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OBJECTIVE: To determine how football head impacts are influenced by self-efficacy (SE), helmetless tackling intervention participation (IP), and years of experience (YE) playing football. DESIGN: Cross-sectional. SETTING: Three high schools. PARTICIPANTS: 120 (male; n = 118, female; n = 2, 15.57 ± 1.23 years) participants were recruited from 5 high school teams (3 varsity and 2 junior-varsity). INDEPENDENT VARIABLES: SE, days of IP, and YE playing tackle football. MAIN OUTCOME MEASURES: SE was measured using a 53-question survey and categorized into 5 subscales. The accumulation of total head impacts (THI) was measured using Riddell InSite Speedflex helmets (Elyria, OH) throughout the season. Head impact exposure (HIE) was standardized as a ratio of impacts per session (games, scrimmages, and practices). Multiple regression analyses tested the relationship between THI or HIE with the predictor variables. RESULTS: For THI, 22.1% was explained by the predictors (r = 0.470, r2 = 0.221). Intervention participation had a negative correlation (B = -4.480, P = 0.019), whereas confidence in performing proper tackling and blocking (SE1) (B = 3.133, P = 0.010) and >8 YE (B = 135.9, P = 0.009) positively correlated with THI. For HIE, 25.4% was explained by the predictors (r = 0.504, r2 = 0.254). Intervention participation negatively correlated (B = -0.077, P = 0.007), whereas SE1 (B = 3.133, P = 0.010) and >8 YE (B = 2.735, P ≤ 0.001) correlated positively with HIE. CONCLUSIONS: Increased head impacts were associated with less helmetless tackling participation, more than 8 YE, and more self-confidence in tackling ability. Increasing the amount of time athletes spend practicing proper tackling and blocking techniques to reduce head first and risky play is warranted to reduce the amount of head impacts received over time.
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CONTEXT: High school football remains a popular, physically demanding sport despite the known risks for acute brain and neck injury. Impacts to the head also raise concerns about their cumulative effects and long-term health consequences. OBJECTIVE: To examine the effectiveness of a helmetless tackling training program to reduce head impact exposure in football participants. DESIGN: A three-year, quasi-experimental, prospective cohort (clinicaltrials.gov #NCTXXX) study. SETTING: Honolulu (XXX, XXX) area public and private secondary schools with varsity and junior varsity football. PATIENTS OR OTHER PARTICIPANTS: Football participants (n=496) ages 14 to 18 years old. Intervention(s) Participants wore new football helmets furnished with head impact sensor technology. Teams employed a season-long helmetless tackling and blocking intervention in Years 2 and 3 consisting of a 3-phase, systematic progression of 10 instructional drills. MAIN OUTCOME MEASURE(S): Head impact frequency per athlete exposure (ImpAE), location, and impact magnitude per participant intervention adherence levels (60% and 80%). RESULTS: An overall regression analysis revealed a significant negative association between ImpAE and adherence (p=0.003, beta=-1.21, SE=0.41). In year 3, a longitudinal data analysis of weekly ImpAE data resulted in an overall difference between the adherent and non-adherent groups (p=0.040 at 80%; p=0.004 at 60%), mainly due to decreases in top and side impacts. Mean cumulative impact burden for the adherent group (n=131: 2,105.84g ± 219.76,) was significantly (p=0.020) less than the non-adherent group (n=90: 3,158.25g ± 434.80) at the 60% adherence level. CONCLUSIONS: Participants adhering to the intervention on at least a 60% level experienced a 34% to 37% significant reduction in the number of head impacts (per exposure) through the season. These results provide additional evidence that a helmetless tackling and blocking training intervention (utilizing the HuTT® program) reduces head impact exposure in high school football players. Adherence to an intervention is crucial for achieving intended outcomes.
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Functional effector T cells in the tumor microenvironment (TME) are critical for successful anti-tumor responses. T cell anti-tumor function is dependent on their ability to differentiate from a naïve state, infiltrate into the tumor site, and exert cytotoxic functions. The factors dictating whether a particular T cell can successfully undergo these processes during tumor challenge are not yet completely understood. Piezo1 is a mechanosensitive cation channel with high expression on both CD4+ and CD8+ T cells. Previous studies have demonstrated that Piezo1 optimizes T cell activation and restrains the CD4+ regulatory T cell (Treg) pool in vitro and under inflammatory conditions in vivo. However, little is known about the role Piezo1 plays on CD4+ and CD8+ T cells in cancer. We hypothesized that disruption of Piezo1 on T cells impairs anti-tumor immunity in vivo by hindering inflammatory T cell responses. We challenged mice with T cell Piezo1 deletion (P1KO) with tumor models dependent on T cells for immune rejection. P1KO mice had the more aggressive tumors, higher tumor growth rates and were unresponsive to immune-mediated therapeutic interventions. We observed a decreased CD4:CD8 ratio in both the secondary lymphoid organs and TME of P1KO mice that correlated inversely with tumor size. Poor CD4+ helper T cell responses underpinned the immunodeficient phenotype of P1KO mice. Wild type CD8+ T cells are sub-optimally activated in vivo with P1KO CD4+ T cells, taking on a CD25loPD-1hi phenotype. Together, our results suggest that Piezo1 optimizes T cell activation in the context of a tumor response.
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Antineoplásicos , Neoplasias , Animales , Ratones , Linfocitos T CD8-positivos , Linfocitos T Reguladores/metabolismo , Microambiente Tumoral , Canales Iónicos/genética , Canales Iónicos/metabolismoRESUMEN
BACKGROUND: Despite its potential utility in delivering direct tumor killing and in situ whole-cell tumor vaccination, tumor cryoablation produces highly variable and unpredictable clinical response, limiting its clinical utility. The mechanism(s) driving cryoablation-induced local antitumor immunity and the associated abscopal effect is not well understood. METHODS: The aim of this study was to identify and explore a mechanism of action by which cryoablation enhances the therapeutic efficacy in metastatic tumor models. We used the subcutaneous mouse model of the rhabdomyosarcoma (RMS) cell lines RMS 76-9STINGwt or RMS 76-9STING-/-, along with other murine tumor models, in C57BL/6 or STING-/- (TMEM173-/- ) mice to evaluate local tumor changes, lung metastasis, abscopal effect on distant tumors, and immune cell dynamics in the tumor microenvironment (TME). RESULTS: The results show that cryoablation efficacy is dependent on both adaptive immunity and the STING signaling pathway. Contrary to current literature dictating an essential role of host-derived STING activation as a driver of antitumor immunity in vivo, we show that local tumor control, lung metastasis, and the abscopal effect on distant tumor are all critically dependent on a functioning tumor cell-intrinsic STING signaling pathway, which induces inflammatory chemokine and cytokine responses in the cryoablated TME. This reliance extends beyond cryoablation to include intratumoral STING agonist therapy. Additionally, surveys of gene expression databases and tissue microarrays of clinical tumor samples revealed a wide spectrum of expressions among STING-related signaling components. CONCLUSIONS: Tumor cell-intrinsic STING pathway is a critical component underlying the effectiveness of cryoablation and suggests that expression of STING-related signaling components may serve as a potential therapy response biomarker. Our data also highlight an urgent need to further characterize tumor cell-intrinsic STING pathways and the associated downstream inflammatory response evoked by cryoablation and other STING-dependent therapy approaches.
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Criocirugía , Neoplasias Pulmonares , Animales , Ratones , Ratones Endogámicos C57BL , Inmunidad Adaptativa , Citocinas , Microambiente TumoralRESUMEN
Osteosarcoma (OS) is an aggressive malignant bone cancer, with refractory and metastatic disease remaining a significant challenge. Transforming growth factor-ß1 (TGF-ß) is a potent immune suppressive cytokine in OS and the TGF-ß is increased in the sera of OS patients and this increase is associated with high-grade OS and lung metastases. Therefore, blocking TGF-ß1 signaling may be a novel therapy for OS treatment. Here we show that blocking TGF-ß1 signaling using TGF-ßR1 inhibitor, Vactosertib, significantly inhibited OS proliferation in vitro and in vivo. Notably, Vactosertib inhibits c-Myc expression in the OS cells. Vactosertib increased immune effectors (IFNγ+CD8+ cells and NK cells) and inhibited immune suppressors (M2-like TAM, MDSC) in the OS tumor microenvironment. Our results suggest that inhibition of TGF-ß1 signaling is an effective therapeutic strategy against OS through a multi-pronged approach that targets tumor intrinsic and extrinsic factors to achieve optimal immune-effector functions and maximal clinical response.
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Arterial and venous thrombosis constitutes a major source of morbidity and mortality worldwide. Long considered as distinct entities, accumulating evidence indicates that arterial and venous thrombosis can occur in the same populations, suggesting that common mechanisms are likely operative. Although hyperactivation of the immune system is a common forerunner to the genesis of thrombotic events in both vascular systems, the key molecular control points remain poorly understood. Consequently, antithrombotic therapies targeting the immune system for therapeutics gain are lacking. Here, we show that neutrophils are key effectors of both arterial and venous thrombosis and can be targeted through immunoregulatory nanoparticles. Using antiphospholipid antibody syndrome (APS) as a model for arterial and venous thrombosis, we identified the transcription factor Krüppel-like factor 2 (KLF2) as a key regulator of neutrophil activation. Upon activation through genetic loss of KLF2 or administration of antiphospholipid antibodies, neutrophils clustered P-selectin glycoprotein ligand 1 (PSGL-1) by cortical actin remodeling, thereby increasing adhesion potential at sites of thrombosis. Targeting clustered PSGL-1 using nanoparticles attenuated neutrophil-mediated thrombosis in APS and KLF2 knockout models, illustrating the importance and feasibility of targeting activated neutrophils to prevent pathological thrombosis. Together, our results demonstrate a role for activated neutrophils in both arterial and venous thrombosis and identify key molecular events that serve as potential targets for therapeutics against diverse causes of immunothrombosis.
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Síndrome Antifosfolípido , Trombosis , Trombosis de la Vena , Anticuerpos Antifosfolípidos , Humanos , Neutrófilos/metabolismo , Trombosis/etiologíaRESUMEN
The endoplasmic reticulum unfolded protein response (UPR) is a conserved adaptive signaling in ER homeostasis and has emerged as critical in highly proliferating cells and potential treatment target for acute T-cell lymphoblastic leukemia (T-ALL). Methods: in this study, we assessed the transcriptomic and phenotypic alterations in UPR response of the bone marrow endothelial cells (ECs) in mice engrafted with T-ALL and in bone marrow specimens from patients who have T-ALL. We used PERK inhibitor and generated endothelial specific PERK knockout mice to study the impact of PERK on leukemia progression and hematopoiesis. We performed chromatin immunoprecipitation (ChIP) to study the mechanistic regulation of JAG1 by ATF4. We characterized small extracellular vesicles (SEV) from leukemia-developing mice and studied the effect of SEVs on EC function. Results: we found that T-ALL development induced a robust activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dominant UPR in the bone marrow endothelial vascular niche. The activation of PERK-eIF2a-ATF4 axis remodels the vascular niche, upregulates angiogenic factors including VEGFα and ATF4-regulated JAG1, and suppresses the expression of SCF and CXCL12, which are important to HSC maintenance and regeneration. Further, targeting endothelial PERK significantly improved T-ALL outcome. EC-specific deletion of PERK abolished the aberrant JAG1 up-regulation, improved HSC maintenance, promoted leukemia apoptosis, and improved overall survival. Finally, we showed that small extracellular vesicles are critical mediators of endothelial PERK-eIF2a-ATF4 activation and JAG1 up-regulation in leukemia. Corroborating animal model studies, activation of PERK-ATF4-JAG1 is prominent in human T-ALL bone marrow and T-ALL xenografts. Conclusion: our studies thus revealed for the first time that the leukemia-initiated PERK-ATF4-JAG1 axis plays a critical role in the remodeling of the bone marrow vascular niche and that targeting vascular niche UPR is a potential therapeutic opportunity in T-ALL.
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Células Endoteliales , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Respuesta de Proteína Desplegada , Factor de Transcripción Activador 4/genética , Factor de Transcripción Activador 4/metabolismo , Animales , Médula Ósea/metabolismo , Retículo Endoplásmico/metabolismo , Estrés del Retículo Endoplásmico , Células Endoteliales/metabolismo , Humanos , Proteína Jagged-1/genética , Proteína Jagged-1/metabolismo , Proteína Jagged-1/farmacología , Ratones , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , eIF-2 Quinasa/metabolismoRESUMEN
OBJECTIVE: To provide evidence-based recommendations for reducing the prevalence of head-first contact behavior in American football players with the aim of reducing the risk of head and neck injuries. BACKGROUND: In American football, using the head as the point of contact is a persistent, well-documented, and direct cause of catastrophic head and cervical spine injury. Equally concerning is that repeated head-impact exposures are likely to result from head-first contact behavior and may be associated with long-term neurocognitive conditions such as dementia, depression, and chronic traumatic encephalopathy. CONCLUSIONS: The National Athletic Trainers' Association proposes 14 recommendations to help the certified athletic trainer, allied health care provider, coach, player, parent, and broader community implement strategies for reducing the prevalence of head-first contact in American football.
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Traumatismos en Atletas , Conmoción Encefálica , Fútbol Americano , Traumatismos Vertebrales , Traumatismos en Atletas/epidemiología , Conmoción Encefálica/epidemiología , Fútbol Americano/lesiones , Humanos , Traumatismos Vertebrales/complicacionesRESUMEN
Conventional dendritic cells (cDC) play a central role in T-cell antitumor responses. We studied the significance of Notch-regulated DC immune responses in a mouse model of colitis-associated colorectal cancer in which there is epithelial downregulation of Notch/Hes1 signaling. This defect phenocopies that caused by GMDS (GDP-mannose 4,6-dehydratase) mutation in human colorectal cancers. We found that, although wild-type immune cells restrained dysplasia progression and decreased the incidence of adenocarcinoma in chimeric mice, the immune system with Notch2 deleted in all blood lineages or in only DCs promoted inflammation-associated transformation. Notch2 signaling deficiency not only impaired cDC terminal differentiation, but also downregulated CCR7 expression, reduced DC migration, and suppressed antigen cross-presentation to CD8+ T cells. Transfer of Notch-primed DCs restrained inflammation-associated dysplasia progression. Consistent with the mouse data, we observed a correlation between infiltrating cDC1 and Notch2 signaling in human colorectal cancers and found that GMDS-mutant colorectal cancers showed decreased CCR7 expression and suppressed cDC1 signature gene expression. Suppressed cDC1 gene signature expression in human colorectal cancer was associated with a poor prognosis. In summary, our study supports an important role for Notch2 signaling in cDC1-mediated antitumor immunity and indicates that Notch2-controlled DCs restrain inflammation-associated colon cancer development in mice.
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Adenocarcinoma/inmunología , Neoplasias Asociadas a Colitis/inmunología , Células Dendríticas/inmunología , Receptor Notch2/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Animales , Trasplante de Médula Ósea , Linfocitos T CD8-positivos/inmunología , Carbohidrato Epimerasas/genética , Carcinogénesis/genética , Carcinogénesis/inmunología , Línea Celular Tumoral , Neoplasias Asociadas a Colitis/genética , Neoplasias Asociadas a Colitis/mortalidad , Neoplasias Asociadas a Colitis/patología , Reactividad Cruzada , Variaciones en el Número de Copia de ADN , Análisis Mutacional de ADN , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Hidroliasas/genética , Cetona Oxidorreductasas/genética , Ratones , Ratones Noqueados , Mutación , Pronóstico , Receptor Notch2/genética , Receptores CCR7/genética , Análisis de Supervivencia , Quimera por TrasplanteRESUMEN
OBJECTIVES: To evaluate a behavioral intervention to reduce head impact exposure in youth playing American football. DESIGN: Nested randomized controlled trial. METHODS: Participants, ages 14-17 years, wore head impact sensors (SIM-G™) during two seasons of play. Those randomized to the intervention group underwent weekly tackling/blocking drills performed without helmets (WoH) and shoulder pads while the control group trained as normal, matching frequency and duration. Research personnel provided daily oversight to maintain fidelity. Head impact frequency (≥10g) per athlete exposure (ImpAE) was analyzed over time (two 11-week seasons) using mixed effect models or ANCOVA. Secondary outcomes included exposure-type (training, game) and participation level (entry-level versus upper-level secondary education). RESULTS: One-hundred fifteen participants (59 WoH, 56 control) met compliance criteria, contributing 47,382 head impacts and 10,751 athlete exposures for analysis. WoH had fewer ImpAE during games compared to control participants at weeks 4 (p=0.0001 season 1, p=0.0005 season 2) and 7 (p=0.0001 both seasons). Upper-level WoH participants had less ImpAE during games than their matched controls at weeks 4 (p=0.017 and p=0.026) and 7 (p=0.037 and p=0.014) in both seasons, respectively. Upper-level WoH also had fewer ImpAE during training at week 7 (p=0.015) in season one. CONCLUSIONS: Tackling and blocking drills performed without a helmet during training reduced the frequency of head impacts during play, especially during games. However, these differences disappeared by the end of the season. Future research should explore the frequency of behavioral intervention and a dose-response relationship considering years of player experience. TRIAL REGISTRATION: ClinicalTrials.gov # NCT02519478.
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Traumatismos en Atletas/prevención & control , Traumatismos Craneocerebrales/prevención & control , Fútbol Americano/lesiones , Dispositivos de Protección de la Cabeza , Acondicionamiento Físico Humano/métodos , Adolescente , Cabeza , Humanos , MasculinoRESUMEN
Regulatory T cells (Tregs) continuously suppress autoreactive immune responses within tissues to prevent autoimmunity, yet the recirculatory behavior of Tregs between and within tissues enabling the maintenance of peripheral tolerance remains incompletely defined. Here, we quantified homing efficiency to and the dwell time of Tregs within secondary lymphoid organs (SLOs) and used intravital two-photon microscopy to measure Treg surveillance behavior of dendritic cells. Tregs homed substantially less efficiently to SLOs compared with conventional CD4+ T cells (Tconvs), despite similar expression of homing receptors. Tregs remained on average 2-3 times longer within the LN than Tconvs before exiting, and retained Tregs differed from recirculating Tregs in phenotype, motility and interaction duration with dendritic cells. Taken together, these data revealed fundamental differences in Treg versus conventional T cell in vivo recirculation and migration behaviors, identified a Treg population with prolonged LN dwell time, and provided quantitative insight into their spatiotemporal behavior within LNs.
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Linfocitos T CD4-Positivos/inmunología , Movimiento Celular , Ganglios Linfáticos/inmunología , Linfocitos T Reguladores/inmunología , Animales , Células Dendríticas/inmunología , Ratones Endogámicos C57BL , Factores de TiempoRESUMEN
Leukocyte adhesion and extravasation are maximal near the transition from capillary to post-capillary venule, and are strongly influenced by a confluence of scale-dependent physical effects. Mimicking the scale of physiological vessels using in vitro microfluidic systems allows the capture of these effects on leukocyte adhesion assays, but imposes practical limits on reproducibility and reliable quantification. Here we present a microfluidic platform that provides multiple (54-512) technical replicates within a 15-minute sample collection time, coupled with an automated computer vision analysis pipeline that captures leukocyte adhesion probabilities as a function of shear and extensional stresses. We report that in post-capillary channels of physiological scale, efficient leukocyte adhesion requires erythrocytes forcing leukocytes against the wall, a phenomenon that is promoted by the transitional flow in post-capillary venule expansions and dependent on the adhesion molecule ICAM-1.
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Biomimética/métodos , Adhesión Celular/fisiología , Leucocitos/citología , Animales , Eritrocitos/citología , Eritrocitos/metabolismo , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Ratones , Ratones Endogámicos C57BL , Técnicas Analíticas Microfluídicas/métodos , ViscosidadRESUMEN
This corrects the article DOI: 10.1038/nm.4475.
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Inflammatory chemokines are critical contributors in attracting relevant immune cells to the tumor microenvironment and driving cellular interactions and molecular signaling cascades that dictate the ultimate outcome of host anti-tumor immune response. Therefore, rational application of chemokines in a spatial-temporal dependent manner may constitute an attractive adjuvant in immunotherapeutic approaches against cancer. Existing data suggest that the macrophage inflammatory protein (MIP)-1 family and related proteins, consisting of CCL3 (MIP-1α), CCL4 (MIP-1ß), and CCL5 (RANTES), can be major determinant of immune cellular infiltration in certain tumors through their direct recruitment of antigen presenting cells, including dendritic cells (DCs) to the tumor site. In this study, we examined how CCL3 in a murine colon tumor microenvironment, CT26, enhances antitumor immunity. We identified natural killer (NK) cells as a major lymphocyte subtype that is preferentially recruited to the CCL3-rich tumor site. NK cells contribute to the overall IFNγ content, CD103+ DC accumulation, and augment the production of chemokines CXCL9 and CXCL10 for enhanced T cell recruitment. We further demonstrate that both soluble CCL3 and CCL3-secreting irradiated tumor vaccine can effectively halt the progression of established tumors in a spatial-dependent manner. Our finding implies an important contribution of NK in the CCL3 - CD103+ DC - CXCL9/10 signaling axis in determining tumor immune landscape within the tumor microenvironment.
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Metastasis results from a complex set of traits acquired by tumor cells, distinct from those necessary for tumorigenesis. Here, we investigate the contribution of enhancer elements to the metastatic phenotype of osteosarcoma. Through epigenomic profiling, we identify substantial differences in enhancer activity between primary and metastatic human tumors and between near isogenic pairs of highly lung metastatic and nonmetastatic osteosarcoma cell lines. We term these regions metastatic variant enhancer loci (Met-VELs). Met-VELs drive coordinated waves of gene expression during metastatic colonization of the lung. Met-VELs cluster nonrandomly in the genome, indicating that activity of these enhancers and expression of their associated gene targets are positively selected. As evidence of this causal association, osteosarcoma lung metastasis is inhibited by global interruptions of Met-VEL-associated gene expression via pharmacologic BET inhibition, by knockdown of AP-1 transcription factors that occupy Met-VELs, and by knockdown or functional inhibition of individual genes activated by Met-VELs, such as that encoding coagulation factor III/tissue factor (F3). We further show that genetic deletion of a single Met-VEL at the F3 locus blocks metastatic cell outgrowth in the lung. These findings indicate that Met-VELs and the genes they regulate play a functional role in metastasis and may be suitable targets for antimetastatic therapies.
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Carcinogénesis/genética , Elementos de Facilitación Genéticos/genética , Neoplasias Pulmonares/genética , Osteosarcoma/genética , Línea Celular Tumoral , Epigenómica , Regulación Neoplásica de la Expresión Génica , Genoma Humano/genética , Humanos , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/secundario , Metástasis de la Neoplasia/genética , Osteosarcoma/patología , Proteínas/antagonistas & inhibidores , Proteínas/genética , Selección Genética , Tromboplastina/genética , Factor de Transcripción AP-1/antagonistas & inhibidores , Factor de Transcripción AP-1/genética , Microambiente Tumoral/genéticaRESUMEN
Converting an immunosuppressive melanoma microenvironment into one that favors the induction of antitumor immunity is indispensable for effective cancer immunotherapy. In the current study we demonstrate that oat-derived ß-(1-3)-(1-4)-glucan of 200 kDa molecular size (BG34-200) previously shown to mediate direct interaction with macrophages could alter the immune signature within melanoma microenvironment. Systemic administration of BG34-200 resulted in reversion of tolerant melanoma microenvironment to an immunogenic one that allows M1-type activation of macrophages, the induction of pro-inflammatory cytokines/chemokines including IFN-γ, TNF-α, CXCL9, and CXCL10, and enhanced IRF1 and PD-L1 expression. In turn, BG34-200 induced a superior antitumor response against primary and lung metastatic B16F10 melanoma compared to untreated controls. The enhanced tumor destruction was accompanied with significantly increased tumor infiltration of CD4+ and CD8+ T cells as well as elevated IFN-γ in the tumor sites. Systemic administration of BG34-200 also provoked systemic activation of tumor draining lymph node T cells that recognize antigens naturally expressing in melanoma (gp100/PMEL). Mechanistic studies using CD11b-knockout (KO), CD11 c-DTR transgenic mice and nude mice revealed that macrophages, DCs, T cells and NK cells were all required for the BG34-200-induced therapeutic benefit. Studies using IFN-γ-KO transgenic mice showed that IFN-γ was essential for the BG34-200-elicited antitumor response. Beyond melanoma, the therapeutic efficacy of BG34-200 and its immune stimulating activity were demonstrated in a mouse model of osteosarcoma. Together, BG34-200 is highly effective in modulating antitumor immunity. Our data support the potential therapeutic use of this novel immune modulator in the treatment of metastatic melanoma.
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Lymph node (LN) plays a critical role in tumor cell survival outside of the primary tumor sites and dictates overall clinical response in many tumor types (1, 2). Previously, we and others have demonstrated that CCL3 plays an essential role in orchestrating T cell-antigen-presenting cell (APC) encounters in the draining LN following vaccination, and such interactions enhance the magnitude of the memory T cell pool (3-5). In the current study, we investigate the cellular responses in the tumor-draining lymph nodes (TDLNs) of a CCL3-secreting CT26 colon tumor (L3TU) as compared to wild-type tumor (WTTU) during the priming phase of an antitumor response (≤10 days). In comparison to WTTU, inoculation of L3TU resulted in suppressed tumor growth, a phenomenon that is accompanied by altered in vivo inflammatory responses on several fronts. Autologous tumor-derived CCL3 (aCCL3) secretion by L3TU bolstered the recruitment of T- and B-lymphocytes, tissue-migratory CD103+ dendritic cells (DCs), and CD49b+ natural killer (NK) cells, resulting in significant increases in the differentiation and activation of multiple Interferon-gamma (IFNγ)-producing leukocytes in the TDLN. During this early phase of immune priming, NK cells constitute the major producers of IFNγ in the TDLN. CCL3 also enhances CD8+ T cell proliferation and differentiation by augmenting DC capacity to drive T cell activation in the TDLN. Our results revealed that CCL3-dependent IFNγ production and CCL3-induced DC maturation drive the priming of effective antitumor immunity in the TDLN.
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Despite use of newer approaches, some patients being considered for autologous hematopoietic cell transplantation (HCT) may only mobilize limited numbers of hematopoietic progenitor cells (HPCs) into blood, precluding use of the procedure, or being placed at increased risk of complications due to slow hematopoietic reconstitution. Developing more efficacious HPC mobilization regimens and strategies may enhance the mobilization process and improve patient outcome. Although Notch signaling is not essential for homeostasis of adult hematopoietic stem cells (HSCs), Notch-ligand adhesive interaction maintains HSC quiescence and niche retention. Using Notch receptor blocking antibodies, we report that Notch2 blockade, but not Notch1 blockade, sensitizes hematopoietic stem cells and progenitors (HSPCs) to mobilization stimuli and leads to enhanced egress from marrow to the periphery. Notch2 blockade leads to transient myeloid progenitor expansion without affecting HSC homeostasis and self-renewal. We show that transient Notch2 blockade or Notch2-loss in mice lacking Notch2 receptor lead to decreased CXCR4 expression by HSC but increased cell cycling with CXCR4 transcription being directly regulated by the Notch transcriptional protein RBPJ. In addition, we found that Notch2-blocked or Notch2-deficient marrow HSPCs show an increased homing to the marrow, while mobilized Notch2-blocked, but not Notch2-deficient stem cells and progenitors, displayed a competitive repopulating advantage and enhanced hematopoietic reconstitution. These findings suggest that blocking Notch2 combined with the current clinical regimen may further enhance HPC mobilization and improve engraftment during HCT.
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Antineoplásicos/farmacología , Movilización de Célula Madre Hematopoyética , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Receptor Notch2/antagonistas & inhibidores , Animales , Antineoplásicos/uso terapéutico , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Ciclo Celular/efectos de los fármacos , Ciclo Celular/genética , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Movimiento Celular/efectos de los fármacos , Autorrenovación de las Células/efectos de los fármacos , Autorrenovación de las Células/genética , Regulación de la Expresión Génica/efectos de los fármacos , Movilización de Célula Madre Hematopoyética/métodos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Células Madre Hematopoyéticas/citología , Humanos , Ratones , Ratones Transgénicos , Receptor Notch2/deficiencia , Receptor Notch2/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Cancer vaccines are designed to elicit an endogenous adaptive immune response that can successfully recognize and eliminate residual or recurring tumors. Such approaches can potentially overcome shortcomings of passive immunotherapies by generating long-lived therapeutic effects and immune memory while limiting systemic toxicities. A critical determinant of vaccine efficacy is efficient transport and delivery of tumor-associated antigens to professional antigen presenting cells (APCs). Plant viral nanoparticles (VNPs) with natural tropism for APCs and a high payload carrying capacity may be particularly effective vaccine carriers. The applicability of VNP platform technologies is governed by stringent structure-function relationships. We compare two distinct VNP platforms: icosahedral cowpea mosaic virus (CPMV) and filamentous potato virus X (PVX). Specifically, we evaluate in vivo capabilities of engineered VNPs delivering human epidermal growth factor receptor 2 (HER2) epitopes for therapy and prophylaxis of HER2+ malignancies. Our results corroborate the structure-function relationship where icosahedral CPMV particles showed significantly enhanced lymph node transport and retention, and greater uptake by/activation of APCs compared to filamentous PVX particles. These enhanced immune cell interactions and transport properties resulted in elevated HER2-specific antibody titers raised by CPMV- vs. PVX-based peptide vaccine. The 'synthetic virology' field is rapidly expanding with numerous platforms undergoing development and preclinical testing; our studies highlight the need for systematic studies to define rules guiding the design and rational choice of platform, in the context of peptide-vaccine display technologies.