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Biomaterial wound dressings, such as hydrogels, interact with host cells to regulate tissue repair. This study investigates how crosslinking of gelatin-based hydrogels influences immune and stromal cell behavior and wound healing in female mice. We observe that softer, lightly crosslinked hydrogels promote greater cellular infiltration and result in smaller scars compared to stiffer, heavily crosslinked hydrogels. Using single-cell RNA sequencing, we further show that heavily crosslinked hydrogels increase inflammation and lead to the formation of a distinct macrophage subpopulation exhibiting signs of oxidative activity and cell fusion. Conversely, lightly crosslinked hydrogels are more readily taken up by macrophages and integrated within the tissue. The physical properties differentially affect macrophage and fibroblast interactions, with heavily crosslinked hydrogels promoting pro-fibrotic fibroblast activity that drives macrophage fusion through RANKL signaling. These findings suggest that tuning the physical properties of hydrogels can guide cellular responses and improve healing, offering insights for designing better biomaterials for wound treatment.
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Fibroblastos , Hidrogeles , Macrófagos , Cicatrización de Heridas , Animales , Hidrogeles/química , Cicatrización de Heridas/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Ratones , Femenino , Comunicación Celular/efectos de los fármacos , Materiales Biocompatibles/química , Ligando RANK/metabolismo , Ratones Endogámicos C57BL , Reactivos de Enlaces Cruzados/química , Gelatina/química , Inflamación/metabolismo , Inflamación/patologíaRESUMEN
Type I interferon (IFN-I) and IFN-γ foster antitumor immunity by facilitating T cell responses. Paradoxically, IFNs may promote T cell exhaustion by activating immune checkpoints. The downstream regulators of these disparate responses are incompletely understood. Here, we describe how interferon regulatory factor 1 (IRF1) orchestrates these opposing effects of IFNs. IRF1 expression in tumor cells blocks Toll-like receptor- and IFN-I-dependent host antitumor immunity by preventing interferon-stimulated gene (ISG) and effector programs in immune cells. In contrast, expression of IRF1 in the host is required for antitumor immunity. Mechanistically, IRF1 binds distinctly or together with STAT1 at promoters of immunosuppressive but not immunostimulatory ISGs in tumor cells. Overexpression of programmed cell death ligand 1 (PD-L1) in Irf1-/- tumors only partially restores tumor growth, suggesting multifactorial effects of IRF1 on antitumor immunity. Thus, we identify that IRF1 expression in tumor cells opposes host IFN-I- and IRF1-dependent antitumor immunity to facilitate immune escape and tumor growth.
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Factor 1 Regulador del Interferón , Animales , Humanos , Ratones , Antígeno B7-H1/metabolismo , Línea Celular Tumoral , Inmunidad , Factor 1 Regulador del Interferón/metabolismo , Factor 1 Regulador del Interferón/genética , Ratones Endogámicos C57BL , Neoplasias/inmunología , Neoplasias/patología , Neoplasias/metabolismo , Neoplasias/genética , Factor de Transcripción STAT1/metabolismo , Masculino , FemeninoRESUMEN
Current antigen delivery platforms, such as alum and nanoparticles, are not readily tunable, thus may not generate optimal adaptive immune responses. We created an antigen delivery platform by loading lyophilized Microporous Annealed Particle (MAP) with aqueous solution containing target antigens. Upon administration of antigen loaded MAP (VaxMAP), the biomaterial reconstitution forms an instant antigen-loaded porous scaffold area with a sustained release profile to maximize humoral immunity. VaxMAP induced CD4+ T follicular helper (Tfh) cells and germinal center (GC) B cell responses in the lymph nodes similar to Alum. VaxMAP loaded with SARS-CoV-2 spike protein improved the magnitude, neutralization, and duration of anti-receptor binding domain antibodies compared to Alum vaccinated mice. A single injection of Influenza specific HA1-loaded-VaxMAP enhanced neutralizing antibodies and elicited greater protection against influenza virus challenge than HA1-loaded-Alum. Thus, VaxMAP is a platform that can be used to promote adaptive immune cell responses to generate more robust neutralizing antibodies, and better protection upon pathogen challenge.
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Vacunas contra la COVID-19 , COVID-19 , Inmunidad Humoral , Glicoproteína de la Espiga del Coronavirus , Animales , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , Ratones , COVID-19/prevención & control , COVID-19/inmunología , Porosidad , Femenino , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Materiales Biocompatibles/química , Ratones Endogámicos BALB C , Linfocitos B/inmunología , SARS-CoV-2/inmunología , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/administración & dosificación , Ratones Endogámicos C57BL , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & controlRESUMEN
Inducible nucleosome remodeling at hundreds of latent enhancers and several promoters shapes the transcriptional response to Toll-like receptor 4 (TLR4) signaling in macrophages. We aimed to define the identities of the transcription factors that promote TLR-induced remodeling. An analysis strategy based on ATAC-seq and single-cell ATAC-seq that enriched for genomic regions most likely to undergo remodeling revealed that the transcription factor nuclear factor κB (NF-κB) bound to all high-confidence peaks marking remodeling during the primary response to the TLR4 ligand, lipid A. Deletion of NF-κB subunits RelA and c-Rel resulted in the loss of remodeling at high-confidence ATAC-seq peaks, and CRISPR-Cas9 mutagenesis of NF-κB-binding motifs impaired remodeling. Remodeling selectivity at defined regions was conferred by collaboration with other inducible factors, including IRF3- and MAP-kinase-induced factors. Thus, NF-κB is unique among TLR4-activated transcription factors in its broad contribution to inducible nucleosome remodeling, alongside its ability to activate poised enhancers and promoters assembled into open chromatin.
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FN-kappa B , Receptor Toll-Like 4 , FN-kappa B/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Nucleosomas , Transducción de Señal , Regulación de la Expresión Génica , Factor de Transcripción ReIA/metabolismoRESUMEN
Case Presentation: A 30-year-old male with a past medical history of hypertension and renal failure on peritoneal dialysis presented to the emergency department with a chief complaint of a rash on his anterior trunk for the prior three weeks. Dermatological examination revealed multiple, discrete folliculocentric, erythematous, and hyperpigmented papules, with scattered adjacent angulated erosions. Discussion: Perforating folliculitis is a rare and often difficult to diagnose skin condition classically seen in patients with chronic renal disease or underlying immunodeficiency.
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Current antigen delivery platforms, such as alum and nanoparticles, are not readily tunable, thus may not generate optimal adaptive immune responses. We created an antigen delivery platform by loading lyophilized Microporous Annealed Particle (MAP) with aqueous solution containing target antigens. Upon administration of antigen loaded MAP (VaxMAP), the biomaterial reconstitution forms an instant antigen-loaded porous scaffold area with a sustained release profile to maximize humoral immunity. VaxMAP induced CD4+ T follicular helper (Tfh) cells and germinal center (GC) B cell responses in the lymph nodes similar to Alum. VaxMAP loaded with SARS-CoV-2 spike protein improved the magnitude and duration of anti-receptor binding domain antibodies compared to Alum and mRNA-vaccinated mice. A single injection of Influenza specific HA1-loaded-VaxMAP enhanced neutralizing antibodies and elicited greater protection against influenza virus challenge than HA1-loaded-Alum. Thus, VaxMAP is a platform that can be used to promote adaptive immune cell responses to generate more robust neutralizing antibodies, and better protection upon pathogen challenge.
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BACKGROUND: Aberrant PI3K/AKT signaling in BRAF-mutant cancers contributes to resistance to BRAF inhibitors. The authors examined dual MAPK and PI3K pathway inhibition in patients who had BRAF-mutated solid tumors (ClinicalTrials.gov identifier NCT01902173). METHODS: Patients with BRAF V600E/V600K-mutant solid tumors received oral dabrafenib at 150 mg twice daily with dose escalation of oral uprosertib starting at 50 mg daily, or, in the triplet cohorts, with dose escalation of both oral trametinib starting at 1.5 mg daily and oral uprosertib starting at 25 mg daily. Dose-limiting toxicities (DLTs) were assessed within the first 56 days of treatment. Radiographic responses were assessed at 8-week intervals. RESULTS: Twenty-seven patients (22 evaluable) were enrolled in parallel doublet and triplet cohorts. No DLTs were observed in the doublet cohorts (N = 7). One patient had a DLT at the maximum administered dose of triplet therapy (dabrafenib 150 mg twice daily and trametinib 2 mg daily plus uprosertib 75 mg daily). Three patients in the doublet cohorts had partial responses (including one who had BRAF inhibitor-resistant melanoma). Two patients in the triplet cohorts had a partial response, and one patient had an unconfirmed partial response. Pharmacokinetic data suggested reduced dabrafenib and dabrafenib metabolite exposure in patients who were also exposed to both trametinib and uprosertib, but not in whose who were exposed to uprosertib without trametinib. CONCLUSIONS: Concomitant inhibition of both the MAPK and PI3K-AKT pathways for the treatment of BRAF-mutated cancers was well tolerated, leading to objective responses, but higher level drug-drug interactions affected exposure to dabrafenib and its metabolites.
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Protocolos de Quimioterapia Combinada Antineoplásica , Imidazoles , Mutación , Neoplasias , Oximas , Inhibidores de Proteínas Quinasas , Proteínas Proto-Oncogénicas B-raf , Proteínas Proto-Oncogénicas c-akt , Piridonas , Pirimidinonas , Humanos , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Femenino , Masculino , Persona de Mediana Edad , Anciano , Adulto , Piridonas/administración & dosificación , Piridonas/efectos adversos , Pirimidinonas/administración & dosificación , Pirimidinonas/efectos adversos , Pirimidinonas/uso terapéutico , Imidazoles/administración & dosificación , Imidazoles/uso terapéutico , Imidazoles/efectos adversos , Imidazoles/farmacocinética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Oximas/administración & dosificación , Oximas/efectos adversos , Oximas/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/efectos adversos , Inhibidores de Proteínas Quinasas/uso terapéutico , Anciano de 80 o más Años , Terapia Molecular DirigidaRESUMEN
Hydrogels are widely used for tissue engineering applications to support cellular growth, yet the tightly woven structure often restricts cell infiltration and expansion. Consequently, granular hydrogels with microporous architectures have emerged as a new class of biomaterial. Particularly, the development of microporous annealed particle (MAP) hydrogel scaffolds has shown improved stability and integration with host tissue. However, the predominant use of spherically shaped particles limits scaffold porosity, potentially limiting the level of cell infiltration. Here, a novel microporous annealed crescent-shaped particle (MAC) scaffold that is predicted to have improved porosity and pore interconnectivity in silico is presented. With microfluidic fabrication, tunable cavity sizes that optimize interstitial void space features are achieved. In vitro, cells incorporated into MAC scaffolds form extensive 3D multicellular networks. In vivo, the injectable MAC scaffold significantly enhances cell infiltration compared to spherical MAP scaffolds, resulting in increased numbers of myofibroblasts and leukocytes present within the gel without relying on external biomolecular chemoattractants. The results shed light on the critical role of particle shape in cell recruitment, laying the foundation for MAC scaffolds as a next-generation granular hydrogel for diverse tissue engineering applications.
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New vaccine platforms that activate humoral immunity and generate neutralizing antibodies are required to combat emerging pathogens, including influenza virus. A slurry of antigen-loaded hydrogel microparticles that anneal to form a porous scaffold with high surface area for antigen uptake by infiltrating immune cells as the biomaterial degrades is demonstrated to enhance humoral immunity. Antigen-loaded-microgels elicited a robust cellular humoral immune response, with increased CD4+ T follicular helper (Tfh) cells and prolonged germinal center (GC) B cells comparable to the commonly used adjuvant, aluminum hydroxide (Alum). Increasing the weight fraction of polymer material led to increased material stiffness and antigen-specific antibody titers superior to Alum. Vaccinating mice with inactivated influenza virus loaded into this more highly cross-linked formulation elicited a strong antibody response and provided protection against a high dose viral challenge. By tuning physical and chemical properties, adjuvanticity can be enhanced leading to humoral immunity and protection against a pathogen, leveraging two different types of antigenic material: individual protein antigen and inactivated virus. The flexibility of the platform may enable design of new vaccines to enhance innate and adaptive immune cell programming to generate and tune high affinity antibodies, a promising approach to generate long-lasting immunity.
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Vacunas contra la Influenza , Gripe Humana , Infecciones por Orthomyxoviridae , Orthomyxoviridae , Animales , Ratones , Humanos , Inmunidad Humoral , Porosidad , Anticuerpos Antivirales , AntígenosRESUMEN
In this randomized phase 2 trial, blockade of cytotoxic T-lymphocyte protein 4 (CTLA-4) with continuation of programmed death protein 1 (PD-1) blockade in patients with metastatic melanoma who had received front-line anti-PD-1 or therapy against programmed cell death 1 ligand 1 and whose tumors progressed was tested in comparison with CTLA-4 blockade alone. Ninety-two eligible patients were randomly assigned in a 3:1 ratio to receive the combination of ipilimumab and nivolumab, or ipilimumab alone. The primary endpoint was progression-free survival. Secondary endpoints included the difference in CD8 T cell infiltrate among responding and nonresponding tumors, objective response rate, overall survival and toxicity. The combination of nivolumab and ipilimumab resulted in a statistically significant improvement in progression-free survival over ipilimumab (hazard ratio = 0.63, 90% confidence interval (CI) = 0.41-0.97, one-sided P = 0.04). Objective response rates were 28% (90% CI = 19-38%) and 9% (90% CI = 2-25%), respectively (one-sided P = 0.05). Grade 3 or higher treatment-related adverse events occurred in 57% and 35% of patients, respectively, which is consistent with the known toxicity profile of these regimens. The change in intratumoral CD8 T cell density observed in the present analysis did not reach statistical significance to support the formal hypothesis tested as a secondary endpoint. In conclusion, primary resistance to PD-1 blockade therapy can be reversed in some patients with the combination of CTLA-4 and PD-1 blockade. Clinicaltrials.gov identifier: NCT03033576 .
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Melanoma , Nivolumab , Humanos , Antígeno B7-H1 , Antígeno CTLA-4 , Ipilimumab/efectos adversos , Ipilimumab/uso terapéutico , Melanoma/tratamiento farmacológico , Nivolumab/efectos adversos , Nivolumab/uso terapéuticoRESUMEN
Metastasis and failure of present-day therapies represent the most common causes of mortality in patients with cutaneous melanoma. To identify the underlying genetic and transcriptomic landscapes, in this study we analyzed multi-organ metastases and tumor-adjacent tissues from 11 rapid autopsies after treatment with MAPK inhibitor (MAPKi) and/or immune checkpoint blockade (ICB) and death due to acquired resistance. Either treatment elicits shared genetic alterations that suggest immune-evasive, cross-therapy resistance mechanisms. Large, non-clustered deletions, inversions and inter-chromosomal translocations dominate rearrangements. Analyzing data from separate melanoma cohorts including 345 therapy-naive patients and 35 patients with patient-matched pre-treatment and post-acquired resistance tumor samples, we performed cross-cohort analyses to identify MAPKi and ICB as respective contributors to gene amplifications and deletions enriched in autopsy versus therapy-naive tumors. In the autopsy cohort, private/late mutations and structural variants display shifted mutational and rearrangement signatures, with MAPKi specifically selecting for signatures of defective homologous-recombination, mismatch and base-excision repair. Transcriptomic signatures and crosstalks with tumor-adjacent macroenvironments nominated organ-specific adaptive pathways. An immune-desert, CD8+-macrophage-biased archetype, T-cell exhaustion and type-2 immunity characterized the immune contexture. This multi-organ analysis of therapy-resistant melanoma presents preliminary insights with potential to improve therapeutic strategies.
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Melanoma , Neoplasias Cutáneas , Humanos , Melanoma/tratamiento farmacológico , Melanoma/genética , Melanoma/patología , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/genética , Resistencia a Antineoplásicos/genética , Transcriptoma/genética , Perfilación de la Expresión GénicaRESUMEN
Biomaterial-enabled de novo formation of non-fibrotic tissue in situ would provide an important tool to physicians. One example application, glottic insufficiency, is a debilitating laryngeal disorder wherein vocal folds do not fully close, resulting in difficulty speaking and swallowing. Preferred management of glottic insufficiency includes bulking of vocal folds via injectable fillers, however, the current options have associated drawbacks including inflammation, accelerated resorption, and foreign body response. We developed a novel iteration of microporous annealed particle (MAP) scaffold designed to provide persistent augmentation. Following a 14-month study of vocal fold augmentation using a rabbit vocal paralysis model, most MAP scaffolds were replaced with tissue de novo that matched the mixture of fibrotic and non-fibrotic collagens of the contralateral vocal tissue. Further, persistent tissue augmentation in MAP-treated rabbits was observed via MRI and via superior vocal function at 14 months relative to the clinical standard.
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An invasive biopsy followed by histological staining is the benchmark for pathological diagnosis of skin tumors. The process is cumbersome and time-consuming, often leading to unnecessary biopsies and scars. Emerging noninvasive optical technologies such as reflectance confocal microscopy (RCM) can provide label-free, cellular-level resolution, in vivo images of skin without performing a biopsy. Although RCM is a useful diagnostic tool, it requires specialized training because the acquired images are grayscale, lack nuclear features, and are difficult to correlate with tissue pathology. Here, we present a deep learning-based framework that uses a convolutional neural network to rapidly transform in vivo RCM images of unstained skin into virtually-stained hematoxylin and eosin-like images with microscopic resolution, enabling visualization of the epidermis, dermal-epidermal junction, and superficial dermis layers. The network was trained under an adversarial learning scheme, which takes ex vivo RCM images of excised unstained/label-free tissue as inputs and uses the microscopic images of the same tissue labeled with acetic acid nuclear contrast staining as the ground truth. We show that this trained neural network can be used to rapidly perform virtual histology of in vivo, label-free RCM images of normal skin structure, basal cell carcinoma, and melanocytic nevi with pigmented melanocytes, demonstrating similar histological features to traditional histology from the same excised tissue. This application of deep learning-based virtual staining to noninvasive imaging technologies may permit more rapid diagnoses of malignant skin neoplasms and reduce invasive skin biopsies.
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Wound healing is a multi-step process to rapidly restore the barrier function. This process is often impaired in diabetic patients resulting in chronic wounds and amputation. We previously found that paradoxical activation of the mitogen-activated protein kinase (MAPK) pathway via topical administration of the BRAF inhibitor vemurafenib accelerates wound healing by activating keratinocyte proliferation and reepithelialization pathways in healthy mice. Herein, we investigated whether this wound healing acceleration also occurs in impaired diabetic wounds and found that topical vemurafenib not only improves wound healing in a murine diabetic wound model but unexpectedly promotes hair follicle regeneration. Hair follicles expressing Sox-9 and K15 surrounded by CD34+ stroma were found in wounds of diabetic and non-diabetic mice, and their formation can be prevented by blocking downstream MEK signaling. Thus, topically applied BRAF inhibitors may accelerate wound healing, and promote the restoration of improved skin architecture in both normal and impaired wounds.
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Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Regeneración/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Administración Tópica , Animales , Diabetes Mellitus Experimental/patología , Femenino , Folículo Piloso/fisiología , Ratones , Ratones Endogámicos BALB C , Ratones Obesos , Proteínas Proto-Oncogénicas B-raf/metabolismo , Piel/patología , Vemurafenib/farmacología , Vía de Señalización Wnt/efectos de los fármacos , beta Catenina/metabolismoRESUMEN
BACKGROUND: Human papillomavirus (HPV) infection is known to promote the development of mucosal squamous cell carcinoma (mSCC), including pathologically high-grade lesions, but its role in cutaneous squamous cell carcinoma (cuSCC) remains unclear, particularly in lesions that are considered high risk. OBJECTIVE: We aimed to determine whether enhanced HPV transcriptional activity can be detected in high-risk cuSCC samples compared with low-grade SCC samples or normal skin. METHODS: We performed RNA sequencing of cuSCC across 23 risk-stratified skin lesions. A subset of samples was tested for the presence of HPV DNA. High-quality, non-human reads from each sample group were used for viral analysis using Microbiome Coverage Profiler. RESULTS: None of the samples analysed had detectable expression of HPV RNA, while 64% of samples tested positive for HPV DNA. All samples were found to have expression of human endogenous retrovirus, and multiple samples showed expression of other viruses. CONCLUSIONS: Viral and prophage gene expression can be monitored in cuSCC or normal skin biopsies, yet no sample in our study showed evidence of active HPV gene expression despite evidence of HPV genome presence. This suggests HPV transcription does not play a role in differentiating high-risk cuSCCs from low-risk cuSCCs or normal skin.
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Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/virología , Expresión Génica , Papillomaviridae/genética , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/patología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/virología , Anciano , Biopsia , Sondas de ADN de HPV , Femenino , Humanos , Masculino , Medición de RiesgoRESUMEN
Melanoma dedifferentiation has been reported to be a state of cellular resistance to targeted therapies and immunotherapies as cancer cells revert to a more primitive cellular phenotype. Here, we show that, counterintuitively, the biopsies of patient tumors that responded to anti-programmed cell death 1 (anti-PD-1) therapy had decreased expression of melanocytic markers and increased neural crest markers, suggesting treatment-induced dedifferentiation. When modeling the effects in vitro, we documented that melanoma cell lines that were originally differentiated underwent a process of neural crest dedifferentiation when continuously exposed to IFN-γ, through global chromatin landscape changes that led to enrichment in specific hyperaccessible chromatin regions. The IFN-γ-induced dedifferentiation signature corresponded with improved outcomes in patients with melanoma, challenging the notion that neural crest dedifferentiation is entirely an adverse phenotype.
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Biomarcadores de Tumor , Desdiferenciación Celular/efectos de los fármacos , Epigénesis Genética/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Inhibidores de Puntos de Control Inmunológico/farmacología , Interferón gamma/metabolismo , Melanoma , Proteínas de Neoplasias , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Biomarcadores de Tumor/antagonistas & inhibidores , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Humanos , Melanocitos/metabolismo , Melanocitos/patología , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/metabolismoRESUMEN
MAPK targeting in cancer often fails due to MAPK reactivation. MEK inhibitor (MEKi) monotherapy provides limited clinical benefits but may serve as a foundation for combination therapies. Here, we showed that combining a type II RAF inhibitor (RAFi) with an allosteric MEKi durably prevents and overcomes acquired resistance among cancers with KRAS, NRAS, NF1, BRAF non-V600, and BRAF V600 mutations. Tumor cell-intrinsically, type II RAFi plus MEKi sequester MEK in RAF complexes, reduce MEK/MEK dimerization, and uncouple MEK from ERK in acquired-resistant tumor subpopulations. Immunologically, this combination expands memory and activated/exhausted CD8+ T cells, and durable tumor regression elicited by this combination requires CD8+ T cells, which can be reinvigorated by anti-PD-L1 therapy. Whereas MEKi reduces dominant intratumoral T-cell clones, type II RAFi cotreatment reverses this effect and promotes T-cell clonotypic expansion. These findings rationalize the clinical development of type II RAFi plus MEKi and their further combination with PD-1/L1-targeted therapy. SIGNIFICANCE: Type I RAFi + MEKi are indicated only in certain BRAF V600MUT cancers. In contrast, type II RAFi + MEKi are durably active against acquired MEKi resistance across broad cancer indications, which reveals exquisite MAPK addiction. Allosteric modulation of MAPK protein/protein interactions and temporal preservation of intratumoral CD8+ T cells are mechanisms that may be further exploited.This article is highlighted in the In This Issue feature, p. 521.
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Resistencia a Antineoplásicos , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/metabolismo , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos/efectos de los fármacos , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Humanos , Inmunidad Celular/efectos de los fármacos , Linfocitos Infiltrantes de Tumor/efectos de los fármacos , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Mutación , Neoplasias/tratamiento farmacológico , Neoplasias/etiología , Neoplasias/metabolismo , Neoplasias/patología , Unión Proteica , Estabilidad Proteica , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Microporous annealed particle (MAP) scaffolds are flowable, in situ crosslinked, microporous scaffolds composed of microgel building blocks and were previously shown to accelerate wound healing. To promote more extensive tissue ingrowth before scaffold degradation, we aimed to slow MAP degradation by switching the chirality of the crosslinking peptides from L- to D-amino acids. Unexpectedly, despite showing the predicted slower enzymatic degradation in vitro, D-peptide crosslinked MAP hydrogel (D-MAP) hastened material degradation in vivo and imparted significant tissue regeneration to healed cutaneous wounds, including increased tensile strength and hair neogenesis. MAP scaffolds recruit IL-33 type 2 myeloid cells, which is amplified in the presence of D-peptides. Remarkably, D-MAP elicited significant antigen-specific immunity against the D-chiral peptides, and an intact adaptive immune system was required for the hydrogel-induced skin regeneration. These findings demonstrate that the generation of an adaptive immune response from a biomaterial is sufficient to induce cutaneous regenerative healing despite faster scaffold degradation.
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Hidrogeles/química , Hidrogeles/farmacología , Regeneración/efectos de los fármacos , Regeneración/inmunología , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/inmunología , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Femenino , Interleucina-33/metabolismo , Ratones , Porosidad , Piel/efectos de los fármacos , Piel/inmunología , Andamios del Tejido/químicaRESUMEN
Plasma membranes of animal cells are enriched for cholesterol. Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins secreted by bacteria that target membrane cholesterol for their effector function. Phagocytes are essential for clearance of CDC-producing bacteria; however, the mechanisms by which these cells evade the deleterious effects of CDCs are largely unknown. Here, we report that interferon (IFN) signals convey resistance to CDC-induced pores on macrophages and neutrophils. We traced IFN-mediated resistance to CDCs to the rapid modulation of a specific pool of cholesterol in the plasma membrane of macrophages without changes to total cholesterol levels. Resistance to CDC-induced pore formation requires the production of the oxysterol 25-hydroxycholesterol (25HC), inhibition of cholesterol synthesis and redistribution of cholesterol to an esterified cholesterol pool. Accordingly, blocking the ability of IFN to reprogram cholesterol metabolism abrogates cellular protection and renders mice more susceptible to CDC-induced tissue damage. These studies illuminate targeted regulation of membrane cholesterol content as a host defense strategy.