摘要:

AbstractThe recovery of humoral antibody responsiveness in chickens following sub‐lethal irradiation at hatching is thymus‐dependent: the antibody response to 5 × 107or 5 × 109sheep erythrocytes between 2 and 6 weeks was significantly suppressed in thymectomized‐irradiated chickens in comparison with irradiated controls. An impairment of response to human serum albumin was observed only with a low dose of antigen (0.5 mg/kg), but not with 100 mg/kg. Both hemagglutinating (mainly IgM) and antigen‐binding (mainly IgG) antibodies were affected. The secondary response to both antigens was also

ISSN:0014-2980    

DOI:10.1002/eji.1830010402

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractCell proliferation and antibody production in a secondary responsein vitroagainst the 2,4‐dinitrophenyl (DNP) group were followed by thymidine uptake, hemolytic plaque formation and inactivation of DNP‐bacteriophage T4. Thymidine uptake and plaque formation were both dependent on the amount of antigen used for stimulation of cellsin vitro, whereas phage inactivation was not. The kinetics of the response as detected by the above three assays revealed that thymidine uptake preceded both plaque formation and antibody product

ISSN:0014-2980    

DOI:10.1002/eji.1830010403

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractRabbits were immunized with 2,4‐dinitrophenyl bovine serum albumin (DNP‐BSA), and the spleen cells were removed and culturedin vitroin the presence of either phytohemagglutinin (PHA) or antigen, or both stimulants. PHA and antigen, when reacted together, had an additive stimulatory effect on thymidine uptake and an inhibitory effect on the production of antibodies as compared to the effect of the antigen alone. Cultures treated with PHA alone contained more antibodies than unstimulated cultu

ISSN:0014-2980    

DOI:10.1002/eji.1830010404

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractSpleen cells of C57BL mice immunized by tumor allografts were separated by differential flotation in albumin density gradients, and the resulting fractions testedin vitrofor cytotoxicity and for alloantibody plaque‐forming cells. The alloantibody plaque‐forming cells were found to accumulate preferentially in the low density fractions, while the cytotoxic lymphocytes were found mainly in fractions of intermediate and high density. Cytotoxic lymphocytes obtained early after immunization or by transfer of spleen cells into irradiated allogeneic hosts were of lower average density than spleen cells collected at the peak of the immune response or la

ISSN:0014-2980    

DOI:10.1002/eji.1830010405

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractThree random basic copolymers of amino acids were tested for their effect on experimental allergic encephalomyelitis (EAE). One of these copolymers denoted as Cop 1, composed of alanine, glutamic acid, lysine and tyrosine, with a molecular weight of 23 000, showed a marked suppressive effect on the disease. The intravenous administration of Cop 1 in physiological saline, as late as 5 days following the challenge with the disease‐inducing dose of the basic encephalitogenic protein, reduced the clinical incidence of EAE from 64% in the control group to 22%; the histological lesions were also decreased both in prevalence and in severity. The suppressive effect on the disease attained by the synthetic copolymer is of the same order of magnitude as that previously reported for the basic encephalitogen.The effect of the copolymers appears to be specific, since neither an acidic amino acid copolymer, nor unrelated basic proteins, had any protective action. On the other hand, a second batch of Cop 1 showed activity identical to that of the first batch. The potential applicability of this non‐encephalitogenic and non‐immunosuppressive material is disc

ISSN:0014-2980    

DOI:10.1002/eji.1830010406

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractHomocytotropic antibodies capable of sensitizing calf skin were demonstrated in serum of cows as early as 7 to 9 days following antigenic stimulation with rabbit serum albumin. In addition, the antibody was present in colostrum of the immunized dam and was taken up by the intestine of the newborn calf as an intact molecule. Skin‐sensitizing activity was also detected in calf urine after uptake of colostrum. Evidence is presented for an anamnestic response, suggesting the existence of an immunological memory for the formation of skin‐sensitizing antibodies. The homocytotropic antibody was shown to be heat labile and sensitive to treatment with 2‐mercaptoethanol. Time course studies revealed that homocytotropic antibodies persist in calf skin for at least 8 weeks.The immunoglobulin class associated with homocytotropic activity was enriched from appropriate antisera by salt precipitation, DEAE‐cellulose chromatography and gel filtration on Sephadex G‐200 columns. The final preparation was still capable of sensitizing calf skin for positive PCA reactions using a minimum dose of 0.009 μg N. The homocytotropic activity of the vinal fraction could not be removed by antibodies specific for the IgG class, but was completely blocked by antibodies against the fraction enriched in homocytotropic activity. The immunoglobulin class associated with skin‐sensitizing activity possesses antigenic determinants which are lacking in μ‐, α‐, and γ‐chains. The results indicate that the homocytotropic activity in the bovine species is associated with a unique immunoglobulin class a

ISSN:0014-2980    

DOI:10.1002/eji.1830010407

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractImmunogenicity of azobenzenearsonate‐N‐acetyl‐L‐tyrosine (ABA‐tyrosine) has been confirmed. This low‐molecular weight conjugate, in a 50 μg dose, in complete Freund's adjuvant, regularly induces an apparently pure state of delayed hypersensitivity in guinea pigs. Binding of ABA‐tyrosine to proteins seems to be very small.In detecting delayed hypersensitivityin vivo, ABA‐tyrosine appears much less efficient than a protein conjugate (ABA‐guinea pig serum albumin). Within vitrosystems (macrophage migration and lymphocyte transformation) ABA‐tyrosine is, on the other hand, as active as the protein conjugate.Experiments conducted with labeled antigens injected intradermally have shown that ABA‐tyrosine was cleared from the skin far more rapidly than the protein conjugate. This fact probably accounts for its weak activity in detecting delayed h

ISSN:0014-2980    

DOI:10.1002/eji.1830010408

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractThe dissociation of complexes between fd phages and inactivating antibodies has been followed between pH 2.2 and 5.0. The resulting dissociation curves measure the fraction of phages reactivated at a given pH. The shape of the curve is not caused by phage heterogeneity. It is a property of any given anti‐serum and reflects the degree of antibody heterogeneity. The dissociation curves for secondary sera from high responding DBA/IJ and low responding AKR/J mice have been compared. The heterogeneity of low responder antibodies is restricte

ISSN:0014-2980    

DOI:10.1002/eji.1830010409

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractA monovalent DNP‐hapten, α, N‐(4‐hydroxyphenacetyl)‐ϵ, N‐DNP‐L‐lysine (6), was synthesized. The 4‐hydroxyphenacetyl residue of this compound can be radioiodinated yielding a labeled hapten of high specific activity, which proves to be a useful reagent for assaying anti‐DNP sera by measuring their capacity to bind the hapten in a salt precipitation test based on the Farr assay. This method appears to be more generally applicable to other haptenic groups which can be bound to the ϵ

ISSN:0014-2980    

DOI:10.1002/eji.1830010410

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY

摘要:

AbstractRabbit lymphocytes were activated by phytohemagglutinin (PHA) and/or an antiserum against rabbit IgG obtained in a goat (GARIG serum). Both stimulants induced cytotoxicity in lymphocytes. The destruction of target cells was followed by measuring51Cr release from labeled fowl erythrocytes. The kinetic analysis of the target cell destruction exhibited striking differences.Following activation with PHA the lysis of the target cells started immediately after the addition of the stimulant and proceeded linearly. With GARIG serum as the activating agent the lysis started after a latent period of 20 h which was the same when the lymphocytes were preincubated with Garing serum for 20 h before the labeled erythrocytes were added. After the lysis had started it proceeded in sigmoidal fashion.When given numbers of lymphocytes were mixed with varying numbers of target cells the maximum velocity of target cell destruction was reached at a ratio of one lymphocyte to one target cell during activation with PHA and at a ratio of five lymphocytes to one target cell during activation with GARIG serum. Using concentrations of target cells at which maximum velocity of target cell destruction occured there was a linear relation between the number of added lymphocytes activated by GARIG serum and the degree of the lysis.Activation of the lymphocytes simultaneously with PHA and GARIG serum resulted in a marked enhancement of the target cell destruction which by far exceeded the sum of the cytotoxicity when the lymphocytes were activated separately.

ISSN:0014-2980    

DOI:10.1002/eji.1830010411

出版商:WILEY‐VCH Verlag GmbH    

年代:1971

数据来源: WILEY