摘要:

AbstractTo analyze the interaction between macrophages and splenic lymphocytes with reference to time and concentration, the Mishell‐Dutton system was divided into two experimental steps. Step 1 consisted of the cocultivation of spleen cells with various doses of macrophages for different periods of time, while in step 2 macrophages were removed, spleen cells transferred to fresh petri dishes and cultivated until plaque assay. Cocultivation of spleen cells with high doses of macrophages for 4–8 h markedly enhanced the DNA synthesis and plaque‐forming cell (PFC) response of sheep red blood cell‐stimulated and unstimulated cultures. A cocultivation longer than 24 h resulted in an inhibition of both DNA synthesis and PFC response of spleen cells. These studies suggest a nonspecific function of macrophages on proliferation and differentiation processes in‐antibody

ISSN:0014-2980    

DOI:10.1002/eji.1830060702

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractA study was made of bovine serum albumin density gradient‐separated bursa cells with respect to their distribution on the gradients, % cytotoxicity with anti‐Ig + complement (C) or anti‐μ + C, and localization of fractions in irradiated syngeneic recipients. Layer A showed a higher cytotoxicity with anti‐Ig + C or anti‐μ + C than the others; layer D showed the lowest % cytotoxicity, although a large % of the cells not killed by anti‐Ig were killed by anti‐bursa serum + C. The C + D layers contained a much larger fraction of the Ig+cells from the bursa in the 1–4‐week‐old than in the 6–12‐week‐old animals, suggesting a relative shift towards lower density of Ig+bursa cells with age.When [3H]adenosine‐labeled bursa cells from density gradient fractions were transferred, the % injected radioactivity found in recipient spleens was higher for fractions A and B than for fraction C + D. While 50–60 % of the cells from fractions A and B which localized in spleen were found in germinal centers and follicles, a much lower % of the cells from fraction C + D seen in spleen localized in these areas. The results were in agreement with those of previous studies suggesting that it is primarily the Ig‐bearing population among bursa c

ISSN:0014-2980    

DOI:10.1002/eji.1830060703

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractMemory B cells which give rise to JgG antibody‐producing cells were generally assumed to be IgG‐bearing cells. However, recent studies indicating that very few IgG‐bearing cells exist in lymphoid tissue brought this assumption into question. In this study, we examined directly the question whether IgG‐bearing cells contain functional precursors of IgG antibody‐producing cells. Using the adoptive secondary immune response, we demonstrated that Ig‐1b‐bearing cells, isolated with the fluorescence‐activated cell sorter (FACS), are the functional precursors of Ig‐1b‐producing cells. Further, we have enriched IgG2and IgG1memory B cells using the FACS. The results show that IgG2‐bearing cells are the functional precursors of the IgG2antibody‐producing cells. Likewise, the IgG1‐bearing cells are the functional precursors of IgG1antibody‐producing cells. Thus, IgG memory cells have surface IgG which indicates the class and allotype commitment of the memory cell and its pro

ISSN:0014-2980    

DOI:10.1002/eji.1830060704

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractTrinitrophenylated Moloney virus‐induced YAC cells induced a higher cytotoxic antibody response and better protection against small tumor cell doses in syngeneic, low‐responsive strain A mice than nonmodified YAC cells that had been inactivated by irradiation or mitomycin C treatment. The results indicated that genetically determined low responsiveness to a virally induced antigen can be overcome, at least to some extent, by coupling the immunizing cells to a strong immunogenic hap

ISSN:0014-2980    

DOI:10.1002/eji.1830060705

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe effect of nonspecific mitogens on the trapping of125I‐labeled aggregated human IgG (125I‐AHGG) in germinal centers (GC) of mouse spleens has been investigated by both radioactivity uptake and immunofluorescence. Phytohemagglutinin and concanavalin A (Con A) significantly decreased trapping. Lipopolysaccharide produced less inhibition, and pokeweed mitogen had no significant effect. The maximum inhibition occurred with 250–500 μg Con A. This had no effect on125I‐AHGG uptake in liver, kidney and blood. No differences were found between i.p. and i.v. routes of Con A injection.The effect of mitogens on the125I‐AHGG trapping in GC is due more likely to modification of the migratory properties of lymphocytes brought about by surface binding, than to their mitogenic properties, since Con A decreased125I‐AHGG localization in thymectomized, x‐irradiated and bone marrow‐ recon

ISSN:0014-2980    

DOI:10.1002/eji.1830060706

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe autoantibody response induced in mice by alloimmunization with liver‐specific F antigen is an example of the circumvention of humoral self‐tolerance. The F molecule has been isolated and shown to be a protein with a mol. wt. of 40 000 Daltons which migrated as a β‐globulin. The purified antigen retains both the immunogenic and antibody‐combining properties of crude liver homogenate. Successful iodination of the protein allowed the establishment of a radioimmunoassay which demonstrated high titers of antibodies in responder strains. At the same time it was clearly shown that no antibody could be detected, either as a result of syngeneic immunization or as a result of alloimmunization in nonresponder strains. The characteristics of the F antigen immune response distinguish it from that induced by other

ISSN:0014-2980    

DOI:10.1002/eji.1830060707

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractSusceptibility to tolerance induction by polysaccharides during the neonatal period has been studied with the α‐1.3 and α‐1.6 glucosyl epitopes of dextran B 1355 in BALB/c mice and the β‐2.6 fructosyl epitope of levan in CBA mice.Acquisition of responsiveness, as measured by plaque‐forming cell (PFC) assays, is relatively late – taking more than 14 days to appear and 2–3 months to attain maturity in the case of α‐1.6 glucosyl and β‐2.6 fructosyl. The mice responded well to sheep red blood cells and 2,4‐dinitrophenylated (DNP) keyhole limpet hemocyanin (KLH) by 14 days, but were refractory to another thymus‐independent antigen DNP‐Ficoll. Nonresponsiveness of 2‐week‐old spleen cells to the polysaccharides was stable on transfer and could not be attributed to suppressor cells.Despite this long post‐natal phase of immaturity, no evidence was obtained of concomitant susceptibility to tolerance induction by dextran and levan. Response curves in mice injected at birth with weight‐adjusted doses revealed similar or even higher “high‐zone” thresholds to those tolerized at 3 months. Only partial α‐1.3 glucosyl tolerance is inducible in adults but this was no greater after neonatal exposure, which led also to short‐lived α‐1.6 tolerance. Repeated injections of B 1355 and levan during the first 10 days was no more tolerogenic, and PFC appeared spontaneously with maturity in mice given these antigens neonatally.Thus, the recognized neonatal susceptibility to thymus‐dependent antigens does not extend to these thymus‐independent antigens. It is therefore considered that tolerance studied with polysaccharides has little relevance to the mechanism of self‐tolerance acquired in the embryo and,in vivo, is determined by interaction with a relatively mature B cell rather than by “c

ISSN:0014-2980    

DOI:10.1002/eji.1830060708

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThese experiments were originally designed to determine whether an anti‐carrier antibody,e.g., anti‐allotype could break hapten‐specific tolerancein vivo.Tolerance to 2,4‐dinitrophenyl (DNP) was induced in C57BL/6J mice using DNP‐BALB/c IgG2aconjugate. When anti‐allotype serum was injected in C57BL/6J mice one day after a single injection of DNP‐IgG2athe mice were not tolerant. In contrast, when tolerance was induced by four weekly injections of tolerogen, the anti‐allotype serum had no effect on the tolerant state. This effect was specific for tolerance‐inducing carrier.Anti‐carrier antibody injected in C57BL/6J mice one day after DNP‐IgG2aproduced a small but significant anti‐DNP response without administration of the immunogen, whereas the tolerogen (DNP‐IgG2a) by itself was not immunogenic. Similarly, despite multiple injections of DNP‐IgG2a, bearing the foreign allotype, only one out of 7 C57BL/6J mice showed a weak anticarrier response. In contrast, a marked anti‐carrier (IgG2a) response was obtained when the anti‐allotype antibody was passively administered in C57BL/6J mice.In conclusion, these experiments suggest that tolerance to an antigenic determinant may be broken by an antibody directed not to this determinant, but to another on the same molecule. The significance of this finding in relationship to the mechanism of the carrier‐determined tolerance and the breakdo

ISSN:0014-2980    

DOI:10.1002/eji.1830060709

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe anti‐PC antibodies of BALB/c origin bear predominantly the idiotype characteristic of the phosphorylcholine (PC)‐binding T15 myeloma protein. Sera from one‐day‐old BALB/c mice contain lower amounts of T15 idiotype than sera from adult mice, and, unlike the latter, they also contain detectable amounts of anti‐T15 antibodies. By 2 weeks of age the anti‐T15 antibodies are no longer detectable while the T15 idiotype has reached adult levels. Injection of neonatal mice with anti‐idiotypic antibodies renders them unresponsive to PC until the 15th week of life. Furthermore, this treatment induces a chronic suppression of the T15 idiotype, since on recovery from unresponsiveness, the neonatally suppressed mice produce anti‐PC antibodies which are predominantly T15‐negative. In contrast, treatment of adult mice with anti‐idiotypic antibodies induces only a transient state of unresponsiveness to PC, and the antibodies produced upon recovery bear the T15 idiotype. These findings are discussed in the context of idiotype anti‐idiotype interactions and their possible rol

ISSN:0014-2980    

DOI:10.1002/eji.1830060710

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractMice were injected with a series of (T, G)‐A–L [poly (LTyr,LGlu)‐poly(DLAla)– poly (LLys)]‐like compounds with side chains of homogeneous sequences: T‐A–L, GT‐A–L, GGT‐A–L, and TG‐A–L. T‐A–L was not immunogenic. However, T‐A–L was able to bind antibodies to (T, G)‐A–L 509, and this binding could not be blocked by A–L. When complexed with bovine serum albumin, T‐A–L, was immunogenic in both responder and nonresponder strains of mice. GT‐A–L and GGT‐A–L were both immunogenic and elicited the characteristic responder‐nonresponder difference induced by (T, G)‐A–L. TG‐A–L was also immunogenic, but there was considerable overlap in the response of responder and nonresponder strains. On the average, responder mouse serum had a slightly higher antigen‐binding capacity than nonresponder mouse serum. In contrast to antibodies against GGT‐A–L, antibodies against TG‐A–L bound heterologous antigens poorly.These data, along with the results of other investigators, are consistent with the hypothesis that there are multiple Ir‐1 genes which recognize different sequences. The specificity of the Ir‐1 genes is extraordinary. The polypeptides

ISSN:0014-2980    

DOI:10.1002/eji.1830060711

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY