摘要:

AbstractLymphocytes belonging to the T lineage were described in athymic nude mice. We showed previously that they were distinguished from usual peripheral lymphocytes by their low density of Θ antigen, their slow electrophoretic mobility and their absence of recirculation through the thoracic duct. We now report that they also express the TL antigen, have a life span of 1 to 2 days, are produced in the bone marrow and are under the homeostatic influence of the thymus. Indeed they appear rapidly in surgically T‐deprived mice and their production is blocked in both surgically or congenitally athymic mice receiving a thymus graft. This homeostatic control may be mediated via a humoral factor. Cells with similar characteristics are present in the thymus at early stages of embryogenesis.The characteristics of these T lineage lymphocytes strongly suggest that they may represent “pre‐thymocytes”,i.e.cells already committed to the T pathway independently of thymic influence but needing the thymus microenvironment to differentiate

ISSN:0014-2980    

DOI:10.1002/eji.1830060202

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractPapain‐solubilized HLA antigens giving only two bands of 34 000 mol.wt. and 11 000 mol.wt. by sodium dodecyl sulfate (SDS) gel electrophoresis and isolated from the cultured human lymphoblastoid cell line RPMI 4265, have been used to prepare antisera in rabbits. Antisera were raised against soluble products of the A (or 1st) series of HLA, bearing the determinant HLA‐A2 (A2 substance), or against a mixture of products of the B (or 2nd) series of HLA, bearing the determinants HLA‐B7 and HLA‐B 12 (B7‐12 substances). Rabbit antisera to A2 substance reacted primarily with A2 substance on Ouchterlony analysis, showing an apparent spur of cross‐reactivity with B7‐12 substances. Rabbit antisera to B7‐12 substances reacted primarily with B7‐12 substances, giving a spur of cross‐reactivity with the A2 material. Neither antiserum precipitated β‐2microglobulin. Both types of sera reacted with membrane molecules of 43 000 mol.wt. and 11 000 mol.wt. by immune precipitation and gel electrophoresis in SDS of detergent‐solubilized radiolabeled membranes from cultured cell lines, as predicted for sera directed towards HLA antigens. F(ab′)2fragments of the antibodies blocked the complement‐mediated cytotoxicity of all HLA alloantisera tested for human peripheral blood lymphocytes. After absorption with B7‐12 substances, F(ab′)2fragments of antisera to A2 substance only blocked the cytotoxicity of HLA alloantisera to A series specificities. After absorption with A2 substance, F(ab′)2fragments of rabbit antisera to B7‐12 substances only blocked the cytotoxicity of HLA alloantisera to B series specificities. The results prove the existence of shared antigenic determinants between all members of the same series. These findings support the genetic evidence that A series HLA antigens are allelic products of a single locus, while B series HLA antigens are allelic products of a separate locus, by establishing some invariance of structure, presumably amino acid sequence, between members of the same series. The apparent cross‐reactivity between A2 substance and B7‐12 substances, and the ability of the unabsorbed F(ab′)2, preparations to block the cytotoxicity of all HLA alloantisera, suggests that some determinants are common to both HLA loci. This may be considered to support the hypothesis t

ISSN:0014-2980    

DOI:10.1002/eji.1830060203

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe amount of natural anti‐DNP‐cap, anti‐NIP‐cap or anti‐ABA‐TYR in human IgM was measured by using immunoabsorbents and hapten elution. We found that 1.0 % of pooled human IgM is specific for DNP‐cap, 0.2 % for NIP‐cap and 0.02 % for ABA‐TYR. Haptens NIP and DNP were found to be cross‐reactive when tested with natural antibodies even though they were not cross‐reactive when tested w

ISSN:0014-2980    

DOI:10.1002/eji.1830060204

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractHLA antigens are coded for by three closely linked loci. The gene products of the first and second locus are known to be very similar in overall structure. Antigens coded for by the third locus were examined with regard to their chemical and immunological relationship to the first and second loci gene products. It is demonstrated that the third locus antigens are composed of two types of polypeptide chains, the smaller of which is identical to β2‐microglobulin. The alloantigenic polypeptide chain has an apparent molecular weight of 48 000 when solubilized by detergent treatment and about 35 000 when released from the cell membrane by proteolysis. These data together with size and shape analyses by gel chromatography and sedimentation velocity determinations show that HLA antigens from the three subloci are indistinguishable with the techniques employed. Suggestive evidence was obtained that the third locus antigens are more sensitive to proteolysis than the first and second locus antigens.The similarity between the three gene products was also evident on cyanogen bromide fragmentation of the polypeptide chains. Furthermore, rabbit antibodies against antigens coded for by the first locus cross‐reacted extensively with antigens from the second and third locus. This study therefore lends strong credence to the view that the three HLA antigen subloci have arisen by gene duplications of a common ancestral

ISSN:0014-2980    

DOI:10.1002/eji.1830060205

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe hydrolysis products from short term exposure of guinea pig IgG2to papain and pepsin have been characterized. Papain hydrolysis liberates 4 types of Fc fragment, only one of which retains both an interchain disulfide bond and an intact CH2 domain, cFc, mol. wt. 56 000. The other three fragments noncovalently linked Fc (nFc) (mol. wt. 56 000), incomplete Fc (iFc) (mol. wt. 39 000) and Fc′ (23 000) represent further degradation products of covalently linked complete Fc (cFc). The cytophilic activities of these fragments as well as F(ab′)2and pFc′ from pepsin hydrolysis, were studied to determine the domain(s) responsible for binding to homologous peritoneal macrophages. Only the native immunoglobulin and the intact cFc manifested cytophilic activity; in particular pepsin‐derived pFc′ and Fc′ were inactive. Following mild reduction and alkylation, performed to affect only the interchain disulfide bonds, the cytophilic activity of cFc was markedly reduced. The low cytophilic activity in the pFc′ fragment suggests that the CH2 domains play a major part in binding to the macrophage Fc receptor through a site(s) stabilized by the interchain di

ISSN:0014-2980    

DOI:10.1002/eji.1830060206

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractIntact antibodies, and F(ab′)2, and Fab′ fragments thereof directed against β2‐microglobulin (β2m) and the HLA alloantigenic polypeptide chain impede the mixed leukocyte culture reaction (MLR). The Fab′ fragments are effective only when bound to the responder cell population. The kinetics of their inhibiting action suggest that they interfere with the recognition phase of the MLR. Thus, it seems possible that β2m may be part of or closely associated with those structures on the responding cells which recognize the stimulatory alloantigens.Antibodies against β2m or the other HLA antigen polypeptide chain are mitogenic for peripheral blood lymphocytes. The antibodies against β2m caused greater stimulation than those against the HLA alloantigenic polypeptide chain. Only bivalent antibodies against β2m were mitogenic and promoted blast transformation of 1 to 2 % of the lymphocytes. Although only B lymphocytes were triggered, the mitogenic response of cultures containing various proportions of B and T cells suggests that cooperation of the two cell types is necessary to obtain optimal mitogeni

ISSN:0014-2980    

DOI:10.1002/eji.1830060207

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractUpon immunization with phosphorylcholine (PC), BALB/c mice produce antibodies bearing mainly one idiotype which is identical to that of the TEPC 15 PC‐binding myeloma protein. By coating sheep red cells (SRC) with TEPC 15 it was possible to detect anti‐idiotypic plaques during the course of an immune response to PC. These plaques are detectable only after the anti‐PC response has reached a peak and begun to decline. They are specific, since addition of free TEPC 15 and not MOPC 315 prevented their detection. It is suggested that such anti‐idiotypic reactive cells might regulate the respons

ISSN:0014-2980    

DOI:10.1002/eji.1830060208

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractRecirculating lymphocytes were collected from the efferent ducts of peripheral somatic nodes and incubatedin vitrowith51Cr. After washing, the labeled cells were returned to the sheep by i.v. injection. The partitioning of the labeled cells between blood and efferent (intermediate) lymph, or between efferent and afferent (peripheral) lymph was monitored for the next 24 h by assaying the radioactivity in appropriate samples of cells.The labeled lymphocytes took several hours to migrate through the nodes so that they equilibrated between blood and lymph in about 10 h. This pattern was not altered grossly during the inductive phase of an immune response.The small numbers of lymphocytes which migrated through peripheral tissues entered the lymph at least as quickly as those that migrated through lymph nodes.

ISSN:0014-2980    

DOI:10.1002/eji.1830060209

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractThe proportion of cells bearing surface immunoglobulin (Ig) and the normal lymphocyte transfer (NLT) reactivity of mononuclear cells obtained from the blood, afferent lymph, and efferent lymph from both somatic and intestinal nodes of sheep were measured.The proportion of Ig‐positive lymphocytes was approximately 30 5% in blood and efferent lymph, but only about 10% in afferent lymph. The proportion of unlabeled lymphocytes (T cells) was about the same in all the preparations, as afferent lymph contains 15–20% macrophages. Despite this apparent uniformity in the T cell content, the NLT reactivity of efferent lymph was 3 to 5 times higher than that of blood or afferent lymph. No humoral factors could be detected by incubating cells in the various plasmasin vitrobefore injection. No inhibitory cells could be detected when mixtures of cell populations were used to initiate lesions.We suggest that lymphocytes in efferent lymph are more reactive than others because they are “groomed” by macrophages during their recirculatory passage through the substance of t

ISSN:0014-2980    

DOI:10.1002/eji.1830060210

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractRabbit peripheral blood leukocytes (PBL) added to cultures of autologous spleen cells, primedin vivoto sheep red cells, are able to suppress with high efficacy the secondaryin vitroresponse of the spleen cells to that antigen. Removal of nylon wool adherent cells from PBL abolishes the suppressive effect. When the PBL are fractionated by velocity sedimentation the suppressor cells can be separated from the responding cells.The circulating lymphocytes, freed from the inhibiting effect, either by nylon wool absorption or by velocity sedimentation fractionation, are able to give a strong secondaryin vitroanti‐SRC response, in which the long latency period, usually observed when PBL are stimulated with antigen in culture, is abolished or at least reduced. The suppressor effect present in the PBL is not due to granulocytes, platelets or erythrocyte

ISSN:0014-2980    

DOI:10.1002/eji.1830060211

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY