In vitro studies of ulcerative colitis. II. Cytotoxic action of white blood cells from patients on human fetal colon cells

The humoral immune system in inflammatory bowel disease. II. Immunologlobulin levels

As there have been reports of differences in mean levels of serum immunoglobulins between patients with ulcerative colitis and Crohn's disease, serum IgG, IgA, and IgM were estimated in 158 patients with inflammatory bowel disease and the results correlated with the clinical features of the patients. Although a higher mean IgG level in ulcerative colitis compared to Crohn's disease was confirmed, no difference was found when the comparison was limited to patients with colonic Crohn's disease. Patients with either disease had higher mean IgM levels than controls, and the IgM levels were higher on treatment with corticosteroids and showed a tendency to rise in remission. IgG and IgM levels were also higher in both diseases if extraintestinal manifestations were present. It is concluded that if clinical features, particularly disease site, are taken into account, the overall immunoglobulin responses in these two diseases show no differences.

Circulating immune complexes in ulcerative colitis. I. Correlation to disease activity

Twenty-two patients with ulcerative colitis were studied for occurrence of circulating immune complexes (IC) by three independent methods, a complement consumption assay, a Clq-binding assay and a RF-binding assay. All patients had the disease in an active stage when the study was initiated. Positiveness in two or more test systems was considered to indicate the presence of IC in the serum sample examined. By this criterion, circulating complement-fixing IC were detected in eight out of the twenty-two patients (36%; 95% confidence limits: 17–60%). IC were detected most frequently in patients with long-standing disease.

A correlation between the occurrence of circulating IC and disease activity, in terms of visible blood in faeces and number of bowel movements per day, was demonstrated. Cytological examination of the rectal mucus indicated moderate to severe inflammation in all IC-positive patients. Six out of the eight IC-positive patients were subjected to short-term glucocorticosteroid treatment; only one of these patients exhibited circulating IC and high disease activity after treatment —this patient was colectomized. Salazosulphapyridine treatment showed no relation to IC occurrence. Four out of the twenty-two patients (18%; 95% confidence limits 5–40%) were positive for organ non-specific antinuclear factor (ANF), but the presence of ANF did not correlate with circulating IC. Neither was any significant correlation between antibody titres to E. coli O119:B14 antigen and IC occurrence demonstrable.

Recurrent aphthous stomatitis: clinical characteristics and evidence for an immunopathogenesis

Recurrent aphthous stomatitis is one of the most common diseases affecting the oral mucosa, and one of its variants is the most painful affliction of the oral mucosa. The lesions of recurrent aphthous stomatitis can be manifested as part of a broad spectrum of clinical disease ranging from the common minor aphthous ulcers to Behçet's syndrome. Differential diagnosis, although not often difficult, must include many conditions capable of producing erosive and ulcerative oral mucosal lesions. The salient features of recurrent aphthous stomatitis suggest that it is a heterogeneous entity. Recent immunologic investigations have focused attention on a possible immunopathogenesis and the evidence for this is reviewed.

Association of some enterobacteria with the intestinal mucosa of mouse in relation to their partition in aqueous polymer two-phase systems

The association of enterobacteria with mouse intestinal mucosa has been investigated by pumping heat-killed, radioactively-labelled bacteria through the gut lumen in vitro. Approximately 20 cm of the small intestine proximal to the ileo-caecal valve was rinsed, excised and maintained in an organ bath. By using two different bacteria labelled with different radioactive isotopes, the relative association of the two bacterial pumped through the same piece of gut was determined. Cross-labelling showed that choice of isotope did not affect the association. Salmonella typhimurium 395 MR10 was used as reference and the other bacteria investigated related to it. S. typhimurium MR10 and Escherichia coli O 14 K7, which are relatively lipophilic, showed greater association than S. typhimurium 395 MS and E. coli O 111 K58, which are more hydrophilic. Prolonged incubation of bacteria with the length of intestine in vitro leading to damage of the brush border of the mucosal epithelium enhanced the association of the bacteria. These data suggest that similar physico-chemical surface properies govern the association certain enterobacteria to the intestinal mucosa as in phagocytosis with professional phagocytes.

Autoimmune disease antigens

The first step towards understanding the cellular interaction which results in autoimmune disease is to determine what triggers the recognition between a specific autoimmune antigen determinant and the cellular receptor. In this review, we have focused on the antigen inducing experimental allergic encephalitis (EAE) because the antigen has been characterized and a relatively large body of information on its biological activities has been accumulated. Clearly, a specific allergic encephalitis-producing determinant is present and is represented on a relatively small portion of the molecule. The determinant induces a wide variety of biological reactivities, some of which are classed as cellular mediated. An attempt is made to dissect activities such as blast transformation (BT), migration inhibitory factor (MIF), in vivo delayed type hypersensitivity reaction (DTH) and EAE and to relate them to the structural requirements which the determinants possess. The complexities which arise indicate that subpopulations of cells with different receptor activities may respond selectively and that recognition of the receptor is produced by an EAE determinant consisting of three amino acids in a specific linear sequence. Furthermore, under experimental circumstances the EAE activity can be dissociated from the other activities (BT, MIF, DTH), indicating that while these tests are used generally to follow various human autoimmune disease activities, they may represent the reaction of a broad spectrum of cells.

Lymphocyte-epithelial cell interactions in oral mucosal inflammatory diseases

Lymphocyte cytotoxicity for target cells is a method for evaluating specific lymphocyte stimulation. In vitro lymphocytotoxicity has been demonstrated in chronic ulcerative colitis and granulomatous colitis, polymyositis and dermatomyositis, systemic scleroderma, recurrent aphthous stomatitis, and periodontal disease. We have investigated lymphocytotoxicity in 36 patients with various oral inflammatory diseases using an automated cell-counting system. This investigation demonstrated in vitro lymphocytotoxicity for gingival epithelial target cells by aggressor lymphocytes harvested from patients with recurrent aphthous stomatitis and periodontal disease. This effect was not seen when the lymphocytes were harvested from normal subjects or from patients with other oral mucosal inflammatory diseases. The automated cell-counting system corresponded very well with the assay technique of exclusion of supravital dye.

Histopathology of cell mediated immune reaction in mouse colon--allograft rejection

Grafts of mouse fetal colon, implanted beneath the renal capsule of adult hosts, have been used to study the growth and development of colonic isografts and the rejection of colonic allografts. Isografts grew normally and maintained a structure similar to normal colon. Grafts between strains with H2 histocompatibility differences were rejected by 13 days after transplantation. Early progressive infiltration of the grafts by lymphoid cells was followed by increasing damage to, and subsequent loss of, the epithelial cell layer and destruction of the underlying muscle, changes which parallel those seen in rejection of skin and small bowel. The increase in survival time which is seen in allografts between strains with H2 identity was longer in the colon than has been seen in the skin or small bowel; none of the allografts of colon were completely rejected before 30 days, and some remained viable at 50 days. Comparison of the appearances of rejection in the colon with those of ulcerative colitis and colonic Crohn's disease does not show the striking similarity which is seen between small bowel rejection and coeliac disease. Many of the individual features of these diseases are, however, present in the course of colonic rejection.

The detection of serological factors in acute ulcerative colitis indicating a favourable short-term prognosis

Large-intestinal epithelial cells were obtained from operation specimens and by biopsy at sigmoidoscopy from 16 patients with acute severe mucosal ulcerative colitis and II control subjects with normal large-bowel mucosa. The ability of lymphocytes to release 51Cr label from large-intestinal epithelial cells was quantitatively assessed as percentage lymphocyte activity. The mean +/- standard deviation of percentage lymphocyte activity in 16 patients with acute ulcerative colitis on admission to hospital (88 +/- 8) was significantly greater than that in II normal subjects (16 +/- 8) (P is less than 0.01). In each study, samples of autologous serum were added to two reactions between lymphocytes and autologous large-intestinal epithelial cells. The results in the seven patients who came to urgent colectomy differed significantly from those in the nine who responded to corticosteroids. The mean +/- S.D. of percentage serological inhibition of lymphocyte activity in the group coming to colectomy was 44 +/- 16, and in those responding to steroids 12 +/- 5. When the serum of these patients was studied for immunofluorescent autoantibodies to normal human colonic mucosa, none of the seven patients treated by colectomy had detectable autoantibodies, in contrast with three of the nine patients with a more favourable short-term prognosis, in that they responded to steroid treatment.

Clinical use of immunosuppressive drugs: part II

In haematological diseases, insufficient data has been accumulated to evaluate the efficacy of immunosuppressive drug treatment in patients with erythroid aplasia or sideroblastic anaemia. Cyclophosphamide may be efficacious in inhibiting circulating anticoagulants in patients who need continued replacement of clotting factors. Azathioprine, 6-mercaptopurine, cyclophosphamide and vincristine have been used successfully in treating patients with idiopathic thrombocytopenic purpura, and some patients with auto-immune haemolytic anaemia may benefit from the addition of purine analogues. However, the use of immunosuppressive therapy seems to accelerate the presence of haematological malignancies in patients with macroglobulinaemia. In gastro-intestinal diseases, uncontrolled studies have shown nitrogen mustard, 6-mercaptopurine and azathioprine to be of modest benefit to patients with ulcerative colitis and Crohn's disease. In a controlled trial azathioprine plus prednisone proved more effective than prednisone alone in sustaining remission in patients with Crohn's disease. In patients with either chronic active hepatitis or primary biliary cirrhosis, however, there seems to be no benefit from immunosuppressive therapy for primary treatment of these diseases. Cyclophosphamide, azathioprine and methotrexate have all been used with some success in treating patient with uveitis, and in a controlled trial cytarabine has been shown to be beneficial to patients with herpes ophthalmicus. However, no benefit has been shown to patients with the eye changes of Graves' disease with either azathioprine or methotrexate. Patients with Paget's disease appear to be helped by mithramycin. Cyclophosphamide, chlorambucil and azathioprine are ineffective in treating patients with multiple sclerosis. 6-Mercaptopurine, azathioprine, methotrexate and cyclophosphamide have all produced some benefit in patients with myasthenia gravis, and some patients with idiopathic pulmonary haemosiderosis have responded to azathioprine, 6-mercaptopurine and cyclophosphamide. Alkylating agents have proved useful in treating some patients with asthma and in treating frequent relapsers among children with the nephrotic syndrome. In adults with membrano-proliferative glomerulonephritis some patients have responded to combination therapy with cyclophosphamide, azathioprine and corticosteroids. Immunosuppressive therapy is also indicated in prolonging graft survivals in patients receiving organ transplants. Drug toxicities of immunosuppressive agents are discussed. Their long-term effects, including mutagenic potential, have as yet not been fully elucidated.

Leucocytotoxicity in malignant and non-malignant colonic diseases

The survival of cells from five different cultures of allogeneic malignant colonic carcinoma, two from normal adult colonic epithelium and eight from foetal colonic epithelium in the presence of leucocytes from patients with neoplastic and inflammatory disorders of the colon has been compared. Cytotoxicity assessed by the reduction of the number of adherent target cells in microplate wells compared with those surviving in wells treated with tissue culture medium alone was observed with leucocytes from donors in all categories examined including those from individuals without any known abnormality. Patients with ulcerative colitis were the only group to reveal consistent reactivity against cultures derived from all three sources, an observation which may reflect sensitization to organ-related antigens in this disease. In contrast, leucocytes from patients with bowel neoplasia showed reactivity for cells derived from colon carcinoma tissue, which was comparable to that of healthy donors. Evidence for tumour-specific cytotoxicity was therefore lacking in this study. It is suggested that the detection of tumour-associated antigens on cultured cells may be limited by a number of factors of which the wide variation in reactivity among controls and unspecified nature of the target cells are likely to be of greatest importance.

An improved fluorescence probe cytotoxicity assay

The phenanthridine dye, ethidium bromide, which is actively excluded by viable cells, undergoes a significant fluorescence enhancement at 5900 A upon binding intracellular double-stranded polyribonucleotides. A rapid and sensitive assay of antibody mediated cytotoxicity to cells grown in vitro has been developed using this phenomenon. In this communication, we describe this fluorescence probe cytotoxicity assay and a sensitive electro-optical system designed to measure the fluorescence enhancement of ethidium bromide as it intercalates with intracellular polyribonucleotides. Basic characteristics of the fluorescence enhancement resulting from the interaction of ethidium bromide and non-viable cells are presented as well as examples of this assay as it has been used to study surface membrane neoantigens of cells tranformed by the oncogenic DNA virus, SV40.

The in-vitro action of lymphocytes on autologous colon epithelial cells in ulcerative colitis

The action in culture of peripheral blood lymphocytes on autologous large-intestinal epithelial cells was studied in 13 patients with severe mucosal ulcerative colitis. Two different methods were used to measure lymphocyte activity. These showed that autologous-lymphocyte-induced release of isotopic label and detachment in monolayer culture of large-intestinal epithelial cells was increased in acute ulcerative colitis when compared with findings in the same studies in six normal subjects. Subsequently in four of the six patients who responded to cortisone it was shown that lymphocyte activity against epithelial cells returned to the normal range. Further control studies showed little lymphocyte activity against autologous skin and ileum, suggesting that autologous-lymphocyte-induced damage of large-intestinal epithelial cells is a tissue-specific reaction in patients with acute ulcerative colitis. The absence of reactivity in other colonic inflammatory diseases also suggested that such increased in vitro lymphocyte activity is disease-specific for ulcerative colitis.

Leukocyte migration test in Crohn's disease, ulcerative colitis, and ankylosing spondylitis using Crohn's colon homogenate, mitochondrial, and microsomal fractions

Leukocytes from 33 patients with Crohn's disease, 20 patients with ulcerative colitis, and 20 patients with ankylosing spondylitis were tested for evidence of abnormal migration in the presence of preparations of colon from a patient with Crohn's disease. None of the patients was on treatment with immunosuppressive drugs. The test was also performed with leucocytes from 12 health subjects. Significant alteration was seen in the Crohn's disease group, particularly when the antigen used was mitochondrial or microsomal fraction of colon mucosa, whereas the patients in the ulcerative colitis group showed reactivity only with the whole colon homogenate and not with the subcellular fractions. The ankylosing spondylitis group showed no statistical difference from the normal controls with any of the antigens.

[The lymphocyte cytotoxicity test in tumor immunology (author's transl)]

The cytotoxic action of lymphocytes on cancer cells in vitro indicates sensitization of the patient against his own tumor. The technical difficulities of this test and possibilities of standardization and simplifying the procedure are discussed. Critical steps are isolation of lymphocytes and culturing target cells without loosing their specific antigenic structure. The need for specificity controls both for lymphocytes and tumor cells is emphasized. Labelling tumor cells with isotopes represents a major improvement in evaluating the result. The role of thymus- and bone marrow-dependent lymphocytes as well as blocking factors in the serum of tumor patients can be analyzed in the cytotoxic assay. A better understanding of these mechanisms may facilitate a therapeutic approach by manipulating the interaction of tumor cells and host.

Immunosuppression in the treatment of inflammatory bowel disease. I. Changes in lymphoid sub-populations in the blood and rectal mucosa following cessation of treatment with azathioprine

Lymphoid subpopulations in the blood and rectal mucosa were studied in six patients with ulcerative colitis or Crohn's disease who had been treated for over three years with azathioprine. Serial assays were performed to observe the changes occurring up to 12 weeks after treatment with azathioprine was stopped. While the patients were on the drug two lymphoid populations showed marked depression. These were the plasma cells of the rectal lamina propria, and blood lymphocytes with cytotoxic activity against antibody-sensitized target cells (`K' cells). After stopping azathioprine, both populations showed a rapid rise to reach near normal levels by 12 weeks. Most of the recovery occurred within 3–5 weeks. There was no significant change in circulating immunoglobulin-staining cells which could be attributed to the drug. Nor was azathioprine shown to have any effect on the mitotic response of lymphocytes to phytohaemagglutinin. Three patients, however, gave very low or erratic responses to PHA, which may have been related either to their disease or to steroid therapy. These results are discussed in relation to the mode of action of purine analogues as immunosuppressive agents.

Autoimmune encephalomyelitis: activation of thymus lymphocytes against syngeneic brain antigens in vitro

Thymus lymphocytes of normal adult rats were autosensitized in vitro against soluble antigens extracted from the brains of syngeneic rats. Injection of the autosensitized lymphocytes into syngeneic rats led to the development of brain lesions suggestive of autoimmune encephalomyelitis. Injection of control lymphocytes or the antigen extract alone did not cause lesions. Since sensitization in vitro requires the presence of lymphocytes programmed with specific receptors, the results indicate that normal rats have lymphocytes capable of recognizing central nervous system self-antigens. Hence, regulatory mechanisms, inoperative in vitro, probably function in vivo to prevent immune activation of self-recognizing lymphocytes and autoimmunity. This concept suggests a new approach to exploring the pathogenesis of autoimmune diseases.

The problem of chronic inflammatory bowel disease

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The effect of lymphocytes from sufferers from recurrent aphthous ulceration upon colon cells in tissue culture

The release of (51)Cr from labelled colon cells was used to assess a possible lymphocytotoxic effect of peripheral blood lymphocytes from patients suffering from recurrent aphthous ulceration. No significant (p > 0.03) difference was observed between the isotope release following incubation with patients' or control lymphocytes. The absence of such a lymphocytotoxic effect, detectable with oral epithelial cells, is discussed in relation to the role of cellular hypersensitivity in the pathogenesis of ulcerative colitis and aphthous ulceration.

Immunological studies in a patient with ulcerative colitis and sarcoidosis

This report describes a patient with both ulcerative colitis and sarcoidosis. This association is of interest because of the anergy for cellular immunity which was characteristic of the sarcoidosis and the cytotoxic effect of the patient's lymphocytes for allogenic colon epithelial cells which characterized the ulcerative colitis. This concordance of immunological findings suggests that the cytotoxic effect may have a basis other than cellular immunity.

In vitro detection of cytotoxic cellular immunity against tumor-specific antigens by a radioisotopic technique

[(3)H]Thymidine-labeled tumor cells are used to evaluate the cytotoxic cellular immune response against tumor-specific antigens; the loss of label due to destruction and detachment of target cells from the surface of the culture vessel is measured. Spleen cells from mice immunized against Moloney virus-induced rhabdomyosarcoma specifically destroyed the sarcoma cells, while cells from normal syngeneic mice did not. Peripheral blood lymphocytes from patients with malignant tumors were specifically cytotoxic to autologous tumor cells and to allogeneic tumor cells histopathologically identical to the autologous tumor, but not to autologous nonmalignant fibroblasts, or to allogeneic tumor cells from a histologically dissimilar tumor. Serum from the same patients specifically protected autologous tumor cells from lymphocyte cytotoxicity. This serum-mediated protection of tumor cells against autologous cellular immunocytotoxicity also extended to histologically identical allogeneic tumor cells. Cross-reactivity of anti-tumor cellular immunocytotoxicity in vitro, and its "blocking" by autologous serum, strongly suggest the presence of common tumor antigens. The antagonism demonstrated in vitro between serum and cellular immunity may explain the continued growth of malignant tumors in the face of demonstrable cellular immunity.

Autosensitization in vitro

Autosensitization of rat or mouse lymphoid cells against syngeneic fibroblast antigens was induced in cell culture. Rat lymphoid cells autosensitized by this method were able to produce immunospecific lysis of syngeneic target fibroblasts in vitro or GvH reactions in newborn rats. Autosensitized mouse spleen cells mediated similar GvH reactions when injected into newborn mice. The nature of the system used to induce immunity in vitro appears to argue against the possibility that lymphocytes capable of reacting against self-antigens could arise by mutation in cell culture. Hence, it is likely that cells potentially reactive against self-antigens preexisted in the lymphoid cell donors. The ability of autosensitized cells to mediate immune reactions in vivo suggests that the immunogenic self-antigens present on sensitizing fibroblasts also were accessible in the intact animals. Loss of natural self-tolerance in vitro, therefore, can be explained most simply by the existence of lymphocytes which are reversibly tolerant to self. Hence, ontogenic elimination of potentially self-reactive cells may not be the only basis for natural tolerance. Regulatory mechanisms, such as antigen excess, may have to function in vivo to prevent differentiation of self-tolerant lymphocytes. These regulatory mechanisms appear to be annulled in the cell-culture system. The present system thus may offer a new approach to studies of tolerance and regulation of cellular immunity.

Experimental myocarditis: in vitro and in vivo studies of lymphocytes sensitized to heart extracts and group A streptococci

Cytotoxicity was found in 78 per cent of rat heart cell cultures in contact with lymphocytes sensitized to rabbit heart extracts and in 65 per cent of those exposed to lymphocytes sensitized to rat heart. Lymphocytes sensitized to group A streptococci were cytotoxic on 82 per cent of the cultures while controls were affected in less than 20 per cent and to a much more limited extent. Agglutination of the sensitized lymphocytes by antilymphocytic serum inhibited the cytotoxic effect.

Passive transfer of lymphocytes from Lewis rats sensitized to rabbit heart produced myocarditis in thirteen of fourteen rats. The significance of these findings is discussed in relation to the pathogenesis of experimental myocarditis.

Mikulicz's recurrent oral aphthae: the effect of anti-lymphocyte serum upon the in vitro cytotoxicity of lymphocytes from patients for oral epithelial cells

Preincubation with rabbit anti-human lymphocyte serum suppressed the in vitro cytotoxicity of peripheral blood lymphocytes from patients suffering from Mikulicz's recurrent oral aphthae for oral epithelial cells. Further studies revealed that although the anti-lymphocyte antibody remained bound to the lymphocytes after the pre-incubation procedure it exerted no demonstrable cytotoxic effect and induced a minimal degree of transformation. The mechanisms by which the anti-lymphocyte serum may have suppressed the lymphocytotoxicity are discussed.

In vitro cytotoxicity by human lymphocytes from individuals immunized against histocompatibility antigens. I. Kinetics and specificity of the reaction. Influence of metabolic inhibitors and anti-lymphocyte serum

Lymphocytes from humans that had rejected allogeneic skin grafts acquired a cytotoxic potential, which was expressed in vitro upon contact with fibroblast monolayer cultures of the skin donor genotype. No cytotoxic effect was obtained on autochthonous fibroblasts, but did occur on other allogeneic fibroblasts, non-related to the skin donor, suggesting shared histocompatibility antigens. The damage to the target cells developed at the area of lymphocyte application and was detected after 48 hr. The cytotoxic effect of the immune lymphocytes on the specific target cells was suppressed by treatment with actinomycin-C, Mitomycin-C and prednisolone, indicating that cellular synthetic processes and cell divisions are required for cytotoxicity to be expressed. Anti-lymphocyte serum also inhibited the cytotoxic reaction, probably by coating the lymphocyte surface.

In view of previous investigations, concerning cytotoxicity exerted by non-immunized lymphocytes stimulated by non-specific agents, the present results suggest that the specificity of the cytotoxic damage by immunized lymphocytes is confined to the initial immunological recognition of the antigen(s) on the target cells. This reaction triggers the lymphocytes to a cytotoxic state which can be non-specifically expressed. The need for synthetic processes within the lymphocytes may be required for magnifying the process by increasing the number of cytotoxically activated cells and probably also for the continuous synthesis of the antigen-specific receptors.