Biology subjects

Schmitter-Sanchez, A. D.

Publications and source records attributed to Schmitter-Sanchez, A. D..

3 recordsLinked to original sources

bioRxiv2026

Dual lineages of Langerhans cells cooperate to restore the immune barrier after skin injury

Langerhans cells (LCs) are key immune sentinels of the epidermis. How this network reorganizes to safeguard epidermal immunity after injury has remained unclear. Here, we uncover a previously unrecognized two-lineage program of LC repopulation during wound repair. Classically, tissue-resident embryonically derived LCs (eLCs) migrate to lymph nodes in response to antigens. In contrast, we find that injury triggers nearby eLCs to migrate into wounds, providing immediate coverage. In parallel, circulating monocytes infiltrate the skin and differentiate into long-lived monocyte-derived LCs (mLCs) that integrate stably into the network. We identify the chemokine receptor CXCR2 as a novel regulator of eLC migration into wounds, distinct from the CXCR4/CCR7 pathways mediating LC egress to lymph nodes. Pharmacological inhibition of CXCR2 impairs directional eLC migration and is accompanied by increased mLC infiltration, preserving immune barrier density. These findings reveal a coordinated and flexible two-lineage repair program that ensures robust restoration of epidermal immunity.

cell biology↗

bioRxiv2025

An intermediate activation state primes Langerhans cell migration from the epidermis

Langerhans cells (LC) are antigen-presenting cells that form dense epidermal networks for immune surveillance. Upon antigen uptake, LCs are activated and subsequently orchestrate immune responses by migrating into the lymphatic system. However, the regulation of transcriptional programs during activation and the behavior of LCs in vivo during this transition remain poorly understood. Therefore, this study combines single-cell transcriptomic analysis with intravital imaging to reconstruct the activation trajectory of epidermal LCs. In particular, the study generates a high-resolution single-cell transcriptomic dataset comprising over 22,000 high-quality epidermal LCs under both homeostatic and injury conditions. Notably, a distinct intermediate activated state that precedes LC migration was identified and characterized at the level of signaling pathways and transcription factors. The integration of this dataset with external datasets from homeostatic and injured skin reveals wound-specific fibroblasts as the major source of C3, which is the central component of the complement cascade. Moreover, intravital imaging of C3-deficient mice and pegcetacoplan treatment demonstrates that C3 contributes to LC accumulation adjacent to wound sites. Collectively, the study findings identify an activated epidermal LC population and implicate complement signaling in the regulation of LC behavior during skin injury.

cell biology↗

bioRxiv2023

Immunometabolic cues recompose and reprogram the microenvironment around biomaterials

Circulating monocytes infiltrate and coordinate immune responses in various inflamed tissues, such as those surrounding implanted biomaterials, affecting therapeutic, diagnostic, tissue engineering and regenerative applications. Here, we show that immunometabolic cues in the biomaterial microenvironment govern CCR2- and CX3CR1-dependent trafficking of immune cells, including neutrophils and monocytes; ultimately, this affects the composition and activation states of macrophage and dendritic cell populations. Furthermore, immunometabolic cues around implants orchestrate the relative composition of proinflammatory, transitory and anti-inflammatory CCR2+, CX3CR1+ and CCR2+CX3CR1+ immune cell populations. Consequently, modifying immunometabolism by glycolytic inhibition drives a pro-regenerative microenvironment in part by myeloid cells around amorphous polylactide implants. In addition to, Arginase 1-expressing myeloid cells, T helper 2 cells and {gamma}{delta}+ T-cells producing IL-4 significantly contribute to shaping the metabolically reprogramed, pro-regenerative microenvironment around crystalline polylactide biomaterials. Taken together, we find that local metabolic states regulate inflammatory processes in the biomaterial microenvironment, with implications for translational medicine.

bioengineering↗