摘要:

AbstractThe mitogenic activity of soybean agglutinin was found to depend on the presence of lectin aggregates formed in lectin preparations stored in the lyophilized state. Such soybean agglutinin preparations gave maximal stimulation of untreated pig lymph node cells and neuraminidase‐treated mouse spleen cells at relatively high concentrations, ranging from 100 to 2000 μg/ml. After separation into unaggregated (divalent) and polymeric (tetra‐and multivalent) fractions, it was found that the unaggregated lectin did not stimulate the cells, while the tetravalent and multivalent fractions were active and gave maximal stimulation at a concentration of 10 μg/ml. These results suggest that soybean agglutinin must have at least four sugar binding sites in order to be able to stimulate lympho

ISSN:0014-2980    

DOI:10.1002/eji.1830060302

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractSpecific and nonspecific lysis of DBA/2 (H‐2d) mastocytoma cells, P815, by concanavalin A (Con A)‐induced cytotoxic T cells was studied. In the assay for nonspecific lysis, phytohemagglutinin (PHA) was present to glue the target and killer cells together. We have presented evidence previously to show that PHA reveals only, and all, cytotoxic T cells. In the assay for specific lysis the only glue present was specific receptors on a fraction of the killer cells and surface antigens of P815. We show that when PHA was present, Con A‐induced cells which were syngeneic, semi‐syngeneic, or allogeneic, lysed P8 15 very efficiently in a 4‐h51Cr release assay. However, only Con A‐induced T cells which were allogeneicanddid not carry H‐2dlysed P815 when the assay was carried out in the absence of PHA. In an experiment with two target cells, Con A‐induced B10 (H‐2b) T cells lysed B 10.D2 (H‐2d) targets specifically but did not lyse B10 targets, while Con A‐ induced B10.D2 T cells lysed B10 targets specifically but not B10.D2 targets. Furthermore, Con A‐induced B6 (H‐2b) T cells from normal mice lysed P815 specifically but Con A‐induced B6 T cells from irradiated F1(B6 × BALB/c) (H‐2b/d) mice reconstituted with B6 bone marrow did not lyse P815 specifically. A fraction of Con A‐induced T cells therefore appear to bear specific surface receptors for nonself H‐2 coded structures. We describe conditions of assay and a new method of plotting the results such that nonspecific (PHA‐revealed) and specific (PHA‐independent) cytotoxicity can be quantitatively compared. We conclude that 1–4 % of the total Con A‐induced cytotoxic effector T cells are directed against any particular foreign H‐2 haplotype. This is the first estimate of the relative fre

ISSN:0014-2980    

DOI:10.1002/eji.1830060303

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractNormal peripheral blood lymphocytes were tested by a mixed rosette method, employing different sized erythrocytes as indicators to identify lymphocytes simultaneously possessing membrane markers found commonly on B and T cells. Only small populations of these lymphocytes were detected regulary in normal lymphocyte preparations. One type of lymphocyte (ranged from 0.5%‐8%) was shown to possess the following markers: receptors for human and rabbit IgG, receptors for the third complement component C3b and C3b inactivator‐cleaved C3b (C3d), and the capacity to rosette spontaneously with uncoated sheep erythrocytes (SRBC). Another lymphocyte cell type was shown to possess both SRBC and IgG receptors but lack membrane immunoglobulins and complement receptors. This population was detected in lymphocyte preparations depleted of complement receptor cells, and an increased number of these cells was found in rosette preparations incubated with human serum. The possible presence of some lymphocytes possessing both complement and SRBC receptors and lacking other markers was considered.The possibility that these small populations of human lymphocytes are sub‐populations of T cells with certain cytotoxic function is postu

ISSN:0014-2980    

DOI:10.1002/eji.1830060304

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractIn a study of healthy human individuals a complete lack of correlation between the results of the agarose leukocyte migration inhibition (LMI) test, using purified protein derivative (of tuberculin) (PPD) and Bacillus Calmette Guérin (BCG) as antigens, and delayed cutaneous hypersensitivity and lymphocyte transformationin vitroto PPD was found. There was a reasonable correlation between PPD‐ and BCG‐induced LMI.Antibodies to PPD proved to have no influence on PPD‐induced LMI. Purified polymorphonuclear leukocytes, whether derived from donors sensitive to PPD in the agarose LMI test or from nonsensitive donors, did not show migration inhibition to PPD.It was concluded that polymorphonuclear leukocytes and lymphocytes need to be present simultaneously for migration inhibition of peripheral blood leukocytes by PPD.Furthermore, because a consistent relation with conventional parameters of cell‐mediated immunity was lacking, it is doubtful whether the agarose LM1 test can be considered as an alternative parameter of this kind of

ISSN:0014-2980    

DOI:10.1002/eji.1830060305

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractRabbit thymus‐dependent lymphocytes were exposed to phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) or anti‐immunoglobulin at various stages of maturation. Proliferation (induction of DNA synthesis) and early membrane events (turnover of membrane phospholipids) were measured in neonatal thymocytes, normal adult thymocytes, prednisolone‐resistant thymocytes and lymph node lymphocytes. In immature thymocytes PHA induced only a marginal increase in DNA synthesis. The mitotic response increased with maturation, but only peripheral T lymphocytes exhibited maximum stimulation. Con A and PWM were able to induce DNA synthesis in immature thymocytes and the degree of stimulation was shown to increase with maturation. In contrast to the different degree of proliferation of thymocytes induced by PHA or Con A the incorporation of [4C]oleate, [14C]choline or [14C]acetate into phospholipids was stimulated to the same degree by these lectins. Reactivity of T lymphocytes, as measured by early membrane changes at different stages of maturation, to different T cell mitogens appears to be identical. Differences in degree of cell proliferation therefore may be secondary phenomena due, in part, to tissue culture conditions. Reactivity to mitogens as measured by phospholipid turnover appears to be an early acquired function in the maturation of lymphocytes of the T cell

ISSN:0014-2980    

DOI:10.1002/eji.1830060306

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractFreshly explanted MDAY murine tumor cells are sensitive to lysis mediated by fresh normal rabbit serum. The sensitivity, which increases with the age of the tumor, is rapidly lost upon short‐term culture, and takes place at 37 °C but not at 4 °C.Cellular components released into the medium during short‐term culture are capable of eliciting xenogeneic antibodies that mediate complement‐dependent lysis of suc

ISSN:0014-2980    

DOI:10.1002/eji.1830060307

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractSubsets 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

ISSN:0014-2980    

DOI:10.1002/eji.1830060308

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractImmune response region‐associated (Ia) antigens and classical H‐2 antigens are glycoproteins which differ in their molecular weight and tissue distribution. Ia and H‐2 molecules also show differences in overall charge, apparent isoelectric point and susceptibility to proteolytic degradation, acid treatment and exposure to 56°C. In the present paper, Ia.11dantigens were shown to have a molecular weight of about 35 000 after solubilization with non‐ ionic detergents. Purified Iadantigens, solubilized by controlled papain digestion, display a molecular weight of about 26 000 after final purification by indirect immune coprecipitation. This figure corresponds to the molecular weight of a highly purified H‐2 polypeptide fragment obtained after papain solubilization. The remarkable size similarity of proteolytic fragments from Ia and H‐2 antigens could suggest that these genetically and functionally related molecules possess some structural featur

ISSN:0014-2980    

DOI:10.1002/eji.1830060309

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe ultrastructure of antibody‐forming cells (AFC) has been studied in the lymph node cell population from rabbits locally immunized with horseradish peroxydase (PO) incorporated in complete Freund's adjuvant, and the kinetics of AFC development followed from day 7 to day 18 after one injection of PO.Identification of the AFC was done by local hemolysis assay, using carboxy‐methyl cellulose solidifying medium and PO‐coated sheep erythrocytes. AFC were thereafter transferred by micromanipulation into a Beem capsule, fixed, treated by PO for fine ultrastructure detection of anti‐PO antibodies, included, sectioned and studied by electron microscopy.It was found that the AFC were essentially of three categories: lymphocytes, proplasmacytes and plasmacytes, with (+), or without (−), intracellular antibody. The proportion of these categories varies with the time elapsed since the injection of antigen and with the plaque‐forming activity of the population: lymphocytes(−) are relatively more numerous (over 30%) at the early stages of immunization (day 7). The number of plasmacytes increases with immunization. If most of them contain intracellular antibody at the early stages (up to day 9), the proportion of plasmacytes (+) decreases markedly afterwards.The cell type distribution is compatible with the idea that the lymphocytes are the precursors of plasmacytes, proplasmacytes being transitional forms, but no direct filiation scheme can actually be deduced from thes

ISSN:0014-2980    

DOI:10.1002/eji.1830060310

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe role of antibody‐forming cell (AFC) blockade in the genesis of hapten‐specific tolerance induced by hapten (2,4‐dinitrophenyl)‐coupled pneumococcal polysaccharide (DNP‐lys‐S3) was investigated. Tolerizing doses of DNP‐lys‐S3 given to mice making antibodies to DNP‐hemocyanin a day before assay markedly reduced numbers of detectable anti‐DNP AFC. Furthermore, anti‐DNP AFC were specifically inhibited by briefin vitroincubation with DNP‐lys‐S3, followed by extensive washing. This inhibition requires multivalent binding of tolerogen to immunoglobulin receptors on AFC, and appears to result from a decrease in the rate of antibody secretion per cell.A variety of data indicate that IgM AFC are more susceptible to blockade than IgG AFC, and the susceptibility of both cell types decreases with time after immunization. This probably reflects differences in the density and in the rate of loss of surface immunoglobulin receptors on IgM and IgG AFC and their immediate precursors.However, we conclude that under “conventional” tolerizing conditions,i.e.when tolerogen is givenpriorto immunogen, DNP‐lys‐S3 suppresses antibody formation primarily by inactivating DNP‐specific precursorcells. AFC blockade is therefore probably only relevant in the suppression of (primary?) IgM responses by large doses of tolerogen. The relative importance of precursor inactivation and AFC blockade in tolerogenesis of IgM responses to T cell‐independent antigens

ISSN:0014-2980    

DOI:10.1002/eji.1830060311

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY