Spontaneous formation of rosettes by autologous human monocyte-macrophages and lymphocytes in cell cultures

Resumen

During studv on ccli cultures ii'oni total human blood leukocytes, we found a rosettc-shaped ceil association fr,ni o 'd hy,monoeytesand 1 yniphocyw.. Cunsidering the immunoiogic roles of thcse two ccli types, we decided to stiiclv such ccli association, the resuts bcing reported here together with data un the Ircquency of thvir odurrence in ('('II cultures of human leukocytes of lx'althy subjccts, at different cultureles.
Total ieukocytes were obtained from blood of healthy human donors (9 wornen, 8 unen; mean age 34, rangc 20-62). Venous blood was drained into svringes prcviouslv treated with phenul-Irce hcparin The piasma containing the whitc celis were seedeci in TC 199 medium plus penicilin-strepto- mycin.

Samples of cultures were prepared at 48 and 96 hours by slight shaking of the respective flask. The celis were centrifugated at 200 g for 10 minutes and the superlaatant was discarded. The ce'] peliet vas gently resuspended in clrops of TC 199 mediurn. Drops of this cytopre para tion were put Oil gias.s sUdes for 5 min in a humidified charnber, and then dessicated by centrifugation on a disk perpendicular to the axi of the centrifuge, as prcviously described 1 . The cytopreparations were stai- ucd with May Criinwald-Giemsa, and observed at a Iight microscope, at 400 x.
Tu considering that the monocytes WC) e found singly and centrally located in the rosettes we have described, the quantification of the rosettes vas made as the percentage of monocytes forming rosettes, by studving 50 of such celis in each case. A rosette was considc'recl when threc oc more lymphocvtes suirroiinded a rnonocytc.