RESUMEN
Gastric cancer is the fourth leading cause of cancer deaths worldwide. The presence of chemoresistant cells has been used to explain this high mortality rate. These higher tumorigenic and chemoresistant cells involve cancer stem cells (CSCs), which have the potential for self-renewal, a cell differentiation capacity, and a greater tumorigenic capacity. Our research group identified gastric cancer stem cells (GCSCs) with the CD24+CD44+CD326+ICAM1+ immunophenotype isolated from gastric cancer patients. Interestingly, this GCSC immunophenotype was absent in cells isolated from healthy people, who presented a cell population with a CD24+CD44+CD326+ immunophenotype, lacking ICAM1. We aimed to explore the role of ICAM1 in these GCSCs; for this purpose, we isolated GCSCs from the AGS cell line and generated a GCSC line knockout for ICAM1 using CRISPR/iCas9, which we named GCSC-ICAM1KO. To assess the role of ICAM1 in the GCSCs, we analyzed the migration, invasion, and chemoresistance capabilities of the GCSCs using in vitro assays and evaluated the migratory, invasive, and tumorigenic properties in a zebrafish model. The in vitro analysis showed that ICAM1 regulated STAT3 activation (pSTAT3-ser727) in the GCSCs, which could contribute to the ability of GCSCs to migrate, invade, and metastasize. Interestingly, we demonstrated that the GCSC-ICAM1KO cells lost their capacity to migrate, invade, and metastasize, but they exhibited an increased resistance to a cisplatin treatment compared to their parental GCSCs; the GCSC-ICAM1KO cells also exhibited an increased tumorigenic capability in vivo.
Asunto(s)
Movimiento Celular , Resistencia a Antineoplásicos , Molécula 1 de Adhesión Intercelular , Células Madre Neoplásicas , Neoplasias Gástricas , Pez Cebra , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Molécula 1 de Adhesión Intercelular/genética , Neoplasias Gástricas/patología , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/genética , Animales , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Metástasis de la Neoplasia , Cisplatino/farmacologíaRESUMEN
BACKGROUND: Pandemic type A (H1N1) influenza arose in early 2009, probably in Mexico and the United States, and reappeared in North America in September for seven more months. An amino acid substitution in the hemagglutinin (HA), D222G, has been reported in a significant proportion of patients with a severe and fatal outcome. We studied the prevalence of HA222 substitutions in patients in Mexico during the second wave and its association with clinical outcome and pathogenicity in a mouse model. METHODS: The nucleotide sequences of hemagglutinin (HA) from viruses collected from 77 patients were determined including 50 severe and fatal cases and 27 ambulatory cases. Deep sequencing was done on 5 samples from severe or fatal cases in order to determine the quasispecies proportion. Weight loss and mortality due to infection with cultured influenza viruses were analyzed in a mouse model. RESULTS: Viruses from 14 out of 50 hospitalized patients (28%) had a non aspartic acid residue at the HA 222 position (nD222), while all 27 ambulatory patients had D222 (p=0.0014). G222 was detected as sole species or in coexistence with N222 and D222 in 12 patients with severe disease including 8 who died. N222 in coexistence with D222 was detected in 1 patient who died and co-occurrence of A222 and V222, together with D222, was detected in another patient who died. The patients with a nD222 residue had higher mortality (71.4%), compared to the group with only D222 (22.2%, p=0.0008). Four of the 14 viruses from hospitalized patients were cultured and intranasally infected into mice. Two viruses with G222 were lethal while a third virus, with G222, caused only mild illness in mice similar to the fourth virus that contained D222. CONCLUSIONS: We confirm the elevated incidence of HA222 (H1N1)pdm09 variants in severe disease and mortality. Both clinical and mouse infection data support the idea that nD222 mutations contribute to increased severity of disease but additional determinants in disease outcome may be present.
Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Gripe Humana/mortalidad , Gripe Humana/patología , Índice de Severidad de la Enfermedad , Factores de Virulencia/genética , Adulto , Animales , Secuencia de Bases , Peso Corporal , Modelos Animales de Enfermedad , Femenino , Histocitoquímica , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Pulmón/patología , Masculino , México/epidemiología , Ratones , Persona de Mediana Edad , Datos de Secuencia Molecular , Mutación Missense , Infecciones por Orthomyxoviridae/patología , Infecciones por Orthomyxoviridae/virología , ARN Viral/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Análisis de SupervivenciaRESUMEN
Immune reconstitution inflammatory syndrome (IRIS) is an exacerbated immune response that can occur to HIV+ patients after initiating antiretroviral therapy (ART). IRIS pathogenesis is unclear, but dysfunctional and exhausted cells have been reported in IRIS patients, and the TIM-3/Gal-9 axis has been associated with chronic phases of viral infection. This study aimed to evaluate the soluble levels of TIM-3 and Gal-9 and their relationship with IRIS development. TIM-3, Gal-9, TNF-α, IFN-γ, IL-6, TNFR1, TNFR2, E-cadherin, ADAM10, and ADAM17 were measured to search for IRIS-associated biomarkers in plasma samples from 0-, 4-, 8-, 12-, and 24-weeks after ART initiation of 61 HIV+ patients (15 patients developed IRIS, and 46 did not). We found that patients who developed IRIS had higher levels of TIM-3 [median 4806, IQR: 3206-6182] at the time of the IRIS events, compared to any other follow-up time evaluated in these patients or compared with a control group of patients who did not develop IRIS. Similarly, IRIS patients had a higher TNF-α level [median 10.89, IQR: 8.36-12.34] at IRIS events than any other follow-up time evaluated. Other molecules related to the TIM-3 and TNF-α pathway (Gal-9, IL-6, IFN-γ, TNFR1, TNFR2, ADAM-10, and ADAM-17) did not change during the IRIS events. In conclusion, our data suggest that a high level of soluble TIM-3 and TNF-α could be used as an IRIS biomarker.
RESUMEN
While combined antiretroviral therapy (cART) has had a great impact on the treatment of HIV-1 infection, the persistence of long-lived cells with an intact provirus precludes virus eradication and sterilizing cure. CRISPR/Cas9 genome editing has become an efficient tool to eradicate HIV-1 genome or prevent replication. Furthermore, regulation of Cas9 gene expression by HIV can induce mutations that could inactivate the proviral genome, making a gene therapy safe by preventing the induction of non-specific mutations, which could compromise the integrity of healthy cells. In this study, isolated HIV-1 LTR, INS and RRE sequences were used to regulate Cas9 expression in HEK293 cells, and guide RNAs (gRNAs) were designed to target mutations in HIV-1 conserved regions such as tat and rev regulatory genes. We demonstrate that Cas9 expression in our system is controlled by the HIV-1 Tat and Rev proteins, leading to self-regulation of gene edition, and showing a strong antiviral effect by inactivating HIV-1 replication. Sequencing analysis confirmed that viral genome was partially excised by multiplex editing (90% efficiency), and viral capsid protein (CA-p24) was undetectable. In conclusion, the self-regulated CRISPR/Cas9 system may be a reliable and accurate strategy for eliminating HIV-1 infection whose effect will be restricted to infected cells.
Asunto(s)
Proteína 9 Asociada a CRISPR/genética , Inactivación de Virus , Productos del Gen rev del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética , Sistemas CRISPR-Cas , Edición Génica , Regulación Viral de la Expresión Génica , Células HEK293 , VIH-1/genética , Humanos , ARN Guía de Kinetoplastida/genética , Replicación Viral/genéticaRESUMEN
How T cells integrate environmental cues into signals that limit the magnitude and length of immune responses is poorly understood. Here, we provide data that demonstrate that B55ß, a regulatory subunit of protein phosphatase 2A, represents a molecular link between cytokine concentration and apoptosis in activated CD8+ T cells. Through the modulation of AKT, B55ß induced the expression of the proapoptotic molecule Hrk in response to cytokine withdrawal. Accordingly, B55ß and Hrk were both required for in vivo and in vitro contraction of activated CD8+ lymphocytes. We show that this process plays a role during clonal contraction, establishment of immune memory, and preservation of peripheral tolerance. This regulatory pathway may represent an unexplored opportunity to end unwanted immune responses or to promote immune memory.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Memoria Inmunológica , Proteína Fosfatasa 2/inmunología , Animales , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/inmunología , Ratones , Ratones Transgénicos , Neuropéptidos/genética , Neuropéptidos/inmunología , Proteína Fosfatasa 2/genética , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/inmunologíaRESUMEN
OBJECTIVES: The aim of this study was to investigate the correlation between the HIV-1 reservoir and the levels of immune activation in chronic patients under fully suppressive cART. METHODS: We quantified the HIV proviral DNA and 2-LTR circles loads from PBMCs, the levels of CD38+ and Ki-67+ T-cells, and the levels of IL-7 in a cohort of patients with more than 5 years of ART at enrollment and after 1 year. RESULTS: In 29 participants with a median of 8 years (IQR, 6.9-9.4) under suppressive cART we found higher levels of CD8+ CD38+ T-cells after 1-year (P = .000). There was a non-statistically significant poor correlation between the levels of immune activation and the proviral DNA of CD4+ and CD8+ T-cells. Ki-67+ T-cells declined without significant differences, and there was no significant correlation with the proportion of CD38+. IL-7 decreased at the follow-up observation (P = .094), but there was no correlation with the levels of CD38+ and Ki-67+ T-cells. CONCLUSIONS: We found a weak but non-statistically significant correlation of the levels of T-cell activation with the proviral DNA and 2-LTR circles. This suggests the likely occurrence of further mechanisms driving chronic versus early immune activation other than viral replication by itself in chronic patients.
Asunto(s)
Terapia Antirretroviral Altamente Activa , ADN Viral/genética , Infecciones por VIH/inmunología , VIH-1/inmunología , Activación de Linfocitos , Secuencias Repetidas Terminales/genética , Adulto , Fármacos Anti-VIH/uso terapéutico , Estudios de Cohortes , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/genética , VIH-1/fisiología , Humanos , Interleucina-7/inmunología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Carga Viral , Replicación ViralRESUMEN
In order to determine if the expression of the activation marker CD38 can correlate with HIV disease progression independently of cycling, we performed a cluster-based multivariate correlation analysis of total circulating CD4(+) T cell counts and viral loads with frequencies of CD38 and Ki67 expression on CD4(+) lymphocytes from patients with untreated HIV infection, stratified in maturation subpopulations, and subpopulation subsets defined by the expression of CXCR5, CXCR3, and CCR4. The frequencies of the activated phenotypes %CD38(+) Ki67(-) and %CD38(+) Ki67(+) of the CXCR5(-) CXCR3(-) CCR4(+) ("pre-Th2") central memory (T(CM)) cell subset clustered together, comprising a significant negative correlate of total circulating CD4(+) T cell counts and a positive correlate of viral load in multivariate analysis. Frequency of cycling-uncoupled CD38 expression in "pre-Th2" T(CM) cells was a negative correlate of total circulating CD4(+) T cell counts in univariate analysis, which was not the case of their %CD38(+) Ki67(+). CXCR5(+) CXCR3(-) CCR4(-) T(CM) cells were underrepresented in patients, and their absolute counts correlated negatively with their %CD38(+) Ki67(-) but not with their % CD38(+) Ki67(+). Our results may imply that CD38 expression either reflects or participates in pathogenic mechanisms of HIV disease independently of cell cycling.
Asunto(s)
ADP-Ribosil Ciclasa 1/metabolismo , Infecciones por VIH/metabolismo , Infecciones por VIH/patología , Antígeno Ki-67/metabolismo , Glicoproteínas de Membrana/metabolismo , Adulto , Recuento de Linfocito CD4 , Ciclo Celular , Progresión de la Enfermedad , Femenino , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/fisiología , Humanos , Masculino , Persona de Mediana Edad , Carga ViralRESUMEN
BACKGROUND: CD4(+) T cell activation indicators have been reported to be a common phenomenon underlying diverse manifestations of immune reconstitution inflammatory syndrome (IRIS). However, we have found that a high frequency of circulating CD8(+) T cells is a specific risk factor for mycobacterial IRIS. Therefore, we investigated whether CD8(+) T cells from patients who develop TB IRIS were specifically activated. METHODS: We obtained PBMCs from HIV+ patients prior to and 4, 8, 12, 24, 52 and 104 weeks after initiating antiretroviral therapy. CD38 and HLADR expression on naive, central memory and effector memory CD8(+) and CD4(+) T cells were determined by flow cytometry. Absolute counts and frequencies of CD8(+) T cell subsets were compared between patients who developed TB IRIS, who developed other IRIS forms and who remained IRIS-free. RESULTS: TB IRIS patients showed significantly higher counts of naive CD8(+) T cells than the other groups at most time points, with a contraction of the effector memory subpopulation occurring later in the follow-up period. Activated (CD38(+) HLADR(+)) CD8(+) T cells from all groups decreased with treatment but transiently peaked in TB IRIS patients. This increase was due to an increase in activated naive CD8(+) T cell counts during IRIS. Additionally, the CD8(+) T cell subpopulations of TB IRIS patients expressed HLADR without CD38 more frequently and expressed CD38 without HLADR less frequently than cells from other groups. CONCLUSIONS: CD8(+) T cell activation is specifically relevant to TB IRIS. Different IRIS forms may involve different alterations in T cell subsets, suggesting different underlying inflammatory processes.