Akshaya Thoutam

National Undergraduate Research Symposium: Poster at the St. Jude Children’s Hospital Abstract: Tumor-infiltrating cells have been described in the context of myeloid cells and T cells, but little is known about the role B cells play in the tumor microenvironment (TME). Using public scRNA-seq data, 132,390 B cells were characterized from 246 tumor samples across 9 human cancer types to identify distinct molecular characteristics across cancer types to create a pan-cancer transcriptional atlas of B cells. Many shared B cell lineages were found in both the TME and normal tissue, however distinct tumor-specific plasma and B cell subtypes exist exclusively in the TME of gastric, colon, breast, clear cell kidney cancer, and non-small cell lung cancer (NSCL). Tumor-infiltrating plasma cells in liver cancer and triple-negative breast cancer (TNBC) were seen to polarize towards an IgG isotype while normal breast and liver plasma cells were polarized to an IgA isotype. Gene set enrichment analysis revealed high oxidative phosphorylation and effector-like phenotype in IgG plasma cell subtypes suggesting their potential role in anti-tumor immunity. These results provide a holistic view of the highly heterogeneous landscape of Tumor-infiltrating B cells and suggest future avenues for potential targeted B cell immunotherapies.

Poster at the Atlanta Workshop for Single Cell Omics: Tumor-infiltrating cells have been described in the context of myeloid cells and T cells, but little is known about the role B cells play in the tumor microenvironment (TME). Using public scRNA-seq data, 133,488 B cells were characterized from 246 tumor samples across 9 human cancer types to identify distinct molecular characteristics across cancer types to create a pan-cancer atlas of B cells. Four major B cell lineages were found in both the TME and normal tissues, however distinct tumor-specific plasma subtypes exist exclusively in the TME of acute lymphoblastic leukemia, colon, HNSCC, breast, and lung cancer. Tumor-infiltrating plasma cells share a distinct transcriptional signature seen as a polarization toward IgG3 and IgG4 in head and neck, breast, lung, and liver cancer. Gene set enrichment analysis revealed a high interferon signature suggesting that the plasma cells reside in a pro-inflammatory TME. Enrichment of IL10RA, a mediator of the immunosuppressor signal IL10, indicates a common immunosuppressed state of IgHG3 and IgHG4 plasma cells in these specific tumor types. These results provide a holistic view of the highly heterogeneous Tumor-infiltrating plasma cells and suggest future avenues for potential targeted plasma cell immunotherapies.

It is now well-accepted that nanoparticles (NPs) introduced into a biological environment will interact with the available proteins that deposit on their surface in a process known as protein corona (PC) formation which control NP interactions with cells and biological barriers. Several investigations have been conducted to understand the mechanisms and kinetics of PC formation. Among the model nanoprobes are gold (Au) NPs that possess unique optical and electromagnetic properties due to their surface plasmon resonance. These properties make Au NPs excellent probes for studying PC formation. In this Review, we describe techniques and approaches that a researcher interested in investigating PC on Au NPs may utilize in order to characterize the PC formation