Lymphocytes bearing receptors for both sheep erythrocytes and complement in patients with neoplastic and non-neoplastic diseases

Secretory leukemic B cells express T cell markers in vitro. A phenomenon suppressed by TPA

Immunological and biochemical markers of leukemia/lymphoma cells have provided valuable insight into hematopoietic malignancy and normal differentiation. The general assumption is that as early lymphoid cells become committed towards terminal differentiation they lose their capacity for bimodal differentiation and cells become restricted to B or T cell development and function. We have observed that phenotypically "late" leukemic B cells close to secretory stage can spontaneously express mature T cell antigens (T11, T4 and T8) after culture in vitro. In further studies of these cells, it was found that the biochemical marker lactate Dehydrogenase (LD) follows the intermediate pattern expressed by thymocytes rather than that of typical B cells. The expression of T cell antigens can be blocked by incubating these cells with the phorbol ester TPA (12-0-tetradecanoyl phorbol 13 acetate) which promotes unidirectional B cell maturation to plasmacytoid cells in a way that mimics normal B cell differentiation. These observations indicate that presecretory malignant B cells are still programmed to express T cell biochemical and antigenic markers and this expression can be influenced by environmental conditions in vitro.

Cerebrospinal fluid and blood lymphocyte subpopulations in acute aseptic meningitis

Lymphocyte subpopulations were determined in cerebrospinal fluid (CSF) from 11 patients with acute aseptic meningitis. The patients had a significantly higher percentage of T lymphocytes (as determined by rosette assays for sheep erythrocyte (E) receptor-bearing cells) in their CSF (86%) than in blood (62%). The percentage of complement (C) receptor-bearing cells was also higher in the CSF (47%), and the sum of E and C receptor positive cells was 133%, indicating a considerable number of cells carrying both receptors in the CSF in contrast to in peripheral blood. However, 8 patients with various neurological diseases had a mean of 65% C receptor-bearing cells in their CSF, while 17 others had 78 +/- 9% E receptor positive cells. Meningitis patients had a lower percentage of CSF Fc receptor-bearing cells (EA-RFC) than other patients. These results indicate the presence of a large percentage of CSF lymphocytes with both E and C receptors also in patients without meningeal disease, and suggest the recruitment of such cells into the CSF.

Differentiation between benign and malignant human lymph nodes by means of immunologic markers

A surface-marker assay combining immunofluorescence with anti-human immunoglobulin or anti-human brain serum (AHBS) and the formation of rosettes with untreated (E), antibody-sensitized (EA) and complement-coated (EAC) sheep erythrocytes was used to study mononuclear cell suspensions of human lymph nodes. The frequency of cells expressing more than one marker was increased in lymphoma nodes as compared to normal and hyperplastic nodes. The cells which simultaneously expressed complement receptors, surface immunoglobulin and the marker identified by AHBS represented the most prominent and characteristic subpopulation identified in neoplastic nodes. Distributions of cells with double and triple markers were studied by combining immunofluorescence with rosetting on frozen tissue sections. The multiple-marker cells had distributions that were characteristic in different human lymphomas. Benign and malignant human nodes could be distinguished on the basis of frequency and distribution of mononuclear cell populations carrying distinctive combinations of T- and B-cell surface markers.

A simple method to detect complement receptors using baker's yeast: Y C rosettes

A technique is described to identify complement-receptor-bearing cells, using serum-treated baker's yeast as a ligand. The method consists of incubation of heat-killed baker's yeasts with fresh AB normal serum, freezing, thawing, and washing of the particles, followed by mixing with the cells. Serum is required to coat the yeasts for the rosette formation. Experiments designed to establish the serum factors responsible for the attachment of the particles to cells show that heat inactivation, chelating agents, or anti-C3 treatment prevent rosette formation. This is taken as evidence that yeasts (Y) are coated with complement (C) to compose the reagent for the YC rosette technique. The application of this technique to twenty-five normal individuals demonstrated that a mean of 11.6 per 100 lymphocytes (+/- 4.3) form rosettes; absolute number: 275 (+/- 160) rosette-forming lymphocytes per mm3. Either AB or autologous fresh serum can be used to coat the yeasts. A combined technique for YC plus E rosettes can be performed allowing the identification and enumeration of four populations of lymphocytes: (a) those having receptors for sheep erythrocytes, (b) complement-receptor-bearing lymphocytes, (c) those having both receptors (D lymphocytes), and (d) non-rosette-forming non-phagocytic cells.