Differential expression patterns of purinergic ectoenzymes and the antioxidative role of IL-6 in hospitalized COVID-19 patient recovery

IntroductionWe have acquired significant knowledge regarding the pathogenesis of severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). However, the underlying mechanisms responsible for disease recovery still need to be fully understood.MethodsTo gain insights into critical immune markers involved in COVID-19 etiopathogenesis, we studied the evolution of the immune profile of peripheral blood samples from patients who had recovered from COVID-19 and compared them to subjects with severe acute respiratory illness but negative for SARS-CoV-2 detection (controls). In addition, linear and clustered correlations between different parameters were determined.ResultsThe data obtained revealed a significant reduction in the frequency of inflammatory monocytes (CD14+CD16+) at hospital discharge vs. admission. Remarkably, nitric oxide (NO) production by the monocyte compartment was significantly reduced at discharge. Furthermore, interleukin (IL)-6 plasma levels were negatively correlated with the frequency of NO+CD14+CD16+ monocytes at hospital admission. However, at the time of hospital release, circulating IL-6 directly correlated with the NO production rate by monocytes. In line with these observations, we found that concomitant with NO diminution, the level of nitrotyrosine (NT) on CD8 T-cells significantly diminished at the time of hospital release. Considering that purinergic signaling constitutes another regulatory system, we analyzed the kinetics of CD39 and CD73 ectoenzyme expression in CD8 T-cells. We found that the frequency of CD39+CD8+ T-cells significantly diminished while the percentage of CD73+ cells increased at hospital discharge. In vitro, IL-6 stimulation of PBMCs from COVID-19 patients diminished the NT levels on CD8 T-cells. A clear differential expression pattern of CD39 and CD73 was observed in the NT+ vs. NT-CD8+ T-cell populations.DiscussionThe results suggest that early after infection, IL-6 controls the production of NO, which regulates the levels of NT on CD8 T-cells modifying their effector functions. Intriguingly, in this cytotoxic cell population, the expression of purinergic ectoenzymes is tightly associated with the presence of nitrated surface molecules. Overall, the data obtained contribute to a better understanding of pathogenic mechanisms associated with COVID-19 outcomes

Entrevista a la Dra. Alicia Cámara acerca de la pandemia causada por el Coronavirus SARS-CoV- 2 (COVID-19), 25 marzo 2020

Preguntas: 1) ¿Qué es el Coronavirus SARS-COV-2 (COVID-19)? 2) ¿Cuáles son las vías de transmisión identificadas hasta el momento? 3) ¿Qué nos puede decir sobre su infectividad y su capacidad de propagación en relación a otros virus respiratorios comunes? 4) ¿Cuáles son las características clínicas típicas de la enfermedad que causa?, ¿en qué etapa de la infección y enfermedad se da la mayor posibilidad de transmitir el virus? 5) ¿Cuál es la mortalidad estimada y qué grupos de personas se encuentran en mayor riesgo de sufrir enfermedad severa y potencialmente mortal por SARS-CoV-2? 6) ¿Es exagerada la alarma generalizada que el SARS-CoV-2 ha causado a nivel global?, ¿son justificadas las medidas tomadas por algunos países de negar el ingreso a personas procedentes de focos de circulación del virus, o bien de indicar cuarentenas a millones de personas como en el caso de Italia? 7) ¿Cuáles son las medidas preventivas principales para la población general, con miras a disminuir y ralentizar la circulación de este virus?, ¿existen medidas preventivas diferenciales para los grupos de personas que se encuentran en mayor riesgo de sufrir enfermedad severa? 8) ¿Existe una vacuna?, en caso negativo, ¿se prevé la pronta disponibilidad de la misma para uso masivo?, ¿quiénes deberían vacunarse?, ¿qué vacunas serían recomendadas para el próximo invierno para la población general y para la población de riesgo? 9) ¿Existen tratamientos específicos contra este virus? 10) ¿Cuál es la situación en Argentina y específicamente en Córdoba? 11) ¿Ante qué síntomas los pacientes deben realizar la consulta médica? Para disminuir la transmisión, ¿podría considerarse una mejor opción promover las consultas telefónicas en vez de presenciales, como lo están realizando en CABA? 12) ¿Cuáles son los centros de referencia locales y nacionales para la realización del diagnóstico? ¿Sobre qué muestras se realiza el diagnóstico y que método se utiliza? 13) ¿Se conoce el genoma completo del SARS-CoV-2?, la cepa de Wuhan, China, ¿es idéntica a la que se ha detectado por ejemplo en Europa y en Sudamérica?, ¿se trata de un virus capaz de mutar fácilmente? 14) ¿Cuáles son las recomendaciones respecto de la indicación de cuarentena? 15) Durante la cuarentena, ¿cuáles son las indicaciones para los miembros convivientes del paciente enfermo? 16) Luego de la enfermedad por SARS-CoV-2 (COVID-19) o de la cuarentena de pacientes asintomáticos, ¿qué condiciones son necesarias para proceder al alta médica? 17) Frente a situaciones de alarma generalizada suelen circular en los medios sociales sugerencias sin bases científicas. Por ejemplo, ¿qué nos puede mencionar sobre la recomendación de hacer buches con agua salada o enjuagues bucales, o de tomar agua cada 15 minutos (entre otras)? 18) La presidenta de Alemania, Angela Merkel, ha declarado públicamente que en ese país estiman que el 60-70% de la población se infectará. ¿Hay estimaciones acerca de la proporción de la población que puede infectarse en nuestro país? 19) Por último, ¿es de esperar que la mayor cantidad de casos se den en los meses de otoño e invierno, como ocurre con otras enfermedades respiratorias de origen viral tales como la gripe y el resfrío común?Entrevista a la Dra. Alicia Cámara (25 marzo 2020), y en la que se abordan múltiples preguntas acerca de la pandemia causada por el Coronavirus SARS-CoV-2 (COVID-19). Dicha pandemia está causando en este momento un impacto global de gran magnitud, debido a que ha golpeado duramente a los sistemas de salud pública en todos los países afectados, habiendo producido más de diez mil fallecimientos en menos de tres meses. Las cuarentenas extensas y el cierre de fronteras en múltiples países, incluyendo a Europa y los EE. UU. de América, están empezando a plantear interrogantes sobre la economía mundial y amenazan con amplificar aún más los efectos negativos de esta pandemia.publishedVersionFil: Cámara, Alicia. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Laboratorio de Clamidias y Virus Papiloma Humano, Instituto de Virología “Dr. J.M. Vanella”; Argentina.Fil: Saka, Héctor Alex. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina

Chronic epididymitis due to Chlamydia trachomatis LGV-L2 in an HIV-negative heterosexual patient: a case report

Chlamydia trachomatis is an obligate intracellular pathogen and the leading bacterial cause of sexually transmitted infections worldwide. Chlamydia trachomatis genovars L1–L3 are responsible for lymphogranuloma venereum (LGV), an invasive sexually transmitted disease endemic in tropical and subtropical regions of Africa, South America, the Caribbean, India and South East Asia. The typical signs and symptoms of C. trachomatis LGV urogenital infections in men include herpetiform ulcers, inguinal buboes, and/or lymphadenopathies. Since 2003, endemic cases of proctitis and proctocolitis caused by C. trachomatis LGV emerged in Europe, mainly in HIV-positive men who have sex with men (MSM). Scarce data have been reported about unusual clinical presentations of C. trachomatis LGV urogenital infections. Herein, we report a case of a 36-year-old heterosexual, HIV-negative male declaring he did not have sex with men or trans women, who presented to the Urology and Andrology outpatient clinic of a healthcare center from Cordoba, Argentina, with intermittent testicular pain over the preceding 6 months. Doppler ultrasound indicated right epididymitis and funiculitis. Out of 17 sexually transmitted infections (STIs) investigated, a positive result was obtained only for C. trachomatis. Also, semen analysis revealed oligoasthenozoospermia, reduced sperm viability as well as increased sperm DNA fragmentation and necrosis, together with augmented reactive oxygen species (ROS) levels and the presence of anti-sperm IgG autoantibodies. In this context, doxycycline 100 mg/12 h for 45 days was prescribed. A post-treatment control documented microbiological cure along with resolution of clinical signs and symptoms and improved semen quality. Strikingly, sequencing of the ompA gene revealed C. trachomatis LGV L2 as the causative uropathogen. Remarkably, the patient did not present the typical signs and symptoms of LGV. Instead, the infection associated with chronic testicular pain, semen inflammation and markedly reduced sperm quality. To our knowledge, this is the first reported evidence of chronic epididymitis due to C. trachomatis LGV L2 infection in an HIV-negative heterosexual man. These findings constitute important and valuable information for researchers and practitioners and highlight that C. trachomatis LGV-L2 should be considered as putative etiologic agent of chronic epididymitis, even in the absence of the typical LGV signs and symptoms

New Carbenicillin-Hydrolyzing β-Lactamase (CARB-7) from Vibrio cholerae Non-O1, Non-O139 Strains Encoded by the VCR Region of the V. cholerae Genome

In a previous study, an analysis of 77 ampicillin-nonsusceptible (resistant plus intermediate categories) strains of Vibrio cholerae non-O1, non-O139, isolated from aquatic environment and diarrheal stool, showed that all of them produced a β-lactamase with a pI of 5.4. Hybridization or amplification by PCR with a probe for bla(TEM) or primers for bla(CARB) gene families was negative. In this work, an environmental ampicillin-resistant strain from this sample, ME11762, isolated from a waterway in the west region of Argentina, was studied. The nucleotide sequence of the structural gene of the β-lactamase was determined by bidirectional sequencing of a Sau3AI fragment belonging to this isolate. The gene encodes a new 288-amino-acid protein, designated CARB-7, that shares 88.5% homology with the CARB-6 enzyme; an overall 83.2% homology with PSE-4, PSE-1, CARB-3, and the Proteus mirabilis N29 enzymes; and 79% homology with CARB-4 enzyme. The gene for this β-lactamase could not be transferred to Escherichia coli by conjugation. The nucleotide sequence of the flanking regions of the bla(CARB-7) gene showed the occurrence of three 123-bp V. cholerae repeated sequences, all of which were found outside the predicted open reading frame. The upstream fragment of the bla(CARB-7) gene shared 93% identity with a locus situated inside V. cholerae's chromosome 2. These results strongly suggest the chromosomal location of the bla(CARB-7) gene, making this the first communication of a β-lactamase gene located on the VCR island of the V. cholerae genome

Presentation_1_Differential expression patterns of purinergic ectoenzymes and the antioxidative role of IL-6 in hospitalized COVID-19 patient recovery.pdf

IntroductionWe have acquired significant knowledge regarding the pathogenesis of severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). However, the underlying mechanisms responsible for disease recovery still need to be fully understood.MethodsTo gain insights into critical immune markers involved in COVID-19 etiopathogenesis, we studied the evolution of the immune profile of peripheral blood samples from patients who had recovered from COVID-19 and compared them to subjects with severe acute respiratory illness but negative for SARS-CoV-2 detection (controls). In addition, linear and clustered correlations between different parameters were determined.ResultsThe data obtained revealed a significant reduction in the frequency of inflammatory monocytes (CD14+CD16+) at hospital discharge vs. admission. Remarkably, nitric oxide (NO) production by the monocyte compartment was significantly reduced at discharge. Furthermore, interleukin (IL)-6 plasma levels were negatively correlated with the frequency of NO+CD14+CD16+ monocytes at hospital admission. However, at the time of hospital release, circulating IL-6 directly correlated with the NO production rate by monocytes. In line with these observations, we found that concomitant with NO diminution, the level of nitrotyrosine (NT) on CD8 T-cells significantly diminished at the time of hospital release. Considering that purinergic signaling constitutes another regulatory system, we analyzed the kinetics of CD39 and CD73 ectoenzyme expression in CD8 T-cells. We found that the frequency of CD39+CD8+ T-cells significantly diminished while the percentage of CD73+ cells increased at hospital discharge. In vitro, IL-6 stimulation of PBMCs from COVID-19 patients diminished the NT levels on CD8 T-cells. A clear differential expression pattern of CD39 and CD73 was observed in the NT+ vs. NT-CD8+ T-cell populations.DiscussionThe results suggest that early after infection, IL-6 controls the production of NO, which regulates the levels of NT on CD8 T-cells modifying their effector functions. Intriguingly, in this cytotoxic cell population, the expression of purinergic ectoenzymes is tightly associated with the presence of nitrated surface molecules. Overall, the data obtained contribute to a better understanding of pathogenic mechanisms associated with COVID-19 outcomes.</p