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At least 37 records · Page 2Linked to original sources
PubMed1979

Dissociation of anti-tumor immune responses in rats immunized with solubilized tumor-associated antigens from a methylcholanthrene-induced fibrosarcoma.

Soluble tumor antigens were prepared from chemically-induced rat fibrosarcoma KMT-17 cells by various methods [Na-deoxycholate (DOC), 3 M-KCI extraction, and crude membrane preparations by mechanical disruption]. Soluble tumor antigens prepared by DOC extraction (DOC-STA) could be detected by a radioisotopic footpad assay (FPA) and they showed the strongest antigenic activity in KMT-17 immune rats. Anti-tumor immune responses in rats previously immunized with DOC-STA were measured by FPA, Winn assay, and transplantation resistance. Significant responses detected by the FPA and Winn assay were demonstrated in rats immunized with DOC-STA. However, rats previously immunized with DOC-STA showed a significant enhancement of tumor growth when challenged with KMT-17 cells. This enhancement was specific for the tumor line used. Normal rats which received adoptive transfer of thymus and spleen cells from rats immunized with DOC-STA produced specific enhancement of tumor growth as compared with non-treated rats. Administration of cyclophosphamide before immunization with DOC-STA abrogated the enhanced tumor growth in the host. These results suggest that immunization with soluble tumor antigens specifically enhanced tumor grwoth by the induction of immunosuppressor cells. Dissociation between the anti-tumor immunity detected by the FPA and Winn assay and the enhanced tumor growth detected by transplantation resistance in rats immunized with DOC-STA is discussed.

Animals↗
PubMed1979

Genetic control of the immune response to mammalian chymotrypsins in mice. II. The immune response to low doses of bovine alpha-chymotrypsin.

The immune response to the antigen bovine pancreatic alpha-chymotrypsin was investigated in ten recombinant strains of mice. Using a fixed antigen-percentage bound isotope technique, it was found that the quantity of antibody produced was related to the H-2 haplotype of the responding animal. A continuous distribution for the mean antibody responses was obtained for the ten strains of mice. High responsiveness was associated with the H-2 haplotype gamma2. The genetic control of the immune response to this immunogen was found to be both quantitative and qualitative.

Animals↗
PubMed1977

Quantity of antibody synthesized in a single cell during the primary immune response.

Following immunization of mice with SRBC the kinetics of antibody synthesis by individual immunocompetent cells during the primary immune response were investigated. The diameter of the average hemolytic plaque using a modified Jerne plaquing technique, was taken to be an estimate of the antibody production by a single cell. We found an increase, followed by a decrease, of the average plaque diameter during the primary immune response. The increase of average plaque diameters is probably due to the raised rate of synthesis of antibody molecules. This increase can be accelerated by adjuvants. The decrease late in the primary immune response could be explained by an internally regulated switch from IgM to IgG antibody synthesis. The results are consistent with the mathematical approach of HELLWIG (1,2).

Adjuvants, Immunologic↗
PubMed1977

Cellular immune responses in guinea pigs immunized with cell walls of Histoplasma capsulatum prepared by several different procedures.

Since guinea pigs immunized with water-washed cell walls of Histoplasma capsulatum developed cellular immune responses detectable with cytoplasmic substances, attempts were made to determine whether cytoplasmic contamination of the walls was responsible for the induction of the immune response. Cell walls were treated by several procedures designed to remove possible contamination, namely, extraction with lipid solvents, incubation with proteolytic enzymes, and washing with sodium dodecyl sulfate, and each of the treated preparations was compared with water-washed walls for its ability to induce cellular responses demonstrable with cytoplasmic substances. For comparison, wall glycoprotein was also used as a test antigen. Immune responses were assessed by gross and histological examinations of skin test sites and by assays for the production of migration inhibition factor. A portion of the material inducing the response detectable with cytoplasmic substances was apparently removed or altered by each of the purifying procedures. The cellular immune responses to wall glycoprotein were also altered, however, indicating that more than the mere removal of cytoplasmic substances had occurred. On the basis of the data collected from each of the cellular assays involving wall glycoprotein as the test antigen, the hypothesis is proposed that sodium dodecyl sulfate altered or removed protein from the wall and thus augmented its ability to induce a more intense immediate-type hypersensitivity, whereas incubation with Pronase altered the walls in such a way as to shift the balance toward a more intense delayed-type hypersensitivity. The latter effect was probably due to the removal of carbohydrate from the wall by glucanase or to mannosidase contaminating the Pronase preparation.

Animals↗
PubMed1978

Determinant selection and macrophage function in genetic control of the immune response.

The immune response to insulin, in both mouse and guinea pig, is under control of H-linked immune response genes. When immunized with either pork or beef insulin in CFA, both strain 2 and 13 guinea pigs respond by antigen-specific lymphocyte proliferation and synthesis of specific antibody. The specificities of the elicited antibodies and indistinguishable between these inbred strains. By constrast, strain 2 T cells recognized a distinct region of the A chain alpha loop consisting of amino acid residues 8, 9 and 10, while strain 13 T cells see an as yet undefined region of the B chain. H2b (A chain alpha loop responder) and H2d (B chain responder) mice similarly discriminate which areas of the molecule are recognized by their T lymphocytes. The function of the Ir gene in both the guinea pig and mouse appears to be an intramolecular selection of discrete regions within the antigen for recognition by the T cell. The data presented suggest that this function operates at the level of the macrophage.

Animals↗
PubMed1976

Immune responses of the bovine fetus and neonate to Escherichia coli: quantitation and qualitation of the humoral immune response.

The humoral immune responses of fetuses and neonates of Escherichia coli O:26:K60:NM were studied in 26 Angus-Hereford crossbred calves. Bacterin (5.0 X 10(10) organism) was injected in utero directly into the amniotic fluid of seventeen 7- to 8.5-month-old fetuses (principals). Saline solution was injected in the same manner into 9 control fetuses. Colostrum-deprived neonates were allotted to 10 groups and either were euthanatized at birth or were subjected to oral revaccination, challenge inoculation with the homologous organism, or both. The resistance to challenge exposure was a function of previous in utero injection of bacterin, age when challenged, and dose of challenge organisms used. Control calves were susceptible to only a large challenge dose, whereas almost all of the prinicipal calves were resistant. Revaccination of principal calves with bacterin at birth, exposure to the large challenge dose, or both, caused a marked increase in anti-O26 passive hemagglutination titers. Results of quantitative and qualitative radioimunossay indicated that the immune response to the O26 antigen was mainly of the immunoglobulin M (IgM) class, although there were also demonstrable changes in immunoglobulins (Ig) G1 and G2. The actively acquired immune responses were serotype specific, and there was no cross reactivity with 4 other E coli serotypes. An unidentified immunoprecipitate band was observed in immunoelectrophoretograms of whole bovine serum which may represent another class of Ig or which may be a subclass of IgG1 or IgG2.

Animals↗
PubMed1975

Cells involved in the immune response. XXIX Establishment of optimal conditions for the primary and secondary immune responses by rabbit lymphoid cells in vitro.

Attempts were made to initiate the primary and secondary humoral immune responses to sheep red blood cells (SRBC) in vitro as determined by the hemolytic plaque-forming cell (PFC) response, with cell suspensions prepared from a variety of lymphoid organs of the rabbit- thymus, bone marrow, spleen, appendix, sacculus rotundus, Peyer's patches, popliteal lymph node and circulating leukocytes. A number of different media and gaseous phases were utilized in order to establish the optimal conditions for the immune response in vitro. The induction of a secondary PFC response was consistently obtained with 'memory' spleen cells obtained from rabbits 3-6 months following intravenous immunization with SRBC but not with cells of any of the other lymphoid organs, and this response probably represents the activity of memory cells which reside in the rabbit spleen. A primary response was observed only with 'normal' spleen cells, and the medium which faciliated the response was different from that which facilitated the induction of the secondary response in vitro. It was also observed, using a medium in which normal spleen cells were incapable of generating PFC', that mixed cultures of normal spleen and normal appendix or bone marrow cells could give a marked PFC reponse in vitro. Whether the PFC response to SRBCs obtained with the lymphoid cells of normal, unimmunized rabbits represent a true primary response, a secondary response, or a response of a different nature as a consequence of continuous subthreshold immunization of the rabbit with enteric microorganisms which cross-react with the antigen, remains to be determined. However, out initial successes with cultures consisting of cells of at least two distinct lymphoid organs in cases where the cells of any one of these organs could not respond, suggest that interaction of at least two functionally distinct cells is required and that the repsonse observed in vitro is probably a primary immune response.

Animals↗
PubMed1979

Immune responsiveness and oral immunization.

The effects on the immune response of daily feeding of 30 mg of human serum albumin to rats have been studied. Feeding for periods of 17-20 days consistently resulted in a specific systemic hyporesponsiveness evident on subsequent parenteral immunogen challenge. Local secretory sites such as the major salivary glands were not made hyporesponsive as evidenced by the salivary antibody titres and the enumeration of glandular plaque-forming cells. The levels and classes of antibodies present in the secretions and sera were identified by passive haemagglutination, and a sensitive red-cell-linked antigen-antiglobulin reaction. By the use of radioimmunoassay and haemagglutination inhibition assays it was possible to quantitate the amount of antigen appearing in the circulation at varying times after feeding. It was shown in the use of oesophagectomised rats that absorption of small amounts of intact protein occurs from undefined sites in the oral cavity. Attempts were made to transfer the specific systemic hyporesponsiveness to syngeneic animals using spleen cell and serum transfers.

Administration, Oral↗
PubMed1977

Immune responses of the bovine fetus and neonate to Escherichia coli: plaque-forming and intestinal immune responses.

The immune responses of 26 Angus-Hereford fetuses and neonates to Escherichia coli O26:K60:NM were studied after bacterin or saline solution was injected (in utero) into the amniotic fluid. Calves were euthanatized at birth or were orally revaccinated; some were challenge exposed with live organisms. The hemolytic plaque assay was used to determine the presence of cells producing immunoglobulins M, G1, and G2 (IgM, IgG1, and IgG2) in 4 segments of the small intestine, mesenteric lymph nodes, and spleen. The passive hemagglutinin activity of intestinal washings was also determined. Anti-O26 passive hemagglutinin activity in the intestinal washings of principal calves was greater than in that of control calves, but in a given segment of the small intestine, usually this activity was relatively small and less consistent than the plaque-forming response. Greater numbers of plaque-forming cells were observed in the small intestine of 14 of the 15 principal calves when compared with the control calves tested.

Animals↗
PubMed1977

Key antigenic determinants in regulation of the immune response.

The immune response to beta-galactosidase (beta-D-galactoside galactohydrolase; EC 3.2.1.23)is characterized by a wave of early help followed by a wave of suppression to a subsequent in vitro challenge with galactosidase-fluorescein. A cyanogen bromide peptide of beta-galactosidase, CB2, mimics the suppression seen with the enzyme. It is time dependent, carrier specific, and anti-theta sensitive; however, this suppression is not preceded by a wave of help. It is possible that CB2 cannot stimulate helpers, and is only able to activate suppressor cells. These data indicate that one small region of an antigen, capable of activating suppressors, can nullify the positive effect induced in helper T cells reactive with other epitopes on beta-galactosidase. Key determinants on macromolecules may in this way be influential in regulating the immune response to the entire antigen molecule.

Animals↗
PubMed1976

Control of the immune response: role of macrophages in regulation of antibody-and cell-mediated immune responses.

The ability of peritoneal macrophage subpopulations, separated into different classes according to their size, to reconstitute antibody or cellular immune responses in macrophage-depleted spleen cells has been investigated. Data are presented to show that whether reconstitution is by "normal" or "activated" macrophages, be they syngeneic or allogeneic to the lymphocyte source, different populations reconstitute antibody and cellular immunity. Reconstitution is in general by two classes of macrophages, small and large. The former seem to reconstitute only if syngeneic to the responding lymphocyte pool, whereas large macrophages reconstitute immune responses from allogeneic lymphocytes as well as syngeneic lymphocytes. Evidence is also presented to show that syngeneic large macrophages can determine the type of immune response reconstituted; that is, with greater numbers of large cells only cytotoxic responses (and not T-dependent antibody formation) were reconstituted and vice versa.

Animals↗
PubMed1978

The effect of ubiquinone-7 and its metabolites on the immune response. IV. Chemical structure-adjuvant activity relationship of quinonyl derivatives on humoral immune response.

The effects of the emulsion of quinonyl acids (QS-n, ES-n, KS-n) and related compounds (QSA-n) in Freund's incomplete adjuvant on the humoral immune response to bacterial alpha-amylase were assayed, and their structure-adjuvant activity relationships were discussed. All the quinonyl acids tested (500 microgram/mouse) enhanced the humoral immune response two to seven times as much as that of the control group, five weeks after immunization. 3'-Methyl and 2', 3'-double bond in the carboxy side chains of ubiquinone metabolites (Q acid-I, -II) were not essential for the adjuvant activity. The conversion of methoxyls on the quinone ring into methyls, and that of benzoquinone into phenol also did not affect the activity, but the activity seemed to depend on the carbon number of the carboxy side chain, and the prominent adjuvant activity was observed in the carboxylates having the carboxyalkyl chain of five to seven carbons. High doses (1 or 5 mg/mouse) of ubiquinone-7 and -2 enhanced the humoral immune response two to three times as much as that of the control group, and quinonyl alcohols (QSA-n) enhanced that with low dose (500 microgram/mouse).

Adjuvants, Immunologic↗
PubMed1976

Effects of contact sensitization and delayed hypersensitivity reactions on immune responses to non-related antigens. Modulation of Immune responses.

Guinea pigs were immunized intracutaneously into the ears with sheep red blood cells (SRBC). Application of a sensitizing dose of the contact allergen dinitrochlorobenzene (DNCB) onto the same ears was shown to suppress or enhance the humoral response to SRBC depending on the time of application. When guinea pigs were sensitized to a contact allergen, application of a sensitizing dose of a non-related allergen on the same ears either had no effect or caused a clear enhancement of the development of delayed type hypersensitivity (DTH). Strongest enhancement was found when both sensitizations were performed on the same day. Further experiments on the effects of a concomitant DTH reaction elicited at the site of application of a contact allergen showed a strong potentiation of DTH when B-cell suppression was minimized by pretreatment with cyclophosphamide (CY). It was considered that CY-DTH-immunopotentiation might be a useful tool for achieving a higher level of sensitivity after epicutaneous sensitization.

Allergens↗
PubMed1977

Mechanism of T-cell help in the immune response to soluble protein antigens II. Reconstitution of primary and secondary in vitro immune responses to dinitrophenyl-carrier conjugates by T-cell-replacing factor.

Spleen cells of dinitrophenyl keyhole limpet hemocyanin (DNPKLH) primed and boosted mice produced a nonantigen-specific helper factor upon in vitro challenge with DNPKLH. This helper factor displays all of the biological characteristics so far described for TRF produced by allogeneic or Concanavalin A stimulation of mouse spleen cells. It restores the primary anti-SRBC response in nude spleen cultures following the same kinetics of action as T-cell-replacing factor (TRF). Conversely, TRF restores the primary in vitro immune response of nude spleen cultures to DNPKLH. TRF also restores the secondary anti-hapten IgG response of T-cell-deprived spleen cell cultures derived from DNPKLH primed and boosted mice. Here the need for carrier specificity is fully overcome. The data therefore suggest that TRF, as a nonantigen-specific maturation signal, is involved in the primary and secondary immune responses to both particulate and soluble antigens.

Animals↗
PubMed1977

Hypothalamic changes during the immune response.

The immune system is subject to an array of identified autoregulatory processes, but immunoregulation may also have a further basis in a network of immune-neuroendocrine interactions. Two antigens each produced an increase of more than 100% in electrical activity of individual neurones in the ventromedial but not in the anterior nucleus of the rat hypothalamus. Animals that failed to respond to antigen manifested no increase in the firing rate. These findings constitute the first evidence for a flow of information from the activated immune system to the hypothalamus, suggesting that the brain is involved in the immune response.

Action Potentials↗
PubMed1976

Effect of therapeutic irradiation on the immune responses.

The immune responses of 60 patients undergoing therapeutic irradiation were evaluated according to four anatomical sites irradiated. In vitro lymphocyte transformation tests with PHA, Con-A, and PWM and quantitative assays of IgG, IgA, and IgM were performed on blood obtained from each patient before and during therapy, and two weeks, two months, and six months after therapy. At these same testing intervals, skin tests with PPD, mumps antigen, Candida antigen, and SD-SK were performed. During irradiation, the mean values of all lymphocyte transformation tests were depressed, varying from 48% to 64% of pretreatment baseline. This depression persisted until about two months after completion of treatment. By six months, response rose to pretreatment values. When response was evaluated according to sites irradiated with all mitogens, the pelvic and pelvic plus abdominal groups showed consistently greater depression than the chest or head and neck groups. Radiation effected no significant changes in the mean values of IgG, IgA or IgM. A decrease in skin sensitivity was noted during radiation; 73% of the subjects responded positively before therapy while only 53% had at least one positive test during therapy. By two months postirradiation, 73% of the group clinically free of disease had positive skin tests. A comparison of clinical condition with test results is significant when one considers the 17 patients who developed metastatic disease or died from disease. The depression for all three mitogens during radiation therapy was greater for this group. Of the 17, only four had IgG levels in the normal range, and consistently fewer positive skin tests were demonstrated.

Abdominal Neoplasms↗
PubMed1979

Additional evidence against measles vaccine administration to infants less than 12 months of age: altered immune response following active/passive immunization.

Quantitative serologic responses following the inoculation of infants less than one year of age with live, further-attenuated measles virus vaccine were compared to those of infants and children inoculated after one year of age. Active/passive immunization resulted in reduced antibody formation in some infants especially those less than 9 months of age. Thirty-seven infants identified as "vaccine failures" following their initial inoculation at less than one year of age were revaccinated after one year of age. Fifty-one percent had no detectable HI antibody by eight months postrevaccination, contrasted to 6.8% of the vaccinees with no detectable HI antibody following one inoculation after one year of age; 49% responded optimally to revaccination. In face of an observed altered response in many infants less than one year of age, it would appear prudent to withhold vaccine in this age group until the consequences of such an approach are better defined.

Age Factors↗
PubMed1976

Genetic control of immune responsiveness to poly (LPro)--poly (LLys)-derived polypeptides by histocompatibility-linked immune response genes in the rat.

In rats responsiveness to branched synthetic polypeptides carrying a Pro--L backbone, such as (T,G)-Pro--L or (Phe,G)-Pro-L and to Pro--L itself is controlled by Ir genes which are linked to the major histocompatibility genes. The level of antibody production to these polypeptides does not fall into strict high or low responder categories but covers the range in between. (T,G)-pro--L and Pro--L elicit a very similar response pattern which, however, differs from that obtained with (Phe,G)-Pro--L. Anti-(T,G),Pro--L antibodies do not cross-react with (T,G)-A--L, but do so extensively with Pro--L. Anti-(Phe,G)-Pro--L antibodies show cross-reactivity to (Phe,G)-A--L only when the antibody-producing strain is a high responder to (Phe,G)-A--L. These results when considered in view of data obtained in mice on genetic control of the immune response to (T,G)-Pro--L suggest that at least two unlinked Ir genes are involved in controlling anti-Pro--L responsiveness.

Animals↗