Showing papers on "Immune system published in 1973"

Function of macrophages in antigen recognition by guinea pig t lymphocytes : i. requirement for histocompatible macrophages and lymphocytes

Abstract: Antigen activation of DNA synthesis in immune thymus-derived lymphocytes of guinea pigs requires the cooperation of macrophages and lymphocytes. We have investigated the role of histocompatibility determinants in this macrophage-lymphocyte interaction using cells from inbred strain 2 and 13 guinea pigs. The data demonstrate that efficient presentation of macrophage-associated antigen to the lymphocyte requires identity between macrophage and lymphocyte at some portion of the major histocompatibility complex. The failure of allogeneic macrophages to effectively initiate immune lymphocyte proliferation was not the result of the presence of an inhibitor of blastogenesis released in mixtures of allogeneic cells, peculiarities of the antigen or lymphoid cells employed, nor differing kinetics of activation by allogeneic macrophages. In addition, data were presented that demonstrated that alloantisera inhibit lymphocyte DNA synthesis by functional interference with macrophage-lymphocyte interaction.

The immune system.

Abstract: The immune system consists of a large number of different types of cells and proteins that function to distinguish between normal and abnormal cellular components and between 'self' and 'non-self'. As an example, when a thorn gets stuck in the body, the immune cells are able to recognized the thorn as a foreign object (i.e. 'non-self') and attack it. The same is true for bacteria, viruses or other organisms that can invade our bodies. A more subtle distinction between self and non-self occurs in the recognition of cancer cells by the forces of the immune system. The cancer cells are recognized and attacked because they differ from the normal 'self' from which they arose.

New Lymphocyte Antigen System (Lna) Controlled by the Ir Region of the Mouse H-2 Complex

Abstract: A new system of lymphocyte alloantigens in mice is described. This Lna (lymph-node antigen) system is associated with the Ir region of the H-2 (histocompatibility-2) gene complex. It has the following distinctive characteristics: (1) The gene or genes controlling these antigens has been mapped in the Ir (immune response) region between H-2K and Ss-Slp. (2) The antigens are most readily detectable on lymph-node cells, although they are also expressed on peripheral blood lymphocytes, splenic lymphocytes, and thymocytes. (3) Cytotoxicity against only about half of lymph-node cells is consistently observed. (4) Cytotoxic antibody titers against these antigens are strikingly high—more than 2000 by 51Cr-release and up to 100,000 in the microcytotoxic test. (5) At least two, probably allelic, forms of the antigen(s) have been defined, one associated with the H-2k haplotype and one with the H-2a haplotype. (6) Antisera against Lna contain multiple antibody specificities that can be fractionated by absorption either with certain recombinants or with other H-2 halotypes that have crossreactive antigens. The antisera against Lna may be of value for definition and characterization of the products of the Ir and MLR (mixed lymphocyte reaction stimulatory) genes associated with the H-2 complex.

Immunological aspects of chemical carcinogenesis.

Abstract: Publisher Summary This chapter focuses on the degree of involvement of immune mechanisms in modifying tumor formation and growth during chemical carcinogenesis. During the past two decades, the concept that tumors express antigens against which the host is capable of evoking an immune response has been firmly established. The validity of these studies, as well as comparable findings with MC-induced rat sarcomas (Baldwin, 1955), was critically analyzed by Prehn and Main (1957) who conclusively showed that the induction of immunity to transplanted sarcoma grafts was a tumor-specific phenomenon because immunized mice could still accept skin grafts from the tumor donor, precluding the involvement of an alloantigenic immune response. Evidence shows that tumor rejection antigens are specific and permanent, or quasi-permanent, characteristics of cells transformed by chemical carcinogens. Chemically induced tumors also express antigens normally present in embryonic, but not adult, tissue that may be viewed as the products of dedifferentiation processes induced by the carcinogen, and concurrently there is frequently a deletion of normal tissue antigens. The immunological responses to neoantigens expressed on preneoplastic and neoplastic cells can influence, either positively or negatively, the course of chemical carcinogenesis.

Protection against enteric disease caused by Escherichia coli--a model for vaccination with a virulence determinant?

Abstract: ALTHOUGH vaccination has assisted the control of many bacterial diseases, parenteral vaccination against enteric disease is not as satisfactory as we could wish1. This is attributable to incomplete knowledge of both the pathogenesis of intestinal infections and the protective immune responses of the alimentary tract, with the result that vaccine development has been largely empirical. New knowledge of the specific determinants of microbial pathogenicity2 provides a sounder basis for the development of effective vaccines and the following report is an example of this approach to disease control.

T and B lymphocytes and immune responses.

Abstract: The recognition of two distinct classes of lymphocytes has been a turning point in immunology. Immunological models and tools may help to provide the answers to many biological problems.

Antigen-Induced Proliferation of Guinea Pig Lymphocytes in Vitro: Obligatory Role of Macrophages in the Recognition of Antigen by Immune T-Lymphocytes

Abstract: Highly purified lymphocytes were obtained from the lymph nodes of CFA-immune guinea pigs. Cultures of these lymphocytes did not exhibit proliferative responses upon stimulation with purified protein derivative (PPD), although they were quite responsive to stimulation with phytohemagglutinin. Addition of macrophages to these cultures resulted in marked enhancement of the PPD-induced lymphoproliferative response, but did not affect lymphocyte responsiveness to phytohemagglutinin. The ability of the purified immune lymphocytes to interact directly with soluble PPD was examined by incubating the cells for 1 hr at 37°C with various concentrations of PPD. The lymphocytes were then washed to remove unbound antigen and placed in culture. Addition of macrophages to cultures of antigen-pulsed lymphocytes did not result in the significant DNA synthesis, suggesting that the specifically immune lymphocytes were unable to bind and carry into culture sufficient antigen to allow for their subsequent activation. These results were not due to the induction of tolerance in the lymphocytes, since cultures of antigen-pulsed and untreated lymphocytes were equally responsive to continuous PPD when macrophages were added to the cultures, even when the antigen-pulsed lymphocytes had been exposed to high concentrations of PPD for 1 or 24 hr. In contrast, macrophages which were incubated for 1 hr at 37°C with a given concentration of PPD were as effective as the same concentration of PPD present continuously in macrophage-lymphocyte cultures in the induction of a lymphoproliferative response. Macrophages appear to play an obligatory role in the presentation of antigen to the immunospecific thymus-derived (T)-lymphocyte.

T. and B. Lymphocytes: Origins, Properties and Roles in Immune Responses

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Neuro-Endocrine Correlates of Immune Response

Abstract: Bilateral symmetrical electrolytic lesions were produced in the following areas of the rat brain: hypothalamus, reticular formation, thalamus, superior colliculus, caudate nucleus and amygdaloid compl

CELL INTERACTIONS BETWEEN HISTOINCOMPATIBLE T AND B LYMPHOCYTES : IV. INVOLVEMENT OF THE IMMUNE RESPONSE (Ir) GENE IN THE CONTROL OF LYMPHOCYTE INTERACTIONS IN RESPONSES CONTROLLED BY THE GENE

Abstract: In the present study we have asked the question of whether F1 carrier-primed T cells can serve as helper cells for either or both parental B cells when (a) the carrier molecule employed is under genetic control such that one parental strain is a responder and the other is a nonresponder, and (b) the determinant specificity of the parental B cells being assessed is not under genetic control and bears no relationship to the specificity of the carrier molecule. Utilizing the system of immune response gene control of responses to the terpolymer L-glutamic acid-L-lysine-L-tyrosine (GLT) to which A strain mice (H-2a) are nonresponders, whereas BALB/c (H-2d) and (BALB/c x A)F1 hybrids (CAF1) are responders, these studies demonstrate that GLT-primed T cells of CAF1 donors can provide for responder BALB/c, but not for nonresponder A/J, the required stimulus for the anti-DNP responses of DNP-specific B cells of these respective parental strains to the DNP conjugate of GLT. The implications of these findings for Ir gene function in physiologic T-B cell interactions are discussed in detail.

Inhibition of hepatoma-immune lymph-node cell cytotoxicity by tumour-bearer serum, and solubilized hepatoma antigen

Abstract: Sera from rats bearing transplanted aminoazo-dye-induced hepatomas inhibited the cytotoxicity of lymph-node cells from tumour-immune rats for plated hepatoma cells, when the sera were incubated with the effector cells, rather than target cells. In contrast, sera from hepatoma-immune rats, which have previously been shown to block lymphocyte cytotoxicity at the level of the target cell, failed to inhibit lymph-node cell cytotoxicity when pre-incubated with the effector cells. The possibility that antigenic determinants could be responsible for lymphocyte inhibition is supported by the demonstration that papain-solubilized hepatoma-specific antigen preparations inhibited lymph-node cell cytotoxicity. The role of specific antibody, antigen and immune complexes in the interaction between cellular immunity and humoral factors during tumour growth is discussed.

Circulating immune complexes in inflammatory bowel disease.

Abstract: Evidence for circulating immune complexes in sera of patients with ulcerative colitis or Crohn's disease is described. Such sera produced significantly greater inhibition of antibody-induced cytotoxicity mediated by lymphocytes than did sera from normal control subjects. Inhibitory activity of patients' sera showed a positive correlation with severity of disease, the height of the ESR and, in the case of ulcerative colitis, with the severity of inflammation as seen at sigmoidoscopy. Using gel filtration on Sepharose 6B, inhibitory activity was found in fractions of higher molecular weight than monomeric IgG but of lower molecular weight than IgM. These fractions were shown to contain IgG measured by immunodiffusion. Evidence that inhibition is not due to aggregated IgG molecules is provided by the fact that no correlation was found between inhibitory activity and total IgG concentration. A possible role of immune complexes in the pathogenesis of ulcerative colitis and Crohn's disease is proposed.

Allergic contact sensitivity in atopic dermatitis.

Abstract: Allergic contact sensitivity toRhuswas investigated in 171 humans, 40 of whom had atopic dermatitis. Rhus dermatitis was found in only 3% of the atopic subjects, while 37% of healthy nonatopic controls claimed to have had rhus dermatitis. Survey patch tests with rhus oleoresin were positive in 61% of controls but in only 15% of atopics. A second rhus patch test revealed that 6% of nonsensitive atopics and 31% of a nonsensitive control group had been sensitized by the first patch test. Resistance of individuals with atopic dermatitis to sensitization by rhus may be an example of immunologic unresponsiveness or due to an epidermal abnormality, and is possibly under genetic control. Atopic dermatitis is hypothesized to be a phenotypic marker for a defect in the human's cell-mediated immune system.

Impaired in Vitro Cell-Mediated Immunity to Rubella Virus during Pregnancy

Abstract: A significant depression in cell-mediated immunity, measured by phytohemagglutinin and mixed-lymphocyte-culture responsiveness was observed in 11 pregnant women. Specific cell-mediated immunity to rubella virus, measured by a 51Cr-release microassay, was also found to be diminished during pregnancy. The mean (± S.D.) specific immune release for 13 seropositive subjects during pregnancy was 4.3 ± 5.9 per cent as compared to a mean of 19.9 ± 0.9 per cent in 14 seropositive nonpregnant women. This impairment in specific cell-mediated immunity to rubella virus was shown to be transient because there was subsequent increase in immunity in each of four subjects studied post partum. Thus, these changes in cell-mediated immunity during pregnancy may contribute to the known increased severity of viral infections in the gravid state. (N Engl J Med 289:604–606, 1973)

Antibodies to a specific surface antigen of t cells in human sera inhibiting mixed leukocyte culture reactions

Abstract: Surface radioiodination of lymphocytes by the lactoperoxidase procedure has permitted demonstration of an assortment of different antibodies to lymphocytes in the sera of patients with systemic lupus erythematosus. One type of antibody proved of special interest because it appeared to be associated with inhibition of the responder cells in the mixed leukocyte culture reactions. This reacted with an antigen on T cells and thymocytes which on sodium dodecyl sulfate acrylamide gel electrophoresis showed a molecular weight of approximately 15,000 daltons. The possible relation of this antigen to T cell receptors and products of immune response genes is discussed.

The macrophage receptor for IgG: number and affinity of binding sites.

Abstract: It is concluded that the relative adherence of soluble immune complexes to macrophages is influenced both by the number of receptor sites for IgG per cell, and by their average association constant.

Inhibitory and stimulatory effects of concanavalin A on the response of mouse spleen cell suspensions to antigen. II. Evidence for separate stimulatory and inhibitory cells.

Abstract: The addition of concanavalin A to mouse spleen cell suspensions can either inhibit or stimulate the immune response to heterologous erythrocytes according to the experimental conditions. Evidence is presented which is incompatible with the hypothesis that these two effects are mediated by a single cell and which favors the hypothesis of separate inhibitor and stimulatory cells.

Participation of Lymphocytes in Viral Infections

Abstract: Publisher Summary There are many aspects of virus–lymphocyte interactions which occur both in vitro and in vivo. This chapter presents an overview of the possible roles lymphocytes play, both in production of and defense against viral disease. It also discusses the effects of viral infections on cell-mediated immunity (CMI). Theoretically, lymphocytes can act in the host defense in two additional ways. Immune lymphocytes have been shown to carry immunoglobulins on their surface membranes, but a cytophilic virus-specific antibody has not yet been demonstrated. Such an antibody on the surface of lymphocytes, which infiltrate infected foci, could neutralize the virus and eradicate the infection. In addition, lymphocytes could take up and inactivate infective viruses. The analysis of the roles of interferon, CMI, and antibody in the defense against viral diseases reveals that these three responses often occur as a sequence following infection. Viruses vary in their sensitivity to each response. Any attempt to utilize these host defenses in the treatment of viral infections must take the specific sensitivities of viruses into account.

Immunosuppression in Gambian trypanosomiasis.

Abstract: Cellular and humoral immune responses were studied in 38 patients with Gambian trypanosomiasis and compared with those of 43 matched controls. Expression of cell mediated immunity, induction of cell mediated immunity and expression of humoral immunity were all impaired in the patients with trypanosomiasis. It is suggested that immunosuppression induced by T. gambiense may contribute to the increased susceptibility to secondary infection observed in patients with African trypanosomiasis.

Thymus-derived rosette-forming cells.

Abstract: Modern immunology has defined the heterogeneity of the lymphocyte response triggered by antigen. Antigen can stimulate both humoral immunity and cellular immunity, and both B and T cells can co-operate in the immune response. Antibodies, effectors of the humoral response, are synthesized by B lymphocytes and plasma cells. The bursa of Fabricius is responsible for the competence of B lymphocytes in birds; the bursa equivalent remains ill defined in mammals. Cellular immunity is the responsibility of T lymphocytes. These T cells are derived, processed or influenced in some way by the thymus in animals and human beings. B and T . . .

The lymphocyte response to primary Moloney sarcoma virus tumors in BALB-c mice. Definition of the active subpopulations at different times after infection.

Abstract: Adult BALB/c mice were injected with Moloney sarcoma virus (MSV) after which the animals' lymphocytes were examined for activity against Moloney leukemia virus (MLV) antigen-bearing target cells at 5-day intervals for 30 days. Lymphocytes from these animals and appropriately matched controls were fractionated into B cell-deficient (primarily T cells) and T cell-deficient (primarily B cells) subpopulations. Macrophages were removed using iron powder and magnetism. The unfractionated lymphocytes, T cells, and non-T cells were then tested in microcytotoxicity tests. Antigen-specific activity was found in the unfractionated lymphocytes from animals that had not yet developed palpable tumors and from regressor animals. The T cells were active just before tumor development and just after regression; however, by day 30 after virus infection (8–10 days after regression) the T cell subpopulation was much less active. The non-T cell subpopulation was also active before tumor development and soon after regression. However, this activity continued to rise after regression and was highest at 30 days. At day 15 (peak tumor size) neither subpopulation was active. The activity was demonstrated to be specific for the MLV-determined cell surface antigen by testing on control target cells that were MLV antigen negative and by comparison of the inhibitory effects with lymphocytes immune to a nonpertinent antigen as well as normal lymphocytes. The non-T cells were tested for activity before and after removal of macrophages with iron powder and magnetism. Such cells were significantly more active after removal of the macrophages. These data demonstrate specific T cell and non-T cell activity in microcytotoxicity tests with a tumor-specific system and strongly suggest that the non-T cell activity described herein is a B cell function.

Quantitative effects of nutritional essential amino acid deficiency upon immune responses to tumors in m ice

Abstract: Protein-calorie malnutrition may produce profound and sometimes paradoxical changes in the immune defense mechanisms against infection and malignancy. 1 Depression of host resistance to pyogenic and intracellular bacterial infection (1) and increased resistance to some viral infections (2, 3) and malignant tumors 1 (4, 5) have been reported in nutritionally deprived animals. Our previous studies have demonstrated that animals fed limiting amounts of a casein diet showed intact cytotoxic cell-mediated immune responses to tumor antigens at a protein intake that resulted in profound depression of specific humoral antibody responses, including serum "blocking antibody" (6). 1 These findings suggested that specific cell-mediated cytotoxic immunity may operate more effectively against tumor ceils in the moderately protein-deficient animal, because of the absence of serum inhibiting factors. Further reduction in the level of protein in the diets of tumor-bearing animals resulted in depression of both humoral and cellular responses. In addition, a persistent defect in cytotoxic cell-mediated function was found in animals after nutritional protein deprivation at a young age3 Thus the animal's immune resistance could be either increased or depressed, depending on the timing and the severity of the nutritional deprivation. Similar inhibitory effects upon the incidence and growth of malignant tumors have been reported in animals fed diets imbalanced or deficient in the essential amino acids (7-11). Ten amino acids have been found essential for normal growth of mice (9, 12, 13). The mouse does not require arginine and can synthesize cystine from methionine (9). The requirement for tyrosine is influenced by the phenylalanine intake. At least tryptophane, phenylalanine, and methionine have been found essential for specific antibody responses (14, 15), but the amino acid requirements for complete humoral and cellular immune responses in the mouse have not been fully defined.