RESUMEN
Preclinical mouse models suggest that the gut microbiome modulates tumor response to checkpoint blockade immunotherapy; however, this has not been well-characterized in human cancer patients. Here we examined the oral and gut microbiome of melanoma patients undergoing anti-programmed cell death 1 protein (PD-1) immunotherapy (n = 112). Significant differences were observed in the diversity and composition of the patient gut microbiome of responders versus nonresponders. Analysis of patient fecal microbiome samples (n = 43, 30 responders, 13 nonresponders) showed significantly higher alpha diversity (P < 0.01) and relative abundance of bacteria of the Ruminococcaceae family (P < 0.01) in responding patients. Metagenomic studies revealed functional differences in gut bacteria in responders, including enrichment of anabolic pathways. Immune profiling suggested enhanced systemic and antitumor immunity in responding patients with a favorable gut microbiome as well as in germ-free mice receiving fecal transplants from responding patients. Together, these data have important implications for the treatment of melanoma patients with immune checkpoint inhibitors.
Asunto(s)
Microbioma Gastrointestinal/inmunología , Inmunoterapia , Melanoma/terapia , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Neoplasias Cutáneas/terapia , Animales , Trasplante de Microbiota Fecal , Microbioma Gastrointestinal/genética , Humanos , Melanoma/inmunología , Metagenoma , Ratones , Neoplasias Cutáneas/inmunologíaRESUMEN
We have previously demonstrated interferon gamma (IFN-gamma) in intestinal mucosa after experimental human Cryptosporidium parvum infection, but expression was limited to sensitized volunteers. To characterize IFN-gamma-independent mechanisms in control of infection, jejunal biopsies from immunocompetent volunteers experimentally challenged with C. parvum were examined by in situ hybridization for interleukin (IL-)15 and IL-4 mRNA with confirmation by immunohistochemistry. Cytokine expression was correlated with prechallenge anti- C. parvum IgG, symptoms, oocyst shedding, and prior IFN-gamma expression data. IL-15 expression was noted only in those without prior sensitization, who did not express IFN-gamma. By contrast, expression of IL-4 was associated with prior sensitization. IL-15 was only detected in those with symptoms (6/14 symptomatic vs 0/3 asymptomatic, P<0.05). Among 14 volunteers who did not express IFN-gamma, oocyst shedding was lower in those expressing IL-15. Overall, 14/15 volunteers who did not shed oocysts expressed either IFN-gamma or IL-15. There was no correlation between expression of IL-4 and symptoms or oocyst shedding. In conclusion, IL-15 expression was associated with control of oocyst shedding in those not expressing IFN-gamma. These data suggest that IL-15 is involved in IFN-gamma independent mechanisms of control of human cryptosporidiosis, perhaps via activation of the innate immune response.
Asunto(s)
Criptosporidiosis/metabolismo , Criptosporidiosis/microbiología , Cryptosporidium parvum/metabolismo , Interferón gamma/biosíntesis , Interleucina-15/biosíntesis , Interleucina-4/biosíntesis , Adolescente , Adulto , Animales , Biopsia , Criptosporidiosis/inmunología , ADN Complementario/metabolismo , Mucosa Gástrica/microbiología , Humanos , Inmunoglobulina G/metabolismo , Inmunohistoquímica , Hibridación in Situ , Interleucina-4/metabolismo , Yeyuno/metabolismo , Yeyuno/microbiología , Persona de Mediana Edad , Plásmidos/metabolismo , Factores de TiempoRESUMEN
Jejunal biopsies from volunteers challenged with Cryptosporidium parvum were examined for tumor necrosis factor alpha (TNF-alpha) and interleukin (IL)-1 beta mRNA. Postchallenge biopsies from 15 of 28 (54%) volunteers expressed TNF-alpha; 14% expressed IL-1 beta. Cytokine expression did not correlate with enteric symptoms, suggesting that TNF-alpha and IL-1 beta are not key mediators of diarrhea in human cryptosporidiosis.
Asunto(s)
Criptosporidiosis/inmunología , Cryptosporidium parvum , Diarrea/etiología , Interleucina-1/biosíntesis , Yeyuno/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Biopsia , Humanos , Interleucina-1/genética , Interleucina-15/biosíntesis , ARN Mensajero/análisis , Factor de Necrosis Tumoral alfa/genéticaAsunto(s)
Aminopeptidasas/antagonistas & inhibidores , Encephalitozoon cuniculi/efectos de los fármacos , Encefalitozoonosis/tratamiento farmacológico , Encefalitozoonosis/mortalidad , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Leucina/análogos & derivados , Péptidos , Animales , Antibacterianos/farmacología , Ciclohexanos , Modelos Animales de Enfermedad , Encephalitozoon cuniculi/crecimiento & desarrollo , Encefalitozoonosis/parasitología , Ácidos Grasos Insaturados/farmacología , Femenino , Leucina/farmacología , Leucina/uso terapéutico , Ratones , Ratones Desnudos , O-(Cloroacetilcarbamoil) Fumagilol , Pruebas de Sensibilidad Parasitaria/métodos , Sesquiterpenos/farmacología , Sesquiterpenos/uso terapéuticoRESUMEN
To investigate the role of interferon (IFN)-gamma in human cryptosporidiosis, jejunal biopsies from experimentally infected volunteers and chronically infected AIDS patients were examined for IFN-gamma expression by in situ hybridization. IFN-gamma expression was compared with oocyst excretion, baseline serum anti-Cryptosporidium antibody, and symptoms. IFN-gamma mRNA was detected in biopsies from 13 of 26 volunteers after experimental infection but not in biopsies taken before C. parvum exposure or in biopsies from patients with AIDS-associated cryptosporidiosis. After challenge, 9 of 10 volunteers with baseline C. parvum antibody produced IFN-gamma, compared with 4 of 16 volunteers without baseline antibody (P<.01). Furthermore, IFN-gamma mRNA was detected in 9 of 13 volunteers who did not excrete oocysts, compared with 4 of 13 with organisms (P<.05). Thus, expression of IFN-gamma in the jejunum was associated with prior sensitization and absence of oocyst shedding. IFN-gamma production may explain the resistance to infection noted in sensitized persons but may not be involved in control of human primary infection.
Asunto(s)
Criptosporidiosis/inmunología , Criptosporidiosis/parasitología , Cryptosporidium parvum/inmunología , Interferón gamma/biosíntesis , Yeyuno/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/inmunología , Infecciones Oportunistas Relacionadas con el SIDA/parasitología , Animales , Anticuerpos Antiprotozoarios/sangre , Biopsia , Criptosporidiosis/patología , Cryptosporidium parvum/crecimiento & desarrollo , Citocinas/genética , Citocinas/metabolismo , Humanos , Inmunohistoquímica , Hibridación in Situ , Interferón gamma/genética , Yeyuno/metabolismo , Plásmidos/genética , ARN Mensajero/metabolismoRESUMEN
Cryptosporidium parvum arginine aminopeptidase (RAP) was studied during in vitro excystation. Specific RAP inhibitors were identified by using C. parvum extracts. Amastatin, a series of alpha-aminoboronic acids, and the chelating agents EDTA and 1,10-phenanthrolene, but not endoproteinase inhibitors, blocked enzymatic activity. RAP inhibitors found to be effective in soluble enzymatic assays were then studied for their effect on in vitro excystation. 1,10-Phenanthrolene, amastatin, and H-boronorleucine (pinacol) inhibited excystation by 84, 57, and 61%, respectively, compared with solvent-treated control oocysts. Sporozoites remained viable within the oocyst as determined by propidium iodide and fluorescein diacetate dye uptake, suggesting that alpha-aminoboronic acids were not directly lethal to the parasite.