The regulatory influence of activated T cells on B cell responses to antigen

Specific and nonspecific cooperation between M-locus-incompatible T and B cells during adoptive anti-hapten antibody responses in mice

CBA and AKR mice are identical at the major histocompatibility locus (H-2) but differ at the strong, non-H-2, mixed leukocyte culture (MLC)-stimulating M-locus. Adoptive secondary in vivo antibody responses using immune spleen cells from mice of these strains demonstrate two interesting findings. One is a non-specific augmentation of the anti-hapten antibody response of CBA B cells by AKR T cells. This allogeneic effect is unidirectional in the same sense as the MLC between cells from these two strains. The second is that, despite an ongoing allogeneic effect, M-locus-incompatible T and B cells show strong specific cooperation. Thus, it seems unlikely that the failure of H-2-incompatible T and B cells to collaborate specifically is due to inhibitory allogenic reactions.

Cell mediated immunity and the inflammatory system

In this review we have considered the evidence for the existence of lymphokines and have focused on the specific mechanisms by which lymphokines modify the behavior of the various inflammatory cells. These mechanisms are based for the most part on in vitro observations. We have therefore discussed in detail data that document an in vivo role for various lymphokines. This evidence is based on experiments falling into two broad categories: the identification of lymphokines in tissue extracts and serum, and the demonstration of various biologic activities of exogenous lymphokines administered locally or systemically. The details of these kinds of experiments have been presented throughout the preceding discussion. The demonstration of lymphokines in vivo adds a new dimension to our ability to study human disease. The detection of migration inhibition factor in serum, for example, is technically simpler than studies of lymphocyte reactivity in patients with altered cellular immunity. Migration inhibition factor has already been found in the serum in several clinical settings, as described. The capacity of exogenous lymphokines for suppressing manifestations of delayed hypersensitivity may provide an explanation for the altered immunoreactivity often observed in some of those diseases. A final comment is in order regarding the significance of lymphokine production in the overall biologic scheme of things. In previous sections we noted that although activation of lymphocytes for lymphokine production by specific antigen is a property of T cells, B cells may be so activated nonspecifically by certain mitogens. Moreover, it has been shown that migration inhibition factor, or substances with similar biologic and physicochemical properties, may be found in certain replicating cultures of nonlymphoid cells. Also, we have recently shown that migration inhibitory activity, as well as certain other lymphokine-like activities such as macrophage and lymphocyte chemotaxis, may appear following the in vitro or in vivo infection of nonlymphoid as well as lymphoid cells by certain viruses. All these results suggest that lymphokine production, rather than "merely" representing an effector mechanism for cell mediated immunity and for certain kinds of helper functions in antibody synthesis, represents a general biologic phenomenon that may play a role in various aspects of host defense. Thus, such mediator substances should be more properly called "cytokines." Lymphokines represent a restricted set of cytokines made by one class of cells (lymphocytes) activated in certain unique ways. In this view the lmyphocyte has acquired some specialized means for triggering such production, not available to other cells.

Separation of helper and suppressor T lymphocytes on a ficoll velocity sedimentation gradient

A 5-20% Ficoll velocity sedimentation gradient has been successfully applied to separate concanavalin A (Con A)-induced helper; and suppressor T cells. When titrated into a constant number of fresh normal spleen cells responding to sheep erythrocytes, cells from the top pool show stimulatory effects while those from the bottom pool show inhibitory activity. Both activities are found to be Con A dependent and anti-theta sensitive. We conclude that Con A-induced helper and suppressor T cells are distinct subpopulations and such separation will allow further characterization of these cell types.

Suppressor cells: dependence on assay conditions for functional activity

Spleen cells educated in vitro with sheep red blood cells (SRBC) suppressed the plaque-forming cell response of Mishell-Dutton assay cultures challenged with optimal doses of SRBC. Changing conditions in the assay cultures changed the effect educated cells had on the assay culture responses. For example, educated cells helped rather than suppressed assay cultures of suboptimal numbers of spleen cells. Similarly, augmentation resulted upon addition of educated cells to assay cultures challenged with suboptimal doses of SRBC. Such a reversal of regulatory effects was not observed when assay cultures were challenged with supraoptimal antigen doses. Educated cells helped assay cultures of B spleen cells, and the addition of normal T cells reinstated suppression. Furthermore, maintenance of assay cultures under stationary rather than the usual rocking conditions allowed educated cells to help rather than suppress the antibody response of assay cultures. These results show that when the response of the target population (assay cultures) is low, the regulator (educated) cells augment the response, and vice versa, supporting the hypothesis that the effect regulator cells produce depends on the activity of the cells they regulate.

Control of t-lymphocyte and B-lymphocyte activation by two complementing Ir-GLphi immune response genes

The possibility that the two complementing alpha- and beta-Ir-GLphi genes are independently responsible for controlling events in T lymphocytes and B lymphocytes, respectively, has been tested in double adoptive transfer experiments utilizing cells from appropriate inbred strains of mice. The results of these studies show that the functions of T lymphocytes and B lymphocytes and the cooperative interactions between T and B cells require the presence of both alpha- and beta-genes in each respective cell type. Moreover, evidence has been obtained in these studies that indicates a preference for the alpha- and beta-Ir-GLphi genes in the cis position to obtain the most effective T-B-cell interactions. The possible implications of these findings are discussed.

Suppressor cell induction in vitro. I. Kinetics of induction of antigen-specific suppressor cells

The induction of antigen-specific suppressor cells in vitro, using high concentrations (100 mug/ml) of keyhole limpet hemocyanin (KLH) in Marbrook flasks is described. Spleen and cortisone-resistant thymocytes were the richest source of suppressor cell precursors, compared to lymph node cells, peripheral blood lymphocytes or thoracic duct lymphocytes. Suppressor cells induced with KLH only suppressed KLH-reactive helper cells, and not B cells or helper cells of other specificity. The suppressor cells were T cells, as judged by their sensitivity to anti-Thy-1.2, heterologous anti-T, but not anti-B antisera.

Cellular responses to murine alloantigens of the major histocompatibility complex: the role of cell subpopulations that express different quantities of H-2 associated antigenic markers

Subsets of lymphoid cells that function in the initiation and differentiation of cell-mediated responses to H-2-coded alloantigens were defined with an antiserum raised between congenic resistant lines of mice that differed for a limited number of components of the H-2 complex. Only those cells that express "Ia markers" can stimulate responses to H-2K, D and/or I region antigens in mixed lymphoid cell cultures, even though all lymphoid cells apparently express the H-2K and H-2D-coded private antigens. Ia markers, therefore, serve to distinguish the subset of cells which includes as its members the stimulating cells. The Ia marker(s) is expressed on the cell membrane of at least one of the two T cell subsets that collaborate in the development of T effector cells to H-2-associated alloantigens, i.e. precursors and helpers. The cells remaining after lysis with our antiserum plus complement no longer can respond in the MLR. Syngeneic non-T cells cannot reconstitute the response. Most activated and proliferating cells express the Ia determinant(s). A proportion of T effector or killer cells, however, does not express the Ia markers. We suggest, therefore, that the MLR-responsive cell in normal lymph nodes is an "activated" cell and the "Ia markers" are involved in the differentiation of T precursor to T effector cells. The end stage T effector probably is devoid of the Ia marker.

Production of specific antisera to human B lymphocytes

Antisera have been prepared, in mice and rabbits, to membrane and sub-membrane fractions of human B lymphocyte derived lymphoid lines. Antisera to a protein subfraction were, after only minimal absorption, specific for human peripheral B lymphocytes, monocytes and B cell derived lymphoid lines. The antigen(s) recognised by these antisera were not the same as the previously described B-cell markers; immunoglobulin, Fc receptor, complement receptor and Ia antigens. The antigen(s) could not be removed from cells by lysostrip with anti- beta2 microglobulin.

Suppressor thymus-derived lymphocytes in fungal infection

Thymus-derived lymphocyte (T-cell) function, as determined in vivo by cutaneous reactivity to several antigens and in vitro by responsiveness to mitogens and antigens, was assessed in 14 patients infected with a variety of fungal organisms. While all patients manifested a normal frequency of peripheral blood T cells, only seven patients reacted to at least one of the antigens used for cutaneous testing and demonstrated normal in vitro T proliferative responses. Three patients exhibited cutaneous anergy but normal in vitro T-cell reactivity while four patients demonstrated persistent anergy and marked in vitro T-cell hyporeactivity which was independent of activity of infection, concurrent medication, or any associated disorders. The marked diminution of in vitro T-cell reactivity noted for these later four patients was not due to a deletion of antigen- or mitogen-reactive cells. Thus, patients' cells which had been initially cultured for 7 days without any mitogenic or antigenic stimulus and which were subsequently washed and recultured with phytohemagglutinin, concanavalin A, or histoplasmin demonstrated a marked increase in their responsiveness. Moreover, this reactivity noted for recultured cells could be suppressed by a nonphagocytic, nonadherent, nonimmunoglobulin-bearing, sheep red blood cell rosette-forming population of cells isolated from the fresh peripheral blood mononuclear cells of the same patient. While these "regulator" T cells were capable of suppressing T-proliferative responses to antigens and mitogens, they did not diminish pokeweed mitogen-induced immunoglobulin synthesis by normal bone marrow-derived lymphocytes. Patients in whom suppressor "T" cells were found were at risk for relapsing, disseminated fungal infection.

Characterization of background anti-trinitrophenyl plaque-forming cells observed in several strains of mice

Normal mice have a large number of background anti-trinitrophenyl (TNP) antibody-forming cells (AFC) in their spleens (about 40-50 anti-TNP PFC/10(6) cells). We investigated this among several mouse strains, i.e., C57BL/6, C3H/He, Balb/c, ddd, and ICR mice, and found that all strains had a similar number of anti-TNP PFC (plaque-forming cells). Developmental aspects of background anti-TNP PFC in the ontogenic process were also investigated. The number of anti-TNP PFC increased logari thmically during the first few days of age, reached a peak on the 13th day and attained a constant value within 30 days. Neonatal thymectomy did not decrease the number of background anti-TNP PFC but such treatment decreased the anti-TNP PFC response to TNP-HRBC (horse red blood cells) immunization. Germ-free ICR mice had a number of background anti -TNP PFC similar to that of conventional ICR mice. Avidity of background anti-TNP PFC was compared among mice of several ages and it was shown that there were no differences among them. These results suggest that the occurrence of these background anti-TNP PFC is not elicited by the immune response but by the natural maturation of precursors of ACF without antigenic stimulation.

Immunotherapy with levamisole in rheumatic diseases

The immuno-modulatory effect of Levamisole in the treatment of rheumatic diseases was studied in an open trial. Nine patients with theumatoid arthritis (RA), 13 with ankylosing spondylitis (AS) and one with Reiter's syndrome (RS) were treated initially with 150 mg Levmisole daily for 4 weeks, then intermittently 3 days a week. Significant clinical improvement was observed in 7 out of 9 patients with RA, in 4 out of 13 patients with AS, and in the one patient with RS. An increased skin sensitivity to a panel of antigens was noted in 3 out of 9 RA patients and in 6 out of 13 AS patients. A fall in rheumatoid factor titre was observed in 2 out of 5 patients with seropositive RA. No development of other auto-antibodies was observed. No significant changes in the absolute lymphocyte counts either of the total counts or of the T, B, and null cell counts, were noted. Drug-related adverse reactions were seen in 13 patients, mostly allergic skin rash which required a short interruption in therapy. Severe leucopenia was observed in 2 patients, whereupon therapy was definitely withdrawn. Levamisole seems to have a definite beneficial effect on RA and a possible effect on AS and RS. Severe adverse reactions, mostly on the haemopoietic system, demonstrated some potential hazardous complications of the drug and required physical and laboratory examinations at short intervals.

Production and evaluation of high-quality thyroxine antisera for use in radioimmunoassay

High-quality thyroxine (T4) antisera were raised in rabbits. Conjugates of protein and T4 or T4 methyl ester were given intracutaneously in Freund's complete adjuvant at one or two sites on the back at 1/2- to 3-month intervals. Eleven of 16 immunized rabbits produced antiserum with titers higher than 2 commercial antisera and 4 antisera from other laboratories. All 16 antisera had equilibrium constants (K) higher than the 6 reference sera. The highest titer observed was 130,000 with 88 fmol labeled T4 per ml incubate. A drastic increase in K from about 4 X 10(8) to 5.8 X 10(10) 1/mol was observed as the immunization proceeded. Cross-reactivity with triiodothyronine (T3) varied but was generally low. Suppression of the T4 synthesis was attempted by giving 30 nmol (20 mug) T3 per os once a day. Antiserum from rabbits given T3 suppression contained less iodine than antiserum from nonsuppressed control rabbits. The possible reasons for the successful production of the high-quality antisera are discussed.

Membrane Ig on MPC11 myeloma cells: correlation between the expression of membrane Ig, a receptor for Ig and the process of secretion

The expression of membrane immunoglobulin (mIg) was examined in three cloned MPC11-derived mouse myeloma cell lines. Membrane immunofluorescence studies demonstrated that IgG2b producer cells (P1) had complete IgG molecules, L-chain producer (L1) had only L-chain determinants and nonproducer (NP2) did not have any Ig determinants on the cell surface. An Ig receptor, with characteristics different from B lymphocyte Fc receptor, has been found to be present on secreting cells (P1 or L1), but not on the NP2 cell variant. The data reported in the present paper indicate that the expression of mIg and of the Ig receptor molecule is clearly correlated with the process of secretion. In the light of previous data reported on Ig secretion, a model is proposed which correlates the process of secretion with the expression not only of mIg, but also of the receptor for Ig.

Clinical evaluation of group A and group C meningococcal polysaccharide vaccines in infants

Group A and group C meningoccal polysaccharide vaccines were evaluated in infants. No significant local or systemic reactions were observed with 908 doses of vaccine given to 396 infants between 3 and 12 mo of age. The antibody response varied with the age of the infant, vaccine dose, molecular weight of vaccine, prior immunization with vaccine, and prior exposure to naturally occurring cross-reactive antigens. Only 7% of 3-mo-old infants had detectable antibody responses to primary immunization with 5-200 mug of A vaccine, presumably because of suppressive effects of high concentrations of maternal anti-A. More than 90% of 7- and 12-mo-old infants responded to A vaccine, achieving geometric mean anti-A concentrations of 0.38 and 0.98 mug/ml, respectively. The dose-response curve was flat between 10 and 200 mug of A vaccine. Geometric mean anti-A concentrations of 2.51 and 4.00 mug/ml were induced in 7- and 12-mo-old infants by booster injections of A vaccine. Approximately 90% of 3-mo-old infants had detectable antibody responses to primary immunization with C vaccine. The 100-mug dose appeared to be optimal, resulting in geometric mean anti-C concentrations of 0.49, 1.55, and 2.64 mug/ml in 3-, 7-, and 12-mo-old infants, respectively. Significant booster responses were not observed with C vaccine. Indeed, except for the 10-mug dose, booster injections of C vaccine in 7- and 12-mo-old infants resulted in lower anti-C concentrations than did primary immunizations.

Response of sublethally irradiated monkeys to a replicating viral antigen

Temporal effects of exposure to sublethal, total-body X radiation (400 R) on responses to vaccination with attenuated Venezuelan equine encephalomyelitis vaccine virus. TC-83, were examined in rhesus monkeys. Viremia, often with delayed onset, was prolonged even when irradiation preceded vaccination by 28 days. Virus titers were increased, articularly in groups irradiated 4 or 7 days before vaccination. Delay in appearance of hemagglutination-inhibition and serum-neutralizing antibody correlated closely with persistence of viremia in irradiated-vaccinated monkeys. The temporal course of antibody response was markedly affected by the intervals between irradiation and injection of this replicating antigen. With longer intervals between irradiation and vaccination, the somewhat depressed antibody responses approached normal or surpassed those of nonirradiated monkeys. Vaccination 14 days after radiation exposure resulted in lethality to 8 of 12 monkeys, apparently as a result of secondary infection. The additional lymphopenic stress due to the effect of TC-83, superimposed on the severly depressed hematopoietic competence at 14 days, undoubtedly contributed to this increased susceptibility to latent infection.

Selective deficiency of thymus-derived lymphocytes in experimental pyelonephritis

Pyelonephritis was induced in experimental animals derived of thymus-derived (T) lymphocytes by adult thymectomy and serial sublethal irradiation. In this model T lymphocytes were reduced to less than 1% of normal adjudged by the in vitro Phytohemagglutinin (PHA) responsiveness of lymphoid cells from deprived animals compared with control animals. Pathologic, bacteriologic and immunologic aspects of renal infection were studied in the T cell-deprived animals during the acute, resolving and chronic stages of pyelonephritis. The experiments have shown that the ablation of lymphocytes did not appreciably alter the course of the disease.

Prostaglandin-induced enhancement of the in vitro anamnestic response

The ability of various prostaglandins (PGs) to affect the in vitro anamnestic immune response of keyhole limpet hemocyanin (KLH)-primed rabbit popliteal lymph node cells was investigated. Of the four PGs studied (PGA1, PGE2 and PGF2alpha), PGE1 was found to have a stimulatory effect, whereas PGA1, PGE2 and pgf2alpha were ineffective in stimulating or inhibiting the in vitro anamnestic response. Under the conditions studied, a 3.5-fold increase in antibody production was obtained in PGE1-treated, KLH-stimulated cultures. Maximum enhancement was obtained when 0.2 mug of PGE1 were added at the time of culture initiation and were allowed to remain in contact with the lymph node cells for 24 hours.

How infection can trigger autoimmunity

The role of infection in the development of autoimmunity is discussed in view of recent advances in the field of immunologic tolerance. Infectious agents may directly damage immune function by impairing the mechanisms of discrimination between self and non-self antigens; alternatively they may "deceive" the immune system by presentation of self-determinants in an immunogenic form or by uncovering of normally sequestered antigenic determinants. The first of these two pathogenetic mechanisms may be responsible for generalized and the second for selective autoimmune reactions. Different clinical conditions are evaluated on the basis of these concepts. The interaction of personal factors with infection and autoimmunity is also taken into consideration.

Specific anti-tumor responses by cultured immune spleen cells. I. In vitro culture method and initial characterization of factors which block immune cell-mediated cytotoxicity in vitro

Spleen cells from BALB/c mice which either bore syngeneic sarcomas or were normal controls were cultured in vitro. The culture supernatants of spleen cells from tumor-bearing mice inhibited (blocked) specific cell-mediated cytotoxicity to the tumor borne by the spleen donor. They also mediated specific antiserum-dependent cytotoxicity with control lymphoid cells. The appearance of blocking activity in culture supernatants was prevented by lysis of theta-positive spleen cells with antiserum and complement. The blocking activity was removed by passing culture supernatants through an anti-mouse immunoglobulin affinity column and was recovered in a 3 M NaSCN eluate of the column.

X-linked recessive progressive combined variable immunodeficiency (Duncan's disease)

Of 18 boys in Duncan kindred, 6 died of a lymphoproliferative disease. They exhibited a subtle, progressive combined variable immunodeficiency disease characterised by benign or malignant proliferation of lymphocytes, histiocytosis, and alterations in concentrations of serum-immunoglobulins. Infectious mononucleosis occurred during or preceding terminal events in at least 3 of the cousins. Fever, pharyngitis, lymphadenomegaly, hepatosplenomegaly, atypical lymphocytosis, and a spectrum ranging from agammaglobulinaemia to polyclonal hyper-gammaglobulinaemia occurred. At necropsy, the thymus gland and thymic-dependent areas in the lymph-nodes and spleen were depleted of lymphocytes. Diffuse infiltrates composed of lymphocytes, plasma cells, and histiocytes, some containing erythrocytes, invaded the haematopoietic organs, viscera, and central nervous system. In addition, 2 half-brothers had lymphomas of the ileum and central nervous system. Approximately half the boys, including the half-brothers, were affected, and girls were spared, implying sex-linked recessive inheritance. Various lymphohistiocytoses resemble Duncan's disease, but it is distinctive from them in the mode of inheritance or by histiological characteristics. This study suggests that the Epstein-Barr virus or other viruses triggered the fatal proliferation of lymphocytes and that progressive attrition of T-cell functions allowed uncontrolled lymphoproliferation.

Antibody response by cultured spleen fragments from carrier-primed mice to hapten-protein conjugates

Hapten-protein conjugates stimulated very poor anti-hapten responses in mouse spleen fragment cultures from unimmunized mice, whereas hapten coupled to type III pneumococcal polysaccharide or polylysine induced good responses. When the donors of the fragments were primed with the carrier protein, hapten-protein conjugates induced a strong anti-hapten response. Both the true primary and the carrier-primed response in vitro consisted mainly of IgA antibodies of 9-13S. In carrier-primed responses also IgM was produced at the beginning and IgG at the end of those responses.