Age-dependent changes in the proportion of macrophages in primary thymus non-lymphoid cell cultures.
Primary murine thymus cell cultures consist of thymus epithelial cells, macrophages and interdigitating dendritic cells. Results of the present study indicated that the proportion of macrophage-like cells in cultures was directly related to the age of the thymus donors through 7 weeks of age. We standardized procedures to compare primary thymic cultures derived from mice, 1 day to 115 days of age. Cultures were grown 6 to 8 days and then tested for nonspecific esterase, acid phosphatase, phagocytosis of latex beads, Fc receptors, and MAC-1 staining. Less than 10% macrophage-like cells were identified in cultures from mice 1 to 3 days-old, but the proportion increased to 50% macrophage-like cells in cultures from 7 week-old mice. Thereafter the proportion plateaued although there was considerable variation among older mice. Further studies showed that the proportions of macrophage-like cells was not affected by the number of cells initially seeded into culture, nor by the amount of serum added to the culture medium. These data suggest that macrophage/interdigitating cell precursors immigrate into the thymus for 4 to 6 weeks after birth and support the hypothesis that these precursors may be influenced to differentiate into thymus macrophages or interdigitating cells by the thymic microenvironment.
Jones
K H
KH
Department of Cell Biology, Ohio State University, Columbus 43210.
Stutz
E J
EJ
Sirinek
L P
LP
D000367:Age Factors; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D007150:Immunohistochemistry; D016177:Macrophage-1 Antigen / Q000032:analysis; D008264:Macrophages / Q000166:cytology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011961:Receptors, Fc / Q000032:analysis; D013950:Thymus Gland / Q000166:cytology*
D016177:Macrophage-1 Antigen; D011961:Receptors, Fc