRETATION: Central to our interpretation of these findings are studies demonstrating: (i) mixed DTwP/DTaP priming improves resistance to pertussis disease and attenuates the IgE-stimulatory component of long term vaccine-specific memory; (ii) IgE-mediated mechanisms can interfere with innate antiviral immunity and accordingly exacerbate airway symptoms in infected children. These observations, taken together with the data presented here, suggest a plausible mechanistic link between baseline pertussis-specific IgE titres in DTaP vaccinees and susceptibility to pertussis disease, which merits testing. Retrospective IgE analyses on sera collected from children at the time of presentation with pertussis could resolve this issue.

Overlap of copper and iron uptake systems in mitochondria in Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, the mitochondrial carrier family protein Pic2 imports copper into the matrix. Deletion of PIC2 causes defects in mitochondrial copper uptake and copper-dependent growth phenotypes owing to decreased cytochrome c oxidase activity. However, copper import is not completely eliminated in this mutant, so alternative transport systems must exist. Deletion of MRS3, a component of the iron import machinery, also causes a copper-dependent growth defect on non-fermentable carbon. Deletion of both PIC2 and MRS3 led to a more severe respiratory growth defect than either individual mutant. In addition, MRS3 expressed from a high copy number vector was able to suppress the oxygen consumption and copper uptake defects of a strain lacking PIC2. When expressed in Lactococcus lactis, Mrs3 mediated copper and iron import. Finally, a PIC2 and MRS3 double mutant prevented the copper-dependent activation of a heterologously expressed copper sensor in the mitochondrial intermembrane space. Taken together, these data support a role for the iron transporter Mrs3 in copper import into the mitochondrial matrix.