Tau is a microtubule associated protein (MAP) that is regularly expressed under normal conditions to stabilize microtubules. However, in several neurodegenerative diseases including Parkinsons, Alzheimers, and epilepsy, tau undergoes excessive post-translational phosphorylation which causes tau to lose affinity for microtubules and become “soluble”. The accumulation of the unbound protein hypothetically promotes aggregate formation, which has become a pathological feature of these neurodegenerative diseases. In animal models of epilepsy, genetic deletion of tau reduces seizure occurrence, and in human epilepsy there is some evidence that phosphorylated tau (p-tau) accumulates in brain tissue. Both of these suggest that downregulation of tau expression and function may protect against seizures. We hypothesized that in an animal model of epilepsy we would similarly find loss of tau expression and increases in p-tau expression. So far, using western blot analysis we have found a decrease in the expression of total tau in the hippocampus (thought to be the focal point of seizures) in a rat model of temporal lobe epilepsy (75.45 ± 3.11 % of age-matched controls; n = 8; p = 0.0014). Also, we are investigating novel and homologous phosphorylation sites for tau when comparing rat brain samples and epileptic human brain samples by mass spectrometry. By uncovering potential tau-mediated pathology of epilepsy via identification of novel tau phosphosites in the disease state in both rats and humans, we may develop biomarkers that may be used to determine hyperexcitable regions in the brains of epilepsy patients.

Group B Streptococcus (GBS), is a pathogen that can cause maternal sepsis, neonatal invasive disease, preterm birth, and stillbirth in pregnant women and neonates. GBS resides in the vaginal tract of approximately 20% of healthy pregnant women in the U.S. and can subsist as a commensal bacteria or become highly invasive. There is currently no vaccine to prevent GBS infection, however, universal screening of pregnant women with intrapartum antibiotic prophylaxis to prevent invasive neonatal disease is employed in the U.S. As GBS strains can express a spectrum of virulence factors, our research objective was to determine if there was a correlation between key virulence factors (hemolysis and pigment production) and invasive GBS maternal/neonatal disease. We investigated GBS virulence factors in one of the largest biobanks of invasive GBS strains in the world, which included 234 GBS isolates obtained from pregnant women and neonates (1988-2009). Results were compared to those obtained using 51 GBS commensal isolates. GBS isolates were plated on sheep’s blood agar and Granada agar, followed by 24 hours of incubation at 37°C. Two individuals separately graded the hemolysis and pigment of each isolate in comparison to low and high controls. Genes in the CovR/CovS promoter region, which direct hemolysis, were also sequenced to identify non-synonymous mutations that might increase hemolytic potential. Invasive GBS isolates were found to be significantly more hemolytic and pigmented (p<0.05). We are currently analyzing the CovR/CovS mutations for evidence of positive selection and to define the virulence of the mutations identified. In summary, our data demonstrate that GBS maternal and neonatal invasive isolates have greater hemolytic potential than commensal isolates, which is the first evidence that routine microbiological testing of GBS may identify pregnant women at higher risk for GBS invasive disease.

Toxoplasma gondii is a prevalent parasitic infection capable of vertical transmission. This particular pathogen is able to infiltrate the placenta, and subsequently cause detrimental cognitive deformities in the growing fetus. Significant factors influencing deviation from typical fetal growth are 1) the pathogenic strain and 2) gestational age at the time of infection. Through this review I will first explore how immune responses vary in relation to the previously stated factors. Then I will evaluate the potential use of focused ultrasound application to stimulate the required immune response to treat Toxoplasma gondii infections in utero. Please note that currently, all results and conclusions are theoretical. Given the adverse effects administration of antiparasitic drugs may have on a growing fetus in terms of toxicity and resistance, the aim is to explore methods which may be capable of improving treatment of vertically transmitted Toxoplasma gondii, as well as other notable in utero infections.

 Cannabis sativa is one of the most widely used drugs in the world. In humans, Cannabis sativa is commonly used to alleviate anxiety and pain, among other things, in medical and recreational contexts. In mice, intraperitoneal (i.p.) injections of its primary psychoactive compound, Δ9-tetrahydrocannabinol (THC) produce a characteristic triad of behavioral responses consisting of hypolocomotion, hypothermia, and analgesia. However, injections of THC do not accurately represent how humans typically administer THC, which primarily consists of inhalation and oral consumption. To better model a typical route of administration used by humans, we developed a voluntary oral consumption paradigm in mice whereby THC is formulated in gelatin. Following habituation, mice were given ad libitum access to THC gelatin for 2 hours. We measured the triad behaviors immediately following consumption to determine whether voluntary oral consumption of THC-gelatin using this paradigm induces acute cannabimimetic behaviors. Due to the slow pharmacokinetic activity of orally consumed THC, we measured triad responses immediately, 1 hour, and 2 hours after consumption. To compare our relative THC-gelatin-induced cannabimimetic behaviors to published data, we replicated the triad experiment and demonstrated our ability to obtain dose-dependent triad responses by using i.p. injections. At high concentrations (4mg/15mL) of THC-gelatin, cannabimimetic behavioral responses matched those of mice treated with low-dose (3 mg/kg) of THC i.p. injections. From these initial studies we conclude that development of THC-gelatin formulation triggers characteristic cannabimimetic behavioral effects in mice. These results suggests that classical THC and cannabinoid-dependent behaviors in mice can feasibly be studied with a more translational model (Funded by DA051558). Optimizing an oral administration model of cannabinoids in mice will enable future research on the pharmacology of oral cannabinoid therapeutics. 

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication, restricted interests, and repetitive behaviors. Symptoms can vary widely in type and severity between individuals, but approximately 23% of children show clinical levels of aggression. Considering evidence for other racial disparities in healthcare, race/ethnicity is also a factor of interest in ASD research on disparities in diagnosis rates and severity. Previous studies have found ASD symptom severity, but not race, to be a significant predictor of physical aggression, though they investigated race alone and not as a moderator. This project aims to look at the relationship between measures of aggression and symptom severity, and the moderating effect of race/ethnicity on that relationship. 145 participants between the ages of 8-17 years with an autism diagnosis from an NIH-funded study were included in the analysis. Symptom severity was determined based on clinician observation of and interaction with the participant using the Autism Diagnostic Observation Schedule Calibrated Severity Score (ADOS CSS). Parents of the participants completed the Child Behavior Checklist (CBCL), rating their child’s level of emotional/behavioral problems. Questions were grouped together to yield scores in different “syndrome scale” categories, including aggressive behaviors. We will use multiple linear regressions to do predictive analysis on the relationships between symptom severity, aggression, and race. We expect that children with greater ASD symptom severity will display more aggressive behaviors. We also predict that there will be a moderating effect of race/ethnicity, with this relationship being stronger in white, non-Hispanic children than others. This study will provide insight into the diversity of ASD presentation, and it may help illuminate (biological or socially constructed) differences in ASD presentation between races/ethnicities and further efforts for equitable treatment.

Adoptive immunotherapies with engineered T cells offer great promise as safe and effective treatments to prevent and treat relapse of leukemia. T cells can be genetically modified to express T cell receptors (TCR-T) that target diverse types of tumor-associated antigens, including neoantigens created from abnormal, malignancy-restricted proteins. TCR-T immunotherapies targeting neoantigens have the advantage of being highly specific for malignant cells and thus should cause little damage to normal tissues. A critical step in developing neoantigen-targeting TCR-T immunotherapies is confirming that the engineered T cells recognize cells bearing the mutation(s) of interest. However, for uncommon mutations, few or no leukemia cell lines may exist that naturally contain mutations of interest. CRISPR/Cas9 offers to be an efficient and reliable method to model relevant mutations expressed under near-physiological conditions in cell lines relative to traditional gene editing tools. We will use CRISPR/Cas9-mediated gene editing to introduce missense mutations into genes encoding proteins involved in RNA splicing. Knock-in mutations will be introduced in acute myeloid leukemia (AML) cell lines by homology directed repair (HDR). These cell lines will then be used in in vitro assays to validate TCR-T cells recognition of neoantigen-bearing leukemia cells and in vivo assays to generate a xenograft model of human leukemia in mice. This project, in conjunction, with the continued work on antigen discovery will contribute to the development of a library of leukemia-antigen specific TCRs to provide T cell immunotherapy options for diverse patients in the future.