Meshes in a mess: Mesenchymal stem cell-based therapies for soft tissue reinforcement.

Surgical meshes are frequently used for the treatment of abdominal hernias, pelvic organ prolapse, and stress urinary incontinence. Though these meshes are designed for tissue reinforcement, many complications have been reported. Both differentiated cell- and mesenchymal stem cell-based therapies have become attractive tools to improve their biocompatibility and tissue integration, minimizing adverse inflammatory reactions. However, current studies are highly heterogeneous, making it difficult to establish comparisons between cell types or cell coating methodologies. Moreover, only a few studies have been performed in clinically relevant animal models, leading to contradictory results. Finally, a thorough understanding of the biological mechanisms of mesenchymal stem cells in the context of foreign body reaction is lacking. This review aims to summarize in vitro and in vivo studies involving the use of differentiated and mesenchymal stem cells in combination with surgical meshes. According to preclinical and clinical studies and considering the therapeutic potential of mesenchymal stem cells, it is expected that these cells will become valuable tools in the treatment of pathologies requiring tissue reinforcement. STATEMENT OF SIGNIFICANCE: The implantation of surgical meshes is the standard procedure to reinforce tissue defects such as hernias. However, an adverse inflammatory response secondary to this implantation is frequently observed, leading to a strong discomfort and chronic pain in the patients. In many cases, an additional surgical intervention is needed to remove the mesh. Both differentiated cell- and stem cell-based therapies have become attractive tools to improve biocompatibility and tissue integration, minimizing adverse inflammatory reactions. However, current studies are incredibly heterogeneous and it is difficult to establish a comparison between cell types or cell coating methodologies. This review aims to summarize in vitro and in vivo studies where differentiated and stem cells have been combined with surgical meshes.

Human prostasomes express CD48 and interfere with NK cell function.

Prostasomes are small vesicles secreted by the prostate gland to the seminal fluid. In male fertility, the fusion of prostasomes to sperm has been associated with an enhancement of sperm function. Prostasomes also contribute to sperm protection within the female reproductive tract and immunologically relevant proteins have been identified on the prostasomal membrane that may prevent immune-mediated destruction of the sperm.The female genital tract is a potentially hostile environment for spermatozoa and a large number of NK cells have been found in the female reproductive tract. Since it has been suggested that NK cells may represent an important component of innate immunity in the female reproductive tract, we have analyzed the role of prostasomes in the regulation of NK cell activity.Flow cytometric analysis revealed that prostasomes expressed high levels of CD48, the ligand for the activating receptor CD244. The interactions between NK cells and purified prostasomes resulted in a decrease of CD244 expression. Moreover, the decreased NK cell activity observed in NK cells cultured in the presence of prostasomes suggests that prostasomes may immunomodulate the local environment within the female reproductive tract preventing immune-mediated sperm destruction and prolonging their survival rate.

Inmunobiología e inmunopatología de las células NKT humanas / Human NKT cells in health and disease

Las células T "Natural killer" (NKT) constituyen un nuevo linaje de linfocitos fenotípicamente y funcionalmente diferente de los linfocitos T alfa /beta convencionales. Las células NKT se caracterizan por una expresión restringida de la cadena alfa del TCR codificada por los segmentos génicos V alfa24/J alfaQ en seres humanos y V alfa14/J alfa281 en ratones, así como por la expresión de los receptores asociados a células NK, CD161 en humanos y NK1.1 en ratones. Tanto las células NKT humanas como las murinas interaccionan específicamente con glicolípidos presentados en el contexto de la molécula CD1d y juegan un papel inmunorregulador importante mediante la producción de Interferon-alfa e Interleuquina-4. Recientemente, el desarrollo de ratones manipulados genéticamente, que presentan pérdida selectiva de células NKT V alfa14, ha permitido elucidar la función de las células NKT en la respuesta frente a diferentes infecciones y tumores en diversos modelos experimentales. Se ha demostrado la existencia de cambios en el número y función de las células NKT en diferentes enfermedades que apoyan la participación de estas células en la regulación de la respuesta inmune particularmente en la regulación de la homeostasis de las respuestas autoinmunes y en la inmunidad tumoral (AU)