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PubMed1987

T-lymphocyte colony formation by lymphocytes from patients with aplastic anaemia.

T-lymphocyte colonies were cultured using lymphocytes from patients with aplastic anaemia and normal donors to assess their respective proliferative activities. Colony numbers from aplastic patient's cells were lower than from normal donors', though this was not significant. When lymphocytes from patients were co-cultured with normal lymphocytes, inhibition of T-colony formation was observed in 8 out of 12 experiments. As the degree of inhibition was greater than if patient cells grew no colonies, then, clearly, normal T-colony formation was inhibited. This ability of patients' lymphocytes to suppress lymphopoiesis might account for the low levels of patient T-colony formation, as well as low in vivo numbers of lymphocytes found in patients with aplastic anaemia. The role of patients' lymphocytes in causing marrow aplasia was investigated. Although the incorporation of patients' lymphocytes in normal granulocyte-macrophage (GM) colony-forming systems inhibited colony growth, in only 1 out of 8 patients was this inhibition significantly greater than that caused by the addition of normal lymphocytes to GM colony systems. Therefore, lymphocytes may not be the primary cause of aplastic anaemia, except for a few rare cases.

Adolescent↗
PubMed1987

Reactivity of B leukemic lymphocytes of patients with chronic lymphocytic leukemia to PWM and PHA.

The ability of leukemic B lymphocytes to proliferate after in vitro stimulation with PWM and PHA was studied in 15 patients with chronic lymphocytic leukemia. Peripheral blood lymphocytes of five healthy subjects as well as purified normal B lymphocytes were used as controls. Leukemic lymphocytes of all donors expressed the same membrane phenotype, M receptor, and B7 and Ia antigens. The lymphocyte populations investigated were not completely free from myelomonocytic cells and contained small numbers of T lymphocytes. DNA synthesis was determined on days 3, 5, and 7 of culture by measuring the incorporation of tritiated thymidine. PWM-induced proliferation of leukemic B lymphocytes of nine patients was within normal limits, while the response of leukemic cells of six patients was very low. On the other hand, all CLL donors responded very well to PHA. Moreover, the response of leukemic B lymphocytes was significantly higher than the response of normal B cells. It was concluded that leukemic B lymphocytes of CLL patients are capable of proliferation after stimulation with PWM and PHA. The mechanisms underlying these responses to PWM and PHA are likely to be different.

B-Lymphocytes↗
PubMed1985

Anchorage and lymphocyte function. Acquisition of spontaneous motile behaviour by human blood lymphocytes and its modulation by concanavalin A.

The majority of splenic lymphocytes were motile, showing lamellipodial activity almost immediately after purification. In contrast, fresh blood lymphocytes were non-motile and maintained their spherical suspension morphology. The number of motile blood lymphocytes increased markedly during a 2-day in vitro culture period. This increase was enhanced by high cell density and required a metabolically active cell with protein synthesis but not exogenous mitogens. The spontaneous development of motility in different subpopulations of blood lymphocytes was analysed by means of monoclonal antibodies. The results indicated that cells which were motile immediately after purification were almost exclusively non-T lymphocytes. Lymphocytes which became motile during in vitro culture included both T and non-T cells. Substrate adhesion mediated by concanavalin A (Con A) changed the morphology of motile T lymphocytes and instead of being polar, the cells flattened over the substratum and acquired a non-polar shape. Furthermore, the morphogenetic response induced by Con A-mediated substrate adhesion appeared to distinguish T and non-T lymphocytes. Thus, the length of the cell perimeter showing lamellar activity was greater in T than in non-T lymphocytes, and the degree of polarity was greater in non-T (with and without B-cell markers) than in T lymphocytes.

Adult↗
PubMed1983

A role of valency of concanavalin A and its chemically modified derivatives in lymphocyte activation. Monovalent monomeric concanavalin A derivative can stimulate lymphocyte blastoid transformation.

A concanavalin A (ConA) derivative of a monovalent monomeric nature, including a monomeric molecular weight at pH 7.4, significantly induces lymphocyte blastoid transformation. The derivative was recently obtained by Tanaka, I., Abe, Y., Hamada, T., Yonemitsu, O., and Ishii, S. ((1981) J. Biochem. (Tokyo) 89, 1643-1646) by a novel procedure of photochemically induced alkylation of tryptophan residues of native tetravalent ConA using a high pressure mercury lamp in the presence of chloroacetamide followed by two steps of column chromatography. This monovalent monomeric ConA (Mm-ConA) was demonstrated to be almost equally potent in producing the maximal response of lymphocytes when compared with native tetrameric ConA, although Mm-ConA was required at about 70 times as high as the concentration of native ConA on a weight basis to attain the maximal response of lymphocyte activation. The binding potency of the former to lymphocytes was about two-thirds as potent as that of the latter. Mm-ConA failed to agglutinate sheep erythrocytes at concentrations 1800-fold higher than native tetravalent ConA, but showed a weak but definite agglutinating activity against guinea pig erythrocytes at a relatively high concentration (approximately 80 micrograms/ml). Cell cluster formation was observed in lymphocyte cultures for 24 to 48 h with Mm-ConA where DNA replication in stimulated lymphocytes was observable. No significant difference was observed between sizes of cell clusters formed in the presence of Mm-ConA and of native tetravalent ConA at this phase of lymphocyte activation. The present results suggest that the multivalency of ConA with respect to sugar-binding sites may not be a stringent requirement for lymphocyte activation, and that another binding site for cell membrane, which has been suggested to exist in the ConA protomer and to be hydrophobic (membranophilic), may play a subsidiary but important role in triggering lymphocyte blastoid transformation as well as hemagglutination with Mm-ConA. The biological significance in lymphocyte activation of lectin valency with respect to sugar-binding sites has been discussed, comparing the effects of various ConA derivatives of different valencies, including a monovalent monomer (Mm-ConA), divalent dimers (beta-ConA, sulfomethylamino-ConA, and succinylated ConA), and tetravalent tetramers (alpha-ConA), on the cell surface.

Animals↗
PubMed1980

Different stimulating capacity of B and T lymphocytes in primary and secondary allogeneic reactions: cellular detection of HLA-D products on T lymphocytes.

The present study was undertaken to define the best way to produce and to test primed lymphocyte typing (PLT) cells using B- and T-enriched lymphocyte suspensions. Intrafamilial PLT cells were produced with primed unseparated and T purified lymphocytes against haplo-identical donors' T and B cells. These PLT cells were then restimulated with a panel of related or unrelated individuals' T and B cells and with allogeneic in vitro activated T cells. The best discrimination was obtained when PLT reagents, regardless of the production method, were restimulated by a B-enriched population of peripheral lymphocytes. Furthermore, the results have shown that enriched primed or unprimed T cell suspensions stimulated by enriched T lymphocytes did not give any proliferation. Experiments performed to explain the results led us to distinguish 2 different phenomena: in primary cultures, the addition of monocytes autologous to the responder cell restored the proliferation of enriched T cells stimulated by T lymphocytes. In secondary cultures, the addition of monocytes autologous to the PLT cell did not restore the proliferation of PLT lymphocytes stimulated by enriched T cells. This was shown to be due to the lack of Dr antigen on the stimulating cell: if allogeneically activated T cells were used as stimulating lymphocytes, a DR-specific proliferative response appeared. This correlates with serologic findings were DR determinants are found on activated T cells and not on unprimed T lymphocytes. However, this difference might be only quantitative, since peripheral lymphocytes could be primed by T cells and be DR specifically restimulated.

B-Lymphocytes↗
PubMed1981

Lactic dehydrogenase in normal and leukemia lymphocyte subpopulations: evidence for the presence of abnormal T cells and B cells in chronic lymphocytic leukemia.

Lactic dehydrogenase (LDH) was quantitated and the isozyme pattern studied in lymphocyte subpopulations from normal people and patients with chronic lymphocytic leukemia (CLL). Normal T lymphocytes differed from normal B lymphocytes in having greater total LDH activity (597.2 versus 252.1). Total LDH activity in CLL T cells (347.1) was lower than normal T cells., but not significantly different than normal B cells. Total LDH activity in CLL B cells (124.6) was lower then normal B cells and normal T cells. The isozyme pattern of normal T lymphocytes showed a higher activity in the LDH-1 band (26.7% versus 5.4%) but showed a lower activity in LDH-5 band (4.3% versus 16.3%) compared to normal B cells. Chronic lymphocytic leukemia T cells could be distinguished from CLL B cells by a high LDH-5 band (22.3% versus 7.6%) and from normal T cells by a high LDH-5 band (22.3% versus 4.3%) and a low LDH-1 band (7.3% versus 26.7%). CLL B cells could be distinguished from normal B cells by a low LDH-5 band (7.6% versus 16.3%). Thus, the LDH isozyme pattern distinguishes normal T lymphocytes from normal B lymphocytes, and normal T and B lymphocytes from CLL T and B lymphocytes.

Adult↗
PubMed1982

Decreased L-system for amino acid transport in chronic lymphocytic leukemic lymphocytes.

We have defined the kinetic parameters of the L-system of amino acid transport in chronic leukemia of B-lymphocytes (B-cell CLL) and have compared them to those of normal blood lymphocytes, tonsillar lymphocytes, a normal B-lymphocytic cell line (RPMI 1788), and chronic leukemia of T-lymphocytes. The L-system was judged by its affinity for and maximal transport velocity of BCH, a synthetic amino acid whose uptake is virtually limited to the L-system. The L-system of B-cell CLL lymphocytes functioned at less than 15% the rate of the other lymphocyte types, and the substrate affinity of the L-system was lower than that of the other lymphocyte types studied. Thus, the L-system of amino acid transport, a hallmark of normal T- and B-lymphocytes, is vestigial in B-cell CLL. This key functional membrane defect is more closely related to the neoplastic nature of CLL-cells than to their B-lymphocyte phenotype.

Amino Acids↗
PubMed1993

[Skin reaction(s) to culture supernatant(s) from Dermatophagoides farinae (Df)-stimulated lymphocytes, and their correlation with Df-induced interleukin 2 responsiveness by lymphocytes from patients with bronchial asthma].

To investigate the inflammatory function of Dermatophagoides farinae (Df)-activated lymphocytes, supernatants from cultures of the lymphocytes were intracutaneously injected into donors' forearms. Injection of the supernatants of Df-stimulated lymphocytes from mite-sensitized atopic individuals with such diseases as bronchial asthma induced a profound inflammatory reaction in the autologous skin, characterized by erythema extending more than 15 mm in mean diameter and edema. The inflammation was at its peak after approximately 20 min, which was followed by gradually re-growing erythema lasting for as long as 24 hours after injection. Supernatants of unstimulated lymphocytes were also capable of inducing the same reaction, indicating the presence of in vivo activated lymphocytes, although the extent of the response was always smaller. The induced response in normal individuals was erythema of less than 15 mm in mean diameter. The supernatants obtained from cultures at 4 degrees C failed to induce such inflammation. The culture supernatants of ovalbumin-restimulated lymphocytes were also incapable of augmenting the response. The combined data show that the production of inflammatory response-inducing factor(s) from Df-stimulated lymphocytes was antigen specific. Significant skin reactions was correlated with the IL2 responsiveness of Df-stimulated lymphocytes. The skin reaction induced by factor(s) derived from Df-stimulated lymphocytes, which might be similar to the bronchial hyperreactivity of patients with bronchial asthma. The in vitro assay for Df-induced IL2 responsiveness by lymphocytes might reflect the in vitro immediate, late and/or delayed type hypersensitivity.

Animals↗
PubMed1997

Endometriosis and autologous lymphocyte activation by endometrial cells. Are lymphocytes or endometrial cell defects responsible?

OBJECTIVE: To determine whether the decreased mitogenicity of the endometrial cell for autologous lymphocytes noted in women with pelvic endometriosis is secondary to endometrial cell interaction with the lymphocytes or due to an inherent defect of the lymphocyte. STUDY DESIGN: The endometrial cells from 30 women with endometriosis and 30 matching controls were cultured. Autologous lymphocyte and endometrial cells were cocultured to observe the lymphocyte proliferative response to autologous endometrium in controls and to ectopic and eutopic endometrial cells from patients. The ability of lymphocytes to be stimulated by phytohemagglutinin (PHA) was simultaneously assayed. RESULTS: Ectopic and eutopic endometrial cells from women with endometriosis were less mitogenic for autologous lymphocytes than endometrial cells from controls. The lymphocytes from both patients and controls exhibited a similar stimulatory response to PHA. CONCLUSION: The diminished proliferative response of lymphocytes from women with endometriosis probably is not the consequence of an intrinsic lymphocyte abnormality. The fundamental defect in endometriosis may reside within the endometrial cell.

Adult↗
PubMed1983

Evidence for cytotoxic T-lymphocyte-target cell interaction in brains of mice infected intracerebrally with lymphocytic choriomeningitis virus.

Murine lymphocytic choriomeningitis is a T-cell-mediated pathologic immune phenomenon. The name of this experimental illness was derived from the principal histopathologic alterations of the central nervous system (CNS) of adult mice infected intracerebrally with lymphocytic choriomeningitis virus, i.e., lymphocytic infiltrations of plexus choroidei and meninges. The general assumption that the main event in the pathogenesis is damage to virus-infected target cells by cytotoxic T-lymphocytes is plausible but direct evidence is scarce. We have studied the ultrastructural alterations of both types of cells that are thought to participate in this immunopathologic interaction. Lymphocytes with signs of T-cell transformation were first evident on day 4 after infection. One day later, lymphoblasts, often extending uropods and containing cytoplasmic dense and compound multivesicular bodies, predominated. They were sometimes seen in intimate contact with connective tissue cells of the leptomeninx and epithelial cells of the choroid plexuses which were shown to be infected by immunofluorescence procedure. Lymphoblasts occasionally invaginated the cytoplasm of the putative target cells with cytoplasmic processes, and were even found inside the latter, exhibiting the phenomenon of emperipolesis. Lymphocytic transformation was at its maximum 6 days after infection. At this time, individual leptomeningeal cells and groups of plexus epithelial cells showed signs of cytolysis, and in a few instances these damaged cells were in close spatial association with lymphoblasts. Similar observations have been reported by others who studied the interaction between cytotoxic T-lymphocytes and their appropriate targeted cells in vitro. We interpret our findings as providing direct evidence for the assumption that one link in the chain of events leading to the cerebral form of lymphocytic choriomeningitis of the mouse is damage to virus-infected leptomeningeal and plexus cells by cytotoxic T-lymphocytes.

Animals↗
PubMed1999

[The effect of memory T lymphocytes on IgE production by B lymphocytes in patients with bronchial asthma].

OBJECTIVE: To study the role of CD(4)(+) CD(45)RO(+) T lymphocytes in the pathogenesis of bronchial asthma. METHODS: CD(4)(+) CD(45)RO(+) T lymphocyte subsets were isolated from peripheral blood of patients with bronchial asthma and healthy donors. Then they were cultured with self-B lymphocytes and designated as pokeweed mitogen (PWM)-stimulated and non-stimulated group. Secreted IgE was measured in the supernatant. RESULTS: CD(4)(+) CD(45)RO(+) T lymphocytes had a positive role on IgE production by B lymphocytes from patients of bronchial asthma in non-stimulated group, but the positive role did not exit in the presence of PWM. The effect of activated and non-activated CD(4)(+) CD(45)RO(+) T lymphocytes from patients with bronchial asthma on the secretion of IgE by B lymphocytes were further investigated. CONCLUSION: The function of activated CD(4)(+) CD(45)RO(+) T lymphocytes returned to normal level. It is suggested that CD(4)(+) CD(45)RO(+) T lymphocytes have adverse effects on IgE production in patients with bronchial asthma; which may be related to the pathogenesis of asthma.

Adolescent↗
PubMed1985

Regulation of human peripheral blood erythroid burst-forming unit growth by T lymphocytes and T lymphocyte subpopulations defined by OKT4 and OKT8 monoclonal antibodies.

To reexamine the influence that T lymphocytes have on the regulation of human peripheral blood burst-forming unit (BFU-E) proliferation in the absence of a statistically significant number of monocytes, very low numbers (3 to 10 X 10(3)/mL) of a null cell fraction highly enriched for BFU-E were cultured alone and in the presence of 5 X 10(5) sheep erythrocyte-purified, autologous T lymphocytes in a methylcellulose culture system containing erythropoietin. T lymphocytes consistently enhanced the growth of BFU-E from the null cell fraction, as reflected in both their number and size. Irradiation of T lymphocytes prior to coculture with null cells markedly reduced this enhancement, strongly suggesting that T lymphocytes synthesize erythroid burst-promoting factors (BPA). To determine whether there were functional differences between the two major T lymphocyte populations as defined by OKT4 (T helper/inducer) and OKT8 (T suppressor/cytotoxic) murine monoclonal antibodies to stimulate the growth of BFU-E, both T cell subpopulations were isolated by negative (panning) or positive (fluorescence-activated cell sorting) selection and cocultured with null cells. No statistically significant differences emerged between unseparated, OKT4+ and OKT8+ T lymphocytes in their ability to stimulate the growth of BFU-E. Thus, these studies provide further evidence that T lymphocytes are a major population of BPA-producing cells and further that OKT4+ and OKT8+ T lymphocytes equally elaborate these factors.

Animals↗
PubMed1990

In rat B lymphocyte genesis sixty percent is lost from the bone marrow at the transition of nondividing pre-B cell to sIgM+ B lymphocyte, the stage of Ig light chain gene expression.

The cycling B precursor cells in rat bone marrow (BM) that carry the B220 antigen and no surface Ig daily produce 780 million new cells. The pool of recirculating B lymphocytes in the rat, however, renew at a rate of only about 40 million cells/day. To analyze at which stages in B lymphocyte genesis the cell loss occurs, we identified post-mitotic cells in the rat BM B lineage, and determined their renewal rates. We used 5-bromo-deoxyuridine (BrdUrd) to label DNA-synthesizing cells, identifying incorporated BrdUrd with the mouse monoclonal antibody BU-1. B lineage cell subsets were identified by the markers HIS24 antigen (rat B220), terminal deoxynucleotidyl transferase (TdT), Ig mu heavy chain, and complete Ig. By use of double and triple immunocytology, we determined the extent of BrdUrd incorporation in the various B lineage compartments [HIS24+TdT-Ig-, TdT+, cytoplasmic mu chain (c mu)+ surface (s) IgM- pre-B, sIgM+ B]. Both sIgM+ B lymphocytes and all B precursors with cell diameters less than 11-12 microns were virtually devoid of DNA synthesis, as indicated by S-phase indices below 2%. In contrast, S-phase indices of large B precursors ranged between 43%-66%. We established the renewal rates of nondividing BM B lineage cells by placing osmotic minipumps containing BrdUrd subcutaneously in the flank of rats. The nondividing BM B lineage cells all renewed rapidly at rates between 2.4% and 5.6%/h, representing average half-lives of 29 to 12 h. In absolute numbers, the renewal/day/whole body BM was 165 X 10(6) for sIgM+ B lymphocytes, 422 X 10(6) for small c mu+ sIgM- pre-B cells, 89 X 10(6) for small TdT+ cells and 35 X 10(6) for small HIS24+TdT-Ig- cells. Assuming that recirculating B lymphocytes in the periphery are the descendants of BM sIgM+ B lymphocytes, which in their turn are the progeny of small pre-B cells, the renewal data indicate the following. Of the 165 million potentially available BM B lymphocytes, only 40 million cells become incorporated in the pool of recirculating B lymphocytes, representing a loss of 75%. BM B lymphocytes, in turn, use only (165/422 X 100% = ) 40% of the potential output from their immediate precursors. The 60% loss that occurs here may reflect the extent of aberrant Ig light chain gene rearrangement in normal B lymphocyte genesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Adhesion molecules and lymphocyte recruitment in lymphocytic thyroiditis, thyroid papillary carcinoma and parotid adenolymphoma.

Lymphocytic infiltrates are usually present in chronic lymphocytic thyroiditis, thyroid papillary carcinoma and parotid adenolymphoma. We selected these conditions to investigate the mechanisms of recruitment and organization of lymphocytic infiltrates in extranodal tissues. MoAbs in immunoperoxidase were used to identify the expression of ICAM-1 and VCAM-1 on endothelial cells (EC), and of their ligands LFA-1 and VLA-4 on lymphocytes and accessory cells. VCAM-1 positive EC were rarely observed in thyroids devoid of lymphocyte infiltration. Conversely, EC in chronic lymphocytic thyroiditis and in papillary carcinoma showed positive immunostaining for VCAM-1 and ICAM-1. These findings were associated with the presence of lymphocytes positive for the ligands VLA-4 and LFA-1. The upregulated expression of VCAM-1 on perifollicular capillaries was co-distributed with an accumulation of VLA-4 positive lymphocytes. In adenolymphoma, all EC were ICAM-1 positive, whereas the majority of vessels were VCAM-1 negative. Consequently the majority of lymphoid cells were LFA-1 positive and VLA-4 negative. We suggest that ICAM-1 and VCAM-1 expression on EC play a role in the recruitment of lymphocyte infiltration in chronic lymphocytic thyroiditis and papillary carcinoma. Furthermore, the upregulation of VCAM-1 and VLA-4 in thyroid reactive and neoplastic conditions may be linked to an immune response possibly related to thyroid tissue antigens.

Adenolymphoma↗
PubMed1980

Mycoplasma-dependent activation of normal mouse lymphocytes: requirement for functional T lymphocytes in the cytotoxicity reaction mediated by Mycoplasma arthritidis.

Syngeneic and allogeneic target cells were killed in the presence of CBA mouse lymphocytes and viable Mycoplasma arthritidis. Medium supplementation had no effect on the response. Nonviable M. arthritidis was also capable of stimulating lymphocytotoxicity, although to a much lesser extent. Cytotoxicity was shown to be largely dependent upon the lymphocytes, since lymphocytes preincubated with mycoplasmas and treated to remove remaining organisms were highly toxic to target cells, whereas supernatants prepared from lymphocyte/mycoplasma mixtures exhibited minimal effects. A 6-h exposure of lymphocytes to mycoplasmas at a ratio of 100:1 was sufficient for commitment to target cell killing. Functional lymphocytes were required for the reaction, since gamma-irradiated lymphocytes did not develop cytotoxic potential despite the fact that the mycoplasmas replicated equally well in the presence of these and untreated lymphocytes. Furthermore, lymphocytes already activated with mycoplasmas lost cytotoxic potential after disruption. The kinetics and degree of lymphocytotoxicity induced by M. arthritidis and phytohemagglutinin toward 51Cr-labeled syngeneic fibroblasts were similar. Removal of most B cells and other adherent cells by column separation did not abrogate the cytotoxic effect. Lymphocyte suspensions treated with anti-Thy 1 antiserum and complement exhibited a marked decrease in their cytotoxic potential when added to labeled target cells in the presence of M. arthritidis. We conclude that the cytotoxic reaction is dependent upon the T-lymphocyte subpopulation.

Animals↗
PubMedDate not supplied

Detection of trisomy 12 by fluorescence in situ hybridization on archival cytopathologic material in chronic lymphocytic leukemia/small lymphocytic lymphoma.

OBJECTIVE: To evaluate fluorescence in situ hybridization (FISH) for the detection of trisomy 12 in archival cytologic specimens of chronic lymphocytic leukemia/small lymphocytic lymphoma. STUDY DESIGN: The cytopathology database was searched for all cases of chronic lymphocytic leukemia/small lymphocytic lymphoma. Six cases of chronic lymphocytic leukemia/small lymphocytic lymphoma obtained by fine needle aspiration and one case of small lymphocytic lymphoma with plasmacytoid features were analyzed for trisomy 12 by FISH. These cases had been archived between 1 week to 16 months prior to analysis. RESULTS: We detected trisomy 12 in four of the six cases of small lymphocytic lymphoma/chronic lymphocytic leukemia. The case of small lymphocytic lymphoma with plasmacytoid features was negative for trisomy 12. CONCLUSION: Detection of trisomy 12 by FISH can be effectively performed on routinely prepared, stained and coverslipped archival cytologic material.

Aged↗
PubMed1986

Expression of IFN-alpha and IFN-gamma receptors on normal human small resting T lymphocytes and large granular lymphocytes.

The expression of interferon (IFN) receptors was studied on freshly isolated human lymphocytes from normal donors. Highly enriched populations of small resting T lymphocytes and large granular lymphocytes (LGL) were found to constitutively express high-affinity receptors for IFN-alpha and IFN-gamma. Both types of lymphocytes also had lower-affinity IFN-alpha binding sites. T lymphocytes had a mean of 230 IFN-alpha and 520 IFN-gamma high-affinity receptors per cell, whereas LGL had 520 IFN-alpha and 760 IFN-gamma receptors. However, because LGL were larger than the T lymphocytes, the IFN receptor density was similar on the two types of lymphocytes. The affinity of binding was similar on the two types of normal lymphocytes and on the cultured lymphoblastoid cell line Daudi. The number of IFN receptors per cell and the affinities of the IFN-receptor interactions varied little among the normal donors. Both the freshly isolated normal lymphocytes and the cultured cell line Daudi had separate receptors for type I (alpha and beta) and type II (gamma) IFN. Taken together, our data indicate that two types of freshly isolated normal lymphocytes constitutively express IFN receptors that are similar to those present on the lymphoblastoid cell line Daudi derived from a patient with Burkitt's lymphoma.

Binding, Competitive↗
PubMed1985

Relationship of dehydroascorbic acid transport to cell lineage in lymphocytes from normal subjects and patients with chronic lymphocytic leukemia.

Dehydroascorbic acid is the principal form for the cellular uptake by blood cells of vitamin C. Since previous studies from this laboratory had shown a higher content of ascorbic acid and dehydroascorbic acid (DHA) in chronic lymphocytic leukemia (CLL) lymphocytes when compared to their normal counterparts, DHA uptake was characterized using these cells. The affinities of CLL and normal lymphocytes for DHA uptake were similar, as demonstrated by the Km values of 3.7 and 3.5 mM, respectively. Differences were found in other kinetic constants of DHA uptake. The Vmax for normal lymphocytes, 634 mumol/liter cell H2O/min, was approximately twice that of CLL cells, 392 mumol/liter cell H2O/min. In addition, the initial velocity and the maximal DHA uptake by normal lymphocytes were greater than that of CLL lymphocytes. These differences were not simply a reflection of lymphocyte subsets since CLL B-cells demonstrated lower uptake rates than did normal B-cells whereas CLL T-cells were similar to their normal counterparts. The alterations appear to be specific for the leukemic B-cell since they were not shared by neoplastic cells from two patients with T-cell CLL. When analyzed in light of the 3-fold greater cellular DHA and ascorbic acid content in B-cell CLL as compared to normal lymphocytes, these kinetic parameters support the occurrence of a concentration-dependent transport system for DHA. We conclude that the DHA uptake properties of CLL lymphocytes of B-cell origin serves to distinguish this lineage from T-cell CLL or normal lymphocytes.

Ascorbic Acid↗