Cancer-related cognitive impairment (CRCI), marked by deficits in attention, processing speed, and memory, affects up to 75% of breast cancer patients during treatment. A phase II clinical trial reported reduced cognitive complaints in survivors taking oxaloacetic acid (OAA), a tricarboxylic acid (TCA) cycle metabolite with proposed roles in glutamate scavenging, reactive oxygen species reduction, and mitochondrial regulation. This study tests the hypothesis that OAA modulates inflammation and mitochondrial metabolism to improve neuroimmune function in aging. Aged female mice with chronic inflammatory phenotypes were treated with OAA, and outcomes were assessed via qPCR and RNA-seq for differential gene expression, flow cytometry for immune cell activation, and open-field assays for locomotor behavior. UMAP analysis of flow cytometry data showed that OAA shifted myeloid populations, particularly in spleen, increasing CD163⁺CD11b⁺ cells to levels comparable to young mice. OAA also partially restored age-associated transcriptional changes in the hippocampus and improved locomotor activity relative to untreated aged controls. Future work will employ HPLC-based metabolomics to quantify glutamate and related intermediates. These findings suggest that OAA-mediated metabolic modulation may attenuate inflammation and improve neuroimmune homeostasis, with potential relevance for alleviating CRCI in breast cancer survivors.

Monkeypox virus (MPXV) is a zoonotic Orthopoxvirus originally endemic to Africa that has re-emerged globally. MPXV is a double-stranded DNA virus that replicates in the host cell cytoplasm. MPXV gene OPG188 encodes Poxin-Schlafen, a nuclease responsible for evasion of host cGAS-STING immunity by cleaving 2’,3’-cGAMP. This blocks STING activation, which normally triggers immune responses against the presence of large, foreign DNA. Proteomic analysis identified four distinct phosphorylated serine sites on Poxin-Schlafen, suggesting phosphorylation may regulate its nuclease activity. To investigate whether these phosphorylation sites modulate immune evasion via inhibition of cGAS-STING signaling, site-directed mutagenesis generated phosphodeficient and phosphomimetic mutant plasmids. The unmodified and mutant constructs were transfected with STING-expressing plasmid into HEK293T cells. After 48 hours, Western blot analysis showed that Poxin-Schlafen blocked STING phosphorylation confirming its role in innate immune antagonism, but one phosphosite mutation doesn’t impede the protein’s downregulation of STING. These results indicate that multiple phosphorylation sites may collectively regulate Poxin-Schlafen-mediated STING dephosphorylation. Next steps would be to mutate these sites in various combinations and observe their effects. Identifying phosphorylation-dependent mechanisms of MPXV immune evasion may provide new insights into viral pathogenesis and inform antiviral therapeutic strategies targeting the cGAS-STING pathway.

Microfold cells (M-cells) are specialized epithelial cells in Peyer’s patches that facilitate antigen sampling and immune responses. RANKL, a protein that activates NF-κB signaling, and tumor necrosis factor-α (TNF-α) have been shown to initiate M-cell differentiation. This project investigates and optimizes the differentiation of M-cells using RANKL and TNF-α. M-cell markers will be used to measure effectiveness. HT29 cells, a human colorectal adenocarcinoma cell line, were treated with a dilution gradient of RANKL with and without TNF-α in 6-well plates with cover slides. After a week of incubation, differentiation was quantified with immunofluorescence staining and qPCR using primers for Sox8, SpiB, and GP2, markers of mature M Cells. Results were analyzed using the 2^-ΔΔCt method normalized to GAPDH. Results showed strong upregulation of Sox8, a crucial transcription factor involved in early-stage M-cell differentiation. Yet, GP2 expression was not significantly upregulated, which may be attributed to incomplete maturation of M-cells. A dose-dependent response to RANKL was seen, and peak Sox8 expression occurred at 100 ng/mL. The findings suggest that RANKL and TNF-α can effectively induce M-cell differentiation. Future experiments will be targeted to achieved M-cell maturation. This work has implications for co-culturing bacteria and epithelial cells to model host-pathogen interactions and immunity.

Strongyloides stercoralis is a skin-penetrating, human-parasitic nematode infecting over 600 million people globally. Preliminary data from the Hallem lab suggest that iL3s increase skin penetration in response to human-associated odorants. However, it is unknown whether this behavior in response to odorants is a mechanism for host selection. The goal of this project is to determine whether host-associated odorants contribute to host selection in skin-penetrating nematodes by utilizing Strongyloides ratti, a rat-parasitic nematode that is closely related to S. stercoralis. To investigate this, S. ratti iL3s were exposed to human or rat odors in an ex vivo skin-penetration assay and time to complete penetration was recorded. We found that S. ratti displays increased skin penetration speed when exposed to rat-associated odors: rat bedding and rat fur. Furthermore, human-associated odors, artificial sweat odor and human foot odor, appear to inhibit S. ratti skin-penetration speed. We identified one human-associated odorant, isovaleric acid, that appears to stimulate skin penetration. While human-associated, isovaleric acid is found broadly on mammalian skin potentially providing an explanation for the stimulatory response to the odorant. Another human-associated odorant, 3-methyl-1-butanol, did not appear to stimulate or inhibit the speed of skin penetration in S. ratti. We are now expanding our analysis to other odorants. The results provide an insight into how chemosensory cues contribute to host selectivity and may enable ne