Biology subjects

Thoms, A.

Publications and source records attributed to Thoms, A..

4 recordsLinked to original sources

bioRxiv2026

Weaning imprints a hybrid cytotoxic-regulatory identity on intestinal CD4+ T lymphocytes

The intestinal immune system must adapt as the neonatal gut shifts from milk to solid food and becomes densely colonized. How the T cell compartment is established under these conditions remains unclear. Using fate-mapping to timestamp naive T cells, with imaging, transcriptomic, and repertoire analyses, we tracked them from suckling to adulthood. Intestinal T cell entry peaked at weaning, coinciding with relocation from crypts to villi guided by the tissue microenvironment and, partly, the microbiota. T cells timestamped at suckling persisted into adulthood and, at weaning, adopted a transient cytotoxic-regulatory state in the lamina propria, with granzyme B expression microbiota-dependent only in the ileum. Clonal expansions at weaning were restricted to the small intestinal lamina propria and absent in germ-free mice. Most expanded clones recognized early-life commensals. Weaning is a physiological window of transient inflammation imprinting a hybrid CD4 T cell compartment, suggesting that early-life commensals modulate T cell selection.

immunology↗

bioRxiv2026

Colorectal cancers with distinct metastatic potential trigger divergent early T cell responses

Colorectal cancer (CRC) remains a leading cause of cancer mortality, with most cases refractory to immunotherapy. Distinguishing tumor-induced from steady-state mucosal T cell responses has been a critical barrier to understanding antitumor immunity in CRC. Using orthotopic transplantation of CRC organoids with and without metastatic potential, combined with temporal T cell fate-mapping, we show that non-metastatic tumors elicit early recruitment of CD8{beta} and CD4 T cells that acquired cytotoxic and Th1-like programs, whereas pro-metastatic tumors induce a naive-like, hypoactivated state. Tumor-infiltrating CD4+ T cells underwent clonal expansion, including clones recognizing microbial and dietary antigens. T cells in physical contact with tumor cells, identified by uLIPSTIC, were enriched for expanded and cytotoxic clones. Fate-mapped T cells from non-metastatic tumors suppressed tumor growth in an IFN-{gamma}-dependent manner, whereas pro-metastatic tumor-derived T cells failed to do so. Mechanistically, pro-metastatic tumors downregulated MHCII, and Ciita targeting in non-metastatic organoids reduced CD4 clonal expansion and led to tumor progression. Together, these findings define divergent early T cell trajectories associated with CRC metastatic potential, indicating that ineffective local immune engagement precedes metastatic dissemination.

immunology↗

bioRxiv2026

One-step generation of TCR knock-in mice targeted to the TCRβ locus results in functional mature T lymphocytes

Transgenic mouse models expressing predefined T cell receptors (TCRs) have been instrumental in advancing our understanding of T cell biology. However, these traditional models rely on random genomic insertion of large constructs, require labor-intensive embryo manipulation, and frequently result in aberrant TCR expression and phenotypes. These limitations render TCR transgenic models insufficient to meet the mounting demands for rapid and precise model systems to evaluate TCR specificities. To address these challenges, we developed a streamlined method that combines Adeno-Associated Virus (AAV), coupled with CRISPR/Cas9 genome editing to precisely integrate pre-rearranged TCR/{beta} sequences into the mouse Trb locus, enabling the rapid generation of first-of-its-kind TCR knock-in mice with physiological TCR expression and functional T cell differentiation. This approach bypasses the need for technically advanced embryo manipulation and enables rapid generation of models through a universally optimized AAV vector system, significantly enhancing the versatility and utility of monoclonal TCR mice in basic immunology and preclinical research such as cancer immunotherapy and vaccine development, providing a transformative resource to accelerate discovery and translation across disciplines.

immunology↗

bioRxiv2024

An in vivo 'turning model' reveals new RanBP9 interactions in lung macrophages.

The biological functions of the scaffold protein Ran Binding Protein 9 (RanBP9) remain elusive in macrophages or any other cell type where this protein is expressed together with its CTLH (C-terminal to LisH) complex partners. We have engineered a new mouse model, named RanBP9-TurnX, where RanBP9 fused to three copies of the HA tag (RanBP9-3xHA) can be turned into RanBP9-V5 tagged upon Cre-mediated recombination. We created this model to enable stringent biochemical studies at cell type specific level throughout the entire organism. Here, we have used this tool crossed with LysM-Cre transgenic mice to identify RanBP9 interactions in lung macrophages. We show that RanBP9-V5 and RanBP9-3xHA can be both co-immunoprecipitated with the known members of the CTLH complex from the same whole lung lysates. However, more than ninety percent of the proteins pulled down by RanBP9-V5 differ from those pulled-down by RanBP9-HA. The lung RanBP9-V5 associated proteome includes previously unknown interactions with macrophage-specific proteins as well as with players of the innate immune response, DNA damage response, metabolism, and mitochondrial function. This work provides the first lung specific RanBP9-associated interactome in physiological conditions and reveals that RanBP9 and the CTLH complex could be key regulators of macrophage bioenergetics and immune functions.

cell biology↗