摘要:

AbstractThe development of T lymphocyte immunocompetence appears to depend upon the function of the thymus gland. To study this function in greater detail, we developed a method for preparing monolayer cultures of thymus reticulum cells. We found that populations of lymphocytes from thymus‐deprived mice acquired the ability to produce T lymphocyte reactions when incubated with reticulum cellsin vitro.These results provide evidence about the role of the thymus reticulum in inducing immunocompetence of T lymphocyte

ISSN:0014-2980    

DOI:10.1002/eji.1830031202

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractThe nature of effector cells mediating cytotoxicityin vitroin a rat tumor allograft model using51Cr release assays has been investigated. On the basis of a series ofin vitrocell depletion techniques including glass absorption, removal of Fc receptor‐bearing cells and lysis of thymus‐dependent lymphocytes with a cytotoxic rabbit anti‐thymus cell sera, the predominant effector cell in this situation appears to be a thymus‐dependent lymphocyte. The main difference from previous published studies in mice appears to be the more rapid evolution of cytotoxic activity in the rat and the difficulty in detecting marked cytotoxic activity in the thoracic duct cells. Determination of the antigenic specificity of these cytotoxic cells by an inhibition assay suggests that their specificity is directed solely to transplantation antigens on the tum

ISSN:0014-2980    

DOI:10.1002/eji.1830031203

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractDifferent strains of mice immunized with lactic dehydrogenase B (LDHB) can be classified into high and low responders. Breeding experiments suggest regulation of this immune response by a dominant gene (Ir‐LDHB), which is linked to the major histocompatibility complex (H‐2). Studies in recombinant inbred mice made it possible to map Ir‐LDHBwithin the H‐2 complex between Ir‐1 and Ss‐Slp. The argument that it is a single gene or only a small gene cluster which regulates immune responsiveness to the multideterminant enzyme molecule is strengthened by our finding of only two levels of responsiveness among a variety of inbred mouse strains.Responsiveness in this system is thymus‐dependent and can be transferred to low responders by transfer of normal or immune spleen cells from high responders. Experiments in an adoptive transfer system, in which 4‐hydroxy‐5‐iodo‐3‐nitrophenacetyl (NIP)‐LDHBwas used as a hapten‐carrier complex, demonstrated that LDHB‐specific helper activity was detectable in LDHB‐primed spleen cells of responder animals only. This indicates a deficiency of LDHB‐specific T cells in low responder mice.Immunization of congenic mice with the hybrid isoenzyme LDHABresults in equal production of anti‐LDHBantibodies in low and high responders.Examination of these sera in isoelectric focussing (IEF) led to the following conclusions. a) Individual sera show, in general, little heterogeneity of anti‐LDHBantibodies. b) Low responders exhibit a similar degree of heterogeneity as do high responders. c) A few groups of bands, indistinguishable in IEF, appear repeatedly in individual sera, irrespective of the H‐2 allele of the donor.We conclude that Ir‐LDHBis expressed ex

ISSN:0014-2980    

DOI:10.1002/eji.1830031204

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractResponsiveness to porcine LDHA(a lactic dehydrogenase isoenzyme) in rats is controlled by a dominant gene, Ir‐LDHA, which is linked to the major histocompatibility locus. This gene is unlinked to the gene coding for an allotypic marker on the major class of rat immunoglobulin light chains.Ir‐LDHAcontrols a specific step in the immune response to the enzyme molecule. The specificity of this step can not be ascribed alone (if at all) to the overall charge of the antigen.High responder lymphocytes retain high responsiveness in a low responder environment. In addition, low responder animals do not appear to contain a material that cross‐reacts with rat anti‐LDHAantibody and that is not present in high responder animals.High, but not low responder lymph node cells could be stimulated by antigen into proliferationin vitro.Low responder animals showed deficiency in developing LDHA‐specific helper function. These data suggest that Ir‐LDHAis expressed at the level of T ce

ISSN:0014-2980    

DOI:10.1002/eji.1830031205

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractLow zone tolerance (LZT) of mice to bacteriophage fd has been further investigated and found to be specific for the antigen and inducible within 24 h. LZT and immunity are retained when spleen cells from tolerant or immune animals are transferred into thymectomized, lethally irradiated recipients reconstituted with fetal liver. Thymocytes, educatedin vivowith antigen doses inducing LZT, are capable of transferring this tolerance into normal syngeneic mice and maintaining it there specifically. Treatment with anti‐Θ serum abolishes the suppressive capacity of the educated thymocytes. The data suggest that LZT is actively maintained by living T cel

ISSN:0014-2980    

DOI:10.1002/eji.1830031206

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractThe reactivity of thymic lymphocytes in the mixed lymphocyte reaction of the toadXenopus laevisis already established in the 4th week after fertilization. The degree of tritiated thymidine incorporation by lymphocytes and stimulation indices were of the same order of magnitude during ontogeny. This stability of the thymocyte reactivity contrasts with other aspects of the thymus development. At metamorphosis, the number of lymphocytes in the thymus is reduced by a factor of 5, as compared to the maximum number of cells in larval stage.The use of a sensitive immunofluorescence technique suggested that a previously noticed decrease in the percentage of immunoglobulin‐bearing thymocytes is likely to be due to the lower expression of immunoglobulin molecules at the surface of the cell. None of these ontogenetic changes seemed to affect the reactivity of thymocytes in the mixed lymphocyte reaction, at least in unidirectional reactions between individuals from unrelated familie

ISSN:0014-2980    

DOI:10.1002/eji.1830031207

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractCyclic AMP, its dibutyryl derivative and prostaglandins, PGE1and PGE2, do not modify the numbers of rosette‐forming cells (RFC), but they do alter these cells' sensitivity toin vitroinhibition by azathioprine (AZ) and anti‐theta serum (ATS). In thymectomized mice, cyclic nucleotides and prostaglandins mimic the action of the thymic factor contained in thymic extracts and in normal serum, correcting the low spleen RFC sensitivity to AZ and ATS induced by thymectomy. Moreover, the mixture of infraliminal active doses of cyclic AMP and of thymic extracts (or normal mouse serum) also gives this effect. In normal mice, the nucleotides (but not prostaglandins) lower the AZ and ATS sensitivity of RFC, which remains insensitive to thymic extracts. Theophylline and isoproterenol have effects similar to those of cyclic AMP, a result in accord with their postulated interactions with the adenyl‐cyclase system. Noncyclic AMP and cyclic GMP show no effect in the RFC assay system at doses 10–100 times higher than active doses of cyclic AMP. Other vasoactive compounds, including epinephrine, phentolamine, propanolol, and angiotensin, do not show any effect

ISSN:0014-2980    

DOI:10.1002/eji.1830031208

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractWe have demonstrated by two separate techniques the formationin vivoof foci of anti‐(4‐hydroxy‐3‐iodo‐5‐nitrophenyl)acetyl (NIP) antibodyforming cells. The initiation and expansion of such foci in the spleens of irradiated mice has been shown to depend on the presence of both hapten‐and carrier‐primed spleen cell populations.Sensitive methods have been developed to assay the heterogeneity of antibody produced in single anti‐hapten foci, usually of less than 1000 plaque‐forming cells. Foci from NIP‐BSA (bovine serum albumin)‐primed spleen cell inocula have been shown to be usually monoclonal. Using mixtures of BSA‐primed and NIP‐ovalbumin primed spleen cells, the effect of changing the ratio of cooperating cell types upon the homogeneity of antibody in foci has been studied. The results are interpreted as preliminary evidence in favor of a high degree of B cell selection operating during focus initiation.An effect of carrier‐primed cell numbers on the size of anti‐hapten foci has been detected and some morphological

ISSN:0014-2980    

DOI:10.1002/eji.1830031209

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractChickens were bursectomized surgically during the first week after hatching and immunized subsequently with human serum albumin (HSA). Bursectomy (Bx) 4 days posthatching suppressed the IgG response, but did not affect the IgM response when tested at 2 weeks. The overall responsiveness had declined by 4 weeks, however, probably due to the nonreplicating character of the early peripherally seeded B cells. Furthermore, these chickens failed to give a memory response. B cells with self‐replicating and memory potential are seeded later than 4 days posthatching. However, 7 day Bx still produced a selective suppression of the primary IgG response while the IgM response, although delayed, reached a normal peak titer. Treatment of memory cellsin vitrowith anti‐μ serum interfered with the adoptive transfer of both IgM and IgG responses. The data are interpreted in terms of sequential seeding of IgM and IgG precursors of the anti‐HSA clones, both of which maintain membrane‐bound μ‐ch

ISSN:0014-2980    

DOI:10.1002/eji.1830031210

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY

摘要:

AbstractVelocity sedimentation of lymphoid cells on linear Ficoll gradients in polycarbonate tubes provides a simple reproducible technique for fractionating lymphocytes from lymphoblasts. Using this method the T lymphoblast was characterized as an important cytotoxic cell in the early immune response to the H‐2dalloantigen of the P‐815‐Y mastocytoma, and at a later time the small lymphocyte was shown to be the predominant cytotoxic cell. Enrichment and depletion of cytotoxic lymphocytes was also demonstrated in fractionated sp

ISSN:0014-2980    

DOI:10.1002/eji.1830031211

出版商:WILEY‐VCH Verlag GmbH    

年代:1973

数据来源: WILEY