Role of suppressor T cells in pathogenesis of common variable hypogammaglobulinaemia

Imbalances in T cell subpopulations associated with immunodeficiency and autoimmune syndromes

Abnormal proportions of the distinct T cell subpopulations binding the Fc portion of IgM (T-M) cells and those bearing receptors for the Fc portion of IgG (T-G) cells, were observed in blood samples from patients who had congenital or acquired abnormalities of the thymus, severe combined immunodeficiency, or an unexplained primary deficiency in cell-mediated immunity; most had too few circulating T-M cells and often an overabundance of T-G cells. In an in vitro evaluation of lymphocyte from one of three thymoma patients with an elevated T-G subpopulation, removal of T-G cells abrogated the suppression of T-M cell help of B cell differentiation induced by pokeweed mitogen. A spectrum of patients with sex-linked infantile agammaglobulinemia, variable hypogammaglobulinemia, and selective IgA deficiency, and a few patients with autoimmune syndromes infrequently had distorted representation of these T cell subpopulations in the circulation. This suggests that B cell dysfunction in many of these patients is not merely due to numerical excesses or insufficiencies of helper or suppressor T cells.

B- and T-cells and Ig-containing blast cells in healthy children

Studies on rosette-forming cells and IgG, IgA, IgM and IgE-bearing lymphocytes were carried out in 70 healthy children aged 5 to 15 years. Furthermore, in 20 of these children, the percentages of IgG, IgA, IgM and IgE-containing blast cells after pokeweed mitogen stimulation of peripheral lymphocytes were evaluated. No differences in the percentages of rosette-forming cells, or in Ig-bearing and Ig-containing cells were found when three different age-groups were compared.

Differentiation of human lymphocytes by pokeweed mitogen in vitro: studies in normal and in immunodeficient subjects

Immunoglobulin (Ig) synthesis and secretion by peripheral blood lymphocytes activated by pokeweed mitogen (PWM), and by phytohemagglutinin (PHA) was measured in normal individuals and in subjects with primary immunodeficiency. Unstimulated cultures demonstrated stable, low Ig synthesis of all major Ig classes; PWM showed a peak of Ig synthesis at day 5; PHA cultures demonstrated a late peak of ig production at day 9. Three cases of common variable immunodeficiency showed different patterns of data when the percentage of B cells in blood and Ig production in vitro were used as parameters. Two persons with immunodeficiency and thymoma showed decreased Ig production in vitro, and had suppressor cells capable of blocking Ig production by normal lymphocytes in co-cultivation experments.

Activated T-cell in autoimmune haemolytic anaemia

In 12 of 14 patients with clinically active autoimmune haemolytic anaemia high levels (9-78%) of homologous and autologous rosetting cells were found in the peripheral blood. In 10 of these patients, who were observed over a period of 2 years, the levels bore a direct relationship to the activity of the disease. The cells so identified were T-lymphocytes. The role of cells, identified by this method in AIHA, is discussed.

In vitro TNP-specific antibody formation by peripheral lymphocytes from patients with systemic lupus erythematosus

Immunological reactivity in patients with systemic lupus erythermatosus (SLE) was assessed by investigating in vitro trinitrophenyl (TNP)-specific antibody formation by peripheral lymphocytes. Peripheral lymphocytes from 16 patients with SLE were cultured with TNP conjugated with horse erythrocytes (TNP-HRBC) in the presence of 2-mercaptoethanol. The hemolytic plaque assay was used to detect hapten (TNP)-specific antibody-forming cells. Peripheral lymphocytes from normal individuals failed to produce antibody to TNP, whereas SLE lymphocytes produced a significant number of plaque-forming cells. Co-culture experiments with SLE and normal lymphocytes suggested that patients with SLE have a defect in T lymphocytes, leading to abnormal antibody production.

Agammaglobulinemia with arthritis and celiac disease developing after infectious mononucleosis. Follow-up study of a case

A previously healthy 2 1/2-year-old boy from a healthy family developed agammaglobulinemia with arthritis 3 months after infectious mononucleosis (IM). The response of serum immunoglobulins at the initial stage of IM was typical, with greatly elevated IgM and a positive IM-specific heterophil antibody test. A secondary celiac disease was diagnosed one year after IM. Considering the serum immunoglobulin levels and the normal half-lives of IgM and IgG, it seems very probable that the synthesis of immunoglobulins ceased about one month after the onset of IM. The role of suppresor T-cells in the development of acquired secondary agammaglobulinemia is discussed.

Depressed in vitro peripheral blood lymphocyte response to mitogens in cancer patients: the role of suppressor cells

The reactivity of peripheral blood lymphocytes from patients with advanced malignancy was assessed by mitogen-induced stimulation of protein synthesis as measured by 3H-leucine incorporation. It was confirmed that the lymphocyte response of patients was depressed. Furthermore, the lymphocytes of 15 out of 27 cancer patients, selected because of their low responses, inhibited the reactivity of normal lymphocytes in co-cultures. The lymphocytes from one patient with Hodgkin's disease were also inhibitory. In contrast, lymphocytes from healthy subjects, patients with chronic lymphocytic leukaemia, lymphosarcoma or multiple myeloma caused no suppression. Experiments with purified cell populations from patients with carcinoma indicated that purified T cells responded to mitogens while unseparated lymphocytes failed to respond and that the inhibitory activity was due to adherent cells, presumably monocytes. There was no evidence for B-cell-mediated suppression. However, in two cases inhibition was caused by isolated T cells of the patients and not by adherent cells. These experiments suggested that one mechanism for the depression of cell-mediated immunity seen in patients with advanced cancer may be the nonspecific suppresssion of certain T-cell functions by circulating monocytes.

Primary deficiencies in humoral immunity

Patients with primary disorders of B lymphocytes and immunoglobulins usually display increased susceptibility to bacterial infections but atopic, autoimmune, and malignant disorders are also more common in these patients. The spectrum of these disorders ranges from a virtual absence of B cells and immunoglobulins to selective deficiencies of immunoglobulin subclasses. The diagnosis is dependent upon the demonstration of the immunologic deficits by specialized laboratory procedures which include the quantitation of immunoglobulins, the formation of antibodies in vivo and in vitro and the demonstration of B cells in the tissues or the peripheral blood. There are five major points in the management of these patients: (1) the delineation of the immunologic defects by laboratory testing, (2) the use of parenterally injected human immunoglobulins, (3) the rapid identification of infecting organisms and the prompt institution of appropriate antibiotic therapy, (4) screening the family for immunodeficiency in those cases which are of genetic origin, and (5) genetic counseling.

Immunodeficiency with lymphoid hyperplasia

A 2 1/2-year-old boy presented with recurrent respiratory tract infections, generalized lymphadenopathy and hepatosplenomegaly. Immunologic evaluation revealed a deficiency of humoral immunity. Repeated lymph node biopsies during a 10-year follow-up constantly showed excessive follicular hyperplasia with huge germinal centers consisting of germinoblasts, but lacking plasma cells. The disease can be interpreted as a subtype of the common variable immunodeficiency in which the commutation of germinoblasts to plasma cells in the evolution of B cells is blocked.

Lymphocyte purine 5'-nucleotidase edficiency in primary hypogammaglobulinaemia

The mean activity of purine 5'-nucleotidase (E.C.3.1.3.5) in lymphocytes was significantly lower in patients with non-familial adult onset "variable" primary hypogammaglobulinaemia than in non-hypogammaglobulinaemic control subjects. These findings suggest that 5'-nucleotidase activity is necessary for normal lymphocyte function. This may be related to its role in facilitating the transfer of newly formed purines across cell membranes by converting them from nucleotides to nucleosides. This enzyme defect may be a characteristic metabolic lesion in at least some of the patients; alternatively, it may be secondary to some other metabolic defect or plasma-membrane change.

Suppression of erythroid-colony formation by lymphocytes from patients with aplastic anemia

To explore the possible role of cell-mediated suppression of erythropoiesis in acquired aplastic anemia, we studied the effect of peripheral blood lymphocytes from seven patients with aplastic anemia on erythroid-colony formation by normal human bone marrow in an in vitro plasma clot-culture system. Varying numbers of peripheral blood lymphocytes (0.5 to 6 X 10(5) cells) were cocultured with 6 X 10(5) normal bone-marrow cells in the presence of 2 IU of erythropoietin for seven days. Peripheral blood lymphocytes from five of the seven patients with aplastic anemia caused a 79 to 94 per cent reduction of erythroid-colony formation. Thus, at a peripheral blood lymphocyte concentration of 2 X 10(5) cells, the numbers of erythroid colonies formed (control vs. experimental) were 374 +/- 16 (S.E.M.) vs. 22 +/- 6, 48 +/- 4, 50 +/- 16, 80 +/- 4 and 27 +/- 3. These results suggest that some patients with aplastic anemia possess a population of lymphocytes capable of suppressing in vitro erythropoiesis.

T-cell regulation of immunoglobulin synthesis and proliferation in pokeweed (Pa-1)-stimulated human lymphocyte cultures

In pokeweed (Pa-1)-stimulated human lymphocyte cultures, T cells are essential for the survival, proliferation, plasma-cell development, and high-rate Ig secretion of B cells. Their effects are T-cell-specific in the sense that B-cell stimulation does not take place in the absence of T cells even when fibroblasts or monocytes are provided. The experimental system is the most effective model for activation of human B lymphocytes so far described. Plasmablast development requires approximately 7 days in culture. In T + B-cell cultures established at 1 X 10(6)/ml (1 X 10(4)/mm2) initial cell density, plasma cells can secrete, on the average, as much as 40-70 pg IgM or IgG per cell per day. When the initial T-cell density is increased well above 1.0 X 10(6)/ml, a T-cell-mediated depression of Ig synthesis becomes predominant. Thus, in the pokeweed model T-cell effects represent a balance of helper and suppressor influences. The study also shows that B cells are heterogeneous. A non-adherent IgG-committed (smIg-?) TONSIL B-cell population seems to be less susceptible to T suppressor effects than normal tonsil B cells. This subset proliferates particularly well and synthesizes large quantities of IgG in the presence of large initial proportions of T cells.

Immunological aspects of purine metabolism

The development of our knowledge of the immune system has been reviewed and evidence presented of the need for a rapid rate of purine synthesis de novo for the proliferative events in this process. The mechanism of the inhibition of the immune system in a model of ADA deficiency has been studied intensively and considerable indirect evidence obtained of adenosine toxicity as a possible mediator of a reversible inhibition of proliferation of T-cells and to a slightly lesser extent B-cells. A secondary inhibition of ADA by inosine accumulation in PNP deficiency is proposed as a unifying hypothesis in which a somewhat lesser adenosine toxicity would inhibit proliferation only only of T-cells. The correction of the immune response by addition of ADA both in vitro and in vivo provides strong evidence in favor of this view. In HPRT deficiency no evidence was found of a gross impairment of the immune system; however, the HPRT enzyme is required for inhibition of the immune response by 6MP in a variety of systems using different mitogenic stimuli.

Suppressor function of peripheral blood mononuclear cells in normal individuals and in patients with systemic lupus erythematosus

Normal peripheral blood mononuclear cells demonstrated increased DNA synthesis and secretion of newly synthesized protein when suboptimal concentrations of Concanavalin A (Con A) were added to the cultures after 24-h incubation in vitro. Cells stimulated by Con A, 1 mug/ml, after 24-h incubation demonstrated 3.0 times more tritiated thymidine incorporation, and 4.4 times more 14C-amino acid incorporation into newly synthesized secreted protein, than cells stimulated at 0 h (P less than 0.001). The acquisition of increased responsiveness was not abrogated by washing and resuspending the cells in fresh medium. Since the increased responsiveness could be inhibited by the addition to the cultures of small numbers of cells previously activated by Con A it is suggested that the enhanced reactivity acquired in culture represents the loss of a subpopulation of suppressor cells that modulate the T-lymphocyte response. Cells from nine patients with active, untreated systemic lupus erythematosus demonstrated normal responses to optimal concentrations of Con A added at 0 h, but an impaired response to Con A, 1 mug/ml. When these cells were incubated for 24 h, a significant increased response to Con A was not observed. This observation suggests that patients with active SLE lack circulating suppressor cells. When seven SLE patients were again studied after corticosteroid therapy had led to clinical improvement, the response to Con A, 1 mug/ml, added after 24-h incubation was similar to that observed in normal controls, suggesting that suppressor function in SLE returns as disease activity declines.

Serological precipitation method for studying biosynthesis and secretion of immunoglobulins by human peripheral blood lymphocytes

A reproducible, serological method to quantify radiolabeled immunoglobulin (Ig) synthesized and secreted by human peripheral blood lymphocytes is described. In contrast to indirect precipitation (rabbit antihuman Ig and goat antirabbit Ig), the direct coprecipitation method using human IgG and rabbit antihuman IgG F (ab)2 showed much smaller, non-specifically precipitable radioactivity (i.e., 2 approximately 14%) without affecting Ig radioactivity.

Enzyme replacement therapy for adenosine deaminase deficiency and severe combined immunodeficiency

To evaluate their role as a form of replacement therapy, frozen irradiated red blood cells were administered to a child with adenosine deaminase deficiency associated with severe combined immunodeficiency disease. In vitro lymphocyte responses to mitogens and allogeneic cells were restored. Subsequently, a "thymus shadow" appeared, and immunoglobulin synthesis was demonstrated. Frozen irradiated plasma, which alone had no effect on lymphocytes numbers or responses, promoted lymphocytosis when given with frozen irradiated red blood cells. The patient received the transfusions with or without irradiated plasma at four-week intervals and remained free of infection for 17 months. The patient's lymphocyte adenosine triphosphate levels were elevated before therapy, which consistently reduced them without altering the lymphocyte adenosine deaminase activity. Enzyme replacement therapy may provide a way to treat patients with adenosine deaminase deficiency associated with severe combined immunodeficiency disease who do not have histocompatible bone-marrow donors.

Polyclonal activation of bone-marrow-derived lymphocytes from human peripheral blood measured by a direct plaque-forming cell assay

A culture and assay system for the stimulation of human peripheral blood lymphocytes with polyclonal activators of bone-marrow-derived lymphocytes (B cells), such as pokeweed mitogen and Escherichia coli lipopolysaccharide, and subsequent measurement of single cell antibody production by a hemolysis-in-bel direct plaque-forming cell assay against sheep erythrocytes has been established. The critical culture requirements have been delineated and a new highly sensitive ultrathin gel assay method has been described. Under these conditions a substantial and highly reproducible plaque-forming cell response was detected in normal human peripheral blood. This system can be readily used to explore the complex events associated with activation of human B cells.

A suppressor T-cell defect in tropical splenomegaly syndrome

Serum-IgM is always abnormally high in tropical splenomegaly syndrome. It is postulated that patients with this disease have an abnormal immunoglobulin response to malaria because they lack effective T suppressor cells. This defect may be genetically determined, thus explaining the tribal and familial aggregation of the disease. Hypermacroglobulinaemia is associated with the formation of large amounts of high-molecular-weight immune complexes. These complexes are important in the pathogenesis of the clinical features of the syndrome.

Aplastic anemia: presence in human bone marrow of cells that suppress myelopoiesis

Bone marrow from a patient with aplastic anemia was shown by multiple criteria to have a block in early myeloid differentiation. This block was overcome in vitro by elimination of marrow lymphocytes. Furthermore, this differentiation block was transferred in vitro to normal marrow by coculturing with the patient's marrow. We suggest that some cases of aplastic anemia may be due to an immunologically based suppression of marrow cell differentiation rather than to a defect in stem cells or their necessary inductive environment.

Idiopathic late-onset immunoglobulin deficiency. Clinical observations in 50 patients

Fifty patients with late-onset idiopathic immunoglobulin deficiency were studied and the frequency of various clinical associations and complications was observed. Men and women were equally affected, although the age at onset in men peaked in the third decade whereas it was more uniformly distributed in women. Sinobronchopulmonary infections were common and were caused by Haemophilus influenzae. Diplococcus pneumoniae, Streptococcus pyogenes and Staphylococcus aureus: bronchiectasis occurred in 28 per cent. Thirty patients (60 per cent) had diarrhea, which was often associated with steatorrhea, giardiasis, achlorhydria, abnormal Schilling tests and morphologic abnormalities on small bowel biopsy specimens, including nodular lymphoid hyperplasia; three patients had pernicious anemia. In the 20 patients without diarrhea these abnormalities were not observed except for giardiasis in one patient and achlorhydria in two patients. Cholelithiasis occurred in both groups in about a third of the patients tested. A high degree of susceptibility to neoplasia was noted. Thyroid abnormalities, including primary hypothyroidism and Graves' disease, were observed in six patients. Additional occasional findings were vitiligo, keratoconjunctivitis sicca and arthritis. Splenomegaly occurred in 14 (28 per cent) patients. The percentage of B lymphocytes in the blood was determined in 10 patients; it was normal or slightly decreased in eight patients and low in two patients.

Heterogeneity of lymphocyte subpopulations in severe combined immunodeficiency. Evidence against a stem cell defect

Surface markers typical of T and B lymphocytes were present on varying proportions of peripheral blood lymphocytes from three infants with severe combined immunodeficiency disease. Despite this, functions mediated by T and B cells were either absent or very minimal in all three, including cell-mediated responses in vivo; the in vitro proliferative response to mitogens, allogeneic cells, or antigens; effector cell function in lymphocyte-antibody lymphocytolytic interaction assays; and in vitro synthesis of IgG, IgA, and IgM. In contrast, mononuclear cells from one of the infants were tested and found capable of lysing both human and chicken antibody-coated erythrocyte targets normally. Co-cultivation experiments with unrelated normal control lymphocytes failed to demonstrate suppressor cell activity for immunoglobulin synthesis in these infants. Augmentations of immunoglobulin production from 310 to 560% over that expected on the basis of individual culture data were noted in co-cultures of one of the infants' cells with two different unrelated normal control cells. These findings suggest that that infant may have had a T helper cell defect or that his T cells were unable to produce soluble factors necessary for B cell differentiation. The finding of cells with differentiation markers characteristic of T and B lymphocytes in each of these patients, though in variable quantities, is further evidence for heterogeneity among patients with the clinical syndrome of severe combined immunodeficiency and argues against the concept that their immunodeficiency was due to a stem cell defect.

Suppression of B-cell differentiation by leukocytes from hypogammaglobulinemic patients

Leukocytes from patients with several forms of immunodeficiency characterized by apparently differing defects in B-lymphocyte maturation produced few or no plasmacytoid cells in vitro, and were capable of suppressing the generation of plasma cells in co-culture with cells of normal persons, in the presence of pokeweed mitogen. Such inhibition was commonly observed in cultures which included cells from patients with primary immunoglobulin deficiency, but was not seen to a significant degree in identical co-cultures of cells from normals. The suppression observed was not dependent upon mixed leukocyte culture reactivity. Both sheep erythrocyte-rosetting lymphocytes and adherent cells appeared to participate in these effects in some patients. In one patient with common variable immunodeficiency, but not in several others, removal of suppressing cells permitted the patient's remaining cells to differentiate into plasma cells in vitro. Because of the diverse syndromes in which suppression was observed, it is likely that, in at least some hypogammaglobulinemic patients, the suppression is secondary to the disease process rather than being the primary pathogenic mechanism.

Pulmonary complications in primary acquired hypogammaglobulinemia: surgical considerations

With the discovery and routine use of antibiotics, a virtually new disease--primary acquired hypogammaglobulinemia--was recognized. More precise clinical, genetic, and laboratory endeavor has proved, in fact, that it is really one of a whole host of individual disease entities, all with the common feature of inadequate production and marshalling of gamma globulin to combat infection. Although the condition has been recognized in children's medicine for two decades, the survival of these early victims into adolescence and adulthood is now bringing them to the attention of surgeons as candidates for drainage or resection of suppurative disease of the lung, air tubes, and pleura. In fact a triad has emerged, with some of these patients having infectious disease in the lungs and sinuses associated with enlargement of the spleen when first seen. Often it is the radiologist who first suspects the diagnosis when he recognizes one or more features of this diagnostic triad. Three personal cases are presented together with a technique of management that appears successful. As with the recognition of any new disease, occult and subclinical presentations become more common as suspicion progresses, and ease of confirmation is afforded.

PHA-induced activation of suppressor cells in normal human peripheral blood lymphocytes

Normal human peripheral blood and tonsil lymphocytes can be stimulated to proliferate by phytohemagglutinin (PHA). When cells cultured with this mitogen for 3 days were transferred fo fresh autologous lymphocytes in fresh medium with PHA, the mitogen response of the fresh lymphocytes was suppressed. The suppression required the presence of viable cells, in that culture supernatants alone were not inhibitory and cell extracts showed only marginal inhibition. Approximately equivalent numbers of previously stimulated cells were required to produce optimal suppression of the PHA response of fresh cells. Cells irradiated after PHA stimulation were as effective as nonirradiated cells is causing suppression. PHA-stimulated cells also inhibited concanavalinA-induced proliferation and a mixed lymphocyte reaction. However, PHA-stimulated cells only partially inhibited the response to pokeweed mitogen. The suppressive effects were fully retained by a nylon-wool-enriched T-cell fraction but not by a B-cell-enriched fraction.

In vitro induction and measurement of hemolytic plaque forming cells in man

Following co-cultivation with sheep red cells or ovalbumin, Hypaque-Ficoll-separated human tonsillar lymphocytes were demonstrated to generate specific hemolytic PFC with maximum numbers at day 5-7. PFC were enumerated on poly-L-lysine coupled red cell monolayers in Microtest-II-plates. Plaque formation appeared to be puromycin-sensitive, complement-dependent and showed clear specificity for the antigen present during the inductive culture. Treatment of PFC with mu-chain specific antisera and complement resulted in complete inactivation of PFC; gamma-chain antisera had no effect. The development of such a simple and sensitive assay system permits the analysis of cellular interactions required for the induction of PFC responses in man.