Synergistic action of two sources of avian growth factors on proliferative differentiation of XXXX embryonic @entity1583 cells.

@entity558 @entity71628 @entity1573 @entity6732 @entity1583 @entity30310
During embryonic development, the components of the avian immune system undergo ontogeny in several distinct organs, including the bone marrow, spleen, thymus, and bursa of Fabricius. This process is regulated and controlled by the complex interactions of various cytokines and colony-stimulating factors (CSF). The objective was to examine the action of two different sources of @entity1583 growth factors, @entity558 ( @entity558 ) and @entity1573 embryo extract (CEE), on the proliferation of @entity1583 cells from various organs and on the differentiation of progenitor cells in semi-solid culture. Spleen and bone marrow cells obtained at Day 16 of incubation responded in a dose-dependent manner to the addition of @entity558 and CEE alone or in combination. No proliferative effect of @entity558 was observed on cells obtained from @entity6732 . Clonal analysis of bone marrow and spleen cells suggested that CEE may contain the avian equivalents of @entity30310 , @entity71628 , granulocyte-macrophage CSF, granulocyte-CSF, and macrophage-CSF. Clonal analysis of @entity558 cultures suggested that in addition to myelomonocytic growth factor, which affects primarily macrophage-granulocyte lineages, a thrombocyte-CSF-like activity was also apparent. The @entity558 alone tended to act upon committed late progenitors. The combination of CEE and @entity558 amplified the size and the total number of colonies obtained and appeared to act synergistically upon progenitors with a high level of proliferative potential. This response on young progenitors was confirmed when cells were cultured in CEE and @entity558 prior to clonal analysis. These results document the presence of thrombocyte CSF in @entity558 and the effect of both CEE and @entity558 on the proliferative differentiation of avian embryonic @entity1583 progenitors.
