Spontaneous and antibody-dependent cell-mediated cytotoxicity by human T cell subpopulations

Expression of ionotropic glutamate receptor GLUR3 and effects of glutamate on MBP- and MOG-specific lymphocyte activation and chemotactic migration in multiple sclerosis patients

The present study was aimed at confirming the presence of GluR3 on T lymphocytes and to assess the effect of glutamate on proliferative responses to myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG) and chemotactic migration to CXCL12/stromal cell-derived factor-1, RANTES, and MIP-1alpha in 15 control subjects and 20 relapsing-remitting multiple sclerosis (MS) patients (10 in a stable clinical phase and 10 during relapse). T lymphocytes of control subjects and MS patients express both mRNA and protein of GluR3 receptors, as shown by RT-PCR and immunoblot analyses. An up-regulation was evident during relapse and in patients with neuroradiological evidence of disease activity. Glutamate and AMPA at concentrations of 10 nM to 10 muM were able to enhance T lymphocyte proliferation to MBP and MOG and the chemotactic migration of T cells both in controls and MS patients. In the latter group, significantly higher proliferation values in response to glutamate were found in patients assessed during relapse and in those with gadolinium (Gd)+ enhancing lesions on MRI. Glutamate concentrations above 10 muM appeared to be inhibitory on MBP and MOG-specific T-lymphocyte proliferation as well as chemotactic response in both patients and controls. Higher GluR3 expression and higher activating effect of glutamate on T cells of MS patients during relapses and with evidence of disease activity on MRI suggests the involvement of glutamate-mediated mechanisms in the T-cell detrimental effects. In MS patients, glutamate within physiological ranges in the cerebrospinal fluid and brain extracellular space might enhance myelin antigen-specific proliferation and chemotactic migration via activation of AMPA receptors, which can be relevant for myelin and neuronal damage in MS. Excess glutamate levels seem to induce an inhibitory effect on lymphocyte function, and therefore the detrimental effect of this excitatory amino acid in this case could be attributed to a direct toxicity on glial and neuronal cells.

Effect of two thymosin fraction 5 polypeptides on human peripheral blood lymphocytes

Thymosin fraction 5 polypeptides beta 4 and alpha 1 were tested for their ability to affect certain immunological parameters of human peripheral blood lymphocytes (PBL). PBL were cultured with various concentrations of the peptides for 24 hours. Thymosin beta 4 was found to induce a significant decrease in the expression of the Fc alpha receptors of PBL, as well as in their ability to express antibody dependent cellular cytotoxic (ADCC) activity. In addition, this peptide had the ability to increase the percentage of T4 lymphocytes in normal and immunosuppressed donors and to decrease the percentage of T8 positive cells in normal donors. Finally, beta 4 peptide caused a small increase in the capacity of peripheral blood lymphocytes to form sheep red blood cell (SRBC) rosettes (ER). In parallel experiments thymosin alpha 1 was found inactive. The results presented here indicate that thymosin beta 4 may be used as an immunoregulatory molecule in patients with immunodeficiencies.

T-cell chronic lymphocytic leukemia with a helper/inducer membrane phenotype: a distinct clinicopathologic subtype with a poor prognosis

T-cell chronic lymphocytic leukemia (T-CLL) accounts for about 2% of the various types of CLL and can be subtyped into helper/inducer (h/i) and cytotoxic/suppressor (c/s) cell membrane phenotypes. Seven patients with CLL were shown to have T-CLL with a h/i cell membrane phenotype; four with monoclonal antibody reagents and three by demonstration of the E-rosette receptor and focal acid alpha naphthyl acetate esterase activity. The clinical courses, treatment responses, and laboratory findings of these seven patients were reviewed to determine the prognosis and unique clinicopathologic features of this subtype. Two patients presented with skin rashes, and five were diagnosed during evaluation for other medical problems. Initially, four patients had splenomegaly and two had lymphadenopathy, but none of the patients had hepatomegaly. Morphologic examination revealed uniform, small lymphocytes in three patients, and the lymphocytes had nuclear indentations in four patients. Sera from the three patients tested were negative for antibody to the human T-cell leukemia/lymphoma virus I. Peripheral blood mononuclear cells from one patient showed normal interleukin-2 production and lacked antibody-dependent cell-mediated cellular cytotoxicity and natural killer activity. Cytogenetic analysis was done on one patient, revealing an abnormal clone with several chromosomal abnormalities, including an X;14 translocation with a break point at 14q11. All patients required chemotherapy, and all died a median of 21 months from the time of diagnosis. The findings in these patients, in addition to those in 31 patients described in the literature, indicate that h/i T-CLL is associated with a poor prognosis and has distinct clinical and pathologic features that separate it from c/s T-CLL, adult T-cell leukemia/lymphoma, the cutaneous T-cell lymphomas, and B-CLL.

Serum antibodies and their role in antibody-dependent cell-mediated cytotoxicity in aspergillosis

A total of 22 sera from patients with aspergilloma and allergic bronchopulmonary aspergillosis (ABPA) were examined concomitantly for specific antibody against Aspergillus fumigatus antigen and for their activity in antibody-dependent cell-mediated cytotoxicity (ADCC) against Aspergillus antigen-coated target cells. These sera demonstrated significant precipitin bands in agar gel double diffusion test (78% of ABPA and 75% of aspergilloma sera), while in indirect immunofluorescence studies all sera showed positive reactivity with a titer distribution of 1:40 to 1:160 and 1:40 to 1:320, respectively, for ABPA and aspergilloma sera. In enzyme-linked immunosorbent assay all sera demonstrated titers varying from 1:200 to 1:6400. Several sera also displayed marked cytotoxic reactions against A. fumigatus antigen-coated SB target cells in ADCC assays using normal lymphocytes as effector cells (35% of aspergilloma and 25% of ABPA sera). These findings suggest a role for ADCC activity in patients with Aspergillus infections.

Thymectomy-induced decrease in T gamma cells and OKT8+ cells in multiple sclerosis

Studies were performed on lymphocytes from patients with multiple sclerosis before and after thymectomy (group I) and before and after thymectomy and azathioprine therapy (group II), and from matched control patients with multiple sclerosis, control patients with other neurological diseases, and healthy control subjects. Following treatment the percentage of T gamma cells in both group I and group II patients decreased from above the mean normal control levels to below this level; OKT8+ cell numbers in group I became lower than in any of the control groups; the percentage of concanavalin A-induced suppressor activity, which was initially normal, fell in group II and suggestively but not significantly in group I; and total blood lymphocytes in group I decreased from normal to below control levels. Other tests showed no significant changes with therapy. No significant difference in changes in clinical status were observed after one year in the treated patients compared with matched controls.

Quantitation of Fc receptor-bearing T-lymphocytes (TG and TM) in oral cancer

The lymphocytes from the peripheral blood of 30 untreated patients with oral cancer and 15 apparently healthy normal controls were studied for quantitation of T-cell subsets. When compared to age-matched controls, the patients as a group showed a significant increase in the proportion and number of TG cells (IgG Fc receptor-bearing T-cells) and a significant reduction in the TM cells (IgM Fc-bearing T-cells). The levels of total lymphocytes, T-cells, and B-cells remained in the control range. The discrepancy in the TG subset was evident in the early stages of the disease, while in TM cells, it was evident only in the advanced stages.

The prognostic value of T-lymphocyte levels in malignant melanoma. A five-year follow-up

Serial immunologic tests (active E-rosettes = T-Ea; total E-rosettes = T-Et; total lymphocytes and null cells) were performed every 3 months for 5 years on 113 melanoma patients. A significant reduction in absolute T-Ea, T-Et, null cells, and total lymphocytes was noted in the patients who died, by comparison with those who are still alive. The latter presented a significant reduction in absolute T-Et only, plus a significant increase in null cells when compared with normals. The 38 patients without metastases, at the end of the study, presented a reduction in T-Et and an increase in null cells compared with the normals, while the 75 patients with metastases presented a reduction in T-Et, null cells and total lymphocytes when compared with the patients without metastases and a reduction in T-Ea, T-Et, and total lymphocytes when compared with the normals. Null cells show a linear decrease in patients who died and a linear increase in those who survived. A total of 80.2% of patients with a fall in T-Et displayed metastases usually within 2 to 10 months (mean, 6.8). Patients with normal T-Ea, T-Et, and total lymphocyte values showed a significant prolonged survival when compared to those with lower values. In addition, survival seemed to be always a function of immunologic test values, irrespective of the tumor site.

Modulation of tumour colony growth by irradiated accessory cells

The ability of human tumour cells to form colonies in soft agar is enhanced by the presence of autologous phagocytic/adherent cells. We investigated the effect of irradiation on the ability of the adherent cells to support human tumour colony formation. Relatively low doses of irradiation significantly increased the growth enhancing ability of adherent cells in 17/19 cases. The possibility that the enhancement was mediated by inactivation of radiosensitive contaminating lymphocytes was explored. Depletion of T lymphocytes from unirradiated adherent cells by a monoclonal antibody and complement resulted in little overall change in tumour colony growth. However, elimination of only the suppressor subset (OKT8+) of T lymphocytes resulted in increased colony growth relative to control values obtained with unirradiated adherent cells. In contrast, depletion of T lymphocytes from irradiated adherent cells by a pan T monoclonal antibody and complement decreased colony formation. Thus, the ability of irradiated macrophages to enhance tumour colony growth appeared to be mediated by a T lymphocyte. The effect of irradiation on isolated populations of macrophages and T lymphocytes was also examined. The enhanced ability of irradiated adherent cells to support tumor colony growth appeared to have been due to treatment of T lymphocytes alone. The results indicate that both adherent macrophages and lymphocytes may influence the growth of clonogenic human tumour cells.

An apparent lack of HLA restriction in the stimulation of granulocyte-macrophage colony formation from normal human null cells by helper T lymphocytes

Haemopoietic progenitor cells capable of producing granulocyte-macrophage (GM) colonies have been demonstrated in the 'null' lymphocyte population of normal peripheral blood. The helper and suppressor roles of different T cell subpopulations have been implicated in the regulation of granulopoiesis in disease as well as in normal individuals. However, it is not certain whether such interactions between T cells and progenitor cells are HLA-restricted. We undertook further investigation of the effect of T cell subpopulations (TG and TnonG) on GM colony formation in vitro. In particular, we studied the possibility of HLA restriction in this process. Our results demonstrate that the enhancement of GM colony growth by T lymphocytes is not restricted by HLA compatibility between T cells and null cells, that such stimulation is radio-sensitive and that it is provided by the TnonG cell subpopulation.

Further evidence for T cell abnormalities in chronic lymphocytic leukaemia of the B cell type

Functional properties were studied in the purified T cell fraction of patients with chronic lymphocytic leukaemia of the B cell type (B-CLL). This analysis included the evaluation of T suppressor activity when investigated patients' T cells were co-cultured together with allogenic normal B and OKT4 enriched T cells in the presence of pokeweed mitogen (PWM). The Ig secreting cells (ISC) were assessed in a reverse haemolytic plaque assay (RHPA). Antibody-dependent cytotoxicity (ADCC) and natural killer activity (NK) were determined in a 51Cr release assay. Furthermore, purified T cells reactive with the monoclonal antibody HNK1, known to recognize most effector cells in ADCC and NK, were enumerated using an indirect immunofluorescence. Our results revealed increased T suppressor cell activity and markedly deficient NK activity in peripheral blood lymphocytes (PBL), T cell and T gamma cell fractions from B-CLL patients, whereas ADCC potential was only increased in T cells and T gamma cells. Accordingly, T cells were recognized by HNK1 in greater numbers in B-CLL patients than in healthy subjects. Our data suggest that there may be a link between our findings and the hypogammaglobulinaemia as well as the increased incidence of second neoplasias reported in CLL.

Deficient spontaneous cell-mediated cytotoxicity and lectin-induced cellular cytotoxicity by peripheral blood mononuclear cells from Thai adults naturally infected with malaria

To assess general cytotoxic effector cell capabilities by peripheral blood mononuclear cells from patients with active malaria infections, we examined antibody-dependent cellular cytotoxicity, spontaneous cell-mediated cytotoxicity, and lectin-induced cellular cytotoxicity by using human and chicken erythrocyte, Chang cell line, and K562 cell line targets. By using human erythrocyte and Change cell line targets, we found that Thai adults naturally infected with malaria had significantly impaired lectin-induced cellular cytotoxicity. In addition, spontaneous cell-mediated cytotoxicity was deficient with K562 but not with Chang cell line targets. Finally, no change in antibody-dependent cellular cytotoxicity was observed when chicken erythrocyte or Chang cell line targets were used. These observations, coupled with our previous observations of a physical loss of peripheral blood T cells, the presence of lymphocytotoxic serum antibodies, and defective T suppressor cell generation in patients with malaria, indicate that major alterations in the cellular immune system occur in patients with active malaria infections.

Characterization of effector cells mediating IgG and IgM antibody-dependent cellular cytotoxicity

Spleen effector cells for IgG- and IgM-induced antibody-dependent cellular cytotoxicity (ADCC) were characterized with respect to density and cell surface markers by using sheep erythrocytes (SRBC) coated with hybridoma-derived monoclonal anti-SRBC IgG or anti-SRBC IgM antibodies as targets. While basically the same effector cells are cytolytic for IgG and IgM antibody-coated SRBC, they differ with respect to their relative killing capacity for IgG- versus IgM-coated target cells. On the basis of physical and biochemical properties three populations with cytolytic capacity could be separated: (I) A light fraction of large cells had high cytolytic potential for both IgG- and IgM-coated SRBC. The cells were negative for the Fc receptor for IgG (Fc gamma-R-) and the C3-receptor (C3-R-), they carried the receptor for Helix pomatia A agglutinin (HP-A+), and reactivity was strongly reduced after treatment with anti-Thy-1 and complement (C). (II) High activity was also observed with a medium-dense fraction, preferably lysing IgG antibody-coated cells. The cells were Fc gamma-R+, partly C3-R+, mostly HP-A-, and only a minor portion of the cells were Thy-1+. (III) A dense fraction, displaying on a per cell basis low cytolytic potential, was more active in IgM than IgG ADCC. The cells were Fc gamma-R+, HP-A+ and Thy-1+. All three effector cell populations were non-adherent, non-phagocytic, and surface immunoglobulin-negative (s-Ig-).

Density distribution profiles of T cells: TM, TG and TA cells and response patterns in autologous versus allogeneic MLRs

Discontinuous Percoll gradients have been used to obtain selected human peripheral blood T lymphocytes without having to resort to interactions with immune complexes in the fractionation of Tm, Tg and Ta cells. Here, we could show that Ta cells represent a heterogeneous population with no distinct density profile, in contrast to light (Tg) and heavy (Tm) cells. Enriched, heavy Tm cells could be shown to be excellent responders in allogeneic MLR while failing to react in autologous MLR. In contrast, T cells of light density preferentially respond in autologous compared with allogeneic MLR.

Increase of T lymphocytes bearing immunoglobulin G receptors during circulation in human renal cell carcinoma

We studied the membrane markers and functions of lymphocytes from venous and arterial blood in kidneys from patients with renal cell carcinoma. The proportion of T lymphocytes that bore the receptors for the Fc portion of immunoglobulin G increased significantly in venous blood compared to arterial blood in kidneys with tumors. The assay of antibody-dependent cellular cytotoxicity demonstrated that lysis of target chicken erythrocytes was significantly less when caused by lymphocytes from the arterial blood (38 plus or minus 18 per cent, standard error) than those from the venous blood (54 plus or minus 21 per cent) in kidneys with tumors. There was no significant difference in the spontaneous lymphocyte-mediated cytotoxicity assay between the venous and arterial blood. Increment of the antibody-dependent cellular cytotoxicity activity seemed to correlate with the increased proportion and absolute number of T lymphocytes bearing immunoglobulin G.

Natural killer cell activity in untreated systemic lupus erythematosus

With strictly selected controls natural killer cell activity was evaluated in 10 untreated patients with systemic lupus erythematosus. Natural killer levels of the patients were significantly lower than those of the age- and sex-matched normal controls. Natural killer levels, however, did not correlate with disease activity.

Analysis of natural killer activity and antibody-dependent cellular cytotoxicity in healthy volunteers and in patients with primary lung cancer and metastatic pulmonary tumors

To clarify the contribution of ADCC and NK activities to host immune response against cancer, the characteristics of cells mediating these activities were examined in the peripheral blood lymphocytes of normal volunteers, and the changes of these activities were also evaluated in patients with lung cancer and metastatic pulmonary tumors before and after chemotherapy. OAT cells derived from small cell carcinoma of the lung and K-562 cells derived from erythroleukemia were used as target cells of ADCC and/or NK assay. ADCC and NK activities were not changed according to age, sex, and blood type. Mild and marked personal difference were observed in ADCC and NK activity, respectively. These activities were also influenced by environment. ADCC and NK activities of normal adult volunteers were diversely correlated at the coefficient of gamma-0.426. NK activities were high against K-562 and CCRF-CEM cells, and low against BALL and OAT cells. NK activity against K-562 cells was strongly inhibited by K-562 or CCRF-CEM cells with high NK sensitivity, on the other hand, it was slightly inhibited by OAT and BALL cells with low NK sensitivity. NK activity against OAT cells was strongly inhibited by OAT, K-562 and CCRF-CEM cells, but not inhibited by BALL cells. The effector cells mediating NK activity were identified as non-adherent, E-receptor-positive, Fc-receptor-positive small lymphocytes. NK activity was not decreased before chemotherapy in patients with stage III primary lung cancer and metastatic pulmonary tumors. It was decreased only in patients of bad performance status, and it was significantly decreased in all patients after chemotherapy. ADCC also exhibited the tendency to decrease after chemotherapy in tumor-bearing patients. The recovery of NK-activity after chemotherapy well correlated with the effect of chemotherapy.

T-lymphocyte subpopulations in chronic lymphocytic leukemia: a quantitative and functional study

In the peripheral blood of patients with chronic B-cell lymphocytic leukemia (B-CLL) absolute numbers of E-rosetting lymphocytes were increased. The proportions of TG and TM cell subsets were analyzed, as were their effects on the pokeweed mitogen (PWM)-dependent differentiation of normal allogenic B cells or of autologous leukemic cells. The TG lymphocyte subset was further studied for its cytotoxic activity in antibody-dependent cellular cytotoxicity (ADCC). A marked increase both in percentages and in absolute numbers of TG cells was found. TM lymphocytes percentages were normal, but because of the T lymphocytosis occurring in all patients, the absolute numbers of TM were increased. TM and TG subsets showed helper and suppressor activity, respectively, in PWM-induced B-cell differentiation. TG cells displayed effector cell activity in ADCC. The results provide further evidence that T lymphocytes from patients with B-CLL are functionally normal. However, a noticeable increase of the T-cell subset having suppressor and cytotoxic activity in ADCC was observed. This may be the consequence of a normal immune reaction to the leukemic population.

Human interleukin 2: production by both TG cells and other T cells

We have investigated the production of interleukin 2 (IL-2) by human T cells after their stimulation by phytohaemagglutinin (PHA). T cells isolated by rosetting with sheep erythrocytes produced high levels of IL-2. Further separation of rosette-forming cells, according to the expression of Fc receptors for IgG, showed that TG and non-TG cells are equally able to produce IL-2. The release of IL-2 by TG cells did not require DNA synthesis or functional Rc gamma receptors, since positively selected TH cells produced IL-2, even though they lacked lymphoproliferative responses to PHA and antibody-dependent cell-mediated cytotoxicity.

Multivariate analysis of T-cell functional defects and circulating serum factors in Hodgkin's disease

A comprehensive immunologic and serologic analysis was performed on 31 untreated patients with Hodgkin's disease. Immune evaluations stressed T-cell functional activity and included traditional parameters (PHA responsiveness and delayed hypersensitivity skin reactivity), as well as newer functional assays (T-cell colony formation, chemotaxis, spontaneous and antibody-dependent cytotoxicity, and concanavalin A-induced suppressor cell activity (CISA). Serum factors included ferritin, prostaglandins, zinc, copper, immune complexes, and thymic hormone activity. Every patient exhibited at least one T-cell or serum abnormality. The greatest percentage of patients exhibited T-cell defects in chemotaxis (85%), colony formation (81%). and PHA reactivity (64%). Immune defects were more common with advanced disease but were not related to absolute T-cell or monocyte count, skin test anergy, or abnormalities of T mu/T gamma cell proportions. Linear relationships were identified among abnormalities in the three assays employing mononuclear cells (PHA, colony formation, CISA) which may have reflected the inhibitory influence of monocytes present in the mononuclear cell preparations. Low serum zinc correlated with marked impairment of T-cell chemotaxis. Elevated prostaglandins were associated with high PHA reactivity and with depressed colony formation. Our results indicate that many complex factors, including intrinsic T-cell defects, contribute to the impaired immunity associated with Hodgkin's disease.

Suppressor cell activity in melanoma patients. II. Concanavalin A-induced suppressor cells in relation to tumor growth and suppressor T-cell subsets

The relative proportions of T, B and T gamma suppressor cells were determined sequentially in peripheral blood of melanoma patients before and after surgery. Concanavalin A (Con A)-induced suppression against lymphocyte mitogenesis of melanoma patients and age matched controls was measured concurrently. The mean percentage of T gamma cells was significantly higher (p less than 0.001) in melanoma patients before surgery (21.8 +/- 5.4) compared to a group of age-matched controls (14.9 +/- 5.4). There was a tendency for the proportion of T gamma cells in patients to decrease after surgery, although the relative levels of T gamma were still significantly elevated (p less than 0.05) 6-8 weeks after surgery when compared to normal controls. The mean percentage of T and B cells in melanoma patients before and after surgery was comparable to that observed in normal controls. The degree of Con-A-induced suppression in patients increased significantly after surgery particularly at 6-8 weeks (p less than 0.02). No difference in con-A-induced suppressor cell activity was observed between melanoma patients and controls before or after surgery. An inverse relationship was found between the amount of Con-A-induced suppression and percentage of T gamma cells in melanoma patients before surgery. Similar associations were not apparent in patients after surgery or in normal control populations. The inverse correlation of Con-A-induced suppression with T gamma cell numbers suggests that the former may measure potential suppressor cell activity whereas the T gamma cells may indicate active suppressor cells. The significance of these findings for the monitoring of suppressor cell activity in vivo and their role in suppression of immune responses in melanoma patients is discussed.

Distribution of IgG and IgM receptors on human peripheral natural killer cells measured on the level of the single effector cell

Using an agarose single-cell cytotoxicity assay simultaneously with the antibody-coated ox erythrocyte assay for detecting Fc receptor (FcR)-positive cells, the number of natural killer (NK) cells in fresh human peripheral blood which bear FcR for IgG or IgM have been determined. Of the target binding blood which bear FcR for IgG or IgM have been determined. Of the target binding cells (TBC) which form conjugates with NK-sensitive target cell lines Molt 4, 1301 and Hd-Mar, 55% had FcR for IgG and 24% had FcR for IgM. In the active NK cell population, which amounts to about 6% in nylon wool column-passed peripheral lymphocytes, cells with FcR for IgG account for 60% and cells with FcR for IgM for 17% of the total killing. Even though there is an increase in the number of FcR-IgM-positive cells from fresh peripheral blood after overnight incubation at 37 degrees C, no increase was found in FcR-IgM-positive NK cells. The reasons why FcR for IgM have not been described earlier on human NK cells are discussed, as well as the functional implications of these and their probable expression on other types of cytotoxic effector cells.

Human T-lymphocyte subset production of immune (gamma) interferon

Human T micron, T gamma, and T PHI lymphocyte subpopulations have the capacity to respond to phytohemagglutinin (PHA) in vitro with proliferation and the production of a pH 2 and heat-labile gamma interferon. This occurs both when the subsets are isolated by direct rosetting techniques or by negative selection. Macrophages enhance the production of the gamma interferon by each lymphocyte subset and do not themselves produce gamma interferon in response to products of PHA-activated lymphocyte subsets. Thus our studies indicate that subpopulations of T lymphocytes known to differ with regard to morphology, surface receptors, RNA content, response to corticosteroids and X-irradiation, and other functional capabilities do not differ with regard to their capacity to produce gamma interferon.

Spontaneous and antibody-dependent cellular cytotoxicity by lymphocyte subpopulations in peripheral blood and spleen from adult untreated patients with Hodgkin's disease

Subpopulations of lymphocytes in the peripheral blood and spleen from adult untreated patients with Hodgkin's disease were studied for spontaneous (SCMC) and antibody-dependent cellular cytotoxicities (ADCC). Peripheral blood from seven of 24 patients demonstrated abnormally low T cell-mediated SCMC when compared to age- and sex-matched healthy controls. Only two of these patients also demonstrated low T cell ADCC and non-T cell-mediated SCMC and ADCC. T cell ADCC in the peripheral blood of patients with involved spleen was significantly higher (P less than 0.05) when compared to those in whom spleen was not involved. When SCMC and ADCC were compared between peripheral blood and splenic lymphocytes with regard to involvement of spleen by Hodgkin's disease, non-T cell SCMC in the involved spleen was significantly lower (P less than 0.05) than their peripheral blood non-T cell SCMC. SCMC and ADCC tended to be higher in patients with stages III and IV of Hodgkin's disease when compared to those with stages I and II. However, the differences were not statistically significant. No direct relationship was observed between T and SCMC or ADCC and the proportion of T cells with IgG Fc receptors (T gamma). The significance of these observations is discussed.

Natural killing and antibody-dependent cytotoxicity by lymphocyte subpopulations in young and aging humans

Natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) were examined in the peripheral blood lymphocytes and their major subpopulations from young and aging subjects. Monocyte-depleted unseparated lymphocyte-mediated NK activity (against cells of K-562) and ADCC (against IgG-coated chicken erythrocytes) were comparable between young and aging subjects. Similarly no significant difference was observed in T cell-mediated NK and ADCC and non-T cell-mediated ADCC between young and aging subjects. Non-T cell-mediated NK activity, however, was significantly (P less than 0.025) greater in aging humans compared to that of young subjects. When the data were analyzed according to gender, T cell-mediated ADCC in aging males was significantly (P less than 0.05) greater than that found in young males. No significant difference was observed between T-cell ADCC among young and aging females. T cell-mediated NK was comparable among young and aging males and young and aging females. Non-T cell-mediated NK as well as ADCC activity was significantly (P[ less than 0.025 or less than 0.05) greater in aging males compared to that in young males. Both non-T-cell NK and ADCC were comparable among young and aging females. This study demonstrates an increase in NK and ADCC activity in aging subjects that is primarily shared by males and not by females. No correlation was observed between the proportion of T gamma cells and T-cell NK or ADCC activity.

Subpopulations of human T lymphocytes. XVIII. T lymphocytes with receptors for IgE (T epsilon) in patients with primary immunodeficiency and hyperimmunoglobulinaemia E states

Four of 18 patients with common variable immunodeficiency and one of eight patients with selective IgA deficiency had increased proportions of T epsilon cells. Three patients with common variable immunodeficiency and two with selective IgA deficiency had increased numbers of T epsilon cells. Three patients with common variable immunodeficiency had decreased numbers of T epsilon cells. Five of six patients with hyperimmunoglobulinaemia E had high proportions of T epsilon cells; this increase was not related to the elevated IgE levels.

Natural and antibody-dependent cellular cytotoxicity in tumour-adherent T lymphocytes: expression of Fc receptors and of a human T-subgroup-specific antigen

Adherence of human lymphocytes to allogeneic tumour cell monolayers was found to depend on the presence of monocytes. Adherent lymphocytes could be separated from tumour cells by treatment with lidocaine followed by nylon wool passage. Tumour-adherent cells (70% E-RFC, 45% Fc gamma-R, 23% Fc mu-R, 5% monocytes) exhibited enriched natural killer (NK) activity not only against the tumour cell line used for isolation but also against seven other targets. When T cells were isolated subsequently as E-rosettes by density gradient centrifugation through Percoll, the enrichment in cytotoxicity was even more pronounced. Tumour-adherent T cells were severalfold enriched in both NK and antibody-dependent cell-mediated cytotoxicity (ADCC) activity. However, this enrichment was not paralleled by a concomitant increase in the number of T gamma cells (tumour-adherent T cells: 17% T gamma, 40% T mu ; tumour-nonadherent T cells: 12% T gamma, 60% T mu). Marked differences could be observed by staining with a monoclonal antibody that was raised against human leukaemic T gamma cells of high NK and ADCC activity. This antibody (T 8-11) stained 60% of tumour-adherent T cells, 20% of nonadherent T cells and 29% of T-cell controls. These results indicate that the spontaneous cytotoxic activity of human T cells resides within a small population, most of which are characterized by a specific surface antigen but not by conventional Fc gamma receptors.

Human colonic intraepithelial and lamina proprial lymphocytes: cytotoxicity in vitro and the potential effects of the isolation method on their functional properties

Colonic mucosal lymphoid cells, selectively enriched for intraepithelial (IEL) or lamina proprial lymphocytes (LPL), were isolated by sequential EDTA-collagenase treatment of resected human colons. Cytotoxic activities of colonic and peripheral blood lymphoid cells (PBL) were tested in three different assays, using chicken erythrocytes (CRBC) and Chang cells as targets. Antibody-dependent cell-mediated cytotoxicity (ADCC) and PHA-induced cytotoxicity (MICC) for both targets were shown by all the isolates of PBL, as was spontaneous cell-mediated cytotoxicity (SCMC) for Chang cells. However, no SCMC or ADCC for Chang cells was found with LPL, and IEL showed minimal or no activity in either assay. PBL, LPL and IEL demonstrated MICC for Chang cells but, contrasting with PBL and LPL, IEL showed no MCC for CRBC. No significant differences were found between the cytotoxic capabilities of colonic lymphoid cells from patients with inflammatory bowel disease and those from patients with other colonic diseases. Importantly, control studies with PBL showed that SCMC for Chang cells and ADCC for CRBC and Chang cells were reduced by collagenase treatment used in the isolation, of LPL. Also, SCMC for Chang cells was reduced by the treatment of PBL with EDTA. In contrast, neither EDTA nor collagenase reduced MICC for CRBC or Chang cells. Both forms of treatment induced variable degrees of cell losses in the PBL. By analogy, it can be implied that the isolation of intestinal mononuclear cells using EDTA and collagenase may influence some of their cytotoxic activities in vitro. This raises an important caveat in the interpretation of such studies.

[The significance of Fc-IgG and Fc-IgM receptors on human T-lymphocytes (author's transl)]

About 15-20% of human circulating T-cells express Fc-IgG receptors (TG cells), and about 70-80% have Fc-IgM receptors (TM cells). TM cell enriched fractions are functionally heterogenous cell populations. TM cells are able to mature into specific cytotoxic T-cells after mixed lymphocyte reaction; TM cell fractions also comprise the helper T-cells for pokeweed mitogen (PWM) induced B cell differentiation; and some TM cells can be induced to act suppressively on PWM induced B-cell differentiation and maturation. TG cells represent activated, relatively radiation resistant suppressor T-cells, and these cells are also active in natural cytotoxicity (NC), antibody dependent cellular cytotoxicity (ADCC) and mitogen induced cellular cytotoxicity (MICC). IgG-immune-complex interaction with the Fc-IgG receptor on TG cells modulates Fc-receptor expression as it leads to loss of Fc-IgG receptors and expression of Fc-IgM receptors on the original TG cells after culture. This modulation of surface markers is accompanied by functional changes since ADCC and suppressor cell activity is reduced following immunecomplex interaction. Fc-IgG and Fc-IgM receptor expression on human T cells seems therefore to characterize distinct functional stages of T cells. IgG immunecomplex interaction in vitro seems to be a potent tool to change the different functional stages.

Age dependent changes in some human lymphocyte sub-populations. Changes in natural killer cell activity

Age-dependent changes in natural killer (NK) cell activity was studied using the K 562 cell line as target in a 20 h 51Cr release assay. Fifteen healthy, high-aged person (76-93 yrs) were compared with 15 sex-matched young adults (20-39 yrs). Peripheral blood lymphocytes from one aged and one young person were assayed simultaneously; and in 12 of the pairs the elderly person expressed the highest cytotoxicity (p = 0.008). When the NK cell activity was expressed as lytic units per ml of blood, however, no difference could be found between the two age groups. T enriched cells showed lower NK activity than peripheral blood lymphocytes, but the age-dependent changes were the same. The NK cell activity was positively correlated to the proportion of lymphocytes bearing receptors for the Fc part of IgG. The numbers of both Fc receptor positive peripheral lymphocytes and Fc receptor positive T cells ( t gamma cells) were significantly elevated in the elderly.

Effect of herpes simplex virus infection on murine antibody-dependent cellular cytotoxicity and natural killer cytotoxicity

Mice intraperitoneally inoculated with a sublethal dose of herpes simplex virus (HSV) produced immunoglobulin G antibody-dependent cellular cytotoxicity (ADCC) and radioimmunoassay (RIA) antibody as early as 3 days after infection. There was a rise in natural killer cytotoxicity (NKC) to infected and uninfected target cells 1 to 3 days postinfection mediated by nonadherent peritoneal cells (PC) in mice inoculated with HSV, but also with other substances commonly used in tissue culture media. HSV caused the highest and most consistent increase in NKC. PC-NKC, as ADCC, was inhibited by latex and silica, both macrophage inhibitors. PC-ADCC markedly declined 3 to 8 days after HSV inoculation. This was not due to a soluble or cellular suppressor factor, was not reversed by incubation or trypsin treatment of PC, was not associated with a change in PC Fc receptors, adherence, or acridine orange staining characteristics, and could not be induced by inactivated HSV. In vitro inoculation of PC with HSV similarly caused a reduction in the ability of PC to mediate ADCC to HSV-infected target cells. These data demonstrate the complex stimulatory and inhibitory interactions between virus and host defense mechanisms.

Surface markers of lymphocytes infiltrating seminoma tissue

Infiltrating lymphocytes were separated from human seminoma tissue obtained surgically. The relative distributions of B and T lymphocytes, and a subset of T lymphocytes with IgG-Fc receptors were measured by the rosette-forming method in peripheral blood and in seminoma tissue from 7 patients with pure seminoma of the testis. The proportions of T and TG cells were increased in seminoma tissue compared to those of peripheral blood from the same patients, whereas the proportion of B cells did not change. This result might correlate with the favorable prognosis of seminoma usually accompanied with lymphocytic infiltration.

Deficient natural killer cell activity in x-linked lymphoproliferative syndrome

The activity of natural killer cells was found to be deficient in 10 of 12 males with X-linked lymphoproliferative syndrome, a life-threatening proliferation of lymphocytes after infection by Epstein-Barr virus. The activity levels of natural killer cells from affected males were increased after treatment with interferon in vitro, but normal levels of killing were not obtained. Deficient activity of killer cells in individuals with immunodeficiency and chronic infection by Epstein-Barr virus may contribute to the development of lymphoproliferative disorders.

Subpopulations of human T lymphocytes. XVI. Maldistribution of T cell subsets associated with abnormal locomotion of T cells in untreated adult patients with Hodgkin's disease

Peripheral blood and splenic T cells from adult patients with Hodgkin's disease were examined for the proportions and numbers of T cells with receptors for IgM (Tμ) or IgG (Tγ) and their locomotor responses to chemotactic stimuli of casein and endotoxin-activated serum (EAS). Thirty per cent of patients had absolute lymphopenia in the peripheral blood. The proportion of Tμ cells was comparable but the proportion of Tγ cells was significantly increased (P<0·001) resulting in an abnormally low ratio of Tμ/Tγ cells when compared to those for age- and sex-matched controls. In the spleens, the proportions of T cells and Tμ cells were significantly increased (P<0·001) and Tγ cells significantly decreased (P<0·001) resulting in an abnormally high ratio of Tμ/Tγ cells when compared with normal spleens. In the peripheral blood both Tμ and Tγ cells were increased and T cells lacking either receptor (Tφ) were significantly decreased in patients in whom spleens were involved by the tumour when compared to those in whom spleens were not involved by the tumour. Peripheral blood T cells from patients with Hodgkin's disease responded poorly to the chemotactic stimuli when compared to T cells from normal controls or T cells from the spleens of the same patients. Tμ cell proportions in patients with combined stages III and IV were significantly lower (P<0·025) than those in the peripheral blood of patients in combined stages I and II. No correlation was observed between the above parameters and histopathological types of Hodgkin's disease. This study demonstrates an abnormal distribution of T cell subsets and abnormality of locomotion of T cells between peripheral blood and spleens in patients with Hodgkin's disease. This might explain the cellular basis of at least certain immunodeficiencies so commonly associated with Hodgkin's disease.

Effector cell potential of two human T-cell subpopulations with different affinities to sheep erythrocytes

Two human T lymphocyte subpopulations were purified on the basis of their different affinities to sheep erythrocytes and compared with unseparated and non-T lymphocytes as effectors in cell-mediated lympholysis (CML) after mixed lymphocyte culture (MCL), in antibody-dependent cellular cytotoxicity (ADCC) against the mouse mastocytoma line P 815, and in spontaneous cell-mediated cytotoxicity (SCMC) against the human myeloid leukaemia line K 562 and the Burkitt lymphoma line RAJI. The low-avidity T cells (T1) had developed into more potent effectors than the high-avidity (Te) when assessed in CML. In ADCC and SCMC both subsets exhibited low but consistent lysis with no demonstrable differences. Addition of human leucocyte interferon to the ADCC and SCMC cultures resulted in enhanced SCMC, most notable and to an equal extent with the T cell subsets. In contrast, ADCC of unseparated cells, non-T cells, and the two T subsets was found to be unchanged after interferon addition. These data are discussed in relation to findings with human T-cell subpopulations purified by other methods.

Subpopulations of human T lymphocytes. XV. T lymphocytes with receptors for IgA (T alpha), a distinct subpopulation of T lymphocytes. Studies in patients with primary immunodeficiency disorders

A receptor for IgA was observed on a subset of T cells (T alpha) that is distinct from other T lymphocyte subsets, T mu or T gamma cells. IgA receptor on T alpha cells is blocked by IgA from human serum through its cytophilic attachment. Neither T mu nor T gamma cells, following an in vitro interaction with insoluble immune complexes during the process of purification and further incubation at 37 degrees C, changed their phenotypes to T alpha cells. However, some T gamma cells demonstrated transition to T mu cells. The numbers and proportion of T alpha cells in patients with selective IgA deficiency were either normal, increased or decreased. The significance of T alpha cell analysis in thirty-one patients with primary immunodeficiency disorders including those with selective IgA deficiency is discussed.

Separation of spontaneous-killing effector populations by target preference

Three populations active in human spontaneous cytotoxicity have been identified. Two of these are E-rosette positive, and differ in their adherence to nylon wool. The third is E-rosette negative. The E-rosette positive fraction which does not adhere to nylon consistently does not lyse a breast-cancer-derived target, MDA-157. When tested simultaneously on 4 other tumour target cells lines--Raji, Chang, K562 and Molt 4--however, all three populations are cytolytic. The MDA-157 target is consistently lysed by a nylon-adherent T-cell fraction, irrespective of whether the E rosettes are formed under optimal or the limiting conditions giving only "high-affinity" T cells. The observation that a given effector fraction can lyse one target but not another, whereas other fractions are cytolytic on both, implies that different targets may differentiate effector populations differing in their lytic mechanism.

Isolation and partial chemical characterization of the IgG Fc receptor of human T lymphocytes and production of an antiserum

We report here the isolation of an IgG Fc receptor from normal human T lymphocytes. The purified receptor has a nonreduced and a reduced component of molecular weights 120,000 and 60,000, respectively, and it was functionally active in the in vitro blocking of rosette formation between T lymphocytes and IgG-coated ox erythrocytes. An antiserum raised to the Fc receptor and an isolated F(ab')2 fragment of this antiserum, also blocked rosette formation between T cells and IgG-coated ox erythrocytes. In contrast, rosette formation between T lymphocytes and IgM-coated ox or sheep erythrocytes was not blocked by the F(ab')2 fragment, demonstrating the marked specificity of this antiserum for the IgG Fc receptor. In addition, this antiserum did not block the Fc receptors of non-T cells, indicating that the T-cell IgG Fc receptor has unique antigenic determinants not shared with B cells.

Neuraminidase treatment of human T lymphocytes: effect on Fc receptor phenotype and function

Purified peripheral blood T cells or T mu cells from normal healthy donors were treated in vitro with neuraminidase and examined for the expression of IgM Fc and IgG Fc receptors. Increasing concentrations of neuraminidase selectively removed IgM Fc receptors, whereas the number of T cells expressing IgG Fc receptors was significantly increased. Following neuraminidase treatment, IgM Fc receptors could be regenerated by reincubation of T cells at 37 degrees C. The regeneration of IgM Fc receptors could be blocked by treatment with cycloheximide. Neuraminidase treatment of purified T mu cells resulted in the expression of IgG Fc receptors on a subpopulation of T mu lymphocytes. A small percentage of the neuraminidase-treated T cells expressed receptors for both IgG and IgM. Treatment of T cells with neuraminidase did not effect T cell-mediated spontaneous cytotoxicity (SLMC) or antibody-dependent cellular cytotoxicity (ADCC). Our results indicate that T cell Fc receptor phenotypes can be modulated in vitro without significantly altering their functional capacity.

Receptors for immunoglobulin isotype on T and B lymphocytes from untreated patients with chronic lymphocytic leukaemia

Peripheral blood lymphocytes from eighteen untreated patients with chronic lymphocytic leukaemia (CLL) were analysed for the proportions of T and B lymphocytes with receptors for IgM, IgG or IgA. T lymphocytes with Fc receptors for IgM (T mu cells) or IgA (T alpha) cells were found in proportions comparable to those found in the controls. However, the proportion of T lymphocytes with receptors for IgG (T gamma cells) was significantly increased (P < 0.001) resulting in an abnormally low ratio of T mu/T gamma (P < 0.001), when compared with normal controls. The proportion of B cells bearing Fc receptors for IgM, IgG or IgA was determined simultaneously. No significant differences were found between the normal controls and the patients with CLL. In vitro treatment of the purified T and B lymphocyte preparations with human leucocyte interferon, did not alter the proportions of the lymphocytes expressing Fc receptors for various immunoglobulin isotypes. The significance of these findings is discussed.

Effects of corticosteroids on natural killer cell activity in systemic lupus erythematosus

The effects of corticosteroids on the natural killer (NK) cell activity of human peripheral blood lymphocytes were evaluated. When six untreated female patients with systemic lupus erythematosus were compared with fifteen age-matched, corticosteroid-treated female patients, NK activity in the latter was significantly suppressed. Although the administration of high doses seemed to suppress cytotoxicity to a greater extent, there was no close correlation between the daily doses of steroids and NK activity. When cytotoxicity levels were followed before and during corticosteroid therapy in the same patient, NK activity decreased markedly during treatment, particularly in patients on high-dose corticosteroids.

Dexamethasone enhancement of the induction of cells bearing receptors for IgM in human peripheral blood lymphocyte culture

Using a low density culture technique which allows normal human peripheral blood T cells to proliferate actively in vitro when stimulated by mitogens, it is shown that dexamethasone enhances the spontaneous induction of cells bearing receptors for the Fc of IgM. Dexamethasone has no effect on the induction of cells bearing receptors for the Fc of IgG.

Antibody-dependent cellular cytotoxicity mediated by subpopulations of human T lymphocytes: killing of human erythrocytes and autologous lymphoid cells

The present study characterized the cytotoxic capabilities of human T lymphocyte subpopulations against human red blood cells (HRBC) and autologous lymphoid cells in an antibody-dependent cellular cytotoxicity (ADCC) assay. T cells bearing Fc receptors for immunoglobulin IgG (TG) were capable of lysis of antibody-coated HRBC and autologous lymphoid cells while T cells with surface Fc receptors for IgM (TM) displayed no ADCC activity TG-cell mediated ADCC could be inhibited by blockage of surface Fc receptors following treatment with aggregated Ig. Null cells and low-affinity E-rosette forming cells were also capable of similar ADCC activity against these targets.

T and B lymphocyte subpopulations and leukocyte terminal deoxynucleotidyl-transferase in energy-protein undernutrition

Children with energy-protein undernutrition showed a reduction in the number of circulating T lymphocytes identified on the basis of their ability to form rosettes with sheep red blood cells. T cells with a receptor for IgM (Tmu) were decreased whereas T cells with a receptor for IgG (T gamma) were increased. Surface immunoglobulin bearing B cells were comparable in well nourished and malnourished subjects but the proportion of B alpha was increased in the latter. "Null" cells without the conventional markers of T or B cells were proportionately increased. Leukocyte terminal deoxynucleotidyl-transferase activity was elevated in the majority of undernourished children and correlated with the proportion of "null" cells. The significance of these observations is discussed and it is suggested that "null" cells represent immature undifferentiated T lymphocytes.