Receptors controlling the cross-presentation of tumor antigens by macrophage subsets in cancer tissues are poorly explored. Here, we show that TIM4+ large peritoneal macrophages efficiently capture and cross-present tumor-associated antigens at early stages of peritoneal infiltration by ovarian cancer cells. The phosphatidylserine (PS) receptor TIM4 promotes maximal uptake of dead cells or PS-coated artificial targets and triggers inflammatory and metabolic gene programs in combination with cytoskeletal remodeling and upregulation of transcriptional signatures related to antigen processing. At the cellular level, TIM4-mediated engulfment induces nucleation of F-actin around nascent phagosomes, delaying the recruitment of vacuolar ATPase, acidification, and cargo degradation. In vivo, TIM4 deletion blunts induction of early anti-tumoral effector CD8 T cells and accelerates the progression of ovarian tumors. We conclude that TIM4-mediated uptake drives the formation of specialized phagosomes that prolong the integrity of ingested antigens and facilitate cross-presentation, contributing to immune surveillance of the peritoneum.
Antigens, Neoplasm , Carcinogenesis , Macrophages, Peritoneal , Animals , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/immunology , Female , Mice , Carcinogenesis/pathology , Carcinogenesis/immunology , Carcinogenesis/metabolism , Humans , Antigens, Neoplasm/metabolism , Antigens, Neoplasm/immunology , Ovarian Neoplasms/immunology , Ovarian Neoplasms/pathology , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/genetics , Membrane Proteins/metabolism , Mice, Inbred C57BL , Cross-Priming/immunology , Cell Line, Tumor , Phagosomes/metabolism , Antigen Presentation/immunology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Actins/metabolism
Cross-presentation by type 1 DCs (cDC1) is critical to induce and sustain antitumoral CD8 T cell responses to model antigens, in various tumor settings. However, the impact of cross-presenting cDC1 and the potential of DC-based therapies in tumors carrying varied levels of bona-fide neoantigens (neoAgs) remain unclear. Here we develop a hypermutated model of non-small cell lung cancer in female mice, encoding genuine MHC-I neoepitopes to study neoAgs-specific CD8 T cell responses in spontaneous settings and upon Flt3L + αCD40 (DC-therapy). We find that cDC1 are required to generate broad CD8 responses against a range of diverse neoAgs. DC-therapy promotes immunogenicity of weaker neoAgs and strongly inhibits the growth of high tumor-mutational burden (TMB) tumors. In contrast, low TMB tumors respond poorly to DC-therapy, generating mild CD8 T cell responses that are not sufficient to block progression. scRNA transcriptional analysis, immune profiling and functional assays unveil the changes induced by DC-therapy in lung tissues, which comprise accumulation of cDC1 with increased immunostimulatory properties and less exhausted effector CD8 T cells. We conclude that boosting cDC1 activity is critical to broaden the diversity of anti-tumoral CD8 T cell responses and to leverage neoAgs content for therapeutic advantage.
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Female , Mice , Animals , Dendritic Cells , Carcinoma, Non-Small-Cell Lung/therapy , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/therapy , Lung Neoplasms/metabolism , CD8-Positive T-Lymphocytes , Cross-Priming
Lung tumor-infiltrating neutrophils are known to support growth and dissemination of cancer cells and to suppress T cell responses. However, the precise impact of tissue neutrophils on programming and differentiation of anticancer CD8 T cells in vivo remains poorly understood. Here, we identified cancer cell-autonomous secretion of CXCL5 as sufficient to drive infiltration of mature, protumorigenic neutrophils in a mouse model of non-small cell lung cancer (NSCLC). Consistently, CXCL5 transcripts correlate with neutrophil density and poor prognosis in a large human lung adenocarcinoma compendium. CXCL5 genetic deletion, unlike antibody-mediated depletion, completely and selectively prevented neutrophils accumulation in lung tissues. Depletion of tumor-infiltrating neutrophils promoted expansion of tumor-specific CD8 T cells, differentiation into effector cells and acquisition of cytolytic functions. Transfer of effector CD8 T cells into neutrophil-rich tumors, inhibited IFN-Ï production, indicating active suppression of effector functions. Importantly, blocking neutrophils infiltration in the lung, overcame resistance to checkpoint blockade. Hence, this study demonstrates that neutrophils curb acquisition of cytolytic functions in lung tumor tissues and suggests targeting of CXCL5 as a strategy to restore anti-tumoral T cell functions.
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Animals , CD8-Positive T-Lymphocytes , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung/pathology , Lung Neoplasms/drug therapy , Mice , Neutrophils
Modified or misplaced DNA can be recognized as a danger signal by mammalian cells. Activation of cellular responses to DNA has evolved as a defense mechanism to microbial infections, cellular stress, and tissue damage, yet failure to control this mechanism can lead to autoimmune diseases. Several monogenic and multifactorial autoimmune diseases have been associated with type-I interferons and interferon-stimulated genes (ISGs) induced by deregulated recognition of self-DNA. Hence, understanding how cellular mechanism controls the pathogenic responses to self-nucleic acid has important clinical implications. Fine-tuned membrane trafficking and cellular compartmentalization are two major factors that balance activation of DNA sensors and availability of self-DNA ligands. Intracellular transport and organelle architecture are in turn regulated by cytoskeletal dynamics, yet the precise impact of actin remodeling on DNA sensing remains elusive. This review proposes a critical analysis of the established and hypothetical connections between self-DNA recognition and actin dynamics. As a paradigm of this concept, we discuss recent evidence of deregulated self-DNA sensing in the prototypical actin-related primary immune deficiency (Wiskott-Aldrich syndrome). We anticipate a broader impact of actin-dependent processes on tolerance to self-DNA in autoimmune disorders.
Autoimmunity , DNA/immunology , Membrane Proteins/metabolism , Nucleotidyltransferases/metabolism , Toll-Like Receptor 9/metabolism , Animals , Autoimmune Diseases/etiology , Autoimmune Diseases/metabolism , Cytoskeleton/metabolism , Endosomes/metabolism , Humans , Phagocytes/immunology , Phagocytes/metabolism , Protein Binding , Protein Transport , Signal Transduction
Dysregulated sensing of self-nucleic acid is a leading cause of autoimmunity in multifactorial and monogenic diseases. Mutations in Wiskott-Aldrich syndrome protein (WASp), a key regulator of cytoskeletal dynamics in immune cells, cause autoimmune manifestations and increased production of type I IFNs by innate cells. Here we show that immune complexes of self-DNA and autoantibodies (DNA-ICs) contribute to elevated IFN levels via activation of the cGAS/STING pathway of cytosolic sensing. Mechanistically, lack of endosomal F-actin nucleation by WASp caused a delay in endolysosomal maturation and prolonged the transit time of ingested DNA-ICs. Stalling in maturation-defective organelles facilitated leakage of DNA-ICs into the cytosol, promoting activation of the TBK1/STING pathway. Genetic deletion of STING and STING and cGAS chemical inhibitors abolished IFN production and rescued systemic activation of IFN-stimulated genes in vivo. These data unveil the contribution of cytosolic self-nucleic acid sensing in WAS and underscore the importance of WASp-mediated endosomal actin remodeling in preventing innate activation.
DNA/immunology , Membrane Proteins/metabolism , Nucleotidyltransferases/metabolism , Wiskott-Aldrich Syndrome Protein/metabolism , Actins/metabolism , Animals , Autoantibodies/immunology , Cells, Cultured , Dendritic Cells/immunology , Endosomes/metabolism , Immunity, Innate , Interferons/metabolism , Mice , Mice, Inbred C57BL , Protein Serine-Threonine Kinases/metabolism
INTRODUCCION: Pertussis es una enfermedad inmunoprevenible respiratoria que afecta a la población infantil y a los adolescentes/adultos. Para diseñar estrategias que mejoren el control de la enfermedad, resulta esencial profundizar el conocimiento de su epidemiología.OBJETIVO: Estimar la frecuencia de casos de pertussis en 5 provincias argentinas, analizar la implicancia de las características socio-sanitarias de la población e identificar la fuente más probable de contagio.METODOS: Se realizó un trabajo multidisciplinario y multicéntrico empleando algoritmos consensuados. Se estudió a niños menores de 1 año (caso índice, CI) y sus contactos. Para los análisis, se incorporó la información obtenida durante el período a una base de datos ya existente.RESULTADOS: Durante 2006-2011 se analizaron 18.106 muestras de pacientes con sintomatología compatible con pertussis, y se confirmaron 3.766 casos. La mayor proporción de casos confirmados y de casos fatales (8 a 21 por año) se registró en los menores de 1 año. Un análisis de la epidemiología de 113 grupos familiares, constituidos por al menos un CI y dos contactos, determinó que en más del 50% el caso primario no se correspondió al CI. Análisis preliminares mostraron a los convivientes adultos jóvenes como posible fuente de infección de la población vulnerable. En relación con la implicancia de la situación socio-sanitaria en la epidemiología de pertussis, la evolución de los síntomas y la distribución por edades de los casos confirmados mostraron una desigualdad entre los barrios carecientes y los no carecientes.CONCLUSIONES: Se detectó la presencia de más de un caso de pertussis en los grupos familiares. Los adultos jóvenes convivientes serían los responsables de transmitir la infección a los más pequeños. Por la influencia de las condiciones socio-sanitarias en la epidemiología de pertussis, se detectaron patrones diferenciales en la distribución de casos.
INTRODUCTION: Pertussis is an immune preventable resporatory disease affecting the pediatric population and teens/adults. To design better strategies for the disease control, it is essential to improve epidemiological knowledge.OBJECTIVE: To estimate the frequency of pertussis cases in 5 Argentine provinces, to analyze the implication of the socio-economic characteristics and to identify the most likely source of infection.METHODS: A multidisciplinary, multicenter study was conducted, using consensus algorithms. The analysis was focused on children under 1 year (index cases, IC) and their contacts. The information obtained was incorporated into a previous database.RESULTS: 18.106 samples of patients with symptoms compatible with pertussis were analyzed during 2006-2011. Of these cases, 3.766 were confirmed in the lab. The largest proportion of confirmed cases and fatal cases (8-21 per year) were registered in children under 1 year. An epidemiologic analysis of 113 family units, consisting in at least one IC and two contacts, found that in over 50% the primary case did not correspond to the IC. A preliminary analysis showed that the young and adult cohabitants were the possible source of infection for vulnerable populations. Regarding the implications of the socio-sanitary conditions in the disease epidemiology, the evolution of symptoms and the age group distribution of confirmed cases were unequeal between poor and non-poor neighborhoods.CONCLUSIONS: The study detected the presence of more than one case of pertussis in family units. Young and adult cohabitants would be responsible for transmitting the infection to children. Due to the influence of socio-sanitary conditions in the epidemiology of pertussis, differential patterns were detected in the distribution of cases.
Infant , Whooping Cough , Whooping Cough/epidemiology , Infant , Sanitary Profiles , Social Class , Argentina , Public Health
INTRODUCCION: Pertussis es una enfermedad inmunoprevenible respiratoria que afecta a la población infantil y a los adolescentes/adultos. Para diseñar estrategias que mejoren el control de la enfermedad, resulta esencial profundizar el conocimiento de su epidemiología.OBJETIVO: Estimar la frecuencia de casos de pertussis en 5 provincias argentinas, analizar la implicancia de las características socio-sanitarias de la población e identificar la fuente más probable de contagio.METODOS: Se realizó un trabajo multidisciplinario y multicéntrico empleando algoritmos consensuados. Se estudió a niños menores de 1 año (caso índice, CI) y sus contactos. Para los análisis, se incorporó la información obtenida durante el período a una base de datos ya existente.RESULTADOS: Durante 2006-2011 se analizaron 18.106 muestras de pacientes con sintomatología compatible con pertussis, y se confirmaron 3.766 casos. La mayor proporción de casos confirmados y de casos fatales (8 a 21 por año) se registró en los menores de 1 año. Un análisis de la epidemiología de 113 grupos familiares, constituidos por al menos un CI y dos contactos, determinó que en más del 50% el caso primario no se correspondió al CI. Análisis preliminares mostraron a los convivientes adultos jóvenes como posible fuente de infección de la población vulnerable. En relación con la implicancia de la situación socio-sanitaria en la epidemiología de pertussis, la evolución de los síntomas y la distribución por edades de los casos confirmados mostraron una desigualdad entre los barrios carecientes y los no carecientes.CONCLUSIONES: Se detectó la presencia de más de un caso de pertussis en los grupos familiares. Los adultos jóvenes convivientes serían los responsables de transmitir la infección a los más pequeños. Por la influencia de las condiciones socio-sanitarias en la epidemiología de pertussis, se detectaron patrones diferenciales en la distribución de casos.
INTRODUCTION: Pertussis is an immune preventable resporatory disease affecting the pediatric population and teens/adults. To design better strategies for the disease control, it is essential to improve epidemiological knowledge.OBJECTIVE: To estimate the frequency of pertussis cases in 5 Argentine provinces, to analyze the implication of the socio-economic characteristics and to identify the most likely source of infection.METHODS: A multidisciplinary, multicenter study was conducted, using consensus algorithms. The analysis was focused on children under 1 year (index cases, IC) and their contacts. The information obtained was incorporated into a previous database.RESULTS: 18.106 samples of patients with symptoms compatible with pertussis were analyzed during 2006-2011. Of these cases, 3.766 were confirmed in the lab. The largest proportion of confirmed cases and fatal cases (8-21 per year) were registered in children under 1 year. An epidemiologic analysis of 113 family units, consisting in at least one IC and two contacts, found that in over 50% the primary case did not correspond to the IC. A preliminary analysis showed that the young and adult cohabitants were the possible source of infection for vulnerable populations. Regarding the implications of the socio-sanitary conditions in the disease epidemiology, the evolution of symptoms and the age group distribution of confirmed cases were unequeal between poor and non-poor neighborhoods.CONCLUSIONS: The study detected the presence of more than one case of pertussis in family units. Young and adult cohabitants would be responsible for transmitting the infection to children. Due to the influence of socio-sanitary conditions in the epidemiology of pertussis, differential patterns were detected in the distribution of cases.
Infant , Social Class , Infant , Sanitary Profiles , Whooping Cough , Whooping Cough/epidemiology , Argentina , Public Health
