Prostaglandin-producing suppressor cells in Hodgkin's disease

[Adenosine deaminase activity in Hodgkin's disease (author's transl)]

The activity of adenosine deaminase (ADA) (EC3.5.4.4.) was determined in the blood plasma, erythrocytes, and lymphocytes of 23 patients with Hodgkin's disease and partly also in 99 control subjects. The enzyme activities were measured using adenosine as substrate and by analysis of ammonia. No correlation was found between the ADA activities in lymphocytes, erythrocytes, and blood plasma. The lymphocytes of the patients revealed lower ADA activities (U/g protein) than the lymphocytes of control subjects. The ADA activity is not reduced in plasma or erythrocytes. The lower activities of ADA in the lymphocytes of patients may be related to the impaired cell-mediated immunity of the Hodgkin's disease.

Increased sensitivity of T cells to regulation by normal suppressor cells persists in long-term survivors with Hodgkin's disease

We have studied the function of T cells in the peripheral blood obtained from long term survivors with Hodgkin's disease in order to determine the sensitivity of those T cells to normal suppressor cell immunoregulatory mechanisms. Concanavalin A-activated suppressor cells from normal donors suppressed the proliferation of lymphocytes obtained from 11 patients (56.8 +/- 3.5 percent) and from 28 allogeneic normal control subjects (39.8 +/- 2.7 percent [p less than 0.001]). When suppressor monocytes from the normal donors were studied, the mean proliferation of lymphocytes from 19 patients was suppressed 76.3 +/- 4.8 percent whereas proliferation of lymphocytes from 26 normal donors was suppressed 46.6 +/- 4.4 percent (p less than 0.0001). There was no tendency for the increased sensitivity to suppression that was observed in either assay system to return to normal as the patients' disease free interval increased from 1.5 years to 12 years. Furthermore, long-term survivors with diffuse histiocytic lymphoma, who had been treated with comparable chemotherapy, had normal sensitivity to the suppressor monocytes (45.1 +/- 3.8 percent). In Hodgkin's disease, the persistent increased sensitivity of T cells to two different normal immunoregulatory cells suggests that the response of the T cell to regulatory signals may be an important cause of the depressed cellular immunity observed in Hodgkin's disease and a clue to the etiology of the disease.

Gamma interferon production by combinations of human peripheral blood lymphocytes, monocytes, and cultured macrophages

Mitogen-induced interferon (IFN) production was studied using human peripheral blood mononuclear cells and subpopulations of lymphocytes, monocytes, and cultured macrophages. Cell populations were prepared in suspension to permit quantitative analysis of the interactions among different cell types. After stimulation by staphylococcal enterotoxin A, nylon column-purified lymphocytes produced only 5% as much IFN as the peripheral blood mononuclear cells from which they were prepared. When lymphocytes were supplemented with as little as 2% monocytes, IFN production increased two- to eightfold; with the addition of up to 20% monocytes, IFN production increased further, to levels approximating those of peripheral blood mononuclear cells. Monocytes alone produced no or very little IFN. Macrophages were derived from monocytes by culturing in vitro for 7 days. The addition of 2 to 5% autologous macrophages augmented IFN production to the same extent as 2 to 5% monocytes. However, more macrophages consistently resulted in less, rather than more, IFN, so that lymphocytes with 20% monocytes produced three- to eightfold more IFN than did lymphocytes with 20% macrophages. Thus, whereas the addition of monocytes over a broad dose-response range (2 to 20%) progressively augmented IFN production, macrophages showed an optimal effect at 2 to 5%, with higher percentages being inhibitory. The IFN induced by stimulation with staphylococcal enterotoxin A was characterized as IFN-gamma by its resistance to neutralization by antibody to IFN- alpha and its inability to induce antiviral protection in embryonic bovine trachea cells.

Diseases associated with immunosuppression

Impairment of any of the major components of the immune system (T-cells, B-cells phagocytes, complement) may result in clinical immunodeficiency. Immune defects can arise from intrinsic or heritable defects of lymphoid elements, failure of normal cellular differentiation, viral infection or other acquired causes. Clinical impairment of immunity is expressed as a marked susceptibility to opportunistic and pathogenic organisms which are difficult to control and by an increased risk of malignancy, allergy and autoimmune disease. Certain immunodeficiency disorders are associated with aberrant immune regulation. The major types of immune deficiency are characterized by unique patterns of infections depending on the level at which the defect occurs and the pathogenic mechanisms of the parasite. The basic defects of representative primary and secondary immunodeficiencies are discussed in relation to observed immunologic consequences.

The in vitro effect of a calf thymus extract (thymostimulin) on the immunologic parameters of patients with untreated Hodgkin's disease

The in vitro effect of a calf thymus extract, thymostimulin (TP--1), on the E-rosette-forming capacity and on the PHA blastogenic response of peripheral blood lymphocytes was evaluated in 20 patients with untreated Hodgkin's disease. The mean percentage of lymphocytes forming E rosettes increased in patients from 44.2% to 57.5% (P less than 0.005). The mean PHA stimulation index rose with all three concentrations tested, but returned to the normal range only with the highest PHA concentration (60 mu/ml). An increase in the immune parameters was greatest in those patients who presented with decreased E-rosetting cells of total lymphocyte counts or whose disease was Stage III or IV or of mixed cellular histology.

Impaired autologous mixed lymphocyte reactivity in Hodgkin's disease

In patients with Hodgkin's disease, the impaired immune reactivity, especially of the thymus dependent system, is well established. This decreased immune response of the lymphocytes from the peripheral blood contrast to an increased lymphocytopoiesis in the the lymphatic organs with a hyperplasia of these tissues. We studied the reactivity of peripheral T lymphocytes from 20 patients with Hodgkin's disease and 26 healthy control persons against autologous and allogeneic non T cells respectively in the mixed lymphocyte culture (MLC). Our experiments show an extremely depressed autologous mixed lymphocyte reactivity (MLR) of T lymphocytes from patients with Hodgkin's disease compared to those from normal donors. In the allogeneic MLC, the proliferation of the patients' T cells was stronger than in the autologous MLC, but significant lower than the proliferation of normal T lymphocytes when stimulated by normal non T cells. Patients' non T cells stimulated T lymphocytes from healthy donors as well as non T lymphocytes from normals did. Finally, the autologous MLR of normal lymphocytes was significantly suppressed by 18 of 23 sera from Hodgkin's patients when these sera were substituted for normal AB serum in the cultures. These results demonstrate an impaired function of T lymphocytes from patients with Hodgkin's disease in the autologous MLC and the presence of one or more factors in their serum which inhibit the proliferation of normal lymphocytes in the autologous MLC. The role of suppressor cells and their factors will be discussed.

Lymphocyte function in untreated Hodgkin's disease: an important predictor of prognosis

One hundred and twenty seven consecutive and previously untreated patients with Hodgkin's disease (HD) (mean age 47 years) from the Stockholm area admitted to Radiumhemmet, Karolinska Hospital, were studied. The age-matched control group consisted of 167 healthy adults. Incorporation of [14C]-dT was measured on Day 1 in unstimulated monocyte-depleted lymphocyte cultures, and on Day 3 in cultures activated by PWM, ConA and PPD, T and B cells were enumerated by surface markers. The patients had significantly decreased relative and total T-cell counts, and the lymphocyte DNA synthesis induced by mitogens and PPD was severely impaired, whilst the spontaneous DNA synthesis was significantly greater than in controls. At follow-up (mean 4 years) 40 patients have died. Deceased patients showed greater spontaneous lymphocyte activation and less response to mitogen and antigen stimulation than the survivors. The 5-year survival of patients with severe lymphocyte impairment was 20%, compared to 80% for the remainder. The lymphocyte tests added prognostic information to that from clinical staging. Disregarding the lack of knowledge of the mechanisms underlying the lymphocyte impairment, we suggest that these relatively simple immunological tests should be included in the clinical evaluation of HD patients and would guide the choice of therapy.

Relationship of the suppression of macrophage mediated tumor cytotoxicity in conjunction with secretion of prostaglandin from the macrophages of breast cancer patients

Peripheral blood monocyte derived macrophages obtained from breast cancer patients are non-cytotoxic towards human tumor cells. However, when indomethacin, a prostaglandin synthetase inhibitor, was added to the macrophage tumor cell incubation mixture, the breast cancer patient's macrophages became capable of killing the tumor cells. Furthermore, the macrophage preparations obtained from breast cancer patients demonstrated a 64% increase in the secretion of PGE2, when compared with macrophages obtained from normal donors. It is already known that prostaglandin can inhibit both natural lymphocyte cytotoxicity and antibody dependent cell-mediated cytotoxicity against human tumor cells in vitro. These results indicate that increased synthesis of prostaglandin can also inhibit macrophage mediated cytotoxicity. Therefore, it is possible that manipulation of this mechanism might enhance the effectiveness of the macrophage response and should be a consideration in assessing macrophage-tumor cell interaction in vitro and in vivo.

Modifying the biological response in acute myeloid leukemia. II. Effect of BCG and leukemic cells on lymphocyte response to mitogens, and on helper and suppressor activity

Lymphocyte response to mitogens and to lymphocyte suppressor and monocyte helper activity was studied in 18 patients with acute myeloid leukemia in complete remission, and in 17 healthy controls. Ten patients were maintained with chemotherapy alone (CT), and eight received chemoimmunotherapy with BCG + leukemic cells (CIT). In late remission the mitogen responsiveness was increased in CT patients and decreased in CIT patients. No significant difference in lymphocyte suppressor activity could be demonstrated between patients and controls, or between CT and CIT. When autologous CIT monocytes were added to mitogen-stimulated lymphocytes they acted as helper cells. CT monocytes, in contrast, seemed to act as suppressor cells. Control monocytes also acted as helper cells, but to a significantly lesser degree than CIT monocytes.

Stimulation of Immunoglobulin production from human B lymphocytes by Staphylococcus aureus: effects of monocytes and con A-induced suppressor cells

Significant immunoglobulin (Ig) production by human peripheral blood lymphocytes was induced in vitro by stimulating the cells with pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (SpA CoI). IgG, IgM, and IgA were determined by a combination of the latex fixation test and radioimmunoassay. High levels (1,000 to 5,000 microgram/ml of IgG and IgM and a lesser amount of IgA were constantly produced during 7 to 8 days of incubation with both stimulants. Ig production induced by SpA CoI stimulation was independent of the presence of T cells, while Ig production induced by PWM required T cells exclusively. Depletion of monocytes in the culture caused but a slight decrease in Ig production (particularly in the case of IgG). While the addition of a small number of monocytes enhanced IgG induction by both stimulants, coculture with an excess number of monocytes inhibited Ig induction (particularly IgG) by PWM stimulation but not by SpA CoI stimulation. Marked suppression of Ig production (IgG, IgM, and IgA) was observed in cocultures with Con A-activated T cells. The phenomena of suppression were observed in both the SpA CoI-stimulated and PWM-stimulated lymphocytes. These data indicated that Ig production from B cells and relatively of independent of monocytes, but could be subjected to the regulation of the Con A-induced suppressor T cells.

Modulation of allogeneic stimulation in man. I. Characterization of an in vitro induced suppressor macrophage population

Cultured human peripheral blood mononuclear cells suppressed the allogeneic response of fresh autologous lymphocytes. This suppressor activity developed gradually over a period of one week. The cells primarily responsible for this effect were enriched by Ficoll density gradient centrifugation. It was found that the suppressor cell is a large, low density nylon wool adherent, radioresistant, phagocytic, and nonspecific esterase positive mononuclear cell. Moreover, these cells did not form E rosettes and were Fc positive. Electron microscopy confirmed that suppressor cells were macrophage like. Suppressor activity was not due to cytotoxicity, crowding, or steric hinderance by the cultured cells. The suppressor macrophage population did not appear to inhibit the allogeneic response via prostaglandin or arginase release, or interfere with the tritiated thymidine uptake by release of endogenous thymidine. The above system is viewed as an in vitro model of immune regulation by suppressor macrophages, in the context of allogeneic response.

Spontaneous suppressor cell function in inflammatory bowel disease

We investigated suppressor cell activity in the peripheral blood of 39 patients with inflammatory bowel disease (30 Crohn's disease and 9 ulcerative colitis) by the short-lived suppressor cell assay. There was a significant decrease in the suppressor cell activity in patients with inflammatory bowel disease (IBD), compared to 26 healthy subjects studied simultaneously. Five other patients with acute bacterial infections had normal suppressor activity. A group of 14 IBD patients was also investigated for concanavalin A-induced suppressor cell activity and decreased suppressor function was confirmed. A significant positive correlation was found between the two assays. A defect in suppressor cell activity may permit the expression or maintenance of immunologically mediated damage to the gut in IBD.

Effects of prostaglandin synthesis inhibition on the immune response

Inhibition of prostaglandin synthesis at the time of antigen presentation was used to test the role of prostaglandins in the inductive stage of the in vivo immune response to several antigens. Indomethacin and Ro 20-5720, two prostaglandin synthesis inhibitors, produced a several-fold enhancement of the primary immunoglobulin (Ig) M and IgG anti-sheep red blood cell plaque-forming cell (PFC) response in CAF1 mice. Indomethacin and Ro 20-5720 also enhanced the antibody response to chicken serum albumin (CSA) in buffered saline. However, the antibody response to CSA in Freund's adjuvant was reduced by indomethacin treatment. Indomethacin treatment enhanced the PFC response to a chicken lysozyme-lipopolysaccharide conjugate, and did not greatly affect the PFC response to pneumococcal polysaccharide. The allogeneic cytotoxic response to the El-4 tumor line was delayed by indomethacin treatment and, since this tumor does not synthesize prostaglandins, we speculate that prostaglandin synthesis by the host is important in the generation of a cytotoxic response to this tumor. It is concluded that the role of prostaglandins in the induction of the immune response varies, and can be proinductive or anti-inductive, depending on the eliciting antigen.

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. I. Relation to tumor growth an immunoglobulin levels in vivo

The effect of tumor growth on the suppressor cell activity of melanoma patients was examined by measurement of immunoglobulin produced in vitro in pokeweed mitogen (PWM)-stimulated cultures of B and T lymphocytes. B and T cells were separated by sheep red blood cell rosetting and suppressor cell activity was assessed by comparison of immunoglobulins produced in cultures with irradiated T cells (2,000 rads) to that with unirradiated T cells. In the majority of patients with localized melanoma, radiosensitive suppressor T cells were detected and appeared to be an augmentation of a normal physiological state. In patients with Stage I and II melanoma, removal of the tumor resulted in a significant decrease in suppressor activity against IgA and IgM but not against IgG production. Similar sequential changes in suppressor cell activity against IgA and IgM but not against IgG production. Similar sequential changes in suppressor cell activity were not generally detected in patients who had surgery for skin graft after previous removal of the primary melanoma or in patients undergoing surgery for non-malignant conditions. Sequential studies on the levels of serum immunoglobulins showed an apparent trend for immunoglobulins to increase after surgery. Of particular importance, the decrease in in vitro suppressor cell activity against IgM and IgG production after tumor removal in individual patients was significantly associated with an increase in immunoglobulin levels in the serum of these patients. It is suggested that these findings may account in part for the absence of detectable antibody responses to melanoma antigens in many patients and for the generalized immunodeficiency in patients with disseminated melanoma.

Suppression of lymphocyte responses by tuberculous plasma and mycobacterial arabinogalactan. Monocyte dependence and indomethacin reversibility

During tuberculosis, exposure of monocytes to circulating factors may induce the suppressor activity observed in some anergic patients. To explore this possibility, we examined the effects of plasma pooled from 28 untreated tuberculosis (TB) patients and the mycobacterial cell wall polysaccharide D-arabino-D-galactan (AG) on the in vitro function of peripheral blood mononuclear cells (PBMC) from healthy donors. In the [3H] thymidine incorporation assay, stimulated responses of PBMC incubated in culture medium supplemented with TB plasma or co-cultured with 3.0 microgram/ml AG were depressed significantly when compared with control responses. Cytotoxicity and altered kinetics of stimulated DNA synthesis did not contribute to the observed suppression. TB plasma and AG-induced suppression of the PBMC response to purified protein derivative was monocyte dependent and indomethacin reversible. In addition, TB plasma and AG directly inhibited the phytohemagglutinin-stimulated responses of T lymphocytes. In a quantitative assay of monocyte attachment to plastic, both TB plasma and AG significantly increased monocyte adherence from basal levels. These effects on monocyte adherence were reversed with indomethacin or antibody to mycobacterial polysaccharide. In addition, TB plasma passed over an immunoabsorbent column of Sepharose-linked antibody to mycobacterial polysaccharide was depleted of the suppressive and monocyte-adherence augmenting factors. 3.0 microgram/ml AG stimulated a fivefold increase in prostaglandin E2 production by cultured mononuclear cells. Our data suggest that AG circulating alone or bound in immune complexes may account for the observed effects of TB plasma. Similar in vivo exposure may contribute to the cell-mediated suppression of lymphocyte responses in tuberculosis.

Spontaneous and conA-induced suppressor lymphocytes: a comparative study

Suppressor monocytes, Concanavalin A(ConA)-induced suppressor T cells, and short-lived suppressor lymphocytes have been describe in humans. The present study was performed to evaluate spontaneous suppression in a test system similar to that employed for the demonstration of ConA-induced suppressor cells: Lymphocytes were either stimulated by ConA (= induced suppressor cells) or immediately mitomycin-treated (= spontaneous suppressor cells). Both preparations were tested for their capacity to suppress mitogen-induced proliferation of autologous cells. Depletion of monocytes or B lymphocytes did not affect spontaneous suppression. The active cells were short-lived in vitro. Therefore the net increase in suppressor activity generated by preculture with ConA is in part related to a loss of spontaneous inhibitory activity in the control cultures kept without mitogen. Spontaneous suppressor cell activity was comparable to that of ConA-induced suppressor cells.

Immune regulation and HLA types in chronic hepatitis

Studies were undertaken in 32 patients with hepatitis B-negative or -positive chronic active hepatitis or chronic persistent hepatitis to define the relationship between immunoregulatory activity and the HLA-B8 and B12 phenotypes. Suppressor T-cell activity measured by a concanavalin A-induced suppressor system using allogeneic responder cells was dependent on which individual was selected as a source of responder cells. No differences were noted using isogeneic cells as responders. Suppressor T-cell activity measured by the effect of a noninduced suppressor cell on a mixed leukocyte culture was not different from controls. Increased prostaglandin-producing suppressor cell activity was found in patients with hepatitis B-negative (p less than 0.005) and hepatitis B-positive (p less than 0.05) chronic active activity hepatitis. When results of the suppressor activities were compared among patients with chronic hepatitis dependent on the presence of HLA-B8, B12, or neither of these phenotypes, no significant differences were present. These results provide further evidence of altered immunoregulatory function in patients with chronic active hepatitis, which may reflect increased suppression by a population of prostaglandin-producing suppressor cells. The results do not, however, suggest that a gene coding for altered immune regulation is linked to HLA-B8 or B12.

Suppressive activity of cell-free ascites obtained from murine tumors. Soluble Fc receptor as a possible active agent

It has been shown that cell-free ascites (CFA) from Ehrlich carcinoma, AKR leukemia, and CBA thymoma, which all had strong suppressive activity in vivo, inhibit EA-rosette formation, complement-dependent hemolysis, and agglutinate EA-complexes. Since these are the characteristics of soluble FcR the data suggest the presence of FcR in CFA tested. To test whether the suppressive activity observed in vivo was due to the soluble FcR and FcR-like fraction was absorbed out from CFA or Ehrlich carcinoma by means of antigen-antibody complexes. The isolated FcR-like fraction was strongly suppressive in vivo. Additional support for the proposition that soluble FcR might be one of the mediators of suppression in vivo was gained by testing cell-free supernatants (CFS) of cell-line cells known to shed off FcR into the medium. It could be shown that CFS of highly FcR positive K-562 cells inhibited PFC stronger than did the CFS of weakly FcR positive Raji cells.

Subpopulations of T-lymphocytes in multiple myeloma

The percentage and absolute numbers of T lymphocytes bearing Fc receptor for IgG and IgM were evaluated in 13 patients with multiple myeloma and in a group of controls of the same age range. An increase in the percentage of the TG cells was found, whereas TM cell numbers were not different from those of the controls. In order to better define the properties of the TG lymphocytes, their ability to suppress the PWM-induced B cell differentiation was tested in an in vitro experimental assay. TG cells from multiple myeloma exert a suppressor activity as the TG of the controls in this system. The possible interpretation of suppressor T cell increases in these patients is discussed.

Effects of prostaglandins E1 and E2 on the in vitro production of immunoglobulin by human peripheral blood lymphocytes

The effects of PGE2 and PGE1 on the response of human peripheral blood lymphocytes to Pokeweed mitogen were studied. Addition of PGE2 inhibited IgM production. This effect was augmented by treating the lymphocytes with 2.0 mug/ml of Indomethacin. Addition of PGE1 alone had little effect but augmentation of IgM production was seen in cultures where the lymphocytes had been treated with Indomethacin and PGE1 then added. The results suggest that PGE1/E2 have a small but measurable effect on in vitro IgM production.

Abnormal suppressor cell function in atopic dermatitis

A status of suppressor cells in patients with atopic dermatitis was studied. As a group, they showed absent concanavalin A-inducible suppressor cell function as measured by proliferative responses to pokeweed mitogen and decreased function as measured by responses to phytohemagglutinin or concanavalin A. Similarly, preincubation in medium enhanced proliferative responses in normal donors but not in atopic dermatitis patients, suggesting an absence of a short-lived suppressor cell population in the latter group. Suppressor cell function correlated negatively with log10 of serum IgE concentrations. Theophylline-sensitive suppressor cell numbers were significantly decreased in atopic dermatitis patients (p less than 0.01). In vitro preincubation of normal lymphocytes with aminophylline or isoproterenol (10 microgram/ml) enhanced subsequent proliferative responses to pokeweed mitogen. In contrast, actual depression was seen with cells from atopic dermatitis patients, suggesting abnormal immunomodulatory effects of these drugs in the disease.

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.

Suppression of in vitro granulocyte-macrophage colony formation by the peripheral mononuclear phagocytic cells of patients with idiopathic aplastic anaemia

To investigate whether phagocytic cells play a role in the pathogenesis of aplastic anaemia, we studied the effect of the mononuclear phagocytic cells in the peripheral blood from patients with idiopathic aplastic anaemia on granulocyte-macrophage colony (GM-colony) formation. There was no apparent infection in the studied patients. In nine out of 20 cases the mononuclear cells suppressed the formation of GM-colonies by normal bone marrow. Removal of the phagocytic cells by carbonyl iron powder caused a loss of this suppressive effect. These results suggest the requirement for phagocytic cells in this suppressive effect and the possible involvement of phagocyte-mediated immunological mechanism in the pathogenesis of some cases of idiopathic aplastic anaemia.

Role of adherent suppressor cells in the depression of cell-mediated immunity in Hodgkin's disease and lung carcinoma

The mechanism of the depression of cell-mediated immunity (CMI) in patients with Hodgkin's disease (HD) and lung carcinoma (LC) was investigated before any treatment. In 9 patients out of 14 with HD and in 4 patients out of 14 with LD, a depressed lymphocyte reactivity to phytohaemagglutinin (PHA) was observed. In 3 out of 9 patients with HD and in 2 out of 4 patients with LC who exhibited a depressed lymphocyte response to PHA, suppression caused by adherent cells and mediated by prostaglandins was evidenced. No relationship was found between this mechanism of suppression and depression of CMI in vivo as judged by skin tests to common recall antigens.

The consequences of the chemotherapy of Hodgkin's disease: The 10th David A. Karnofsky Memorial Lecture

The most important consequence of using chemotherapy for Hodgkin's disease is its cure. Results of the MOPP program, developed at the National Cancer Institute in 1964, indicate that the majority of the 80% of patients who attain complete remission, who are at risk for ten years, have remained disease-free. The presence of symptoms and the histologic subtype, nodular sclerosis, has had important negative influences on prognosis. Review of three long-term adverse consequences of chemotherapy revealed sterility to be the most significant effect of drug treatment in this young population. Adverse effects of the immunosuppressive drugs in MOPP proved to be minimal. The carcinogenic effect of MOPP when used alone was surprisingly small, but increased significantly when combined with irradiation. National mortality from Hodgkin's disease has decreased abruptly since the introduction of effective chemotherapy for Hodgkin's disease in 1970.

Hodgkin's disease: pathology and pathogenesis

The pathogenesis of Hodgkin's disease has been the subject of intensive investigation for nearly a century. Numerous lines of inquiry have been pursued and the resulting quantity of literature on the subject attests to the enigmatic nature of the disease. Periodically, it becomes prudent to review progress in the study of a disease such as this, in light of recent methodologic and conceptual advances. By so doing, a more integrated view of the disease process may emerge, thereby guiding future research endeavors. The present report is undertaken to explore, in depth, recent advances in the study of the pathology and pathogenesis of Hodgkin's disease. Contemporary classifications, clinicopathologic and epidemiologic studies, cellular and humoral derangements, and the controversial nature of the Reed-Sternberg cell are considered.

Prostaglandin generation by separated human blood mononuclear cell fractions

Prostaglandins (PGs) have been widely implicated as modulators of immuno-inflammatory reactions. The cellular source of such immunoregulatory PGs has generally been thought to be the macrophage/monocyte, however several workers have suggested that adherent T-lymphocytes may be involved. We have attempted to resolve this question and have assayed PGE2 and thromboxane B2 release by purified sub-populations of human blood lymphocytes. Separated lymphocyte populations produce little PGEs when compared to monocytes and we concluded that the levels of PGs generated could be explained by monocyte contamination. In conclusion, we feel that the monocyte/macrophage acts as the source of immunoregulatory prostaglandins.

Short- and long-term effects of radiation on T-cell subsets in peripheral blood of patients with Hodgkin's disease

The present study was undertaken to determine the effect of radiotherapy on subpopulations of peripheral blood T cells from patients with Hodgkin's disease. T cell were purified from each specimen, and proportions and absolute numbers of T lymphocytes bearing receptors for the Fc portion of IgG (TG) and for Fc portion of IgM (TM) were enumerated by rosetting T cells with ox red blood cells (ORBC), which had been coated with anti-ORBC rabbit IgG or IgM, respectively. In untreated patients, the percentage of TG cells was significantly increased, and the percentage of TM cells was significantly decreased when compared with control values. In patients examined after radiotherapy, there was a severe depletion of total T lymphocytes. The percent and absolute values of TM cells were also markedly decreased in comparison with those found in either normal controls or untreated patients. In contrast, relative proportions of TG cells were significantly increased in the same treated patients, but the absolute numbers of these cells were essentially unchanged in comparison with those found before radiation therapy. There was a partial and progressive restoration of the number of TM lymphocytes some years after the treatment, but reduced percentages of TM lymphocytes and increased percentages of TG lymphocytes were still found in patients in continuous complete remission for at least five years or more. Similar alterations of the two T-cell subsets were also found in the peripheral blood of a small group of patients treated with radiation for testicular seminoma. These data clearly demonstrate that radiation therapy has a differential effect on identifiable and distinct subsets of cells in the human T-cell class.

Regulation of cyclic AMP levels in human lymphocytes and lymphoblasts by prostaglandins

The sensitivity of human lymphocytes to prostaglandins was compared to that of two lines of cultured lymphoblasts. It was found that 25 nM PGE1 increased lymphocyte cyclic AMP levels twofold, but had no effect on lymphoblasts. At 2.8 micrometers PGE1 the increase of cyclic AMP in lymphocytes was 14 fold versus a 1-3 fold increase in lymphoblasts. Lymphoblasts maintained a response to 6-keto-PGE1, isoproterenol and histamine similar to that observed in lymphocytes. Thus, it appears that the rapidly proliferating lymphoblasts excape signals inhibiting proliferation by impairing the function of the PGE receptor.

Influence of anti-inflammatory drugs on the interaction of lymphocytes and macrophages

The helper function of macrophages in lymphocyte stimulation is well known, but there are indications that macrophages may also exert a suppressor effect on lymphocytes. This effect might be due to prostaglandins secreted by the macrophages. In order to test this hypothesis anti-inflammatory drugs, some of which are known inhibitors of prostaglandin synthesis, were added to a series of phytohaemagglutinin (PHA)-stimulated lymphocyte cultures containing different proportions of macrophages and lymphocytes. The experiments showed that high concentrations of all drugs were inhibitory. Moderate concentrations of some of the PG-synthesis-inhibiting drugs (like indomethacin and mefenamic acid), however, appeared to have a stimulatory effect. The stimulation was more pronounced in cultures containing a high proportion of macrophages. These results support the assumption that macrophages release prostaglandins, which suppress PHA-induced lymphocyte proliferation.

Indomethacin-mediated enhancement of lymphocyte response to mitogens in healthy subjects and lung cancer patients

Indomethacin (prostaglandin synthetase inhibitor) was found to be capable of enhancing the mitogen-induced lymphocyte proliferative responses of healthy subjects and patients with lung cancer. A whole-blood culture technique was used. Indomethacin had no mitogenic activity. We observed a greater enhancement of lymphocyte response by indomethacin in weak responders as compared with strong responders in healthy subjects and lung cancer patients. A greater enhancement was also noted in lung cancer patients with active disease as compared with lung cancer patients in remission. In a separated cell culture system, the indomethacin exerted no effect on purified T cells in the absence of monocytes, while this agent exerted its enhancement effect on T lymphocyte response in the presence of autologous monocytes of lung cancer patients. This suggests that monocytes (suppressor cells) may secrete prostaglandins, which are responsible for the impairment of T lymphocyte response in lung cancer patients.