Biology subjects

Rudd, C. E.

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

3 recordsLinked to original sources

bioRxiv2026

Rapid Vascular Activation Precedes Immune Cell Infiltration Following Corneal Alkali Burn

Under homeostatic conditions, the cornea is avascular and contains few immune cells, but this changes rapidly following injury. Although the long-term consequences of corneal damage are well characterized, the earliest vascular and immune responses remain poorly understood. Here, we used a murine corneal alkali-burn model to examine limbal vascular activation and leukocyte recruitment immediately and at 2, 6, and 24 hours after injury. Limbal blood vessels underwent immediate dilation; however, vascular leakage into the corneal stroma occurred only in males. Lymphatic capillaries rapidly formed directed extensions toward the injury without significantly increasing their total vascular area, with males exhibiting longer extensions than females. Fluorescent dextran uptake provided evidence that these lymphatic vessels were functionally engaged in early tracer drainage. Despite pronounced vascular activation, early recruitment of neutrophils, monocytes, dendritic cells, macrophages, T cells, B cells, and natural killer cells remained limited. Thus, limbal blood and lymphatic vessels initiate the earliest response to corneal alkali injury before substantial leukocyte infiltration. These findings reveal sex-dependent differences in vascular permeability and lymphatic remodeling and identify the limbal vasculature as an early regulator of corneal inflammation and tissue repair.

pathology↗

bioRxiv2025

GSK-3 regulates CD4-CD8 cooperation needed to generate super-armed CD8+ cytolytic T cells against tumors

While immune checkpoint blockade (ICB) has revolutionized cancer treatment, the key T-cell signaling pathways responsible for its potency remain unclear. GSK-3 is an inhibitory kinase that is most active in resting T-cells. In this study, we demonstrate that GSK-3 facilitates PD-1 blockade, an effect seen by modulating CD4 T-cell help for CD8+ CTL responses against ICB resistant tumors. We show that GSK-3 controls metabolic reprogramming towards glycolysis and synergizes with PD-1 to induce a transcriptional program that reduces suppressive CD4+ Treg numbers while generating super-armed effector-memory CD8+ CTLs that express an unprecedented 7/9 granzymes from the genome. Crucially, we found that GSK-3 cooperates with PD-1 blockade to determine the dependency of CD8+ CTLs on help from CD4+ T-cells. Our study unravels a novel cooperative PD-1 blockade-dependent signaling pathway that potentiates CTL responses against tumors, offering a new strategy to overcome immunotherapy resistance by modulating CD4+ helper and CD8+ cytotoxic functions. SignificanceThis study demonstrates for the first time that GSK-3 controls the crosstalk between CD4+ and CD8+ T cells, synergizing with anti-PD-1 therapy to overcome resistance to checkpoint blockade and to generate super-armed CD8+ effector cells in cancer immunotherapy. This newly uncovered GSK-3-dependent CD4-CD8 T-cell crosstalk mechanism presents a new approach to enhance anti-PD-1 immunotherapy.

immunology↗

bioRxiv2024

PD-1 endocytosis unleashes the cytolytic potential of check-point blockade in tumor immunity

PD-1 immune checkpoint blockade (ICB) is now a promising first-line treatment for many cancers. While the steric blockade of PD-1 binding to its ligand plays a role, the role of internalisation in promoting the efficacy of ICB has not been explored. In this study, we show that PD-1 internalisation also contributes by unlocking the full cytolytic potential of ICB in cancer immunotherapy. We found that anti-mouse and human PD-1 downregulate a subset of PD-1 surface receptors on T-cells with high-density surface PD-1 leaving T-cells with intermediate expression resistant to further internalisation. Down regulation was seen on both CD4 and CD8 cells but was maximally effective on CD8 effector cells. In human T-cells, nivolumab outperformed pembrolizumab in terms of rate and efficacy. We also found that PD-1 internalisation depended on bivalent antibody (Ab)-induced crosslinking, while monovalent Ab sterically blocked PD-1 without inducing endocytosis. Immunologically, while both monovalent and bivalent Ab limited B16-PD-L1 tumor growth, bivalent Ab was significantly more effective. In molecular terms, while both antibodies increased granzyme B (GZMB) expression in CD8+ cytolytic T-cells, the induction of the second key cytolytic pore-forming mediator, perforin, was dependent on the blockade and internalisation mediated by bilavent anti-PD-1. Our findings unveil a novel mechanism in checkpoint blockade where steric blockade combined with the removal of PD-1 from the cell surface by endocytosis can complement and optimize therapy. The targeting of PD-1 internalisation holds promise for enhancing anti-tumor immunity and improving PD-1 checkpoint blockade therapy. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/591549v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1cbb458org.highwire.dtl.DTLVardef@ad15eborg.highwire.dtl.DTLVardef@17a2bf6org.highwire.dtl.DTLVardef@1dc5ba0_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefBen Saad et al define the mechanism of PD-1 inhibitory endocytosis and show that the removal of surface PD-1 by endocytosis plays a role in complementing and optimizing checkpoint blockade. Targeting PD-1 internalisation holds promise for enhancing anti-tumor immunity and improving the efficacy of PD-1 checkpoint blockade therapy.

immunology↗