The Human Rosette-Forming Cell as a Marker of a Population of Thymus-Derived Cells

Abstract

A B S T R A C T Sheep red blood cells can surround, in vitro, some human peripheral blood lymphocytes in a formation called a rosette. The number of rosetteforming cells (RFC) in 50 normal persons had a wide range (4-40%).The organs of 13 human fetuses (11-19 wk conceptional age) were examined for the presence of RFC. The thymus possessed the highest percentage of RFC, the maximum being 65% of total thymocytes in two 15-16 wk fetal specimens. Blood RFC were always present and their number slightly increased in the oldest fetuses. The bone-marrow showed 0-8% in the six fetuses studied. RFC were found in the spleen around the 13th wk and in the liver around the 17th wk of gestation. These observations lead to the hypothesis that human blood RFC may be chiefly thymic derived. Studies of patients with immunological disorders support this hypothesis: one patient with Nezelof syndrome had no blood RFC and four patients with Wiskott-Aldrich syndrome had a low number of blood RFC (1 and 1.5%). Patients with acquired hypogammaglobulinemia showed a normal percentage of RFC. With the fetal thymocytes, the percentage of inhibition with anti-i, serum increased with the fetal age to become complete in the oldest fetuses studied. Incubation of the oldest fetal thymocytes or the blood lymphocytes with anti-e serum or anti-ja serulmi completely inhibited the rosette formation. These results suggest that u-chain determinants are presenit on human fetal thymocytes and blood RFC. The significance of the presence of y-chain determinants on these cells is uniclear.Presented in part at the 84th annual meetiing of the Association

Enzyme-induced modification of the surface properties of lymphoid cells in malignant disease. I. Effect of trypsin on rosette formation by lymphocytes in myelomatosis

“…The depressed E-rosette formation by trypsin-treated normal lymphocytes confirmed the suggestion that the sheep erythrocyte receptor sites on the lymphocyte surface membrane are sensitive to trypsin and may be protein in nature (Wybran et al, 1972). An alternative explanation is that the surface changes on normal lymphocyte membranes have been markedly altered by trypsin, so that the electrostatic attraction between the lymphocyte and sheep erythrocyte had been reduced.…”

Colony formation by normal and malignant human B-lymphocytes

“…Then, T lymphocytes were removed from the populations as described previously (Minden et al, 1979) by using sheep erythrocytes (SRBC) to form rosettes (Wybran et al, 1973) and remnoving these rosettes by centrifugation inFicoll-Hypaque. In some instances, SRBCs treated with 2-5 aminoethylisothiouronium (AET, Sigma) were used (Kaplan et al, 1976).…”

Walter Hubert Lecture, delivered 1 April 1980 to the 21st AGM of the BACR Malignant lymphomas as tumours of the immune system

“…These areas fail to bind EAC and are usually rich in normal-looking lymphocytes of presumed T-cell type. It is known that activated T lymphocytes appear to bind E more readily than T cells not stimulated or not actively involved in an immunological reaction (Wybran et al, 1972). The so-called "active E rosette test" is based upon this observation (Wybran et al, 1972).…”

“…It is known that activated T lymphocytes appear to bind E more readily than T cells not stimulated or not actively involved in an immunological reaction (Wybran et al, 1972). The so-called "active E rosette test" is based upon this observation (Wybran et al, 1972). Perhaps the small lymphocytes in the internodular areas are an inactive, unstimulated population of T cells with little or no affinity for EN in frozen sections.…”