Search bioRxiv⌕ Search

Biology subjects

Thefaine, C. E.

Publications and source records attributed to Thefaine, C. E..

3 recordsLinked to original sources

Diverse Microbial Exposure Enhances CD8+ T Cell Effector Memory Output and Function

Mice with normalized microbial exposure (NME) harbor an immune system that more accurately reflects that of humans compared to mice maintained as specific pathogen-free (SPF). An explanation for the observed alterations in the composition of the T cell compartment in NME mice has not been reported. We compared the T cell landscape in NME versus SPF mice at baseline and after acute LCMV infection. Using the immgenT dataset, we found no unique T cell populations in NME, but the landscape shifted towards activated T cells with increased propensity for effector functions and improved pathogen clearance. CD8+ KLRG1+ cells (immgenT CD8_cl12) are significantly expanded in NME mice. Their predominance was a result of both increased formation and the conversion of other memory populations to a KLRG1+ phenotype. Thus, NME mice provide insight into a diverse T cell compartment rich with cells previously found to be limited in SPF mice.

immunology↗

immgenT: A Comprehensive Reference of Convergent T-cell States in the Mouse

The immgenT collaborative project generated a comprehensive molecular atlas of T cells spanning virtually all mouse organs and disease states, profiling ~800,000 cells from 750 samples with RNA, 128-plex surface protein, and {beta}TCR sequence. Applying a deep generative model to joint RNA and protein data defined the landscape of T-cell states organized into eight lineages and 107 robust clusters, integrating similar cells from different contexts, and resolving prior nomenclatures. Analysis of effector molecules, transcription factors and modules showed that both immunological functions and regulatory programs are shared across cell states. This framework provides a stable, reusable reference, demonstrated by computationally integrating 16 external datasets from diverse biological contexts. A set of public web tools supports browsing of these data and mapping of any dataset onto the immgenT framework. These results propose a molecular classification of T cells organized around a set of shared states reused across immunological contexts.

immunology↗

Ablation of SYK kinase from primary human Natural Killer cells via CRISPR/Cas9 enhances cytotoxicity and cytokine production

Cytomegalovirus (CMV) infection alters natural killer (NK) cell phenotype and function toward a more memory-like immune state. These cells, termed adaptive NK cells, typically express CD57 and NKG2C but lack expression of the Fc receptor {gamma} chain (Gene: FCER1G, FcR{gamma}), PLZF, and SYK. Functionally, adaptive NK cells display enhanced antibody-dependent cellular cytotoxicity (ADCC) and cytokine production. However, the mechanism behind this enhanced function is unknown. To understand what drives cytotoxicity and cytokine production in adaptive NK cells, we optimized a CRISPR/Cas9 system to ablate genes from primary human NK cells. ADCC by human NK cells is exclusively mediated by the CD16A (Fc{gamma}RIIIA) signaling apparatus, which includes FcR{gamma}, CD3{zeta}, SYK, SHP-1, ZAP-70, and the transcription factor PLZF. We ablated the genes encoding these molecules and tested subsequent ADCC and cytokine production. We found that ablating the FcR{gamma} chain caused a modest increase in TNF production. Ablation of PLZF did not enhance ADCC or cytokine production. Importantly, SYK kinase ablation significantly enhanced both cytotoxicity and cytokine production, while ZAP-70 kinase ablation diminished function. Ablation of the phosphatase SHP-1 resulted in mixed effects on function, with NK cells demonstrating enhanced cytotoxicity but reduced cytokine production. These results indicate that the enhanced cytotoxicity and cytokine production of CMV-induced adaptive NK cells is more likely due to the loss of SYK than the lack of FcR{gamma} or PLZF. The lack of SYK expression may limit SHP-1-mediated inhibition of CD16A signaling, leading to enhanced cytotoxicity and cytokine production. In addition to providing mechanistic answers about CMV-induced adaptive NK cell functionality, our results indicate that NK chimeric antigen receptor (CAR) therapeutics that invoke ADCC signaling molecules (e.g., CD3{zeta} chain) may benefit from ablating SYK, while maintaining ZAP-70, to increase functionality.

immunology↗