Pig bone marrow and peripheral blood granulocyte-macrophage progenitor cells

The pig is widely used as a large animal model for biomedical research and could be an interesting experimental model for studes of the hematopoietic system and its response in physiological and pathological conditions. With the intention of using the pig as a large animal model in hematopoietic research, a clonal assay in methylcellulose was developed and standardized for detection of committed progenitors of the granulocyte-macrophage lineage from adult pig bone marrow and peripheral blood. Progenitor cells were stimulated to proliferate and differentiate in vitro by adding pig leukocyte conditioned medium (LCM) as a source of homologous growth factors. The number of CFU-GM (Colony Forming Unit Granulocyte-Macrophage) directly depended on the concentration of LCM. The proliferative rate of CFU-GM progenitor cells was determined by the cytosine arabinoside suicide technique. The percentage of bone marrow and peripheral blood CFU-GM cells in S phase of the cell cycle was 34.7% and 22.2%, respectively. The data obtained regarding the number and characteristics of pig bone marrow and peripheral blood CFU-GM confirmed that the organization of the pig CFU-GM progenitor cell compartment is similar and comparable to that in miniature swine, other animal species and humans.