Toshiki Sakamoto

Production of macrophage colony-stimulating factor by adult murine parenchymal liver cells (hepatocytes)

The activity of macrophage colony‐stimulating factor (M‐CSF) was found in the culture supernatant of mouse parenchymal liver cell fractions in a bone marrow colony‐forming assay. The activity of an M‐CSF‐like substance purified by a four‐step procedure was neutralized by goat anti‐mouse M‐CSF antiserum. M‐CSF mRNA was detected in cellular UNA prepared from cultured parenchymal liver cell fractions by Northern blot analysis and also in cultured parenchymal liver cells by in situ hybridization. These results indicate that parenchymal liver cells have the capacity to produce M‐CSF. We discuss the role of M‐CSF in hematopoiesis, the immune response, and other biological phenomena.

The liver and the hematolymphoid system: I. The regulation of nylon-passed spleen cell proliferation by active factors released from syngeneic nonparenchymal liver cells.

Nylon‐passed spleen cells were found to proliferate when cultured with syngeneic nonparenchymal adherent liver cells and their culture supernatants. The supernatants contained IL‐1, IL‐6, GM‐CSF, and IFN (α + β) activities but not IL‐2 and IL‐3 activities. The IFN level was higher in early culture sup (2–24 hr) than in later culture sup (48–72 hr). Proliferation was greatly increased by anti‐IFN (α + β) serum in the spleen cells cultured in the earlier sup. This antiserum increased the spleen cell proliferation only slightly in the later culture sup. This suggests that nonparenchymal liver cells produce two factors, one having a suppressor, and the other an enhancer action, with IFN being one of the suppressor factors. With culture time, DNA synthesis of spleen cells increased and IL‐2 and IL‐3 activities were generated in the culture sup. Cells proliferated during culture were found to be morphologically lymphocytes, granulocytes, and macrophages. The mechanisms by which nonparenchymal liver cells regulate the hematolymphoid system are discussed based on our observations.

Abstracts of selected papers presented at the 77th General Meeting of the Japanese Society of Gastroenterology

M E E T I N G OF T H E J A P A N E S E S O C I E T Y OF G A S T R O E N T E R O L O G Y March 28-30, 1991-Tokyo, Japan Chairman: Yutaka MATSUO, M.D.