Monocytes are a type of white blood cells found in peripheral blood that differentiate into macrophages as part of the inflammatory response. White blood cells are easy to isolate on the basis of a whole blood sample processed by means of Ficoll-based density gradient.
We have found that monocytes isolated from peripheral blood of pigs and grown using simple tissue culture procedures produce large numbers of mesenchymal cells that exhibit differentiation into mesodermal lineages in vitro.
Peripheral blood samples were obtained from 2, 4, and 6 months old male pigs. The cells were isolated by a Ficoll-based density gradient and cultured in cell culture media. All isolates exhibited mesenchymal morphology and continued to expand at least to passage 7. The expansionary potential was greatest for the cells obtained from the 2 mo. old pigs.
In regards to immune-phenotype, the cells are strongly positive for the leukocyte maker CD 14 and SLA-DR- II. Approximately 50% of the cells are positive for CD 45, and they are negative for CD 105, CD 31, and CD 90.
The monocyte-derived cells express mRNAs for TLR-3,4,5, 7, and 9. They also express the pluripotency-associated gene Nanog but only weakly express Sox-2 and Oct-4. In vitro the cells are capable of differentiation into adipogenic, osteogenic, and chondrogenic lineages. They also exhibit phagocytosis as measured by in vitro assay.
The cells isolated in this study represent a novel subset of monocytes with characteristics overlapping those known for mesenchymal stem cells. Swine are physiologically similar to humans and it is conceivable that a similar population might exist in human peripheral blood. Further work is needed to characterize these cells for regenerative medicine applications.
Fecha y Horario: Miércoles 14 de Febrero 10:00-11:00.
Dirigido a: Estudiantes de Maestría y Doctorado en Ciencias de la Computación.
Instructor: PhD. Cesar Guillermo Caballero Vidal (Kansas State University)