摘要:

AbstractA panel of 18 monoclonal antibodies (mAb)Δto insulin have been prepared and used to begin to map antigenic determinants on the insulin molecule. All 18 mAb were of the IgG class, with 14 IgG1, 2 IgG2aand 2 IgG2b. The affinities of these mAb for their immunizing insulin ranged from 1 × 106to 3 × 1081/M. The epitope recognized by three of the mAb, 1, 7 and 16 involves the three residues of the A chain, A 8‐10, the so called A chain‐loop determinant. This A chain loop is one of the most evolutionarily diverse regions of insulins from different species. Another mAb, 10, has been hypothesized to recognize a nearby epitope composed of the A chain residues, A4 and A8 and a B chain residue, B29, that are adjacent on the surface of the insulin molecule. Four of the mAb bind to synthetic B chain. The epitopes recognized by these 4 mAb and the last 10 mAb are unknown but the mAb are grouped according to their ability to bind to different species of insulin or proinsulin. The results of an 18 × 18 matrix analysis of pairs of mAb binding simultaneously to insulin indicate that, despite the finding that some mAb see similar antigenic sites on the insulin molecule, each of the mAb recognizes a unique site on the insulin molecule. Finally, a lower estimate of the number of possible antibodies made to insulin has been calculated to be ≧ 115, a number only 10‐fold lower than the lower limit of antibodies made to dinitrophenyl (DNP) or (4‐hydroxy‐5‐iodo‐3‐nitrophenyl)acetyl (NIP), following hapten

ISSN:0014-2980    

DOI:10.1002/eji.1830130902

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe detailed kinetics of the appearance of clones of anti‐fluorescein cytotoxic T lymphocytes (CTL) in a primary limiting dilution response have been examined. The addition of factors from the supernatants of concanavalin A‐stimulated rat spleen cell cultures was necessary to obtain linear dose‐response curves and strong primary responses. In a standard primary response the maximum detectable number of specific clones was found, on day 5, to be derived from precursors having a frequency of 1 in 10000 spleen cells. When limiting dilution cultures were restimulated on day 3, responses on day 5 were unaffected but new clones appeared on day 7 with a frequency of 1 in 1000. The emergence of the day‐7 response depends on the addition of factor(s) on day 3. It is proposed that the early low frequency precursors detected on day 5 and the high frequency precursors detected on days 7–9 are derived from two stages in the differentiation lineage of CTL precursors. Restimulation of limiting dilution cultures involves not only the continued clonal expansion of primary responses but also the emergence of new “clones” of

ISSN:0014-2980    

DOI:10.1002/eji.1830130903

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThis study reports the examination ofin vivoandin vitroproperties of an antigendependent murine cytotoxic T cell (Tc) clone T5/5 specific for type A influenza virus. This clone differs morphologically and in its migratory pattern and biological properties from a previously examined anti‐influenza Tcclone L4 which grew in T cell growth factor independently of antigen. Unlike Tcclone L4, T5/5 cells do not release significant amounts of immune interferon on contact with influenza‐infected target cells nor do they limit virus replicationin vivo, although they efficiently lyse influenza‐infected target cells and can release interferon in the presence of concanavalin A. Thus individual Tcclones vary in function and further work is required to establish the properties of Tcthat are associated with host protection against virus infe

ISSN:0014-2980    

DOI:10.1002/eji.1830130904

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe (4‐hydroxy‐3‐nitrophenyl)acetyl (NP)‐specific T suppressor cell hybridoma 7C3‐13 was established by fusing splenic B10.BR T cells enriched on NP‐coated petri dishes with the AKR thymoma BW5147. 7C3‐13 was selected by anti‐NPbidiotypic and anti‐I‐Jkantibodies in microcytotoxicity tests. The hybridoma expressed H‐2k, I‐Jk, Qa‐1, Thy‐1.1 as well as idiotypic (binding site‐related) and framework Ig VHdeterminants, while it was negative for I‐A, I‐E/C, Thy‐1.2, Lyt‐1, Lyt‐2 and Ig constant region determinants. Hapten‐binding receptor material could be isolated from 7C3‐13 cells on NP‐coupled nylon nets and functionally active T suppressor factor (TsF) could be extracted from the hybridoma. Both types of soluble molecules express NPbidiotype, but the TsF carries I‐J determinants in addition while the isolated receptors do not. The molecular weight of the isolated receptor material is 80000, that of the TsF activity is 27000 and 57000–64000, respectively. We thus were able to show that NP‐binding molecules can be obtained in the form of cellular surface receptors, isolated receptor material and extracted

ISSN:0014-2980    

DOI:10.1002/eji.1830130905

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe requirements for activation and growth of T lymphocytes capable of mediating either cytolytic activity or help to B lymphocytes were studied in unprimed splenic T cell populations. The selectivity of expression of Lyt‐2 antigens, the reactivity to soluble concanavalin A (Con A), to partially purified interleukin 2 (IL2, T cell growth factor[s]) and to lectin‐pulsed macrophages (MΦ) were used in this analysis. Lectin‐dependent cytotoxicity assays and a novel method that allows for the detection of all effector helper cells, regardless of their clonal specificities, were used for the functional identification of the responding T cells.The results show a marked contrast between cytolytic and helper T cells in their growth and activation requirements. Thus, while Lyt‐2+cytotoxic T lymphocyte precursors grow exponentially in IL2 after a short pulse with soluble Con A in the absence of accessory cells, Lyt‐2−helper cell precursors completely fail to proliferate under the same conditions and require the continuous presence of lectin‐pulsed MΦ for significant growth. Furthermore, addition of IL2 to MΦ‐stimulated cultures of Lyt‐2−cells has no effect. T cells which produce IL2 have the same growth characteristics as helper cells. In both cases, effector helper functions could be expanded more than 10‐fold on a per cell basis by a 5‐day‐culture period under those growth supporting conditions. The development of effector helper functions, however, was strongly inhibited by t

ISSN:0014-2980    

DOI:10.1002/eji.1830130906

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractIn the present study we use two monoclonal anti‐idiotope antibodies (Ac38 and Ac146; Ab1) against the germ line‐encoded, λ1 chain‐bearing and (4‐hydroxy‐3‐nitrophenyl)acetyl (NP)‐binding antibody Bl‐8 (Ab1) for the induction of complementary antibodies (Ab3) and ask the question to what extent antibodies bearing Bl‐8‐like idiotopes (Ab3β) are represented in the Ab3 population. In this experimental system, Ab3β is distinguished from the remaining Ab3 population (Ab3α) by three properties which Ab3β may share with Bl‐8: (a) the binding of NP, (b) the binding to Ac146 (if induced by Ac38) or the binding to Ac38 (if induced by 146) and (c) that they carry λ1 chains.Antibodies with all three properties are induced in low amounts by both anti‐idiotopes. Also, Ac146 induces only Ab3α (bearingxchains and not binding NP and Ac38). In contrast, Ac38 triggers almost exclusively a λ1 chain‐bearing response,i.e.Ab3β. The response has an unusually large size, reaches its maximum after a week and is long‐lasting. An analysis at the level of lipopolysaccharide‐reactive precursor B cells demonstrates that, in this case, cells expressing Ab3β occur at exceedingly high frequency (≈ 10−3) and are at least 10 times more frequent than cells expressing Ab3α. The high frequency of Ab3β‐expressing cells correlates with the contribution of several VH, D and J genes to the expression of this particular idiotope. In the case of the Ac146 anti‐idiotope antibody, the response is dominated by Ab3α. Ab3β represents less than 10% of the total response, reaches maximal levels 2 weeks after immunization and declines rapidly. This correlates with a low frequency of precursor B cells expressing Ab3β (≈ 10−5) and a restriction of the corresponding idiotope to rare VH‐D combinations, caused presumably by a stringent contribution of the H chain to this idiotope which covers the NP‐binding site.Our data suggest that anti‐idiotypic antibodies (Ab2) against Ab1 will preferentially induce antibodies idiotypically related to Ab1 if the corresponding idiotopes are expressed in high frequency in the B cell compartment. This is expected in cases where Ab2 recognizes an idiotope tha

ISSN:0014-2980    

DOI:10.1002/eji.1830130907

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractHuman T cell clones specific for tetanus toxoid (TT) or for alloantigens were isolated and expanded in culture using antigen stimulation and soluble growth factors. When stimulated by the specific antigen, the clones were able to proliferate in the absence of exogenous growth factors and to provide help to B cells. The alloreactive and TT‐specific clones were compared for their capacity to help an anti‐TT as well as a polyclonal antibody response. The frequency of the B cells activated to the production of specific antibody was determined by limiting dilution analysis in cultures containing limiting numbers of responding B cells and optimal numbers of cloned T helper cells. In these conditions a single activated B cell was able to produce about 10 ng of antibody. TT‐specific clones, in the presence of low TT concentrations, selectively induced a number of TT‐specific B cells to produce IgG antibody in the absence of a detectable polyclonal B cell activation. On the other hand the alloreactive clones activated higher numbers of TT‐specific B cells as a part of a strong polyspecific B cell activation. In this case the antibody production did not require the presence of TT in culture; furthermore cells producing antibodies of unrelated specificities were also activated in allostimulated cultures. IgG anti‐TT were produced only by immune donors, while IgM anti‐TT were produced by immune and nonimmune donors, providing the B cells were activated by alloreactive clones.These data demonstrate that human memory B cells can be triggered by both antigenspecific and alloreactive T cells to antibody production. The alloreactive clones can therefore be used to analyze at the clonal level the repertoire of a pool of B cells that contain most, if not all, the memory antibody

ISSN:0014-2980    

DOI:10.1002/eji.1830130908

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractInbred mouse make 3 λ chain subtypes. The λ1 and λ3 chains have similar variable (V) regions (in both the same V gene segment [Vλ1] is used), whereas λ2 and λ3 have similar constant (C) regions. Despite the λ1 and λ3 V region similarity, λ1 occurs much more frequently than λ3 (and λ2) in the serum immunoglobulins and antibody responses of most inbred strains of mice. To explore the basis for the λ1 predominance, we compared the rates of synthesis of the 3 subtypes and the frequencies of the B cells that synthesize them, focussing on “resting” (i.e., unstimulated) and on polyclonally stimulated B cells from spleens of unimmunized BALB/c mice.In resting cells the relative rates of synthesis and the relative frequencies of the respective B cells were in accord, indicating that the rate of λ chain synthesis is approximately the same per resting B cell, regardless of the λ subtype it produces. However, in the polyclonally stimulated cells, λ1 was made 7 times faster than λ2 and 10 times faster than λ3; normalizing these rates by the frequencies of the respective stimulated cells suggests that in stimulated B cells λ1 chains are made 5 times faster per cell than λ2 or λ3, while the latter are made at about the same rate per cell. In view of the marked structural homology between λ2 and λ3 genes in segments other than the V‐gene segment, we suggest that the pronounced differences among polyclonally stimulated B cells in expression of the genes for the various λ subtypes may be due to the presence of less potent enhancer‐like sequences in the λ2 a

ISSN:0014-2980    

DOI:10.1002/eji.1830130909

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe natural cytotoxic activity of yolk sac (YS) cells from 10‐day mouse embryos against YAC‐1 tumor targets was characterized for its sensitivity to modulation by a variety of factors. Experiments demonstrated the observed levels of tumor cell lysis to be unaffected by the strain of origin of the YS cells, trypsin pretreatment of the YS population, as well as a prior stimulation by environmental pathogens. Both the YS natural cytotoxic (YSNC) activity and the adult natural killer (NK) cell activity were found to be depressed when assayed in the presence of amniotic fluid. YS cells were tested for antibody‐dependent cell‐mediated cytotoxic activity, but were not found to generate significant levels of lysis.Experiments presented here demonstrate the YSNC activity to be dependent upon only a subpopulation of YS cells. The YSNC activity was found to be associated only with the cells exhibiting high forward angle light scatter as determined by flow cytometry. Additionally the activity was unaffected by the removal of plastic‐adherent cells from the effector population.In this study, YSNC cells are also examined for the presence of a variety of lymphocyte antigens. The effector cells, as well as the total YS population, were found to lack Lyt‐1, Lyt‐2, Thy‐1, Ly‐5, NK‐1, Qa‐5, asialo GM1, and H‐2 antigens. While these experiments demonstrate the YSNC cells to be distinct from the NK cells of the adult, they do not rule out a potential common lineage for the two natur

ISSN:0014-2980    

DOI:10.1002/eji.1830130910

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe antibody response of (H‐2b× H‐2k)F1mice to pig insulin (PI) has previously been shown to be under the control of H‐2‐linked, complementing Ir genes. In addition, this response was reported to depend on the genetic background of the parental strains (Keck, K.,Eur. J. Immunol.1977.7: 811). Here it is demonstrated that the secondaryin vitroresponse of proliferating T cells shows the same dependence on H‐2‐linked Ir genes yet an influence of the background genes could not be detected. The complementing genes were mapped to the Kb, I‐Aband Kk, I‐Akregions. For restimulation of F1T cells by PI, the Ir genes of both parental chromosomes have to be expressed in the same antigen‐presenting cell, suggesting complementation at the molecular rather than at a cell interaction level. With a long‐term cultured, PI‐specific T cell line (ST2) of (B10 × B10.BR)F1origin the complementation data could be confirmed by mapping the Ia restriction elements to Kb, I‐Aband I‐Ak. The reactivity pattern of this line towards species variants of insulin and the isolated A and B polypeptide chains in the presence of syngeneic accessory cells suggests that the glutamic acid residue in position 4 of the A polypeptide chain (Asp in mouse insulin) is essential for recognition in conjunction with an (I‐Ab× Ak)F1hybrid Ia complex. I‐Ab‐encoded molecules carrying specificity Ia. W39 which, according to Rosenwasser, L. J. and Huber, B. T. are essential for the presentation of BI to (CBA/N × C57BL/6)F1T cells, are not required as components of the F1‐unique restriction element recognized by the F1T cells of the ST2 line in conjunction with PI. This is indicated by the fact that accessory cells of (CBA/N × B10)F1hybrids, regardless of their sex, could present PI as well as beef, sheep and horse

ISSN:0014-2980    

DOI:10.1002/eji.1830130911

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY