Use of Diffusion Chambers for Studying Cell Interactions: Sequential Studies of Eosinophil Granulocytopoiesis In Vivo

Abstract

A diffusible eosinophilopoiesis stimulating factor (EoSF) is produced by certain antigen-stimulated spleen cells. This EoSF results in increased eosinophil production by normal murine bone marrow cells as demonstrated with the Quadrachamber Diffusion Assembly (QDA).

In this study we have defined the response of murine bone marrow to EoSF within QDA with respect to time. Normal murine bone marrow populations were placed within diffusion chambers across a Millipore filter from spleen cells from either tetanus toxoid (TT)-primed or normal mice. Such antigen-primed cells produce an EoSF on rechallenge with this antigen. Assemblies were implanted intraperitoneally into normal isogeneic host mice. The host mice then received an intraperitoneal injection of TT. Groups of mice were killed at various intervals following initiation of the in vivo cultures. Total chamber bone marrow (CBM) cellularities, total CBM noneosinophil granulocytes (NEG), and CBM percent NEG did not differ as a function of the origin of the respective transfilter spleen cells over a 9-day period. Values for total eosinophils, percent eosinophils, and the percentage of granulocytes that were eosinophils were significantly higher from the 2nd through 9th day of culture in the CMB population transfilter from the spleen cells obtained from the tetanus toxoid-primed mice, when compared with CBM transfilter from the normal spleen cell population.

The increased eosinophil production appears to be facilitated through an increase in the number of immature eosinophils during the first 48 h following implantation and challenge. A larger eosinophil precursor base for subsequent production is thereby provided, and may explain the fourfold difference between the two populations seen on the 4th day of culture.