Biology subjects

Do, P.

Publications and source records attributed to Do, P..

4 recordsLinked to original sources

bioRxiv2024

The T-cell niche tunes immune function through modulation of the cytoskeleton and TCR-antigen forces

Obesity is a major public health crisis given its rampant growth and association with an increased risk for cancer. Interestingly, patients with obesity tend to have an increased tumor burden and decreased T-cell function. It remains unclear how obesity compromises T-cell mediated immunity. To address this question, we modeled the adipocyte niche using the secretome released from adipocytes as well as the niche of stromal cells and investigated how these factors modulated T-cell function. We found that the secretomes altered antigen-specific T-cell receptor (TCR) triggering and activation. RNA-sequencing analysis identified thousands of gene targets modulated by the secretome including those associated with cytoskeletal regulation and actin polymerization. We next used molecular force probes to show that T-cells exposed to the adipocyte niche display dampened force transmission to the TCR-antigen complex and conversely, stromal cell secreted factors lead to significantly enhanced TCR forces. These results were then validated in diet-induced obese mice. Importantly, secretome-mediated TCR force modulation mirrored the changes in T-cell functional responses in human T-cells using the FDA-approved immunotherapy, blinatumomab. Thus, this work shows that the adipocyte niche contributes to T-cell dysfunction through cytoskeletal modulation and reduces TCR triggering by dampening TCR forces consistent with the mechanosensor model of T-cell activation.

bioengineering↗

bioRxiv2022

Multicolor Light-Induced Immune Activation via Polymer Photocaged Cytokines

Cytokines act as potent, extracellular signals of the human immune system and can elicit striking treatment responses in patients with autoimmune disease, tissue damage, and cancer. Yet despite their therapeutic potential, recombinant cytokine-mediated immune responses remain difficult to control as their administration is often systemic whereas their intended sites of action are localized. To address the challenge of spatially and temporally constraining cytokine signals, we recently devised a strategy whereby recombinant cytokines are reversibly inactivated via chemical modification with photo-labile polymers that respond to visible LED light. Extending this approach to enable both in vivo and multicolor immune activation, here we describe a strategy whereby cytokines appended with heptamethine cyanine-polyethylene glycol are selectively re-activated ex vivo using tissue-penetrating near-infrared (NIR) light. We show that NIR LED light illumination of caged, pro-inflammatory cytokines restores cognate receptor signaling and potentiates the activity of T cell-engager cancer immunotherapies ex vivo. Using combinations of visible- and NIR-responsive cytokines, we further demonstrate multi-wavelength optical control of T cell cytolysis ex vivo, as well as the ability to perform Boolean logic using multicolored light and orthogonally photocaged cytokine pairs as inputs, and T cell activity as outputs. Together, this work demonstrates a novel approach to control extracellular immune cell signals using light, a strategy that in the future may improve our understanding of and ability to treat cancer and other diseases.

bioengineering↗

bioRxiv2020

Rapid Assembly and Screening of Multivalent Immune Cell-Redirecting Therapies for Leukemia

Therapies that bind with immune cells and redirect their cytotoxic activity towards diseased cells represent a promising and versatile approach to immunotherapy with applications in cancer, lupus, and other diseases; traditional methods for discovering these therapies, however, are often time-intensive and lack the throughput of related target-based discovery approaches. Inspired by the observation that the cytokine, IL-12, can enhance antileukemic activity of the clinically approved T cell redirecting therapy, blinatumomab, here we describe the structure and assembly of a chimeric immune cell-redirecting agent which redirects the lytic activity of primary human T cells towards leukemic B cells and simultaneously co-targets the delivery of T cell-stimulating IL-12. We further describe a novel method for the parallel assembly of compositionally diverse libraries of these bi-specific T cell engaging cytokines (BiTEokines) and their high-throughput phenotypic screening, requiring just days for hit identification and the analysis of structure-function relationships. Using this approach, we identified CD19 x CD3 x IL12 compounds that exhibit ex vivo lytic activity comparable to current FDA-approved therapies for leukemia and correlated drug treatment with specific cell-cell contact, cytokine delivery, and leukemia cell lysis. Given the modular nature of these multivalent compounds and their rapid assembly/screening, we anticipate facile extension of this therapeutic approach to a wide range of immune cells, diseased cells, and soluble protein combinations in the future.

bioengineering↗

bioRxiv2020

Optical Control of Cytokine Signaling via Bioinspired, Polymer-Induced Latency

Cytokine signaling is challenging to study and therapeutically exploit as the effects of these protein are often pleiotropic. A subset of cytokines can, however, exert signal specificity via association with latency-inducing proteins which cage the cytokine until disrupted by discreet biological stimuli. Inspired by this precision, here we describe a strategy for synthetic induction of cytokine latency via modification with photo-labile polymers that mimic latency while attached, then restore protein activity in response to light, thus controlling the magnitude, duration, and location of cytokine signals. We characterize the high dynamic range of latent cytokine activity modulation and find that polymer-induced latency, alone, can prolong in vivo circulation and bias receptor subunit binding. We further show that protein de-repression can be achieved with near single-cell resolution and demonstrate the feasibility of transcutaneous photoactivation. Future extensions of this approach could enable multicolor, optical reprogramming of cytokine signaling networks and more precise immunotherapies.

bioengineering↗