Autologous mixed lymphocyte reaction in health and disease states in man

Does the Selenium (SE) Level and Se-Dependent Enzyme Activity in Blood Plasma Correlate with Human Lymphocyte Subpopulations and Function?

Recent literature data on the effects of Se on subpopulations of T lymphocytes, on autologous mixed lymphocyte reaction (AMLR) and on natural killer (NK) cell cytotoxicity are limited or poorly defined. In healthy volunteers we have estimated se levels, glutathione peroxidase (GSH-Px) activity and lipid peroxide levels in human plasma and simultaneously, the subpopulations of T lymphocytes, proliferation in AMLR, and activity of NK cells.

We found a significantly positive correlation between the selenium level and GSH-Px activity. The proliferative response in AMLR significantly correlated with plasma selenium levels but not with GSH-Px activity. NK cytotoxicity, subpopulations of T lymphocytes, and lipid peroxide levels did not correlate with both selenium concentration and GSH-Px activity. We suppose that the effect of Se on the proliferation of suppressor T lymphocytes (Ts) in AMLR is not mediated through GSH-Px activity and fluctuations of Se concentration within a physiological range in healthy persons do not affect NK cytotoxicity.

Efficient replication of human immunodeficiency virus type 1 in resting CD4+ T lymphocytes is induced by coculture with autologous dendritic cells in the absence of foreign antigens

Dendritic cells (DC) are considered to be important contributors to human immunodeficiency virus type 1 (HIV-1) transmission and pathogenesis. As the first target cells in mucosal tissues, they can be become productively infected and can also capture virions and transfer them efficiently to CD4(+) T cells located within lymphoid tissues. Resting CD4(+) T cells appear to be another major target of HIV-1 in vivo, yet several blocks restrict replication in such cells. We report here that physical contact between virus-infected quiescent CD4(+) T cells and uninfected autologous immature DC in the absence of any foreign antigen relieves these restrictions, allowing a highly productive HIV-1 replication.

Analysis of monocyte chemotactic protein-1 production in different major histocompatability complex-restricted antigen presentation systems

In the present study the production of the CC chemokine monocyte chemotactic protein-1 (MCP-1) in several MHC II-restricted antigen presentation systems was investigated in vitro. To assess which type of antigen-presenting cell (APC) influences MCP-1 production during antigen presentation, cultures enriched for different APC populations were prepared and MCP-1 production was determined. Our results showed that APCs that effectively induce a T cell response also produce elevated amounts of MCP-1. The MCP-1 production is highest in the memory-driven secondary response against a single antigen. Despite a massive T cell proliferation, low MCP-1 concentrations are found in Con A-induced cultures. These results suggest that T cell proliferation alone is not sufficient for MCP-1 production and that stimulation of the APC during the process of antigen presentation results in MCP-1 production. Based on our results and the literature, we propose a model for MCP-1 as an enhancer of the adaptive immune response.

Cytolytic (TIA-1+) tumor infiltrating lymphocytes in B cell non-Hodgkin's lymphomas. SWOG Central Repository Members

TIA-1 is a monoclonal antibody (mAb) that identifies cytolytic cells. We studied eleven B cell non-Hodgkin's lymphomas (NHL) of low grade, eleven B cell NHL of intermediate-high grade, and 10 benign lymphoid hyperplasias (BLH) to investigate potential differences in the number of host cytolytic tumor infiltrating lymphocytes (TILs). Frozen sections were immunostained with TIA-1 mAb and the number of immunoreactive cells (TIA-1+) per mm2 of tissue was quantitated within reactive or neoplastic lymphoid follicles or random areas of diffuse NHL. The number of TIA-1+ cells/mm2 was significantly higher in intermediate and high grade B cell NHL than in low grade NHL or BLH with means +/- se of 1377.8 +/- 173, 866.2 +/- 92.3 and 774.1 +/- 76.2, respectively (p < 0.0183 and p < 0.0125). There was no significant difference between BLH and low grade NHL. The increased number of TIA-1+ TILs in B cell NHL of intermediate and high grade suggests the possibility of a host cytolytic immune response versus the tumor. Paradoxically, B cell tumors of worst biological outcome contained more cytolytic TILs. Functional defects of host cytolytic TILs in NHL patients should be investigated in future studies.

Host tumor infiltrating lymphocytes in B cell non-Hodgkin's lymphomas

Tumor-infiltrating T lymphocytes (TIL-T) were quantitated by three color flow cytometry in cell suspensions from excisional biopsy specimens of 43 B cell non-Hodgkin's lymphomas (NHL) and 8 benign lymphoid hyperplasias (BLH) to identify potential differences in host T cell responses. We quantitated three TIL-T subsets: CD3+CD4+CD8- (helper-inducer), CD3+CD4-CD8+ (suppressor-cytotoxic) and CD3+CD25-HLADr+ (long term activated TIL-T) and compared them in three diagnostic groups: BLH, low grade B cell NHL (LG NHL) and intermediate-high grade B cell NHL (IG-HG NHL). The following results were obtained: Mean percentage +/- s.e. of activated TIL-T for BLH, LG-NHL and IG-HG NHL: 10.3 +/- 1.9, 23.2 +/- 4.6 and 38.8 +/- 9.5, respectively. Mean percentage +/- s.e. of suppressor-cytotoxic TIL-T for same groups: 13.9 +/- 1.5, 14.9 +/- 1.9 and 34.4 +/- 4.5, respectively. Mean percentage +/- s.e. of helper-inducer TIL-T cells for the same groups was 38.2 +/- 12.7, 32.1 +/- 7.2 and 22.5 +/- 4.6, respectively. Helper/suppressor ratio +/- s.e. for same groups was 3.0 +/- 1.1, 2.4 +/- 0.6 and 1.3 +/- 0.4, respectively. Activated and suppressor-cytotoxic TIL-T percentage progressively increased from BLH toward IG-HG NHL. The percentage of these two TIL-T subsets were significantly higher in IG-HG NHL than in BLH and LG-NHL (P < 0.0007, 0.0002, 0.0001 and 0.0260 for the comparisons TIL-T in BLH vs IG-HG NHL and LG-NHL vs IG-HG respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased lymphocyte blastogenesis, IL2 production and NK activity following nifedipine administration to healthy humans

The effects of a single oral dose of nifedipine on part of the immune response in healthy humans has been investigated in terms of two different immune functions: T lymphocyte proliferation and NK activity. Both functions are known to require calcium ions. Ten healthy subjects were bled before and 30 min, and 4 and 24 h after receiving 10 mg nifedipine. Lymphocyte proliferation, both in mitogen-activated lymphocyte cultures, and in autologous and allogeneic mixed lymphocyte reactions, was significantly reduced (up to 48%) 30 min after drug administration and reverted to normal 4 h later. The inhibition could be attributed to reduction in IL2 production by the T cells isolated 30 min following the administration of nifedipine, since they normally express IL2-receptors. The addition of recombinant IL2 of 200 U.ml-1 to the cell cultures restored their responsiveness. NK activity was significantly reduced 30 min and 4 h after drug administration and returned to normal at the 24th h. This function was also restored by the addition of IL2. The data suggest that calcium channel blockers may inhibit, at least transiently, lymphocyte functions in vivo.

Markers of T lymphocyte activation in HLA-B8, DR3 positive individuals

Many autoimmune diseases are associated in Caucasians with HLA-B8 and/or HLA-DR3 antigens. There is evidence that bearers of these antigens may display significant changes in immune parameters when compared to individuals not having these antigens. Recently, increased numbers of blood activated T lymphocytes have been reported in the majority of these diseases. The increase in activated blood T lymphocytes is paradoxically characterized by an in vitro impairment of T cell activation. Particularly, an inadequate production of interleukins has been observed. We have studied blood levels of activated T cells in HLA-typed, healthy subjects. The results show that the percentage of activated T cells, as recognized by monoclonal antibodies anti-CD25, anti-Ia and anti-MLR3, was more frequent in HLA-B8, DR3 positive individuals. On the other hand, in the 24 h, PHA stimulated cultures IL-2, IFN-gamma and the percentage of T cells CD25 positive were decreased. Thus, there was an apparent discrepancy between the increase of blood activated T cells and the in vitro impaired T cell activation. Since there is evidence that HLA-B8, DR3 positive subjects are genetically low responders, a possible reason for the discrepancy might be their relative inability to remove antigenic stimuli from the body. In this case, the increased number of activated blood T cells may reflect a cellular activation caused by persistent antigenic stimulation.

Soluble interleukin-2 receptor secretion defect in vitro in HLA-B8, DR3 positive subjects

Several studies have shown that HLA-B8,DR3 positive subjects may display T cell dysfunctions. Recently, a soluble form of the receptor for IL-2 (sIL-2R) has been demonstrated in human sera and in vitro-stimulated culture supernatant from human T lymphocytes. In the present paper we report sIL-2R serum levels and sIL-2R production from peripheral blood mononuclear cells in HLA-B8,DR3 positive subjects. We found that HLA-B8,DR3 positive subjects have the highest values of serum sIL-2R, but comparing the values of these subjects with those of negative ones no significant difference was observed. As regards the in vitro production of sIL-2R, no difference exists for unstimulated cultures, whereas after stimulation, the HLA-B8,DR3 positive subjects showed the lowest values compared with negative ones. It is noteworthy that these changes are observed in autoimmune diseases linked to this HLA phenotype.

Suppression of autologous mixed leukocyte reaction in type 1 diabetes mellitus by in vivo-activated T lymphocytes

In vivo-activated interleukin 2 receptor-positive T lymphocytes (Tac cells) are demonstrable and the autologous mixed leukocyte reaction (AMLR) is impaired in several autoimmune diseases, including type 1 insulin-dependent diabetes mellitus (IDDM). We investigated AMLR in greater detail, together with possible relationships between AMLR and Tac lymphocytes in IDDM. Coculture experiments with HLA identical patient-healthy sibling pairs revealed that both responder and stimulator cells of diabetic patients function abnormally in AMLR. Suppressive Tac lymphocytes among responder T cells seemed to impair their proliferation. The removal of Tac cells by immunomagnetic beads led to a striking enhancement of proliferation, while the restoration of AMLR cultures with enriched Tac cells was accompanied by a diminished response. The reasons for the poor stimulatory capacity of patient cells are at present unknown but may be due to altered function and/or structure of HLA-DR molecules.

Expression of HLA-class II antigens and proliferative capacity in autologous mixed lymphocyte reactions of human T lymphocytes exposed in vitro to alpha-endorphin

alpha-Endorphin (aEP) inhibited the expression of HLA-Class II antigens by PHA-primed T lymphocytes and reduced mitogen-induced T-cell proliferation up to 35%. This action was time related and not naloxone sensitive. When aEP was added to autologous and allogeneic lymphocyte cultures (both of non-T/T and T/T type), it inhibited lymphocyte blastogenesis up to 40%. These findings, indicating that aEP can influence some functions of immunocompetent cells, provide evidence for the functional interrelationship between the neuroendocrine and the immune systems.

In vivo effect of chronic ethanol abuse on membrane alpha 1-glycoprotein of lymphocytes and immune response to various stimulating agents

Data on the immune status of chronic alcoholic patients are rather conflicting probably due to the interference of liver disease and/or malnutrition on immune function. In order to avoid this kind of interference, peripheral lymphocytes from 12 chronic alcoholic patients in good nutritional status and without heavy liver damage and 15 healthy controls were examined in this study. Lymphocyte functional activity was evaluated by means of response to phytohemagglutinin, calcium ionophore A 23187, and autologous non-T-cells [autologous mixed lymphocyte reaction (AMLR)]. Phenotypical analysis was carried out by the indirect immunofluorescence technique using monoclonal antibodies specific to CD5 (mature T-lymphocytes), CD4 (helper/inducer T-lymphocytes), CD8 (suppressor/cytotoxic T-lymphocytes), glycoproteins, and an immunoglobulin fraction from rabbit directed to membrane alpha 1 acid glycoprotein (AGP) that is involved in T-cell activation process. Our results show significant impairment in AMLR while response to phytohemagglutinin, heterologous non-T-cells and carcinoma ionophore did not differ from controls. No differences were present in circulating T-lymphocytes expressing CD5, CD4, and CD8 on their membrane, whereas AGP-bearing lymphocytes were significantly lower in chronic alcoholics (14.4 +/- 8.6) than in controls (31.9 +/- 8.1; p less than 0.001). These results support the hypothesis of a direct action of alcohol on one of the pathways of lymphocyte activation and the role of the lymphocyte membrane AGP on the AMLR.

Functional study of T lymphocyte responsiveness in patients with dementia of the Alzheimer type

The autologous mixed lymphocyte reaction (AMLR) was used to study T lymphocytes in a group of patients with dementia of the Alzheimer type (DAT) in order to confirm the observation that their T cell proliferation in AMLR was greater than in age-matched controls, and to investigate other pathways of T cell activation, searching for correlations between immunologic and clinical findings in DAT. The mean proliferative response in AMLR was increased in patients with DAT. No differences between patients and age-matched controls were detected when other pathways of T cell activation were investigated. The degree of response in the AMLR varied among patients with DAT. This fits with the suggestion that the disorder may be a heterogeneous syndrome.

Immunomodulatory effect of naloxone in duodenal ulcer patients

The effect of a single dose of the opiate receptor antagonist naloxone (NAL) on some immune parameters in chronic duodenal ulcer patients and healthy controls was investigated. Twelve hospitalized men, aged 19-23 years (nine duodenal ulcer patients and three controls) were given NAL intravenously at a dose of 0.03 mg/kg. Blood samples were drawn before and 30 and 150 min after NAL injection. Results obtained in duodenal ulcer patients and healthy subjects revealed the same direction of changes despite a rather wide scatter. Baseline NK cell activity was lower in duodenal ulcer patients than in healthy persons. In approximately one fourth of patients the changes in individual parameters observed following NAL injection were slight. Numbers of total lymphocytes, Th, Ts, NK cells, monocytes and Th/Ts ratio did not significantly change after NAL administration. T-lymphocyte counts moderately decreased at 30 min after NAL injection. NAL did not affect spontaneous IL-2 receptor expression and it moderately increased PHA-induced IL-2 receptor expression in most of the investigated persons. IL-2 generation and NK cell activity slightly, but significantly, increased at 30 min following NAL injection. NAL markedly inhibited lymphocyte proliferation in an AMLR test 30 min after its administration. Most of the investigated parameters returned to their initial levels after 150 min following NAL administration. The studies showed that not only endorphins and enkephalins may have an immunomodulatory action, but NAL, their antagonist, may also affect some functions of the immune system in humans, although its action is transient.

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)

Autologous mixed lymphocyte reaction in man. XX. The cellular and molecular basis of deficient T-T AMLR in aging humans

In the T-T AMLR, suppressor functions are generated, and because in human aging a deficiency of suppressor function has been observed, we examined the T-T AMLR in aging humans. Non-T cells were irradiated and used as stimulators against fresh autologous responder T cells to generate activated T cells (TA). TA cells were irradiated and used as stimulators against fresh autologous responder T cells (T-TA AMLR), CD4+ cells (CD4-TA AMLR), or CD8+ cells (CD8-TA AMLR) in the presence or absence of recombinant interleukin 2 (rIL-2). T cells from young and aging subjects were stimulated with phytohemagglutinin and examined for the expression of IL-2 receptors (IL-2R) and transferrin receptors. A significant decrease in T-TA, CD4-TA, and CD8-TA AMLR was observed in aging humans when compared with simultaneously studied sex-matched young controls. In vitro addition of rIL-2 resulted in an enhanced AMLR in both young and aging subjects; however, the total [3H]thymidine incorporation by T cells and T-cell subsets from aging in the presence of rIL-2 was lower than that of young subjects' T cells and T-cell subsets in the presence of rIL-2. The net increase (over the baseline values) in [3H]thymidine incorporation in T-TA and CD8-TA by rIL-2 was significantly less in the aging group when compared to the young group. In contrast, the rIL-2-induced net increase in [3H]thymidine incorporation in CD4-TA AMLR in both groups was comparable. T cells expressing IL-2R and transferrin receptors were of similar proportions in two groups. These data show a deficiency of the T-T AMLR in aging humans that appears to be, at least in part, due to deficient response to rIL-2. This deficiency of the T-T AMLR might be responsible for deficient suppressor activity, hyperimmunoglobulinemia, and the presence of autoantibodies in aging humans.

Enhanced autoreactivity of T-lymphocytes in primary sclerosing cholangitis

Primary sclerosing cholangitis is a chronic, cholestatic liver disease in which immune mechanisms are thought to play a role in the pathogenesis. We have determined the frequencies and functional phenotypes of autoreactive T-lymphocytes in peripheral blood specimens from patients with primary sclerosing cholangitis and healthy adults as an indicator of autoreactivity in primary sclerosing cholangitis. We found a significant increase in the percentage of autoreactive suppressor/cytotoxic T-lymphocytes that become activated in the T-, non-T-autologous mixed lymphocyte reaction in primary sclerosing cholangitis patients (p less than 0.002). Blastogenesis in autologous mixed lymphocyte reaction cultures from primary sclerosing cholangitis patients was significantly decreased (p less than 0.02), and the magnitude of the decrease correlated directly with the percentage of activated suppressor/cytotoxic T-lymphocytes (r = 0.56, p less than 0.01). The percentage of autoreactive, suppressor T-lymphocytes was increased in autologous mixed lymphocyte reaction cultures from primary sclerosing cholangitis patients (p less than 0.0001); and suppression of mitogen-induced blastogenesis by autologous concanavalin A-treated mononuclear cells was significantly enhanced. These results, which were unrelated to the histologic stage of liver disease and the presence or absence of active colitis, document the presence of an expanded population of T-lymphocytes in the peripheral blood of patients with primary sclerosing cholangitis that became activated on exposure to autologous major histocompatibility antigens in the autologous mixed lymphocyte reaction. We hypothesize that these autoreactive cells may be a marker or may participate as effector cells in cell-mediated autoimmunity in primary sclerosing cholangitis.

Langerhans cell- and T-lymphocyte functions in patients with atopic dermatitis with disseminated cutaneous herpes simplex virus infection

We studied whether Langerhans cell (LC)- and T-lymphocyte functions of atopic dermatitis (AD) patients are impaired. Our study groups consisted of 6 patients with AD with previous disseminated herpes simplex virus infection (AD + HSV), 8 patients with ordinary AD, and 5 healthy subjects. Suction blisters were performed on abdominal skin and LC isolated on the basis of their attachment to IgG-coated erythrocyte monolayers. Antigen-presenting function of purified LC was studied by measuring the proliferation of HSV-stimulated T cells. Langerhans cells were also used to stimulate T cells in autologous mixed cell reaction (AMCR). In addition, the production of epidermal cell thymocyte-activating factor (ETAF) by crude epidermal cells was measured. The HSV-induced T-cell proliferation in AD + HSV and AD patients was comparable with that of controls. The AMCR responses of patients with AD + HSV and AD were clearly diminished when compared with healthy controls. Patients with AD also produced significantly less ETAF than controls. Our results suggest that HSV antigen-presenting function of LC from patients with AD + HSV seems to be intact. Defective AMCR may reflect an abnormality in autoregulation and generation of effector cells and this together with decreased ETAF production may have pathogenetic significance in AD.

Alpha 1-acid glycoprotein (alpha 1-AGP) on the membrane of human lymphocytes: possible involvement in cellular activation

A glycoprotein termed alpha 1-acid glycoprotein (alpha 1-AGP) is a component of normal human serum; its concentration is often increased in several pathological disorders, including acute inflammation and cancer. Inhibitory effects of alpha 1-AGP on some in vitro T and B cell function assays have been reported but our recent data indicated that alpha 1-AGP is indeed a T cell mitogen at physiological concentrations. The present study was designed to investigate: (a) the relationship between this glycoprotein and two other glycoproteins of the T and B cell membrane, i.e. the T3 and Ia antigens; (b) the ability of lymphocytes to take up exogenous alpha 1-AGP; (c) the different expression of alpha 1-AGP on the T cell membrane upon different activation pathways, i.e., autologous non-T-cells (B cells and monocytes) phytohemagglutinin and anti-T3 monoclonal antibody (MAb) stimulations. The data reported herein show no competition at the membrane level between anti-alpha 1-AGP and anti-T3 or anti-Ia MAbs. In addition, (1) the lymphocytes were able to absorb alpha 1-AGP from the culture medium and (2) the expression of this glycoprotein was enhanced upon T cell stimulation (all three stimulants employed induced an increase of alpha 1-AGP positive T cells), thus suggesting a possible role of this glycoprotein in in vitro T cell activation.

Interleukin 2 induces proliferation of normal "resting" human T cells in the absence of other known external stimulation

Interleukin 2(IL-2) is known to stimulate the progression of activated T cells from G1 through the rest of the cell cycle. We have demonstrated that addition of purified recombinant human IL-2 (rIL-2) to fresh normal human peripheral blood mononuclear cells (PBM), which were IL-2 receptor (Tac) negative by FACS analysis, stimulated marked proliferation of the PBM. IL-2-induced proliferation was also observed with umbilical cord blood mononuclear cells. Monocyte depletion of PBM resulted in a marked reduction of rIL-2-induced proliferative response which could be restored by adding back autologous irradiated monocytes but not by interleukin 1. The T cells preincubated with rIL-2 showed a five to six times enhanced autologous mixed-lymphocyte reaction (AMLR) compared to controls. The rIL-2-induced proliferative response of PBM was inhibited in a concentration-dependent fashion by preincubation of PBM with an anti-HLA-DR framework monoclonal antibody. The proliferating cells were shown by two-color flow cytometric analysis to be primarily Leu-1+ and Leu-4+ T cells (both leu-3+ and Leu-2+ subsets); however, 6 to 19% of responding cells had surface markers for B cells or NK cells. The data demonstrate that rIL-2 can induce proliferation of "resting" human T cells. The phenomenon may be related to a monocyte-dependent AMLR which induces IL-2 receptors and IL-2 responsiveness in a subset of T cells.

Autologous mixed-lymphocyte reaction in man. XVII. In vitro effect of ion channel-blocking agents on the autologous mixed-lymphocyte response

The in vitro effect of ion channel-blocking agents verapamil (V), 4-aminopyridine (4AP), tetraethylammonium (TEA), and quinine (Q) was examined on the proliferative response of human peripheral blood T lymphocytes in the autologous mixed-lymphocyte reaction (AMLR). All the above channel blockers in a dose-dependent manner inhibited the AMLR. Tetramethylammonium (TMA), an analog of TEA that does not block K+ channel currents, did not inhibit the AMLR. 4AP at 1 mM/ml concentration inhibited the expression of IL-2 receptors, as defined by monoclonal antibody anti-Tac, on T-cell activated in the AMLR. In vitro addition of recombinant interleukin 2(rIL-2) completely corrected the inhibition of the AMLR by channel blockers. Furthermore, the concentrations of ion channel blockers required for blocking 50% response of T cells in the AMLR was much lower than that reported for 50% block of T-cell proliferation in response to phytohemagglutinin or in allogeneic mixed-lymphocyte culture (MLC). These data suggest a role of ion channels in T-cell functions and show that the AMLR provides a more sensitive system, as compared to lectin stimulation or MLC, to examine any immunosuppressive effects of ion channel-blocking agents in disease states where they are used as therapeutic modalities.

Does normal lymphocyte DNA synthesis in response to PHA exclude cell-mediated immunodepression?

PHA stimulation assay was the first in vitro method for evaluating the T-cell function, and this T-cell proliferative response has been routinely used to discriminate between normal subjects and patients with deficiency in cell-mediated immunity. However, [3H]thymidine incorporation into lymphocyte DNA can be studied by using additional in vitro assay methods since they measure different lymphocyte activation pathways. In the present study we selected three different tests to investigate the reliability of this single approach: PHA induced lymphocyte DNA synthesis; T lymphocyte DNA synthesis to anti-T3 monoclonal antibody (OKT3); autologous mixed lymphocyte reaction (AMLR). In addition, IL-2 receptor expression on the membrane of T-cell stimulated in AMLR both with PHA and anti-T3 was evaluated. This study was performed in various groups of subjects: normal young controls, aged healthy individuals, and patients with Alzheimer's disease (AD), Retinitis Pigmentosa (RP), and with cell-mediated immunodeficiency and clinical evidence of recurrent viral infections (ID). The data reported herein show heterogeneity of results in each group studied and demonstrate the necessity of employing more than one laboratory test for the routine evaluation of T-cell-mediated immunity.

Abnormality of Leu 2+7+ cells in acquired immune deficiency syndrome (AIDS), AIDS-related complex, and asymptomatic homosexuals

Peripheral blood mononuclear cells from patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC), asymptomatic homosexuals, and healthy heterosexuals were analyzed for the proportions and numbers of Leu 7+ cells and double-labeled Leu 2+7+ cells and for the natural killer functions. A significant increase in the proportions and numbers of Leu 7+ cells was observed in patients with AIDS and ARC and in asymptomatic homosexuals compared to healthy heterosexual men. The proportions of Leu 2+7+ cells were significantly increased in AIDS, ARC, and asymptomatic homosexuals, whereas the numbers were increased in asymptomatic homosexuals and ARC but not in AIDS compared to heterosexual controls. A significant increase in the number of Leu 2+7+ cells was observed in AIDS with Kaposi's sarcoma but not in AIDS with opportunistic infections. The natural killer function was significantly depressed in patients with AIDS and ARC and in asymptomatic homosexuals. These data suggest that the quantitative abnormalities of Leu 2+7+ cells appear early during the evolution of immunologic changes in HTLV III/LAV infection.

Inhibitory effect of an antibody against alpha 1-acid glycoprotein (alpha 1-AGP) on autologous mixed lymphocyte reaction and anti-T3 T-lymphocyte activation

The action of an anti-alpha 1-AGP antibody on AMLR, anti-T3 and PHA T-lymphocyte proliferative response was evaluated. We observed a strong dose-dependent inhibition on T-lymphocyte proliferative responsiveness to autologous non-T cells and to anti-T3 stimulus, whereas PHA activation was unaffected. A lower degree of inhibition of the proliferative response was also observed on pretreating both T and non-T cells with the antibody; the addition of anti-alpha 1-AGP in the culture containing cells pretreated with the antibody showed a further inhibition of thymidine incorporation. The data suggest a direct influence of the antibody on membrane alpha 1-AGP and support a positive role of this glycoprotein (distinct from Ia and T3 antigens) on both anti-T3 and autologous non-T cell T-lymphocyte responsiveness, thus indicating the involvement of alpha 1-AGP in the T3-Ti antigen-specific pathway of T-cell activation.

T cells from patients with chronic liver diseases: abnormalities in PHA-induced expression of HLA class II antigens and in autologous mixed-lymphocyte reactions

The expression of HLA Class II antigens by resting and phytohemagglutinin (PHA)-activated T cells and their functional properties in autologous mixed-lymphocyte reactions (MLR) were investigated in patients with chronic active hepatitis, with alcoholic cirrhosis, and with primary biliary cirrhosis. In all groups of patients the percentage of resting T cells expressing HLA Class II antigens was significantly higher than that in controls. The percentage of T cells which acquired HLA Class II antigens following PHA stimulation was reduced in patients with chronic active hepatitis, serum hepatitis B surface antigen (HBsAg) positive, and in those with alcoholic cirrhosis, HBsAg negative, although the level of [3H] thymidine incorporation was within normal limits. The degree of proliferation in autologous MLR with PHA-T cells was significantly reduced in patients with chronic active hepatitis, HBsAb positive, and in those with alcoholic cirrhosis, HBsAg positive. A reduced proliferation was also detected in autologous MLR with non-T cells, in patients with chronic active hepatitis, HBsAg positive. The abnormalities of autologous MLR are selective, since the proliferative and stimulatory activities of cells from patients with chronic liver diseases in allogeneic MLR were within normal ranges. The immunoregulatory role of HLA Class II antigens and of autologous MLR suggests that the abnormalities we have identified may play a role in the immunological dysfunctions underlying chronic liver diseases.

In vitro enhancement of the proliferative response of human T cells to autologous non-T cells by hydralazine

While high doses of hydralazine inhibit the proliferative response of T lymphocytes to mitogens and antigens, low doses (0.15 microgram/ml) selectively enhance the proliferative response of T cells to autologous non-T cells. The effect is especially pronounced on lymphocytes which express the HLA-DR4 allospecificity. These results suggest that the autologous mixed lymphocyte response with non-T cells may represent a useful in vitro model to analyse the mechanism(s) of the immunologic abnormalities induced by hydralazine.

Autologous mixed lymphocyte reaction (AMLR) in man. XVI. The AMLR and monoclonal antibody-defined T cell subsets and HNK 1+ natural killer cells in normal human pregnancy

Peripheral blood mononuclear cells from 27 pregnant women and 10 age-matched non-pregnant women were examined for monoclonal antibody-defined T cells, immunoregulatory T-cell subsets, natural killer cells, activated T cells and surface Ig+B lymphocytes using a fluorescence-activated cell sorter (FACS analyzer). The autologous mixed lymphocyte reaction (AMLR) and in vitro influence of interleukin 1 (IL-1) and interleukin 2 (IL-2) on the AMLR were also studied. No significant difference was observed in the proportions of Leu 3+ (helper/inducer phenotype) and Leu 2+ (suppressor/cytotoxic) T cells during all three trimesters of pregnancy and in post-partum period when compared to non-pregnant healthy control women. T cells expressing DR antigen (evidence of T-cell activation) were significantly increased during second trimester (P less than 0.02) and in post-partum period (P less than 0.05). However, Tac+ T cells (IL-2 receptor positive T cells, another but distinct marker for T cell activation) were normal throughout pregnancy and in the post-partum period. Leu 7+ (HNK 1+) lymphoid cells (containing a population of natural killer cells) were normal during all 3 trimesters of pregnancy but were increased during post-partum period. Surface Ig+B cells were comparable to control group throughout pregnancy and during post-partum period. The AMLR was significantly deficient (P less than 0.01) during first and third trimester of pregnancy. In vitro addition of purified IL-2 restored the AMLR to the baseline levels of the controls but the AMLR was still lower than the levels in controls with IL-2.(ABSTRACT TRUNCATED AT 250 WORDS)

PHA-T cells in systemic lupus erythematosus and in rheumatoid arthritis: abnormalities in HLA class II antigen induction and in autologous mixed lymphocyte reactions

Analysis of T cells from patients with systemic lupus erythematosus (SLE) and with rheumatoid arthritis (RA) identified a deficit in the induction of HLA Class II antigens by PHA although the proliferative response was normal and in the [3H]thymidine incorporation in autologous mixed lymphocyte reactions (MLR) with PHA-T cells as stimulators. In RA these abnormalities were more marked in patients with active disease than in those in clinical remission. The deficit of autologous MLR with PHA-T cells was more marked than that of autologous MLR with non-T cells and of allogeneic MLR. Serum from patients with SLE and with RA did not display any detectable inhibitory activity on the induction of HLA Class II antigens by PHA, on the proliferative response of lymphocytes to PHA, on autologous MLR with PHA-T cells and with non-T cells as stimulators and on allogeneic MLR. These results suggest that the abnormalities we have identified reflect an intrinsic defect of T cells.

Deficiency of autologous mixed lymphocyte reaction in patients with idiopathic autoimmune hemolytic anemia

Alterations in the autologous mixed lymphocyte reaction (autologous MLR) have been reported in many autoimmune diseases and in diseases with a derangement of T regulatory function. We have studied autologous MLR in 10 patients with idiopathic autoimmune hemolytic anemia (IAHA). All patients had decreased autologous MLR which averaged 4,106 +/- 1,332 cpm (SEM) compared to 12,153 +/- 4,166 cpm for simultaneously studied controls. A marked decrease in phytohemagglutinin response and an imbalance of T-cell subsets were also observed. These findings suggest a possible abnormality of T immunoregulatory function in IAHA patients.

Circadian variations of autologous mixed lymphocyte reactions and endogenous cortisol

The degree of proliferation of human T cells stimulated with autologous PHA-T cells and with autologous non-T cells displays circadian variations. The highest proliferation occurs with cells isolated from blood drawn at 8 a.m. in mixed lymphocyte reactions (MLR) with autologous PHA-T cells and from blood drawn at 8 p.m. in MLR with autologous non-T cells. The circadian variations of autologous MLRs appear to reflect changes in the proliferative response of T cells. In autologous MLRs with non-T cells as stimulators the extent of proliferation was inversely correlated with the level of endogenous cortisol. The circadian variations of autologous MLRs do not reflect non-specific changes in the proliferative and stimulatory properties of T and non-T cells, since circadian variations were not observed in the proliferative response of T cells to mitogens and in allogeneic MLRs. Circadian variations of autologous MLRs must be taken into account when analyzing abnormalities of these reactions in pathological conditions.

Immunological profile in children with minimal change nephrotic syndrome

Peripheral blood from patients with active stage of minimal change nephrotic syndrome (MCNS) was examined for concanavalin A (ConA)-inducible suppressor T cell activity, proliferative response to phytohemagglutinin (PHA) and in the autologous (AMLR) and allogeneic (MLR) mixed lymphocyte reaction, proportions of T cells with receptors for IgM (Tu) or IgG (T gamma) and the levels of serum immunoglobulin M, G and A. Six of 9 patients with MCNS studies showed deficiency of ConA-induced suppressor cell activity. In the AMLR, only one of 9 patients with MCNS demonstrated depressed proliferative response (p less than 0.05). In the allogeneic MLR, T cells from 5 of 9 patients with MCNS demonstrated poor proliferative response when stimulated with normal control non-T cells. Five of 9 patients with MCNS had depressed proliferative response to PHA. The proportion of total T cells, Tu cells and T gamma cells in the patient group were comparable to healthy control group. Serum IgG was significantly decreased in 7 of 11 patients. This study demonstrates multiple immunological abnormalities in patients with MCNS that might play a role in its pathogenesis.

Impaired killer cell generation in the autologous mixed leukocyte reaction by rheumatoid arthritis lymphocytes

Natural killer-like cells are generated along with interleukin-2 (IL-2) in the autologous mixed leukocyte reaction (AMLR). Patients with active rheumatoid arthritis (RA), but not those whose disease is in remission, are poor producers of AMLR killer cells. This defect cannot be explained by age, medications, or serum factors. The impaired generation of natural killer-like cells was not influenced by gamma-interferon but could be partially restored by addition of indomethacin to the AMLR culture, or by culturing RA T cells with exogenous IL-2. However, the response of RA T cells to IL-2 was significantly less than that of controls. These results suggest that the defect in the generation of AMLR killer cells in patients with active RA may be due in part to defective production of IL-2 and a lesser sensitivity of RA T cells to IL-2.

Analysis of the role of xenogeneic antigens in the proliferation of human T cells stimulated with autologous non-T cells and phytohemagglutinin-activated T cells

Since conflicting results have been reported about the role of xenoantigens in the proliferation of T cells stimulated with autologous non-T cells, the effect of the exposure of cells to xenogeneic proteins during the isolation procedure and/or the culture period on autologous mixed lymphocyte reactions (AMLR) with non-T cells and phytohemagglutinin-activated T cells as stimulators was investigated. T and non-T cells were isolated by rosetting with 2-aminoethylisothiuronium bromide-treated sheep red blood cells (AET-SRBC), by nylon-wool filtration, and by positive or negative selection with anti-class II HLA antigens and anti-T-cell monoclonal antibodies. Isolation and cultures were performed in presence of fetal calf serum (FCS) or of autologous serum. In both types of AMLR, proliferation of responding cells did not require exposure to xenoantigens. However xenoantigens enhanced the proliferation of cells from some, although not all, the donors tested. There were differences in the degree of proliferation of the cells from the donors tested, but without correlation with the two types of AMLR. These results suggest that both types of AMLR reflect a self-recognition event and not a response to xenoantigens. However the potential interference of xenoantigens, as well as the individual variability, should be taken into account when interpreting the significance of abnormalities of AMLR in immunopathologic processes.

Autologous mixed lymphocyte reaction in man. XIII. Characterization of the T-T autologous mixed lymphocyte reaction

In this study we have demonstrated that in the T-TA autologous mixed lymphocyte reaction (AMLR), OKT4+ T cells are the major responders; however, in the presence of additional interleukin-2 (IL-2), OKT8+ T cells also respond by proliferation. Both OKT4+ and OKT8+ T cells, activated in the T-non-T AMLR, act as stimulators in the T-TA AMLR. OKT4+ T cells activated in the T-TA AMLR suppress the proliferative response of the fresh T-non-T AMLR; control OKT4+ cells show no immunoregulatory activity in this system. In contrast, control OKT8+ T cells spontaneously suppress the proliferation of the T-non-T AMLR, but activation of OKT8+ T cells in the T-TA AMLR does not result in a further increase in the suppressor activity of OKT8+ T cells. In summary, in the T-non-T and T-TA AMLR phenotypically similar T-cell subpopulations proliferate but express distinct immunoregulatory functions and perhaps regulate the tempo of the AMLR.

The role of xenoantigen in the human autologous mixed lymphocyte reaction: ability to respond in the absence of exposure to xenoantigen depends on the method of T-cell preparation

Recent reports have suggested that the autologous mixed lymphocyte reaction (AMLR) is attributable to contaminating xenoantigen. T-cell populations separated from peripheral blood mononuclear cells (PBM) over Percoll fail to produce an AMLR in the absence of xenoantigen. However, T-cell populations that do not adhere to plastic and to nylon wool will in the absence of added xenoantigen produce an AMLR comparable to that obtained with E-rosetted populations. In the nonadherent cells separated sequentially by passage through nylon wool and Percoll, the presence of two lymphocyte subpopulations was demonstrated. One is xenoantigen dependent, the other xenoantigen independent in the AMLR. Further, the xenoantigen-independent population may provide help to the dependent population. In the previous reports with Percoll-separated cells that attributed the AMLR to contaminating xenoantigen, the xenoantigen-independent T-cell population was excluded from the responding fraction.

Defective autologous mixed lymphocyte reactions in patients with renal insufficiency--evidence for cellular and serum factors

The autologous mixed lymphocyte reaction (AMLR) was studied in 10 patients who were azotemic from renal diseases not considered to be immunologically mediated. These patients were not on chronic dialysis. The AMLR was significantly depressed in patients with azotemia when compared to the AMLR in normals. When the AMLR was performed utilizing lymphocytes from normals, the proliferative response was markedly decreased if azotemic serum was substituted for normal serum. However, when the AMLR was performed utilizing lymphocytes from azotemic patients, the proliferative response did not significantly improve if normal serum was substituted for azotemic serum. In addition, the proliferative responses of T cells to concanavalin A (Con A) and phytohemagglutinin (PHA) were not significantly depressed in azotemic patients when compared to normal controls. These data suggest that the AMLR is abnormal in azotemic patients because of an intrinsic defect in the mononuclear cells, possibly in the stimulating non-T cells, and an inhibitory factor in the serum.

Characterization of the defective autologous mixed lymphocyte response in rheumatoid arthritis

In order to characterize the autologous mixed lymphocyte response (AMLR) in patients with rheumatoid arthritis (RA) and to define the relationship with disease activity, peripheral blood T lymphocytes were stimulated with either a B lymphocyte-enriched (B cells) or a macrophage-enriched (macrophages) population. A significant reduction (P less than 0.01 to P less than 0.001) of T cell proliferation stimulated both by B cells and macrophages was observed in patients with active disease. The B lymphocytes were significantly less stimulatory (P less than 0.02 to P less than 0.001) than macrophages in the patients compared with the controls. In the normal controls, macrophages in higher concentrations were capable of suppressing the B lymphocyte-stimulated AMLR, but macrophages from patients with RA were not excessively suppressive. A significant association (P less than 0.02) was observed between disease activity and the AMLR. Using the B-enriched population, the AMLR proliferative response was significantly associated (P less than 0.001) with the production of interleukin-2. Defects in proliferation could only be partially restored by the addition of interleukin-2. These data indicate that the defective AMLR observed in patients with RA is related to disease activity and is associated with altered cellular interactions among T lymphocytes, macrophages, and the B lymphocyte-enriched population.

Autologous mixed lymphocyte reaction in man: XV. Cellular and molecular basis of deficient autologous mixed lymphocyte response in insulin-dependent diabetes mellitus

The autologous mixed lymphocyte response (AMLR) and the allogeneic mixed lymphocyte response were deficient in a subset of patients with newly diagnosed insulin-dependent diabetes mellitus (IDDM). Using a single set of HLA-identical twins, the cellular and molecular basis of deficient AMLR was investigated and appears to be due to a defect in both responder T cells and stimulator non-T cells. Interleukin-2 production was diminished in the patient but not in the healthy twin. The in vitro addition of purified interleukin-2 enhanced the depressed AMLR in the diseased twin. This suggests that the deficient AMLR in IDDM may be in part due to a deficiency in the production of interleukin-2.

Human T cells in cord blood: abnormalities in IA antigens induction by phytohemagglutinin and in autologous mixed lymphocyte reactions

About 25% of human T cells isolated from cord blood acquired la antigens, following stimulation with phytohemagglutinin (PHA) for 72 hr. This percentage is markedly lower than that found in PHA-activated T-cell populations (PHA-T cells) isolated from peripheral blood of adults. The low expression of la antigens by human T cells from cord blood does not reflect abnormalities in the sensitivity to PHA stimulation and/or in the kinetics of induction of la antigens. PHA-T cells from cord blood display a low stimulatory activity in autologous mixed lymphocyte reactions (MLR). The defect does not reflect a nonspecific abnormality in the stimulatory activity of PHA-T cells from cord blood, since the latter do not differ from PHA-T cells from adults in their ability to stimulate allogeneic T cells from adults. Furthermore the defect does not reflect a nonspecific abnormality in the proliferative response of T cells from cord blood, since the latter display a normal proliferative response to PHA-T cells from adults. The defect in the proliferative response is not restricted to the autologous MLR with PHA-T cells, since it was found also in autologous MLR with non-T cells as stimulators. Correlation of the temporal evolution of the abnormalities of human T cells with the maturation of the immune system may contribute to our understanding of the role of la antigens in cell-cell interactions and of the biological significance of abnormalities of autologous MLR.

Heterogeneity of human T-lymphocyte clones generated from autologous mixed-lymphocyte cultures

To assess the heterogeneity of T cells activated during the autologous mixed-lymphocyte reaction (AMLR), a cloning procedure based on the soft agar colony assay was developed. Supernatants of allogeneic MLR cultures were used as a source of interleukin 2 (IL-2) to generate two types of colonies: upper and lower colonies. Both types of colonies were expanded in long-term cultures using supernatants of phytohemagglutinin (PHA)-activated lymphocyte cultures. Cloned cells underwent secondary proliferation when stimulated by autologous monocytes, although certain clones also responded to autologous B cells. Most autoactivated clones expressed the serological determinants of HLA-DR, MB, and MT and were OKT3+, OKT4+, OKT8-. They did not induce cytolysis of autologous monocytes, B lymphoblasts, or PHA blasts nor did they express natural killer-like activity toward K562 cells. Several autoactivated clones (irradiated with 500 R) expressed helper activity, shown by an enhancing effect on AMLR proliferation. Furthermore, many irradiated clones were capable of inducing proliferation of autologous T cells in the absence of accessory cells. These observations suggest that autoactivated clones generated from soft agar colonies may interact with autologous T lymphocytes.

Study of activated T cells in man. I. Discrepancy between Tac antigen and DR Antigen on T cells in patients with primary immunodeficiency

DR and Tac antigens are present on T cells activated in vitro with mitogens and antigens but lacking on resting T cells. Freshly prepared peripheral blood T cells from patients with common variable immunodeficiency ( CVI ) and isolated IgA deficiency ( IAD ) were examined for the presence of DR and Tac antigens, using monoclonal antibodies and a fluorescence-activated cell sorter. Both Tac+ and DR+ T cells were significantly (P less than 0.05) increased in the patient group when compared with age- and sex-matched controls; however, a discrepancy was observed in the proportions of Tac+ T cells and DR+ T cells. This study demonstrates that, in certain patients with CVI and IAD , T cells are activated in vivo, and Tac and DR antigens could be expressed during different stages of T-cell activation.

Strong lymphoproliferative suppressive function of PLT clones specific for SB-like antigens

From a total of 37 different priming combinations between donors matched for HLA-A,B, and/or Dw/DR, but mismatched for SB, antigens, T cell clones strongly restimulated with concordance for SB specificities were isolated from only two. Most of the alloproliferative (PLT) clones obtained were restimulated by determinants not correlated with any currently known HLA product. Nonetheless, their stimulation was inhibited by a monoclonal antibody TU 39, which preferentially blocks stimulation by SB-, rather than by Dw/DR-associated determinants. Despite having an OKT4+, OKT-, Leu8- phenotype, and secreting Interleukin-2 after contact with stimulatory cells, these clones strongly suppressed proliferative responses of cloned PLT reagents as well as unprimed lymphocytes in mixed leukocyte cultures. They may thus represent a novel type of immunoregulatory T cell, stimulated by SB-related antigens, which despite their "helper/inducer" phenotype are able directly to suppress lymphoproliferative responses.

Monoclonal antibody analysis of responder and stimulator cells in the human autologous mixed lymphocyte reaction

Responder and stimulator cell subpopulations in the autologous mixed lymphocyte reaction (AMLR) were determined with the OK series of monoclonal antibodies. Mitomycin-C-treated, monocyte-enriched cell populations were used as stimulator cells in the AMLR. Treatment of these monocytes with either OKM and/or OKI monoclonal antibodies and complement resulted in a marked loss of ability of these cells to act as stimulators in the AMLR. Removal of OKT3+ and OKT4+ cells diminished the proliferative responses of AMLR cultures. Interaction of T cells with autologous monocytes resulted in generation of cells capable of suppressing both MLR and AMLR cultures. The suppressor activity of these cells was diminished by treatment with OKI , OKT4 or OKT8 monoclonal antibodies. No cytotoxic activity to autologous or allogeneic monocytes was observed. Additional studies showed an increased number of OKT9 + and OKI + as well as OKT8+ T cells in the AMLR responder cell population. This study indicates that cultures of T lymphocytes with autologous monocytes yield T cell subset(s) which suppress MLR and AMLR reactivity.

Autologous mixed lymphocyte reaction in man. IX. Autologous mixed lymphocyte reaction and lymphocyte subsets in aging humans

Peripheral blood from 15 young (20-30 years) and 15 aging (65-80 years) subjects was analysed for the proliferative response of T cells upon stimulation with non-T cells in the autologous mixed culture reaction (AMLR) and allogeneic MLR, and for the proportion of monoclonal antibody-defined lymphocyte subsets and monocytes. No significant difference was observed in the AMLR or allogeneic MLR between T and non-T cells in aging and young subjects. However, when non-T cells were further fractionated into adherent monocytes and non-adherent B cells (B cells and null cells), the AMLR between macrophages and T cells was significantly (P less than 0.05) higher in young subjects than in simultaneously studied aging subjects. In contrast, the AMLR between T cells and B cells was significantly (P less than 0.05) higher in the aging subjects than in the young group. In the T-T AMLR (using phytohaemagglutinin-stimulated T cells as stimulators), aging subjects had a significantly (P less than 0.05) lower proliferative response than simultaneously studied young subjects. In vitro addition of purified interleukin 2 reconstituted the T-T AMLR to the base-line T-T AMLR in young humans. No significant difference was observed in the allogeneic MLR and lymphocyte subsets between the two groups. The significance of these observations is discussed.