Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lymphocytes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1997

Immunophenotyping of blood lymphocytes in childhood. Reference values for lymphocyte subpopulations.

OBJECTIVE: Immunophenotyping of blood lymphocytes is an important tool in the diagnosis of hematologic and immunologic disorders. Because of maturation and expansion of the immune system in the first years of life, the relative and the absolute size of lymphocyte subpopulations vary during childhood. Therefore we wished to obtain reference values for the relative and the absolute size of all relevant blood lymphocyte subpopulations in childhood. STUDY DESIGN: We used the lysed whole blood method for analysis of lymphocyte subpopulations in 429 blood samples from neonates (n = 20), healthy children (n = 358), and adults (n = 51). The following age groups were used: 1 week to 2 months (n = 13), 2 to 5 months (n = 46), 5 to 9 months (n = 105), 9 to 15 months (n = 70), 15 to 24 months (n = 33), 2 to 5 years (n = 33), 5 to 10 years (n = 35), and 10 to 16 years (n = 23). RESULTS: Our results show that the absolute number of CD19+ B lymphocytes increases twofold immediately after birth, remains stable until 2 years of age, and subsequently gradually decreases 6.5-fold from 2 years to adult age. The CD3+ T lymphocytes increase 1.5-fold immediately after birth and decrease threefold from 2 years to adult age. The absolute size of the CD3+/CD4+ T-lymphocyte subpopulation follows the same pattern as the total CD3+ population, but the CD3+/CD8+ T lymphocytes remain stable from birth up to 2 years of age, followed by a gradual threefold decrease toward adult levels. In contrast to B and T lymphocytes, the absolute number of natural killer cells decreases almost threefold in the first 2 months of life and remains stable thereafter. Our study also showed that changes in the absolute size of lymphocyte subpopulations are not always consistent with changes in their relative size. This demonstrates that the relative counts of lymphocyte subsets do not reflect their actual size and are therefore of limited value. CONCLUSION: On the basis of this study we strongly recommend that immunophenotyping of blood lymphocytes for the diagnosis of hematologic and immunologic disorders be based on the absolute rather than on the relative size of lymphocyte subpopulations. Our data can be used as age-matched reference values for blood lymphocyte immunophenotyping.

Adolescent↗
PubMed1993

Lysis of CD4+ lymphocytes by non-HLA-restricted cytotoxic T lymphocytes from HIV-infected individuals.

Individuals infected with HIV have elevated numbers of total and activated CD8+ lymphocytes in peripheral blood. CD8+ lymphocytes from HIV-infected individuals have been shown to mediate non-human histocompatibility-linked antigen (HLA)-restricted suppression of viral replication, HLA-restricted killing of cells expressing HIV antigens, and killing of uninfected lymphocytes. We studied CD8+ T lymphocytes that lysed autologous CD4+ lymphocytes. heterologous CD4+ lymphocytes from HIV-infected individuals and uninfected CD4+ lymphocytes. Killing in all cases required T cell receptor (TCR)-mediated recognition or triggering. However, these CD8+ cytotoxic T lymphocytes (CTL) killed HLA class I mismatched CD4+ lymphocytes and CD4+ lymphocytes treated with a MoAb against HLA-A, B and C antigens (PA2.6) which blocks HLA class I-restricted killing. HLA class II-negative CD4+ T lymphoma cells (CEM.NKR) were also killed by anti-CD3 inhibited CTL. Stimulation of peripheral blood lymphocytes (PBL) from HIV-infected individuals, but not uninfected controls, with concanavalin A (Con A) and IL-2, induced non-HLA-restricted TCR alpha beta+, CD8+ CTL which lysed CD4+ lymphocytes. Activation of CD4+ lymphocytes increased their susceptibility to CD8+ CTL-mediated lysis. In HIV infection, a population of non-HLA-restricted CTL which lyse activated CD4+ lymphocytes is expanded. The expansion of CTL with unusual characteristics is interesting, because the stimulus for this expansion is unknown. CTL which recognize activated CD4+ cells could play a role in immune regulation and the pathogenesis of AIDS.

CD4-Positive T-Lymphocytes↗
PubMed1999

Transendothelial migration of lymphocytes in chronic lymphocytic leukaemia is impaired and involved down-regulation of both L-selectin and CD23.

Chronic lymphocytic leukaemia (B-CLL) is characterized by a progressive accumulation of B lymphocytes in blood and bone marrow and high concentrations of soluble CD23 and L-selectin are found in the serum of these patients. In this study lymphocytes from normal subjects and patients with B-CLL were allowed to undergo transendothelial migration across confluent layers of human umbilical vein endothelial cells. Lymphocytes in B-CLL samples showed an impaired capacity to migrate while the minor proportion of normal T cells was enriched by a mean of 2.5-fold in the transmigrated lymphocytes. In contrast, the ratio of B to T lymphocytes in normal preparations was unchanged in the transmigrated population. The expression of adhesion molecules on B-CLL lymphocytes before and after transendothelial migration was studied by flow cytometry which showed that 71 +/- 5% of L-selectin was lost from the surface of transmigrated lymphocytes. T and B cells from normal subjects also showed a major loss of L-selectin after transmigration. B-CLL lymphocytes and normal B cells expressed CD23 but this molecule was down-regulated following transendothelial migration, whereas the expression of VLA-4, ICAM-1, LFA-1 and CD44 was unchanged. Lymphocytes incubated with oxidized ATP, an irreversible inhibitor of P2Z/P2X7 purinoceptors, retained their capacity for transendothelial migration and showed the same loss of L-selectin as control leukaemic lymphocytes. Our results show that B-CLL lymphocytes have impaired ability for transendothelial migration compared to normal peripheral blood lymphocytes. Moreover, transendothelial migration involves a universal loss of L-selectin and CD23 from lymphocytes which suggests that the high serum levels of soluble L-selectin and CD23 observed in B-CLL may be generated by shedding during the process of transendothelial migration.

B-Lymphocytes↗
PubMed1988

B lymphocyte function in patients with rheumatoid arthritis: impact of regulatory T lymphocytes and macrophages--modulation by antirheumatic drugs.

The present work analyses B lymphocyte functions in vitro in patients with rheumatoid arthritis (RA). The impact of gold salts and penicillamine on human B lymphocyte function in vitro is discussed. Synovial fluid monocytes/macrophages increased both the polyclonally induced and the antigen-induced blood lymphocyte proliferation and increased the numbers of immunoglobulin-secreting blood B lymphocytes generated by pokeweed mitogen (PWM), a T cell-dependent polyclonal activator. The lymphostimulatory factor(s) interleukin-1, which can be produced by monocytes/macrophages, was found in most cell-free synovial fluid specimens, but only in a few paired serum samples. Thus, in vivo activated synovial monocytes/macrophages may modulate lymphocyte functions. Compared to blood, synovial fluid T lymphocytes comprised fewer T4+ (helper/inducer) cells and more T8+ (suppressor/cytotoxic) cells. Synovial fluid lymphocytes proliferated poorly when stimulated polyclonally. However, the proliferative responses to microbial antigens as well as the lectin-induced lymphokine production equaled those of blood lymphocytes. In about half of RA patients, T4+ cells from synovial fluid increased the PWM-induced immunoglobulin secretion by autologous blood B lymphocytes to higher levels as compared to similar experiments with blood T4+ cells. Synovial fluid T8+ cells suppressed PWM-induced immunoglobulin production of autologous mononuclear cells to the same degree as seen with blood T8+ cells. A large proportion of synovial fluid T subsets expressed Ia antigens, probably due to in vivo activation. Thus, synovial T helper/inducer and T suppressor/cytotoxic cells may modulate the functional activities of synovial B lymphocytes. Among mononuclear cells isolated from synovial fluid and synovial tissue, considerable numbers of B lymphocytes spontaneously secreting IgG were found; fewer B cells secreted IgM and IgA. Rheumatoid factor activity was noted in about 7% of the IgG-producing cells. Synovial fluid mononuclear cells did not produce immunoglobulins in cultures stimulated with PWM, unless synovial T cells were removed and replaced with autologous blood T cells. Under these conditions synovial fluid B lymphocytes were induced by PWM to considerable IgG synthesis; fewer cells secreted IgM and IgA. About 8-9% of the induced IgM- and IgG-synthesizing cells displayed rheumatoid factor activity. Aurothiomalate markedly inhibited PWM-induced immunoglobulin production by normal lymphocytes cultured in vitro, probably by affecting monocyte/macrophage-lymphocyte interactions. The drug also had a direct inhibitory action on B lymphocytes, whereas T cells were resistant.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Inflammatory Agents↗
PubMed1987

The interaction of human T-lymphocytes and Entamoeba histolytica: killing of virulent amoebae by lectin-dependent lymphocytes.

Clinical and experimental studies indicate that following invasive disease due to Entamoeba histolytica, development of human cell-mediated immune mechanisms may provide protective immunity. Activated, human monocyte-derived macrophages in vitro can kill virulent axaenic amoebic trophozoites. This study describes the interaction of lectin-stimulated T-lymphocytes and E. histolytica trophozoites (virulent strain HM1-IMSS). Amoebae progressively killed unstimulated nonimmune T-lymphocytes over 18 h incubation with no effect on amoebic viability. T-lymphocytes, stimulated with phytohaemagglutinin (PHA), were progressively cytotoxic for virulent HMI amoebae over 18 h incubation, but were also reduced in viability themselves. Lymphocyte cytotoxicity for amoebae was absent if PHA was removed before or added only during the assay. PHA-stimulated T-lymphocytes killed amoebae at cell ratios of lymphocytes to amoebae as low as 50:1 and cytotoxicity was antibody-independent. PHA-stimulated T-lymphocytes, depleted of T8-bearing cells by complement-mediated lysis, were unable to kill amoebae. Adherence of PHA-stimulated T-lymphocytes to amoebae was greater than with unstimulated T-lymphocytes. Inhibition of the amoebic adherence lectin with N-acetyl-D-galactosamine decreased lymphocyte-amoebic adherence and resulted in increased lymphocyte amoebicidal activity and lymphocyte survival. Suspension of amoebae with or without adherent PHA-stimulated T-lymphocytes in a 10% dextran solution indicated that cytotoxicity was contact dependent. In summary, PHA-stimulated T-lymphocytes of the T8-phenotype can kill virulent axaenic E. histolytica trophozoites through a contact-dependent, antibody-independent mechanism.

Animals↗
PubMed1984

Multicomponent analysis of amino acid transport in human lymphocytes. Diminished L-system transport in chronic leukemic B lymphocytes.

We have examined the amino acid transport in B cell chronic lymphocytic leukemia and compared it with the amino acid transport in isolated B lymphocytes from human blood and tonsils. L-system transport was measured with 2-amino-2-carboxy-bicyclo (2,2,1)-heptane, which is a synthetic amino acid whose transport is limited to the L-system. Amino acid uptake was subjected to a multicomponent analysis that partitioned the total uptake into the saturable carrier-mediated transport system and the uptake by diffusion. The maximal velocity of L-system transport in chronic lymphocytic leukemia cells, 81 mumol/1 cell water per min, was less than 10% that of blood B lymphocytes, which was 1,029 mumol/1 cell water per min. The uptake of 2-amino-2-carboxy-bicyclo (2,2,1)-heptane by tonsillar B cells, by a B lymphocyte cell line, and by blood T-lymphocytes was also 10-fold greater than that observed in chronic lymphocytic leukemic cells. Similarly, the L-system uptake of leucine and phenylalanine, which are naturally occurring amino acids usually transported primarily by the L-system, was reduced in chronic lymphocytic leukemic B cells to 15 and 10% of normal B cells, respectively. Total leucine uptake by chronic lymphocytic leukemic cells, however, was sustained at 30% of that expected because of transport via an alternative transport system. The A- or ASC-systems, the other major amino acid transport pathways, were not defective in chronic lymphocytic leukemic cells. These data indicate that there is a specific, profound decrease in L-system carrier-mediated amino acid transport in chronic lymphocytic leukemic B cells, as judged by the system-specific synthetic amino acid, 2-amino-2-carboxy-bicyclo (2,2,1)-heptane. This defect was confirmed by studies with two naturally occurring L-system amino acids, leucine and phenylalanine. This specific abnormality of membrane transport by chronic lymphocytic leukemic B lymphocytes is not shared by other B lymphocyte types, and thus appears to be related to the neoplastic nature of the leukemic B cells rather than to their immunologic subtype.

Amino Acids↗
PubMed1983

T-cell subsets in human lymphocytes maintained in IL-2 medium after PHA or mixed lymphocyte reaction activation.

The culture of human T lymphocytes in interleukin-2 (IL-2) containing growth factor medium results in a significant shift in the T-lymphocytes subsets isolated from such cultures at weekly intervals. If normal peripheral blood mononuclear cells are stimulated with phytohemagglutinin (PHA) or in a mixed lymphocyte reaction (MLR), the resulting T lymphoblasts can be propagated in growth factor medium. Staining of the cultured cells with monoclonal antibodies was evaluated by indirect immunofluorescence on a laser-activated flow cytometer (Ortho Spectrum III). The antibodies used were: OKT3 (mature T lymphocytes), OKT4 (helper/inducer T lymphocytes), OKT8 (cytotoxic/suppressor T lymphocytes, OKT10 (immature and "activated" lymphocytes), OKT11a (cells which rosette with sheep erythrocytes), and OKIa-I (HLA-DR constant region). Both PHA and MLR activation resulted in initial preservation of the OKT4+ subset predominance over OKT8+ T lymphocytes noted on normal circulating blood lymphocytes. However, during culture in T-cell growth factor medium, there was a progressive increase in the percentage of OKT8+ cells, and a concomitant decrease in OKT4+ lymphoblasts. The increase in OKT8+ cells in the MLR-stimulated cultures was paralleled by an increase in specific cell-mediated cytotoxicity against the stimulating lymphocyte population. In addition to the shift in T-lymphocyte subset, there was virtual 100% staining with OKT3 and OKT11a, indicating the T-cell nature of the proliferating cells. OKT10 which was present on a small subset of fresh blood lymphocytes appeared rapidly in stimulated cultures, and was retained on virtually all lymphoblasts of either OKT4+ or OKT8+ subset. OKIa-1 cells increased slowly in PHA-stimulated cultures. HLA-DR+ T cells were detected earlier in MLR cultures. The activation of T lymphocytes results in a significant increase in the number of molecules of OKT11a bound per cell, in concert with the increased avidity of T lymphoblasts for sheep erythrocytes. The significant change in the phenotype and function of lymphoblasts isolated from long-term cultures demonstrates the importance of monitoring cultures, and the potential hazards in equating a cultured cell population with a freshly isolated one.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1976

T and B lymphocytes. Exclusive role as responders and stimulators in human one-way mixed lymphocyte reaction.

Four different combinations of one-way mixed lymphocyte reactions between human peripheral blood T and B lymphocytes (at a ratio of 1:1), purified by the E-rosetting technique, were carried our. A significant mixed lymphocyte reaction was observed only in a combination in which T lymphocytes, as responding cells, and B lymphocytes, as stimulating cells, were utilized. No significant mixed lymphocyte reaction was noted in the other three combinations of cells, using T or B lymphocytes as responders and T lymphocytes as stimulators, and also B lymphocytes as both responders and stimulators. Mixed lymphocyte reactions between T lymphocytes as responders (at constant concentration) and T and B lymphocytes as stimulators (varying proportions) showed that the response decreased proportionately with decreasing numbers of B cells and increasing numbers of T cells used as stimulators. Addition of increasing numbers of stimulating T cells to a constant number of stimulating B cells did not suppress or enhance the T-cell response to B cells. These observations indicate that the human peripheral blood T and B lymphocytes play an exclusive role as responding cells and stimulating cells, respectively.

B-Lymphocytes↗
PubMed1979

Cellular cooperation in lymphocyte activation. II. Cooperative response of human peripheral T and B lymphocytes to rabbit anti-human beta 2-microglobulin.

In the present study we attempted to clarify the effects of anti-beta 2-microglobulin (a-beta 2m) on lymphocyte activation. Neither a-beta 2m IgG fraction nor F(ab')2 had a mitogenic effect on either highly purified T or B lymphocytes alone, while their mitogenic effect was observed when T and B lymphocytes were appropriately reconstituted. When T lymphocytes were reconstituted with mitomycin C (MMC) treated B lymphocytes, a negligible decrease in the response to a-beta 2m was observed compared to the response of an untreated mixture to a-beta 2m. On the other hand, when B lymphocytes were reconstituted with MMC-treated T lymphocytes, the response was markedly diminished. It was found, moreover, that the response of T lymphocytes separated by a semipermeable membrane from MMC-treated B lymphocytes was not enhanced, while a mixture of T and MMC-treated B lymphocytes in the same chamber showed a marked response. These results lead to the conclusion that the cells responding to a-beta 2m are mainly T lymphocytes whose response is strongly enhanced by B lymphocytes, and that for the mitogenic effect of a-beta 2m direct cell-to-cell interaction between T and B lymphocytes is necessary.

Animals↗
PubMed1992

Phenotypic determination of T-lymphocytes responding to chemotactic stimulation from fMLP, IL-8, human IL-10, and epidermal lymphocyte chemotactic factor.

Human T lymphocytes were collected after they had migrated towards N-formyl-methionyl-leukylphenylalanine (fMLP), rIL-8, human IL-10 (hIL-10), and epidermal lymphocyte chemotactic factor (ELCF). They were stained for determination of their phenotype by FACS analysis using anti-CD4, -CD8, -CD18, -CD45R0 and OPD4 antibodies. Human IL-10 increased the percentage of CD8+ T lymphocytes in the migrating cell population by 152% compared with cells migrating towards the medium and decreased the number of CD4+ T lymphocytes by 79%. ELCF increased the number of CD4+ T lymphocytes by 18%, and the number of CD45R0+ T lymphocytes by 52%, while the number of CD8+ T lymphocytes was decreased by 20%. rIL-8 increased the number of CD4+ T lymphocytes and decreased the CD8+ T lymphocytes. The distribution of the different subpopulations of T lymphocytes was not changed significantly by fMLP. The observed changes in the phenotypes did not occur when incubating T lymphocytes with the chemotaxins. Our observations demonstrate that individual chemotactic factors will attract specific subsets of T lymphocytes. They may help to explain the predominance of memory T lymphocytes (CD4R0+, CD4+) in allergic contact dermatitis and certain other skin diseases. They also confirm the results of a recent study, that showed hIL-10 to be selectively chemotactic for CD8+ T lymphocytes.

Antigens, CD↗
PubMed1998

Resident human hepatic lymphocytes are phenotypically different from circulating lymphocytes.

BACKGROUND/AIMS: Murine and human studies have documented the existence of subpopulations of lymphocytes in particular tissues that differ phenotypically and functionally from those in peripheral blood and may mature locally. Since little is known about lymphocyte subpopulations in the normal human liver, we have analysed the surface phenotypes of lymphocytes isolated from liver specimens taken from 15 donors at the time of liver transplantation, and compared these with those of peripheral blood lymphocytes. METHODS: Hepatic lymphocytes were prepared by mechanical dissociation and enzymatic digestion of liver tissue. The cells were stained with a panel of monoclonal antibodies (CD3, CD4, CD8, CD19, CD56, gammadeltaTCR, alphabetaTCR, CD8alpha-chain, CD8alphabeta dimer), and analysed by flow cytometry. In situ characterisation of hepatic lymphocytes was by haematoxylin and eosin staining of fixed liver sections and by immunohistochemical staining for common leukocyte antigen and CD3. RESULTS: Significant numbers of hepatic T lymphocytes were localised to the portal tracts and parenchyma of normal liver specimens. Flow cytometry revealed that the CD4/CD8 ratio (1:3.5) was consistently reversed compared with that in peripheral blood (2:1). Other lymphocyte populations identified include double positive CD3+CD4+CD8+ cells which accounted for a mean of 5.5% (range 3-11.6%) of hepatic CD3+ cells compared with 1.3% in blood (range 0.7-3.6%; p < 0.007), and double negative CD3+ CD4-8- cells (14.5%; range 2.7-29% compared with 5.0%; range 2.1-10.8%, p < 0.02). Over 15% (range 6.8-34%) of all hepatic CD3+ cells expressed a gammadeltaTCR compared to 2.7% (range 0.9-4.7%) of CD3+ peripheral blood lymphocytes (p < 0.004) and almost 50% of these coexpressed CD8. The CD8 alpha-chain was expressed without the beta-chain (CD8alpha+beta-) by 15.4% (range 4-29.1%) of hepatic T cells, but this phenotype was undetectable among peripheral blood lymphocytes (p < 0.009). Cells expressing both the T cell marker CD3 and the natural killer cell marker CD56 constituted 31.6% (range 14-54%) of all hepatic CD3+ lymphocytes but were rarely present amongst peripheral blood lymphocytes (0-6%; p < 0.0001). CONCLUSIONS: These data are the first to describe and quantify unconventional T lymphocyte subpopulations in the normal adult human liver which may have specialised functions in regional immune responses and which may differentiate locally. These findings have important implications for our understanding of hepatic immunoregulation and the pathogenic mechanisms involved in viral and immune-mediated liver disease and allograft rejection.

Adolescent↗
PubMed1978

T-lymphocyte dependency of B-lymphocyte blastogenic response to phytomitogens.

Human peripheral blood T and B lymphocytes were separated by a method based on the stable rosette formation of T lymphocytes with neuraminidase-treated sheep erythrocytes, followed by centrifugation over a Ficoll-Hypaque gradient. Monocytes were isolated from the T-depleted B lymphocyte preparation by allowing the monocytes to ingest iron particles and by subsequent centrifugation over a Ficoll-Hypaque gradient. The T lymphocytes responded extremely well to PHA and very well to PWM, while the B lymphocytes were unresponsive to either PHA or PWM. However, when the B lymphocytes were cultured together with irradiated autologous or allogeneic T lymphocytes (1:1, 1:2 or 1:4 ratio), both PHA and PWM became mitogenic to B lymphocytes. Irradiated T lymphocytes alone did not respond to either PHA or PWM, indicating that the 3H-thymidine incorporation seen in the mixed-cell culture was due to the activation of unirradiated B lymphocytes. The B lymphocytes failed to respond to these phytomitogens in the presence of lower concentrations of irradiated T lymphocytes. The monocytes were found to be incapable of helping the B lymphocytes to respond to PHA or PWM.

B-Lymphocytes↗
PubMed1979

In vitro functional studies of mononuclear cells in patients with CLL: evidence for functionally normal T lymphocytes and monocytes and abnormal B lymphocytes.

In vitro functional studies of mononuclear cells from 34 patients with B-cell type CLL were investigated and the results of these studies were as follows: 1) The T lymphocytes from patients with CLL were capable of responding normally to PHA or PWM, of inducing allogeneic normal B lymphocytes to respond to these mitogens and of stimulating normally to allogeneic lymphocytes in "one-way" mixed lymphocyte reaction; 2) The monocytes from these patients were capable of enhancing the T lymphocyte response to mitogens and of stimulating normally to allogeneic lymphocytes; and 3) The leukemic B lymphocytes were incapable of responding to mitogens even in the presence of normal T lymphocytes and their enhancer cell activity on T lymphocyte response or their stimulating capacity on allogeneic lymphocytes was depressed. These observations suggest that the T lymphocytes and monocytes from patients with CLL are functionally normal while the leukemic B lymphocytes from these patients are functionally abnormal.

Adult↗
PubMed1999

Lymphocytic colitis: a distinct clinical entity? A clinicopathological confrontation of lymphocytic and collagenous colitis.

BACKGROUND AND AIMS: It is not known whether lymphocytic colitis and collagenous colitis represent different clinical entities or constitute part of a spectrum of disease. METHODS: Detailed clinical features and histological findings were compared in a large series of patients with confirmed lymphocytic and collagenous colitis. RESULTS: Histological diagnosis was confirmed in 96 patients with collagenous colitis and 80 with lymphocytic colitis. Twenty eight per cent of patients with collagenous colitis and 26% of patients with lymphocytic colitis had overlapping but less pronounced histological features. Both groups were equal in terms of age, use of aspirin and non-steroidal anti-inflammatory drugs, associated autoimmune conditions, arthritis, diarrhoea, and abdominal pain. The male:female ratio was 27:73 for collagenous colitis and 45:55 for lymphocytic colitis (p=0.013). Twenty five per cent of patients with collagenous colitis compared with 14% of patients with lymphocytic colitis were active smokers; only 8.3% of patients with collagenous colitis had stopped smoking compared with 23% of patients with lymphocytic colitis (p=0.013). Drug induced disease was suspected for ticlopidine (two collagenous colitis, four lymphocytic colitis) and flutamide (four lymphocytic colitis). Mean duration of symptoms before diagnosis was two months for lymphocytic colitis and four months for collagenous colitis. Overall prognosis was generally mild; 84% of patients with lymphocytic colitis and 74% of patients with collagenous colitis reported resolution or significant improvement (p=0.033). CONCLUSIONS: Collagenous and lymphocytic colitis are similar but not identical. Patients with lymphocytic colitis present somewhat earlier and are less likely to be active smokers. Symptoms are milder and more likely to disappear in lymphocytic colitis. Ticlopidine and flutamide should be added to the list of drugs inducing colitis.

Adult↗
PubMedDate not supplied

The autologous mixed lymphocyte reaction in primary biliary cirrhosis: analysis of activation and blastogenesis of autoreactive T lymphocytes.

Blastogenesis of autoreactive T lymphocytes in the autologous mixed lymphocyte reaction has been shown to be decreased in patients with primary biliary cirrhosis, but the mechanisms underlying this abnormality are not known. To investigate further the abnormal autologous mixed lymphocyte reaction in primary biliary cirrhosis, we measured the activation of autoreactive helper/inducer and suppressor/cytotoxic T lymphocytes concurrently with blastogenesis in 35 patients with primary biliary cirrhosis and 18 healthy controls. Blastogenesis was diminished in autologous mixed lymphocyte reaction cultures from primary biliary cirrhosis patients compared to the control subjects (25,273 +/- 20,259 dpm vs. 36,004 +/- 14,951 dpm, p less than 0.02), but cultures from patients with primary biliary cirrhosis contained significantly increased percentages of activated helper/inducer and suppressor/cytotoxic T lymphocytes: 20.6 +/- 7.9 vs. 15.5 +/- 5.3%, p less than 0.008, and 9.8 +/- 7.8 vs. 5.4 +/- 3.0%, p less than 0.02, respectively. These findings were not related to the histologic stage of liver disease or to the serum bilirubin concentration and were not associated with abnormalities of lymphocyte subsets in fresh peripheral blood specimens. We conclude that the percentage of autoreactive T lymphocytes in autologous mixed lymphocyte reaction cultures from peripheral blood is increased in patients with primary biliary cirrhosis and diminished blastogenesis in autologous mixed lymphocyte reaction cultures is not due to the loss of autoreactive T lymphocytes from peripheral blood. Diminished blastogenesis reflects a diminished proliferative response of activated, autoreactive T lymphocytes in primary biliary cirrhosis. Possible mechanisms that may account for the paradoxical findings of decreased blastogenesis and increased activation of autoreactive T lymphocytes in primary biliary cirrhosis are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1997

Modulation of bovine leukemia virus-associated spontaneous lymphocyte proliferation by monoclonal antibodies to lymphocyte surface molecules.

Both human T lymphotropic virus (HTLV) and bovine leukemia virus (BLV) infections are characterized by in vitro proliferation of peripheral blood lymphocytes in the absence of exogenous antigens or mitogens. Differential expression of lymphocyte surface molecules in HTLV and BLV infection suggests that lymphocyte dysregulation may involve signaling through surface molecules involved in immune regulation. We examined the expression of adhesion and major histocompatibility (MHC) molecules on circulating lymphocytes from BLV-infected cows with persistent lymphocytosis and the ability of monoclonal antibodies to these molecules to modulate spontaneous lymphocyte proliferation. The integrin molecule, CD11c, and both MHC class I and MHC class II molecules were upregulated on B and T lymphocytes from PL cows. Anti-CD11c antibody was stimulatory to lymphocyte proliferation regardless of BLV status and had a greater stimulatory effect on spontaneously proliferating lymphocytes from persistently lymphocytotic cows than on normal bovine lymphocytes. Antibodies to bovine class I and class II inhibited spontaneous lymphocyte proliferation. Results suggest that lymphocyte dysregulation in BLV-induced persistent lymphocytosis involves upregulation of and signaling through lymphocyte surface molecules which are involved in immune activation of lymphocytes.

Animals↗
PubMed2004

Expression of tyrosine hydroxylase in lymphocytes and effect of endogenous catecholamines on lymphocyte function.

OBJECTIVES: To comprehend the changes and significance of the endogenous catecholamines in the immune system, we explored the synthesis of catecholamines by lymphocytes in various lymphoid organs and in different activated states, and the effect of the endogenous catecholamines synthesized by lymphocytes on the function of the lymphocytes themselves. METHODS: Immunohistochemistry for lymphoid organs (mesenteric lymph nodes, spleen and thymus) and lymphocytes was used to observe their expression of tyrosine hydroxylase (TH), an initial rate-limiting enzyme of the catecholamine synthesis. The contents of catecholamines, including norepinephrine (NE), dopamine (DA) and epinephrine (E), in lymphocytes were tested by means of high-performance liquid chromatography with electrochemical detection. Western blot was used to examine the character and relative quantity of TH-stained protein in lymphocytes, lymph nodes and adrenal medullary tissue. The effect of alpha-methyl-P-tyrosine (alpha-MT), an inhibitor of TH activity, on concanavalin A (Con A)-induced interleukin-2 (IL-2) production was determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. RESULTS: TH-positive cells were found in the three examined lymphoid organs, but the lymph nodes had the highest and the thymus had the lowest density. Both TH expression and the contents of NE, DA and E in the Con A-activated lymphocytes were markedly increased in comparison with those in the nonactivated lymphocytes. A band with TH immunoreactivity was seen in the extracts from either Con A-activated lymphocytes or nonactivated cells and the molecular weight of the protein was 59.4 +/- 0.3 kD. However, the relative quantity of the protein was notably higher in the activated lymphocytes than in the nonactivated cells. As a positive control, a similar band of TH immunoreactivity in the adrenal medullary tissue was also obtained. Alpha-MT at the doses of 10(-11), 10(-10) and 10(-9) M was found to significantly facilitate the Con A-induced IL-2 production. CONCLUSIONS: These results suggest that lymphocytes can synthesize catecholamines and their synthesis levels may increase in the activated state, and that endogenous catecholamines synthesized by the lymphocytes can regulate the function of the lymphocytes themselves.

Animals↗
PubMed1979

[In vitro stimulation of peripheral blood lymphocytes with allogeneic lymphocytes or phytomitogens in patients with insulin-dependent diabetes mellitus (author's transl)].

The lymphocyte transformation response to the allogeneic lymphocytes (mixed lymphocyte culture, MLC) was determined in nineteen well-controlled insulin-dependent diabetics (IDD) and nineteen matched normal subjects. All possible combinations between lymphocytes from the patients and controls were mixed in both one-way and two-way MLC. From the results of one-way MLC, the stimulatory capacity (SC) and responding capacity (RC) of IDD lymphocytes were compared with those of normal lymphocytes as follows: (1) Nm leads to N: 10,538 +/- 3,937 N; normal lymphocytes (2) Nm leads to D: 8;466 +/- 5,387 D; IDD lymphocytes (3) Dm leads to N: 7,562 +/- 3,088 m; mitomycin-treated stimulating lymphocytes (4) Dm leads to D: 7,102 +/- 4,873 (leads to; stimulatory direction, results; M +/- SD cpm) IDD lymphocytes showed a marked depressive function as stimulators (SC, (1) -- (3)), but the RC of IDD lymphocytes was unchanged ((1) -- (2)). Phytomitogen-response was studied simultaneously for the same responding lymphocytes (N, D) of MLC. IDD lymphocytes exhibited significantly decreased responses to phytohemagglutinin P, pokeweed mitogen and concanavalin A.

Adult↗