摘要:

AbstractA carcinogen‐induced lymphoid tumor, denoted 38C‐13, obtained in a T cell‐depleted mouse of C3H/eB strain, was adapted to continuous culturein vitroand characterized with respect to its cell surface components. The cells possess IgM class immunoglobulins on their surface but do not secrete it. This membrane IgM is composed of μ and L‐chains that are similar in apparent molecular weight to those of an IgM myeloma protein. It is also homogeneous as revealed by isoelectric focusing. The cells possess Fc receptors but lack complement receptors as well as Thy‐1 and Ia alloantigens. These characteristics indicate that 38C‐13 cells are transformed counterparts of small B lymphocytes at an early stage of dif

ISSN:0014-2980    

DOI:10.1002/eji.1830070702

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractThein vitroproduction, assay and partial characterization of an extremely potent antigen‐specific T helper cell factor to poly‐L‐(Tyr, Glu)‐poly‐DL‐Ala‐poly‐L‐Lys [(T, G)‐A–L] which may be an important physiological mediator of T cell functionin vivois described. The factor has an antigen‐binding site, Ia and Ig‐like determinants on the same molecular complex. The response to (T, G)‐A‐L is under H‐2‐linked Ir gene control, some but not all low responder h

ISSN:0014-2980    

DOI:10.1002/eji.1830070703

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractThe distribution has been studied of the foci of antibody‐secreting cells in the spleens of mice responding to two different haptens, 4‐hydroxy‐5‐iodo‐3‐nitro‐phenacetyl (NIP) and 2,4‐dinitrophenyl (DNP) on identical or different carriers, using a sensitive focus assay technique.Mice were irradiated and repopulated with an excess of spleen cells from donor mice primed with the two haptens and a limiting number of cells primed to one carrier. The recipient mice were then challenged with both haptens, each conjugated to a different sample of the identical carrier. The incidence of monospecific foci occurring in different areas of the spleen was 21 % for each hapten, and the coincidence of foci directed to the different haptens occurring in the same area of the spleen was about 31%. This distribution was not significantly different from that seen in experiments when a further population of cells primed to a second carrier was also injected, followed by challenge with the two haptens conjugated to the different carriers. Experiments in which small fragments of the spleens were cultured confirmed, in the single carrier system, the presence of regions in which antibody to one hapten only was secreted, and of other regions in which antibodies to both NIP and DNP were secreted.These results support the hypothesis that cooperation is an extremely local and selective phenomenon, such that in our system one effective T cell is able to help only one B cell precursor to develop into a clone of antibody

ISSN:0014-2980    

DOI:10.1002/eji.1830070704

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractThe antibody response of BALB/c mice directed against the idiotype of the BALB/c myeloma protein MOPC 315 (M315) is T cell‐dependent. The specificity of helper T cells for M31 5 was investigated. Helper cells were primed with M31 5, M315 affinity‐labeled with Nα‐bromoacetyl‐Nε‐2,4‐dinitrophenyl‐L‐lysine, M315 L‐chain and H‐chain the M315 Fv fragment, myeloma protein MOPC 460 and monoclonal human kappa and lambda chains. The primed cells were transferred together with (4‐hydroxy‐5‐iodo‐3‐nitrophenyl(acetyl)) (NIP)‐primed B cells to 500 R‐irradiated recipient syngeneic BALB/c mice which were challenged with NIPsM315. The anti‐NIP antibody responses were augmented by helpers primed with all derivatives and subunits of M315. This effect disappeared almost completely when the helper cells were treated with anti‐Thy‐1,2 and C prior to transfer. Priming with M460 induced weak and inconsistent helper effects, which opens the possibility that some of the helper cells may recognize nonidiotypic determinants on M315. The strong and consistent helper effect induced by free M315 L‐chain (L‐31 5)‐primed cells was not due to dissociation of NIP‐L‐315 from intact NIP5M315 used for challenge, because L‐315‐primed T cells also augmented the antibody response against the idiotype of M315 which is only expressed on associated (H+L) chain pairs. In contrast, BALB/c antibodies elicited by free L‐315 were specific for a determinant which was present on free L‐chains but which was not or only minimally accessible on the complete M315. The data indicate that the helper cells recognize determinants which are separate from the ligand binding site of M315 and which are accessible on both the complete M315 7 S subunit and its isolated chains. In contrast, B cells stimulated by free L‐315 recognize determinants which are hidden on associated (H+L) chains. Moreover, the associated (VL+VH) domains of M31 5 Fv fragm

ISSN:0014-2980    

DOI:10.1002/eji.1830070705

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractDextran B1355 induces separate IgM responses in mice against its α(l→3) and a(l→6)‐linked glucosyl linkages. The maximum injectable dose (10 mg) produces α(l→3) immunity and α(l→6) tolerance in the BALB/c strain. The same amount will tolerize the CBA strain for both epitopes, whereas 1 mg will produce α(l→3) tolerance and α(l→6) immunity. The converse dissociation in these strains between tolerance and immunity to the two intrinsic epitopes of dextran B1355 seems, in the face of the corresponding minimum immunogenic doses, incompatible with B cell tolerance mechanisms invoking either an excess of “one nonspecific signal” or lack of a “second signal”.A basis was sought for the exceptional resistance of BALB/c mice to α(l→3) tolerization, for dextran B1355 behaved like a typical polysaccharide antigen in the CBA strain. The induction time for α(l→3) tolerance in CBA was even shorter (<6 h) than that for α(l→6), and the unresponsive state was as stable on cell transfer as α(l→6) tolerance in either strain. Macrophage involvement in this strain difference had been previously sought but not found (Immunology 1976.30: 221.). Although BALB/c mice are “high responders” for the α( l→3) epitope, the B cell clone did not show any superior capacity to regenerate. Indeed, the slow recovery of responsiveness to both epitopes in bone marrow‐reconstituted, irradiated mice was notably prolonged in the case of BALB/c.PFC inhibition by oligosaccharides of the nigerose series revealed that the α(l→3) response corresponded to at least a tetrasaccharide determinant in CBA but to only a trisaccharide in BALB/c. As B cells specific for isomalto‐tetraose have a higher tolerance dose threshold than those for isomaltohexa‐ose (Immunochemistry1977.14: 253), it seems probable that genetic resistance of BALB/c to α(l→3) tolerance depends on recognition of a relatively small epitope which could involve instabili

ISSN:0014-2980    

DOI:10.1002/eji.1830070706

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractNude mice which have been grafted with an allogeneic H‐2‐incompatible thymus are frequently specifically tolerant to skin grafts from the thymus donor strain. The evidence presented here indicates that both clonal deletion and peripheral suppressor cells play a part in maintaining this tolera

ISSN:0014-2980    

DOI:10.1002/eji.1830070707

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractH‐2 gene‐dependent nonresponsiveness and responsiveness to H‐2‐matched male cells can be observed in cytotoxic assays in several mouse strains. H‐2 genes of several low responder strains can complement each other in cis or trans position to produce high responders. One of the H‐2 gene products functions at the level of antigen‐presenting cells (stimulators, targets), the other must be expressed in the responding T ce

ISSN:0014-2980    

DOI:10.1002/eji.1830070708

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractNylon wool column‐purified T cell populations depleted of la‐bearing cells do not respond to the T cell mitogen concanavalin A (ConA). The response of this population can be restored by admixture of untreated nylon wool‐nonadherent T cells. These promoter cells express Thy‐1, are not sensitive to mitomycin C treatment and cannot be replaced with adherent spleen cells. Experiments using the T6 chromosome marker demonstrate that Ia‐depleted populations respond to ConA only in the presence of the Ia‐positive

ISSN:0014-2980    

DOI:10.1002/eji.1830070709

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractMouse lymph node cells were exposed to carbonyl iron and a magnet to remove phagocytic cells, and passed over Sephadex G‐10 and nylon wool and incubated for 12 h on plastic to remove adherent cells and their precursors. More than 99 % of the cells in this macrophage‐depleted population (which constituted 3‐5 % of the starting population) were Thy‐1+and Ly‐1+, while less than 2 % were Ly‐2+. These cells usually did not synthesize detectable amounts of DNA when cultured with concanavalin A and responded poorly to phytohemagglutinin. These proliferative responses were completely reconstituted by small numbers of syngeneic or allogeneic peritoneal cells, purified peritoneal macrophages or cells from tertiary cultures of mouse embryo ‘fibroblasts’, but not by 3T3 cells, P815 mastocytoma cells or Nulli SCC‐1 embryonal carcinoma cells, or by 2‐mercaptoethanol. The reconstituting peritoneal cells were Thy‐1−, Ia+and present in nu/nu mice; although they had to be alive to reconstitute, they did not have to divide. These results are consistent with the hypothesis that T cell proliferation induced by lectins, like that induced by antigens, may involve the dual recognition of stimulating ligand in association with major histocompatibility co

ISSN:0014-2980    

DOI:10.1002/eji.1830070710

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY

摘要:

AbstractCH strain chickens selected from the F2 progeny of a cross between CH (B10/10) and B14B (B14/14) strains camed bursa (BA) and thymus (TA)‐specific alloantigens of B14B parental origin. The BA marker was present on 95 % of bursal cells but only on 10 % of splenic and blood B lymphocytes. The TA marker was expressed by 80 % of thymus cells and weakly by 45 % of splenic and 70 % of blood T lymphocytes. The adopted immunolo‐gical and genetic protocol offers a feasible approach towards detection of differentiation antigens in major histocompatibility complex‐homozygous but ‘minor’ alloantigen‐segregating

ISSN:0014-2980    

DOI:10.1002/eji.1830070711

出版商:WILEY‐VCH Verlag GmbH    

年代:1977

数据来源: WILEY