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Results for “Lymphocytes, Null”

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At least 19 recordsLinked to original sources
PubMed1977

Abelson virus-transformed lymphocytes: null cells that modulate H-2.

A-MuLV-transformed lymphoid cells from Balb/c mice had the properties of null lymphocytes. They did not secrete Ig and all but one did not have detectable cell-associated Ig; one line synthesized, but did not secrete, the mu chain of IgM. The cells expressed H-2D and H-2K, but not H-21 histocompatibility antigens or theta-antigen; they had Fc receptors. Most cell lines grew to form donor cell tumors after inoculation into (Balb/c X C57B1/6)F1 mice. The tumor cells have more H-2Dd than cells passaged in vitro. Cell lines carried in vitro progressively lost H-2Dd. A line in which 5-30% of the cells were lysable by anti-H-2Dd was cloned; all eleven clones had H-2Dd (13-69% lysable) demonstrating that H-2 modulates in vitro. A clone with little H-2Dd (10-15% lysable) was tumorigenic even after treatment with anti-H-2Dd sera; at least 50% of the tumor cells were lysed by anti-H-2Dd. Thus A-MuLV-transformed lymphocytes modulate H-2 in vivo to higher levels and in vitro to lower levels.

Animals↗
PubMed1981

The in vitro development of immunoglobulin producing cells from the human bone marrow null lymphocyte.

The distribution of human bone marrow lymphocyte population was studied on twenty normal adults. The distribution of bone marrow lymphocytes were as follows: null lymphocytes 79.4%, E-RFC 8.9%, Thy+ lymphocytes 0.4%, Tgamma 0.9%, Tmi 1.4%, SmIg+ cells 7.8%, EAC-RFC 11.7%, EA-RFC 6.2%, and K cells 2.7%. Bone marrow null lymphocytes were intermediate in their size between small lymphocytes and lymphoblasts. The presence of a lot of short microvilli on null lymphocytes was demonstrated by scanning electron microscopic examinations. The bone marrow null lymphocytes had no cytoplasmic Ig. When the bone marrow null lymphocytes were mixed-lymphocytes-cultured with allogeneic T lymphocytes and then stimulated with PWM, there developed Ig producing cells. Differences between pre-B cells and bone marrow null lymphocytes were discussed.

Antibody-Producing Cells↗
PubMed1978

Rosette formation of human null lymphocytes with Rhesus monkey erythrocytes.

Human null lymphocytes which lack B- and T-lymphocyte markers were found to form spontaneous rosettes with uncoated Rhesus monkey erythrocytes. Rosette-forming null lymphocytes were determined in null lymphocyte-enriched preparations of healthy persons and of patients with lymphoproliferative diseases. Quantitative determinations of these rosette-forming lymphocytes and other cells bearing B- or T-cell markers showed that some, and not all, of the null lymphocytes possess this rosette-forming capacity. The possibility of these null lymphocytes being related to T lymphocytes, but at a different cellular stage, is discussed.

Animals↗
PubMed1985

Identification of erythroid colony progenitors in a subset of human peripheral null lymphocytes devoid of Fc receptors.

This study was aimed at purifying the progenitors of erythroid burst units (BFU-E) from human peripheral blood. Human mononuclear leukocytes from five normal donors were fractionated into several mononuclear cell subpopulations, including null lymphocytes with (null Fc+) and without (null Fc-) receptor for the Fc fragment of immunoglobulin G, through a succession of rosetting procedures and discontinuous Ficoll-Hypaque gradient centrifugations. The fractionated cells were separately cultured for 14 days in plasma clots in the presence of erythropoietin. Among fractionated cell subpopulations large and numerous BFU-E derived colonies grew only from the Fc- null lymphocyte subpopulation. This fraction, representing less than 4% of all mononuclear cells, also contains cells (42 + 11%) capable to differentiation towards the B-cell and plasma-cell lineages. The Fc+ null lymphocytes, representing less than 9% of all mononuclear cells, contained 15.2 + 3.3% cells capable of differentiation toward the T-cell lineage. The whole null lymphocyte subpopulation generated half the number of BFU-E colonies expected from its content in Fc- null lymphocytes. These data demonstrate that the progenitor of erythroid cells (BFU-E) resides in a small heterogeneous null Fc- subpopulation of circulating lymphocytes and suggest that its in vitro differentiation, though generally subjected to inhibitory and enhancing influences from other circulating cell subpopulations, does not necessarily require interaction with other peripheral blood cells.

Adult↗
PubMed1976

B and T lymphocytes in man. III. B, t, and "null" lymphocytes in multiple sclerosis.

T, B, and "null" lymphocytes were determined in peripheral blood obtained from 24 control subjects and 15 multiple sclerosis patients. The total number of lymphocytes and T lymphocytes were reduced significantly in multiple sclerosis patients as compared with those of controls. Although the percentage of B lymphocytes increased in these patients, the absolute number of B lymphocytes was similar to controls. The mitotic response of lymphocytes from multiple sclerosis patients to phytohemagglutinin and pokeweed mitogen in 7-day-old cultures was decreased as compared with that of controls.

Adult↗
PubMed1980

Discrimination of T, B, and null lymphocytes by electronic sizing.

T, B, and null lymphocytes isolated by sheep red blood cells (SRBC) rosetting or adherence to a nylon wool column had distinct size differences according to Coulter counter size analysis. The diameters in microns were as follows: B = 6.42, T = 6.76, null = 7.16, granulocytes = 8.42, and monocytes = 9.02. Coulter size distributions of cell preparations were compared to the proportions of cells with E, EAC, and surface immunoglobulin (SIg) markers in these preparations as well as their reactivity to HLA--DR antisera and rabbit anti-B-lymphocyte antisera. Cell preparations monitored by Coulter sizing produced the expected results in mixed lymphocyte culture (MLC) testing. That is, T cells responded but did not stimulate whereas B lymphocytes and monocytes stimulated but did not respond. NULL lymphocytes both stimulated and responded. In antibody-dependent cell-mediated cytotoxicity (ADCC), null lymphocytes and monocytes functioned as effectors, whereas T lymphocytes and granulocytes did not. B lymphocyte preparations were intermediate in activity. Coulter sizing is a rapid, simple means of assessing the purity of suspensions enriched for T, B, and null lymphocytes.

Animals↗
PubMed1979

B and T lymphocytes in man. IV. Circulating B, T and "null" lymphocytes in aging population.

T, B and "Null" lymphocytes were determined in the peripheral blood of 98 adults, 26 of them were between 20 to 40 years of age and 72 between 60 to 96 years of age. The total number of lymphocytes were about the same in both groups. The percent and absolute number of T cells decreased significantly in the aged. Although the percent of B lymphocytes increased with age, the absolute number of B lymphocytes remained about the same.

Adult↗
PubMed1979

Do human B and null lymphocytes form a single immunoglobulin-bearing population?

Human "null" lymphocytes have been recognised because they lack T-lymphocyte membrane markers and the surface membrane immunoglobulin (smIg), detectable by direct immunofluorescence, which conventionally characterises B lymphocytes. But almost all null lymphocytes express smIg determinants which are demonstrable by the direct antiglobulin and mixed antiglobulin rosette tests. It is argued that the definition of a B lymphocyte should be extended to include the null cells which react in these tests. If the heterogeneity of the B-lymphocyte population is more widely recognized, the precise nature of human natural and antibody-dependent killer cells may become clearer.

Antibody Affinity↗
PubMed1983

Lack of prognostic value of T-, B- and null-lymphocytes in adult acute leukemia.

The distribution of T-, B- and null-lymphocytes was studied in the peripheral blood of 38 adult patients with acute nonlymphocytic leukemia (ANLL) and 15 with acute lymphocytic leukemia (ALL) at first diagnosis, during induction treatment, and in remission. Thirteen ANLL and 9 ALL patients were followed until relapse and during reinduction therapy. T- and B-cells were detected by specific membrane marker. The pre- and posttreatment pattern of lymphocyte subpopulations was analyzed to determine their prognostic significance for remission incidence, remission duration, and survival. It was observed that in both types of leukemia, T-cells are more affected by the leukemic process and cytostatic drugs than B-cells. Nonresponding patients possibly have a reduced potential for recruiting precursor T- and B-cells. At first diagnosis, no significant correlation was found between pre- or posttreatment variables and prognosis. At relapse, ANLL patients had a longer second remission when a high proportion of B-cells was found; ALL patients with a high lymphocyte count before and after treatment, experienced longer survival.

Acute Disease↗