IL-10-producing regulatory B cells exhibit functional defects and play a protective role in severe endotoxic shock.

Dysregulated host immune homeostasis in sepsis is life-threatening even after a successfully treated bacterial infection. Lipopolysaccharide (LPS) is an endotoxin that is a major contributor to the aberrant immune responses and endotoxic shock in gram-negative bacterial sepsis. However, the current knowledge of the role of B cells in endotoxic shock is limited. Here, we report that CD1d expression in B cells and the percentage of CD5+CD1dhi regulatory B (Breg) cells decreased in a mouse model of endotoxic shock. Interestingly, IL-10 but not FasL expression in CD5+CD1dhi Breg cells in response to endotoxin was dramatically reduced in severe septic shock mice, and the regulatory function of CD5+CD1dhi Breg cells in vitro to control the Th1 response was also diminished. Adoptive transfer of CD5+CD1dhi Breg cells from healthy WT mice but not IL-10 deficient mice downregulated the IFN-γ secretion in CD4+ T cells and conferred protection against severe endotoxic shock in vivo. Our findings demonstrate the change and notable therapeutic potential of IL-10-producing Breg cells in endotoxic shock.

Validación de sybr-14 y 6-cfda para evaluar la viabilidad e integridad de la membrana plasmática en espermatozoides caninos de raza chihuahua / Validation of sybr-14 and 6-cfda to evaluate the viability and plasma membrane integrity in sperm of chihuahua canine breed

En la aplicación de técnicas reproductivas es importante determinar in vitro la capacidad fecundante de los espermatozoides, para ello se utilizan combinaciones de tinciones para evaluar los diferentes parámetros de función espermática, aumentando así la precisión de la estimación de la muestra. El objetivo del estudio fue comparar la efectividad de la utilización de los fluorocromos 6-CFDA y SYBR-14 combinados con PI para determinar la viabilidad e integridad de la membrana plasmática por citometría de flujo. Se utilizó semen fresco de caninos (n=5) de raza Chihuahua, con una concentración espermática >150x106 esp/ml y motilidad progresiva >80%. Tres protocolos fueron ensayados: grupo 1: SYBR-14/PI, grupo 2: 6-CFDA/PI y grupo 3: PI. La integridad de la membrana plasmática de los espermatozoides fue similar entre grupos 1 y 2, independiente del fluorocromo utilizado (37,26±13,9 y 33,8±14,6, respectivamente; p=0,4601). Asimismo, la viabilidad espermática entre los grupos 1, 2 y 3 (62,7±13,9, 66,1±14,6 y 66,4±13,3, respectivamente; p=0,8987). En conclusión, no se evidenció diferencias en la efectividad para determinar la viabilidad e integridad de la membrana plasmática mediante la utilización de SYBR-14 y 6-CFDA, ambas tinciones pueden ser incorporadas al análisis de rutina de semen canino de raza Chihuahua.

In applying reproductive techniques in vitro it is important to determine the fertilizing capacity of the sperm, for this a combination of dyes were used to assess different parameters of sperm function, thereby increasing the accuracy of the estimation of the sample. In dogs (Canis lupus familiaris) Chihuahua breed there is no precedent for evaluating sperm function parameters. The aim was to assess the viability and plasmatic membrane integrity, basic parameters of sperm function. Propidium iodide (PI) was used, a fluorescent dye-specific DNA, which combined with fluorochromes permeable acts as marker of the sperm membrane integrity. The effectiveness of the use of 6-CFDA and SYBR-14 fluorochromes combined with PI was also compared to determine viability and sperm membrane integrity using flow cytometry. Fresh semen of dogs (n=5) Chihuahua breed was used with a concentration of >200x106 sp/ml and progressive motility >80%. Three protocols were performed: group 1: SYBR-14/PI, group 2: 6-CFDA/PI and group 3: PI. The plasma membrane integrity of sperm was similar, independent of the fluorophore used between groups 1 and 2 (13.9±37.26 and 33.8±14.6, respectively, p=0.4601). This also applied to sperm viability between groups 1, 2 and 3 (62.7±13.9, 66.1±14.6 and 66.4±13.3, respectively, p=0.8987). No difference was demonstrated in effectiveness to determine the viability and integrity of the sperm membrane using SYBR-14 and 6-CFDA, both dyes can be incorporated in to routine analysis of semen in canine Chihuahua breed.