Prostaglandin-producing suppressor cells in Hodgkin's disease

Effect of nonsteroidal antiinflammatory drugs on immune function

Nonsteroidal antiinflammatory drugs (NSAID) have been thought to act by inhibiting the production of prostaglandins. Until recently, prostaglandins have been considered to be mainly proinflammatory compounds, responsible for pain, increased blood flow, and edema. It has more lately been realized that prostaglandins, particularly PGE2, have important immunoregulatory properties. Thus NSAID, by inhibiting PGE2 production, modulate immune responses in vitro and in vivo. One or more of these immunomodulating effects of NSAID may play a role in their efficacy as arthritis medications. The purpose of this paper is to review the immunologic role of PGE2 and the immunologic effects of NSAID.

Potentiation of the canine lymphocyte blastogenic response by indomethacin

Cultivation of normal canine peripheral blood lymphocytes in the presence of indomethacin, a potent prostaglandin synthetase inhibitor, produced a consistent potentiation of their in vitro response to mitogenic stimulation as compared to cultures without indomethacin. The enhancing effect of indomethacin increased with decreasing concentrations of mitogens. Indomethacin had to be added to the cultures during the first four hours for the potentiating effect to be observed. These data suggest that prostaglandins may play an important role in the regulation of the dog's immune response.

Prostanoid synthesis by cultured intestinal epithelial and mononuclear cells in inflammatory bowel disease

Intestinal epithelial and mononuclear cells were isolated from normal colonic mucosa and from intestinal mucosa of inflammatory bowel disease patients. Prostanoid synthesis by primary cultures of intestinal mononuclear cells were four to six fold higher than its synthesis by primary cultures of epithelial cells. Prostaglandin E2, prostacyclin and thromboxane A2 synthesis by cultured mononuclear cells isolated from inflamed ileal mucosa of four Crohn's disease patients: 5.6 +/- 1.2; 3.2 +/- 1.9 and 2.4 +/- 1.4 (mean +/- SE) ng/1 X 10(6) cells were significantly higher than their respective synthesis by cultured mononuclear cells isolated from uninflamed ileal mucosa isolated from the same patients: 0.8 +/- 0.1; 0.3 +/- 0.1 and 0.2 +/- 0.03 ng/1 X 10(6) cells or from normal colonic mucosa: 1.5 +/- 0.3; 0.3 +/- 0.1 and 0.5 +/- 0.1 (N = 12) ng/1 X 10(6) cells. Prostanoid synthesis by primary cultures of intestinal mononuclear cells isolated from colonic mucosa of five ulcerative colitis patients was enhanced but not significantly different from its synthesis by cells isolated from normal subjects. These results suggest that the enhanced intestinal prostanoid synthesis in active Crohn's disease is derived from stimulated local mononuclear cells and may have an important role in the pathogenesis of the disease.

Inhibition of lymphocyte response by prostaglandin-producing suppressor cells in patients with melanoma

Peripheral blood mononuclear cells (PBMC) from 11 patients with metastatic melanoma (group II) had a significant decrease in blastogenesis to concanavalin A (Con A) (38.7 +/- 7.7 cpm X 10(3); mean +/- SE) compared to 21 patients who were disease free (70.6 +/- 6.7) or 16 healthy controls (83.6 +/- 10.3). If PBMC from patients were preincubated for 72 hr prior to exposure to mitogen, blastogenesis was restored to normal. In group II patients a similar improvement in reactivity of fresh PBMC occurred with indomethacin addition or following rigorous depletion of adherent monocytes. Supernatants from cells cultured with and without Con A in several group II patients contained very high levels of endogenous PGE2. Patients had a greater percentage of T lymphocytes bearing Fc receptors for ox erythrocytes (T gamma) than controls, which appeared to correlate with the increased sensitivity to suppression by exogenously added PGE2. These data suggest that the decreased blastogenesis in certain melanoma patients is due to an increase in PGE2 production by monocytes, along with an increase in lymphocyte sensitivity to its effects.

Effect of factors other than pathologic status on responsiveness of peripheral blood mononuclear cells from patients with chronic periodontitis

Studies were designed to assess factors other than pathologic status of the cell donor which affect the blastogenic responsiveness in vitro of peripheral blood mononuclear cells (PBMs) from normal donors and patients with periodontitis. Cultures were established and activated using phytohemagglutinin-P (PHA) or homogenates of Actinomyces viscosus (AVIS), a gram-positive plaque microorganism, and Fusobacterium nucleatum (FUSO), a gram-negative plaque microorganism. Activation was assessed by measuring the incorporation of labeled precursor into DNA. The effects of incubation time, vessel shape, cell concentration, prostaglandin E2 and indomethacin on blastogenic responsiveness were studied. Blastogenic responsiveness became maximal after 5 to 8 days' activation with the bacterial substances, and after 3 days' activation with PHA. Radioactivity incorporated by cultures in microtest wells with flat, round and conical bottoms was 5.9, 7.8 and 10.6 X 10(3) cpm, respectively. Cultures of cells from all of the patients and normal subjects were activated by PHA, AVIS and FUSO, and cell concentration was a major determinant of the magnitude of the blastogenic response. Responsiveness of cultures from all patients and control subjects activated with AVIS and FUSO was inhibited significantly by prostaglandin E-2 (PGE2) at a concentration of 10 microM. Inhibition was generally 50% or greater. Indomethacin, an inhibitor of prostaglandin production, at a concentration of 0.5 micrograms/ml significantly enhanced responsiveness of AVIS- and FUSO-activated cultures from control donors and patients, indicating that prostaglandins are produced endogenously, and that they affect cell responsiveness. The effect of PGE2 and indomethacin on PHA-activated cultures was more variable and, where present, of a lesser magnitude than that observed for cultures activated with bacterial homogenates. In most cultures the effects were not statistically significant. Our data show that in studies of lymphocyte activation, the incubation time, culture-vessel shape, cell concentration and presence of endogenous inhibitors need to be taken into account.

Suppressor substance produced by the K562 cell line in vitro

Supernatant fluids from three human cultured cell lines, K562, NALM-1, and Daudi, all isolated from patients with lymphoreticular malignancies, were tested for suppressive activity toward normal lymphocytes in vitro. It was found that the K562 line elaborated material which effectively suppressed the response of normal human blood lymphocytes to the T-cell mitogens phytohemagglutinin and concanaval in A as well as the mixed lymphocyte reaction. Little or no suppressive activity was evident when supernatants from Daudi or NALM-1 were used. In contrast, a recent report [29] indicates that K562 does not inhibit the induction of immunoglobulin synthesis of B lymphocytes by pokeweed mitogen. The findings are discussed in the context of the immunosuppression associated with cancer and the apparent selective inhibition of different lymphocyte functions by material elaborated by different neoplasms.

Abnormalities of in vitro immunoglobulin synthesis by peripheral blood lymphocytes from untreated patients with Hodgkin's disease

The immunoglobulin-synthesizing activities of peripheral blood mononuclear cells from 57 untreated patients with Hodgkin's disease and 47 normal subjects were compared. Cumulative amounts of IgM and IgG synthesized and secreted by unstimulated and pokeweed mitogen-stimulated cells over a 7-d period were determined in a solid-phase radioimmunoassay. Synthesis of IgM in unstimulated cultures and of both IgM and IgG in cultures stimulated with pokeweed mitogen was markedly reduced in patients with Hodgkin's disease, whereas the mean level of the spontaneous IgG synthesis was enhanced. The degree and frequency of in vitro abnormalities were not influenced by disease stage or histology. Depression of pokeweed mitogen-induced immunoglobulin synthesis did not correlate with excessive number of monocytes and it was unaffected by removal of phagocytic cells or addition to the cultures of monocytes from normal individuals. On the other hand, monocytes isolated from blood of patients with Hodgkin's disease were even more effective than normal monocytes in supporting pokeweed mitogen-induced immunoglobulin synthesis by normal phagocyte-depleted mononuclear cells. Synthesis of both IgM and IgG induced by pokeweed mitogen remained subnormal after addition to patient B cell cultures of autologous irradiated T cells or allogeneic normal T lymphocytes. T cells from patients with Hodgkin's disease appeared at least as effective as normal T cells in helping pokeweed mitogen-induced immunoglobulin production by normal B cells. However, when normal T cells were co-cultured with B cells from patients with Hodgkin's disease, spontaneous IgG synthesis declined, whereas the addition of patient T cells to normal B cells resulted in an increase of spontaneous IgG synthesis. In patients showing depression of pokeweed mitogen-induced immunoglobulin synthesis the lymphoproliferative response and immunoglobulin synthesis stimulated by Staphylococcus aureus bacteria of the Cowan first strain, a T cell independent B cell mitogen, were also markedly reduced. These studies demonstrate impairment of immunoglobulin synthesis by cultured lymphocytes from untreated patients with Hodgkin's disease after stimulation with polyclonal B cell activators and suggest that the in vitro abnormalities may be, at least in part, the result of a preexisting in vivo activation of lymphocytes in Hodgkin's disease patients.

Application of indomethacin as a potentiator of lymphocyte blastogenesis in Brucella abortus exposed cattle

Lymphocytes from Brucella abortus field strain infected, strain 19 vaccinated, non-exposed and field strain infected, but immunologically unresponsive cattle were incubated with B. abortus antigen and indomethacin. There were significant increases (P less than 0.005) in the blastogenic responses, as measured by [3H] thymidine uptake, in cultures with indomethacin as compared to cultures without indomethacin. Lymphocyte blastogenic responses to B. abortus antigen were potentiated by indomethacin in both B. abortus exposed and non-exposed cultures. However, potentiation of sensitized lymphocyte blastogenic responses by indomethacin was significantly greater (P less than 0.005) than that in non-exposed lymphocytes. Additionally, indomethacin significantly potentiated Brucella-induced lymphocyte blastogenic responses in lymphocytes from anergic cattle.

Alterations of peripheral blood lymphocyte cyclic AMP and cyclic GMP in untreated patients with hodgkin's disease

Cyclic AMP and cyclic GMP are important regulatory agents of lymphocyte functions. Depressed T-lymphocyte functions are frequently associated with Hodgkin's disease and suppressor monocytes have been implicated in the pathogenesis of this defect. In the present study cAMP and cGMP resting levels were measured in lymphocytes from 18 untreated patients with Hodgkin's disease using a sensitive radioimmunoassay. A significant decrease of cAMP (P less than 0.001) and, to a lesser degree, of cGMP (P less than 0.01) was found in monocyte-depleted lymphocyte suspensions from the patients compared to controls. Studies of patient and control lymphocyte subpopulations showed in patients a clear deficit of cAMP in T-depleted lymphocytes, rather than in T cells, with a low cAMP/cGMP molar ratio in both subpopulations. From this data it is clear that factors other than prostaglandin-mediated suppression of monocyte origin are involved in the pathogenesis of the T-lymphocyte depression associated with Hodgkin's disease.

Altered intracellular enzyme activity of monocytes and lymphocytes in Hodgkin's disease

To evaluate metabolic functionality of monocytes and lymphocytes in Hodgkin's disease (HD) we studied 3 enzymes of the intermediary metabolism, G-6-PDH, PHI, ICDH, and the acid hydrolases, NAG and ACP. These enzymes were measured in purified cell fractions of 9 patients with advanced disease and 11 normal controls. The cells were isolated with cell scatter-monitored counterflow centrifugation. Enzymes were measured in the cell lysates by means of fluorimetric microassays. In the monocytes of HD patients a significantly increased G-6-PDH activity was found (P less than 0.01), indicating an enhanced activity of the hexose monophosphate shunt. The other enzymes showed no clear differences compared to normal controls. The lymphocytes of HD patients showed a significantly augmented activity of both G-6-PDH (P less than 0.001) and PHI (P less than 0.01), pointing to an increased HMPS and glycolytic activity. These findings are in support of an enhanced metabolic activity of both monocytes and lymphocytes in HD.

Nonsteroid antiinflammatory drugs and tamoxifen for desmoid tumors and carcinoma of the stomach

The results of treatment of desmoid tumor patients with nonsteroid antiinflammatory drugs alone or in combination with tamoxifen are described. Tumor growth was inhibited in six of seven patients. Nonsteroid antiinflammatory drugs administered along with 5-fluorouracil and cyclophosphamide and other inhibitors of T-suppressor cells were used to treat nine patients with metastatic carcinoma of the stomach. Survival of these patients was extended so that after 12 months minimal follow-up the majority are well. A prospective controlled clinical trial is indicated.

Plasmapheresis in a patient with angioimmunoblastic lymphadenopathy. Improvement in clinical and immunologic abnormalities

A patient with steroid resistant, allergen related angioimmunoblastic lymphadenopathy underwent a course of six plasmaphereses during a three-week period. A 75% reduction in lymph node size along with the disappearance of her night sweats occurred. Immunologic abnormalities prior to plasmapheresis included the presence of elevated levels of circulating immune complexes, high levels of spontaneous mononuclear cell blastogenesis and abnormal mitogen responses to Conconavalin A and phytohemagglutinin. Following plasmapheresis there was a marked reduction in immune complex levels, and return of spontaneous blastogenesis and mitogen responses to normal levels. Mechanisms for the beneficial effect seen in this patient include removal of: (1) the antigenic stimulus; (2) antigen antibody complexes; and (3) other humoral factors which may modulate lymphocyte or macrophage function. Additional studies of plasmapheresis are warranted in selected patients with allergen related AIL.

Increased antibody-dependent cytotoxicity mediated by purified monocytes in Hodgkin's disease

Monocyte antibody-dependent cytotoxicity was studied in 19 patients with Hodgkin's disease and 14 normal controls. This function was investigated after isolation of the monocytes by means of a modified elutriation technique. Direct sizing and counting of the cells present in the effluent enabled individual adjustment during each separation procedure. The absolute monocyte count in the peripheral blood of patients with Hodgkin's disease was higher (P less than 0.002) than in normal controls. Nearly 90% pure monocyte suspensions, representing 82% of all elutriated monocytes, were obtained. The elutriation characteristics of the monocytes in both groups were essentially the same, irrespective of marked interindividual differences. Kill of antibody-coated chicken red blood cells was measured by DNA flow cytometry. In comparison to normal controls, a significantly increased (P less than 0.0004), stage-independent, monocyte antibody-dependent cytotoxicity was found in patients with Hodgkin's disease. The percentage of kill in symptomatic patients tended to be higher than in the asymptomatic group; no correlation was found with the absolute number of circulating monocytes.

Monocyte-induced inhibition of lymphocyte response to phytohaemagglutinin in progressive systemic sclerosis

In patients with progressive systemic sclerosis (PSS) lymphocyte responses to phytohaemagglutinin (PHA) are abnormal (27.2 +/- 3.5 X 10(-3) counts per minute (cpm) versus 69.8 +/- 4.4 X 10(-3) for normal persons, p less than 0.005). Removal of adherent peripheral blood mononuclear cells improves the response of PSS lymphocytes (42.3 +/- 3.4 X 10(-3) cpm, 155% of control) but diminishes the response of normal lymphocytes (60.3 +/- 5.9 +/- 10(-3), 86% of control). Supernatant fluids from cultures of PSS unfractionated and adherent cells depress normal T cell response to PHA (64% and 55% of control respectively), but supernatant fluids from normal unfractionated and adherent cells do not (104% and 101% of control). Supernatant fluids of PSS and normal adherent cells, cultured in the presence of indomethacin, are not inhibitory to normal T cells (109 +/- 15% and 124 +/- 14% of control respectively). Supernatant fluids from PSS patients are more inhibitory than comparable fluids from patients with systemic lupus erythematosus (60 +/- 8% of control versus 80 +/- 5% of control). These data support the hypothesis that cellular immunity is abnormal in patients with PSS and indicate that adherent mononuclear cells mediate at least one component of the abnormality via an indomethacin-sensitive mechanism.

Modification by biological products of the generation of suppressor cells in culture

This report describes the effects of prostaglandin E2 (PGE2), indomethacin, and human prealbumin on the generation of culture-induced and allo-antigen-induced suppressor cells. The ability of the suppressor cells to affect cell-mediated immunity (CMI) generation cultures was assessed by 3H-thymidine uptake and cell-mediated lympholysis (CML). The generation of culture-induced suppressor cells is dependent on the fetal calf-serum (FCS) used in the medium and at least 4 days are necessary for their generation. Suppression is totally abolished by 2,000r X-irradiation of suppressor cells prior to their testing in CMI generation cultures. Spleen cells cultured in the presence of 0.03 to 3 microM PGE2 are not suppressive, while 3 nM PGE2 only partially abolishes their suppressive activity. Indomethacin has little effect on the development of this suppressor cell activity. Spleen cells cultured in the presence of human prealbumin have augmented cellular proliferation but do not develop suppressor cell activity. Alloantigen-activated cells added to CMI generation cultures suppress cellular proliferation (3H-thymidine uptake), but suppress CML development only after X-irradiation. PGE2 inhibits the proliferation of alloantigen-activated cells in a dose dependent manner. The ability of PGE2 to abolish their suppressive activity (after X-irradiation) in CMI generation cultures is directly proportional to its effects on cell proliferation. Indomethacin augments the proliferation of alloantigen-activated cells but does not further augment suppression. Human prealbumin augments the cellular proliferation of alloantigen-activated suppressor cell culture systems, but does not affect the generation of alloantigen-activated suppressor activity.

Rosette and blastogenesis inhibition by plasma from Hodgkin's disease and other malignancies. Positive correlation in State I and II Hodgkin's disease

The simultaneous presence of both rosette- and mitogen-induced blastogenesis inhibitors was measured in the plasma from 29 patients with active Hodgkin's disease, 21 patients with advanced lung cancer, nine patients with diffuse histiocytic lymphoma, 25 patients with non-Hodgkin's lymphoma, and 17 patients with a variety of solid tumors. Only patients with active Hodgkin's disease consistently demonstrated factors which interfered with both rosetting and mitogenesis when normal allogeneic cells were utilized. While a similar proportion of patients with early and late Hodgkin's disease possessed plasma which could inhibit both tests, a significant correlation between these tests was observed only in Stage I and II disease. Varying degrees of inhibition of these tests was also observed when plasmas from patients with other malignancies were tested. Both lung cancer and histiocytic lymphoma plasma contained a factor which was capable of significantly inhibiting in the rosette assay when compared to normal human serum. Plasma from these patients also demonstrated inhibition of blastogenesis, but unlike Hodgkin's disease, no correlation between these activities could be demonstrated. Neither patients with diffuse or nodular lymphocytic lymphoma nor patients with solid tumors had significant plasma inhibition in either assay.

The role of prostaglandins in the modulation of histamine suppression of mitogen responses in atopic and normal subjects

We have shown that lymphocytes from atopics are more sensitive to histamine-induced suppression of mitogen transformation than are cells from normal subjects. Recent reports have suggested that histamine suppression may act via prostaglandin synthesis. We have investigated this and found that indomethacin partially reversed the histamine suppression seen in atopics, but not that in normals. This effect was seen even when the direct enhancing effect of indomethacin was taken into account. The direct effect of indomethacin on mitogen-induced transformation was similar in both normal and atopic cultures, which suggests that these results are not due to the presence of PG producing cells in atopic cultures, but rather that histamine modulates the function of these cells. It was found that a specific H2 agonist, but not an H1 agonist could partially mimic the effect of histamine this system.

Enhancement of T lymphocyte proliferative response to mitogens by indomethacin in breast and colorectal cancer patients

The present study confirms previous observations that in vitro T lymphocyte proliferative response to mitogens is depressed in only some untreated patients with advanced or metastatic breast and colorectal cancer. Indomethacin, a prostaglandin synthetase inhibitor, at 1.0 microgram or 0.1 microgram/ml concentration significantly enhances the PHA, Con A or PWM response in these patients with breast and colorectal cancer (P less than 0.05 - P less than 0.01). Indomethacin has no mitogenic activity. Ethyl alcohol (0.01%), in which indomethacin is dissolved, also has no mitogenic or cytotoxic activity. Although the in vitro effect of indomethacin has been well-demonstrated, the in vivo effect of this agent on cell-mediated immunity in man has not yet been thoroughly investigated and thus, further studies of the effect of indomethacin administration on in vivo and in vitro cellular immunity seem warranted.

Excessive prostaglandin E2 production by suppressor monocytes in head and neck cancer patients

The proliferative response of peripheral blood mononuclear cells (PBMC) to the mitogens PHA and Con A significantly depressed in 86% of 45 head and neck cancer patients compared with 44 normal controls. This depression of immune competence was greatest in older patients and in those with more advanced disease stages. The abnormal mitogen responses could be restored toward normal (especially with Con A stimulation) by incubating the cells with either of two prostaglandin synthetase inhibitors (indomethacin or RO-205720). This augmentation of immune response was independent of other factors, including the primary tumor site, disease stage, treatment (surgery, radiation therapy, or chemotherapy) or the patients's age or race. The most likely explanation for this depressed level of immunocompetence was an excessive production of PGE2 by suppressor cells. This was confirmed by the finding that PBMC from patients produced more PGE2 than PBMC from normal individuals (8.4 ng/ml vs. 5.2 ng/ml, p=0.002). This difference was greatest among patients less than 60 years of age whose cultured PBMC produced 91% more PGE2 than controls (p less than 0.0007). Virtually all of the PGE2 was produced by a population of monocytes defined by a monoclonal antibody and purified with a fluorescence-activated cell sorter. Patients with epidermoid cancer of the head and neck thus have an abnormality of immunoregulatory monocytes that can contribute significantly to their depression of cellular immunity by elaborating prostaglandin E2. This abnormality could be partially corrected in vitro by incubating their PMBC with a prostaglandin synthetase inhibitor.

Effects of endogenous and exogenous inhibitors on the incorporation of labeled precursors into DNA by human mononuclear cells

The degree of responsiveness of lymphoid cells to activation by mitogens and antigens is commonly assessed in vitro by measuring radioactive DNA precursor incorporation. Several lines of evidence indicate that artifacts affect the results and that these measurements may not be an accurate reflection of cell activation. Cultures of blastogenically activated lymphocytes contain soluble, noncytotoxic factors that inhibit the incorporation of radioactive nucleosides into DNA by dividing cells without affecting their rate of DNA synthesis. Inhibitors were found in the serum component of the medium and in the bacterial homogenates used to activate the cells, and they were produced by the activated cells. Inhibitor activity in serum has properties expected of a nucleoside such as thymidine, including a molecular weight of less than 10(3). The inhibitor activity present in some bacterial homogenates and that produced by activated cells enzymically degrade labeled DNA precursors, thereby preventing their availability for incorporation. Other bacterial preparations contain DNA precursors, which compete with labeled nucleosides for incorporation, and additional low-molecular-weight inhibitor is produced when the preparations are incubated. Preparations of various bacteria differ greatly with regard to the potency of their inhibitor activity. In some cases incorporation of label in activated cultures is reduced to background levels. Inhibition by these substances leads to erroneous conclusions regarding the proliferative activity of cultured lymphocytes, since the amount of label incorporated does not accurately indicate the true rate of DNA synthesis of the cells.

Elevation of serum prostaglandin E levels following electrical stimulation of the midbrain

Serum prostaglandin E (PGE) levels were measured in rats immediately following electrical stimulation of the mesencephalic periaqueductal gray (PAG) region and the nucleus raphe magnus (NRM) and compared to controls. An additional group received aspirin prior to PAG stimulation. A significant increase in serum PGE levels was found after stimulation of the PAG, but not the NRM. Aspirin inhibited the stimulation-induced increases in PGE.

Effect of serum on lymphocyte blastogenesis. I. Basic characteristics of action by diseased dog serum

The immunoregulatory effect of serum on phytomitogen-induced lymphocyte blastogenesis was studied in 4 sera from diseased dogs and 1 serum from a clinically healthy dog. The results indicated that: (1) Each of the diseased animals responded to the given infection with a specific pattern of blastogenesis inhibition. (2) The blastogenesis suppression in vitro was proportional to the content of the suppressive serum in the medium. (3) A simultaneous presence of the mitogen and the suppressing "serum's lymphocyte immunoregulatory factors" (SLIF) was necessary for inducing blastogenesis suppression. (4) The suppressive sera most probably acted directly on the cells. (5) The final effect of the sera on lymphocyte blastogenesis was a result of an orchestrated action of blastogenesis-supporting, augmenting, and suppressing SLIF cooperating with the mitogen. (6) The suppressive pattern varied with the individual peripheral blood lymphocytes populations used in the test. (7) The blastogenesis-suppressing SLIF was heat-stable, noncytotoxic, and was not or only partially removable by absorption with peripheral blood lymphocytes. (8) The testing of SLIF activities required the use of various animal lymphocytes and a relatively complex setup of mitogens and control serum combinations for correct interpretations.

Depressed spontaneous natural killing and interferon augmentation in patients with malignant lymphoma

A substantial proportion (44%) of peripheral blood lymphocyte samples from 41 patients with malignant lymphoma have been shown to have depressed or undetectable levels of natural cytotoxicity against the leukaemic cell line K562 in a 4-hr [51Cr]-release assay. No correlation was found between low levels of natural killer (NK) cell activity and either the age of the patients, total or differential white blood counts, or the type or stage of disease. Furthermore, pre-treatment of lymphocytes with human lymphoblastoid (Namalva) interferon failed to enhance NK levels in 5/11 patients with Hodgkin's disease and 5/8 patients with non-Hodgkin's lymphoma, and was in contrast to the response of control peripheral blood lymphocytes assayed under the same test conditions. The lack of responsiveness to interferon of peripheral blood NK cells from lymphoma patients was not wholly associated with those patients shown to have low levels of spontaneous NK activity.

Effect of indomethacin on phytohemagglutinin-stimulated peripheral blood lymphocytes in thyroid autoimmune diseases

Suppressor lymphocyte function was evaluated in control subjects and in patients with autoimmune thyroid disease, utilizing an assay in which indomethacin was added to lymphocyte cultures to inhibit prostaglandin-producing suppressor cells. This assay is based on the observation that the addition of indomethacin, a potent prostaglandin synthesis inhibitor, to phytohemagglutinin-stimulated peripheral blood lymphocytes should cause an increase in the incorporation of iododeoxyuridine in control subjects and a smaller increase in diseases with reduced prostaglandin-producing suppressor cells. The addition of indomethacin, 1 microgram/ml, stimulated iododeoxyuridine incorporation in phytohemagglutinin-stimulated cultures in control subjects to an index value of 1.43 (i.e., the increment in iododeoxyuridine incorporation with both indomethacin and phytohemagglutinin was 43% greater than the incorporation with phytohemagglutinin alone). The stimulation index was significantly lower in patients with Graves' disease who were toxic and untreated (1.18 +/- 0.25, mean +/- SD; P less than 0.003). Patients who were toxic while receiving antithyroid drugs or after radioiodine therapy or patients euthyroid after treatment had a mean stimulation index in the normal range, although the spread of data was very large in these groups. Responses in patients with Hashimoto's thyroiditis were also quite variable. The average response was 1.74 +/- 0.72, with 40% of the patients showing a high stimulation index. This study supports our previous investigations in which we used different assay systems for measuring suppressor-cell function in patients with thyroid autoimmune diseases and indicates that a defect in suppressor lymphocyte function is measureable by another technique. The abnormality persists in some cases after metabolic control has been achieved, but usually returns toward normal over months or years.

Monocyte-dependent serum suppression of lymphocyte blastogenesis in Hodgkin's disease: an association with nephrotic syndrome

A factor inhibitory to PHA-induced lymphocyte blastogenesis was found to be present in the serum of a patient with advanced Hodgkin's disease and nephrotic syndrome. The inhibitory activity for both syngeneic and allogeneic lymphocytes was dependent on the presence of peripheral blood monocytes. The Raji-cell serum assay, as well as immunofluorescence and light and electron microscopy of the renal biopsy, showed no evidence of immune complexes. Nevertheless, a high serum IgE level as well as the finding that ultracentrifugation and heating at 56 degrees C significantly reduced the inhibitory activity (P less than 0.01) suggested the possibility that an immune complex might have mediated the suppressive activity. Treatment of the Hodgkin's disease with combined chemotherapy caused a marked reduction in the monocyte-dependent serum inhibitory activity which in turn coincided with a prompt remission of the nephrotic syndrome and marked regression of disease.

Influence of autologous monocytes on the pokeweed mitogen-induced generation of immunoglobulin-secreting cells in man

The regulatory influence of autologous blood monocytes on the PWM-induced generation of Ig-secreting cells was assessed using a reverse haemolytic plaque forming cell (PFC) assay. The PWM-induced PFC responses of monocyte-depleted cells were low or absent in most cases. Addition of 12-42% freshly isolated monocytes fully reconstituted the IgM-, IgG- and IgA-PFC responses. With more monocytes added, the PFC responses declined. Monocytes precultured for 48 h supported the PFC responses of monocyte-depleted cells less well and addition of monocytes stimulated with phorbol myristate acetate (PMA) did not increase the response. The low responses of monocyte-depleted cells co-cultured with precultured monocytes were not increased by addition of supernatant from monocyte cultures. The PFC responses of mononuclear cells induced by PWM were significantly inhibited by unstimulated precultured monocytes, and to a larger degree by PMA-treated monocytes, indicating the presence of suppressor cells among the precultured monocytes. The PWM-induced thymidine incorporation by monocyte-depleted cells with precultured monocytes added was only slightly lower than that obtained with freshly isolated monocytes added, suggesting that the suppressive role of precultured monocytes was not due to cytotoxicity.

Impaired T-cell and NK-cell function in patients with preleukemia

The responses to the T-cell mitogens Phythemagglutinin (PHA) and Concanavalin A (Con A) and the natural killer (NK) cell activity are tested in patients with preleukemia (PL). The results are compared with those of healthy controls. The PL patients show low responses to T-cell mitogens and low NK cell activities. It is discussed that the data are not of prognostic value in PL as to development of overt leukemia. However, the results suggest that PL impaired cell functions are not limited to erythropoiesis, granulopoiesis, and thrombopoiesis but are also found in the immune system.

Impaired PWM-induced polyclonal B-cell activation in patients with malignancies treated with various intermittent combination chemotherapies including doxorubicin

The effect of various intermittent combination chemotherapies on the immune status of 30 patients with malignancies was examined 1-3 weeks after they received their last injection. PWM-induced polyclonal B-cell activation of lymphocytes from patients treated with combination chemotherapies that included doxorubicin was impaired despite a normal 3H-thymidine uptake by lymphocytes stimulated with PHA, PWM, and insoluble SPA. This suppressive effect was always found in patients with ALL. However, in patients with solid tumors, PWM-induced immunoglobulin production returned to normal 7-8 weeks after the last doxorubicin injection. Serum immunoglobulin levels in patients treated with doxorubicin were slightly lower than in those treated without doxorubicin. It is hypothesized that doxorubicin may change the lymphocyte surface membrane and interrupt the T- and B-cell interaction that is needed for immunoglobulin production.

The in vivo effect of a thymic factor (thymostimulin) on immunologic parameters of patients with untreated Hodgkin's disease

The in vivo effect of a calf thymus extract (thymostimulin, TS) on the E-rosetting capacity, PHA blastogenic response, serum migration inhibitory activity (LIF) and skin reactivity to recall antigens was evaluated in 19 untreated patients with Hodgkin's disease. In patients the mean percentage of peripheral blood lymphocytes forming E-rosettes increased from 47 to 55.7% (P less than or equal to 0.001; normal: 58.9). The mean PHA stimulation index rose with all three concentrations tested but did not reach normal values. Serum LIF was positive in only one patient prior to treatment with a mean LIF for all patients of 0.75 (P less than or equal to 0.005). Skin tests were positive in ten patients (52.6%) prior to therapy and 18 patients following therapy (94.7%; P less than or equal to 0.05). Thymostimulin, in vivo, appears to return immunologic competency to a population of untreated patients with Hodgkin's disease.

Indomethacin sensitive suppressor cell activity in head and neck cancer patients pre- and postirradiation therapy

The effects of the addition of indomethacin to PHA or Con A stimulated lymphocytes from patients with untreated squamous cell carcinoma of the head and neck or from patients with the disease who have just finished irradiation therapy from the disease was quantitated and compared to those of the control group. Lymphocytes from eight of 26 patients with untreated carcinoma were significantly augmented by the addition of indomethacin. The remaining eighteen patients were equal to the controls. For all 17 patients who had just finished extensive field irradiation therapy, significant enhancement of PHA and Con A reactivity by indomethacin was found, which did not appear to be solely a function of low baseline mitogen reactivity. In additional studies, stimulated lymphocytes of irradiated patients were tested for their sensitivity to the inhibitory effect of PGE2. The mitogen treated lymphocytes from all patients that had just finished irradiation therapy were found to be significantly more sensitive to the inhibition by PGE2 as compared to the normal lymphocyte response. This effect was also found not to be related merely to a low PHA or Con A reactivity of the lymphocytes. In both patient groups there was a striking correlation between the percent augmentation of indomethacin and the percent inhibition of PGE2 in that when the percent augmentation values were low so were percent inhibition values and when the degree of augmentation by indomethacin was elevated so was the inhibition by PGE2. This data suggests that increase sensitivity of stimulated lymphocytes to PGE2 may be responsible, at least in part, for the depressed mitogen response and the significant augmentation of this immune response by indomethacin in about 1/3 of the untreated patients with advanced head and neck carcinoma and in those patients who have just finished irradiation therapy. The results of this study support the hypothesis that perhaps patients receiving irradiation therapy may benefit by the oral administration of indomethacin, an approach that needs further consideration.

Effects of indomethacin on lymphocyte proliferation, suppressor cell function, and leukocyte migration inhibitory factor (lmif) production

The in vitro effect of indomethacin (IND) on PHA- and Con-A-induced immune responses was studied. The results showed that the enhancement of both PHA and Con A responses by IND does not significantly depend on the concentrations of mitogens or IND. A significant negative correlation was found between the initial PHA response and augmentation index, whereas there was a positive correlation between the initial Con A response and the enhancement of the Con A responses. Indomethacin significantly increased the Con-A-induced suppressor cell activity and PHA-induced leukocyte migration inhibitory factor production (LMIF), whereas the effects on the PHA-induced suppressor cell activity and Con-A-induced LMIF production were not significant. The findings indicate the indomethacin has a dual effect on PHA- and Con-A-induced immune responses probably reflecting intrinsic differences among T cells, for example, distinct lymphokines produced by different T-cell subpopulations.

Diminished autologous mixed lymphocyte reaction in patients with Hodgkin disease: evidence for non-T cell dysfunction

In the autologous mixed lymphocyte reaction (AMLR), T lymphocytes are stimulated to proliferate by autologous non-T mononuclear cells. In five untreated patients with Hodgkin disease, the AMLR was diminished. In addition, in the same five patients, T cell response PHA was inhibited by a cell in the non-T cell fraction, the response of non-T cells to PWM was diminished, and there was a diminished ability of the non-T cell population to stimulate in allogeneic MLR. However, the response of T cells from patients with Hodgkin disease to allogeneic antigen was normal. The AMLR and allogeneic MLR were then studied in an additional five untreated patients before and after monocyte depletion of the stimulating non-T mononuclear cell population. In this second group of Hodgkin disease patients, the AMLR was again diminished when T cells were incubated either with non-T cells or non-T cells depleted of monocytes. In the Hodgkin patients, monocyte depletion did not alter the T cell response in the AMLR. In the controls, monocyte depletion greatly diminished the proliferative response. The diminished AMLR in untreated Hodgkin disease patients may be the result of a failure of adequate monocyte stimulation of autologous T cells.

Partial restoration of local GVH reaction in cancer patients by depletion of theophylline-sensitive suppressor T-cells

Theophylline-resistant T-cell subpopulations were assessed in terms of numbers and function among patients with disseminated cancer, and compared to normal controls. Within the total E-rosetting T-cells (65 +/- 6.5% for normal donors versus 34 +/- 1.0% for cancer patients; P less than 0.001) the proportion of theophylline-resistant Te cells was 56 +/- 1.5% and 26.6 +/- 1.1%, respectively (P less than 0.001). This significant difference in distribution between theophylline-resistant (effector) and theophylline-sensitive (suppressor) cells in favor of the latter was also reflected by the poor performance of unseparated T-cells in the local GVH reaction. Thus, the mean GVH reaction among normal donors was 159 +/- 30 mm3 versus 44 +/- 28 mm3 among cancer patients (P less than 0.001). Removal of the theophylline-sensitive suppressor T-cells resulted in significant augmentation of the local GVH reaction among normal donors and in significant, although partial, immune restoration of the local GVH reaction in some patients but not in others. The mean local GVH reaction after removal of theophylline-sensitive suppressor T-cells was 196 +/- 89 mm3 among normal donors and 68 +/- 46 mm3 among cancer patients (P less than 0.05). This immune restoration following depletion of suppressor T-cells was only partial among cancer patients because of an apparent intrinsic defect in the capacity of their effector T-cells to exert vigorous local GVH reaction. In one small group of four patients, this intrinsic defect was so profound that even after removal of the theophylline-sensitive suppressor cells, the restoration of the local GVH reaction was negligible (12 +/- 10.8 mm3 versus 24 +/- 9.8 mm3; P greater than 0.1). The quantitative and qualitative changes in effector and suppressor T-cell distribution during the development of the malignant process and the possible interaction between them are discussed.

Suppression of T lymphocyte proliferation during lymphoma growth in mice: role of PGE2-producing suppressor macrophages

The suppressed T lymphocyte response occurring during lymphoma growth in mice was largely due to the generation of suppressor macrophages which released high amounts of prostaglandin E2 (PGE2). Based on these findings, the role of macrophage-derived PGE2 as a regulating and potentially immunosuppressive agent of the immune response is discussed.

Exogenous additions of prostaglandins variably alter the blastogenic response of B and T lymphocytes from different mice lymphoid organs

Prostaglandins A1 and E2 enhance the 3H-thymidine (TdR) uptake in spleen cell cultures stimulated by two B-lymphocyte mitogens (E.coli lipopolysaccharide (LPS) and dextran sulfate (DXS) at concentrations ranging between 10(-8) and 10(-6) M. The same prostaglandin (PG) concentrations inhibited concanavalin A (Con A) activation of mouse spleen cells depleted or not from a glass-adherent prostaglandin-producing population of suppressor cells. After fractionation of spleen cells by nylon wool adherence, PGs diminished 3H-TdR uptake by nylon nonadherent (T-enriched) cells cultured in the presence of Con A and enhanced the activation of nylon adherent (B-enriched) cells by LPS. The proliferative response of thymic lymphocytes to Con A was drastically inhibited (70-95% by PGE2 10(-8)-10(-6) M. In cultures of purified bone marrow lymphocytes, PGE2 induced a dose-dependent inhibition of either LPS- or DXS-induced activation reaching a 30-40% inhibition at a PGE2 concentration of 10(-6) M. In the spleen, treatment of cells with anti-T sera and complement resulted in abrogation of PG-induced enhancement. Nevertheless, no inhibition of B-cell mitogenesis was observed in the presence of 10(-6) PGE2. From these results, it can be concluded that a different sensitivity of the proliferative response of lymphoid cells to exogenous PGs exists, depending on the subset (T or B) affected and/or the organ used as a source of these cells.