摘要:

AbstractFluorescein‐specific cytolytic hybrids were obtained by fusion of an interleukin 2 (IL2)dependent murine cytotoxic T lymphocyte clone with the thymoma BW5147. The hybrid cells grow and retain cytolytic activity in medium with recombinant IL2. In medium without IL2 rare variants can be selected which grow in the absence of exogenous IL 2; these variants are not cytolytic. Anti‐IL2 receptor antibodies bind to and inhibit the growth of the cytolytic hybrids while they do not bind to and do not inhibit the growth of the variants. The cytolytic hybrids as well as the non‐cytolytic variants produce interferon gamma in response to antigen. These findings indicate that the noncytolytic IL2‐dependent variants lost IL2 receptors but not antigen re

ISSN:0014-2980    

DOI:10.1002/eji.1830150802

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractInterleukin 2 (IL 2)‐dependent cytolytic hybrids usually loose IL 2 dependence and cytolytic activity concomittantly. Here we describe an exceptional IL 2‐independent variant which lost IL2 receptor but retained cytolytic activity. When the IL 2‐independent cytolytic hybrid cells were fused with IL 2‐dependent cytolytic clones which express IL2 receptors constitutively, IL 2‐dependent hybrids were obtained. This suggests that the expression of IL 2 receptors can interfere with IL 2‐independent growth

ISSN:0014-2980    

DOI:10.1002/eji.1830150803

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractMice bearing the recessive gene Ipr develop an age‐dependent, massive lymphoproliferation, primarily in the lymph nodes (LN), with associated autoimmunity. LN cells from these mice express T cell receptor protein on the cell surface at 50–70% of normal levels. Normal levels of T cell receptor α, β and γ mRNA were found in these cells as compared to normal LN cells. Southern blot analysis of MRL‐lpr/lprLN DNA showed rearrangements in 80–90% of the chromosomes at the β gene loci. The pattern of rearrangement indicated that a polyclonal rather than monoclonal expansion of T cells occurred. These data support a lymphokine‐induction model of lymphoproliferation i

ISSN:0014-2980    

DOI:10.1002/eji.1830150804

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractWe have analyzed 210 λ‐producing hybridomas derived from lipopolysaccharidestimulated spleen cells from a singlex‐suppressed mouse. All were classified as λ1, λ2 or λ3 with the exception of four unusual lines. Two of these were due to Vλ2Jλ1and the other two to Vλ2Jλ3rearrangements. The lines were clonally independent since the point of VJ recombination in each one was different. Southern blot analysis of the Vλ2Cλ1‐producing lines showed no evidence for an inversion. Under the assumption of a simple deletion model of rearrangement these findings place the Vλ2cluster upstream of the Vλ1cluster oriented in t

ISSN:0014-2980    

DOI:10.1002/eji.1830150805

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractA hybridoma from the λ‐defective mouse strain SJA has been established. It produces a λ1‐bearing IgG2b, dextran B 1355‐binding antibody. The DNA sequence of the VJ and C gene segment was in complete accordance with the published germ‐line sequence. The rate of secretion and the steady state level of cytoplasmic RNA of this line was comparable to that of cell lines from normal mice. The idiotype was closely related to that of MOPC 104E indicating that the λ1 light chain is associated with the same VHregion and in a similar fashion as in BALB/c mice. This antibody should be useful for further experiments on the λ defect of SJL

ISSN:0014-2980    

DOI:10.1002/eji.1830150806

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractIn this study we report that cloned Thy‐1+, L3T4−, Lyt‐1−, Lyt‐2+, H‐Y‐specific and H‐2Db‐restricted cytotoxic T cell lines (CTLL) when induced by lectin or antigen secrete a soluble mediator(s) (SF) that inhibits proliferation and generation of cytotoxic lymphocytes (CTL) in mixed lymphocyte cultures (MLC). The biological activity was separable by gel filtration and appeared as a broad peak in the molecular mass range between 10 000 and 50 000 kDa. It was found that the suppressive activity released by CTLL neither strictly correlates with their cytotoxic potential nor with their ability to produce immune interferon or lymphotoxin. SF was shown to elicit its activity in an antigen‐nonspecific manner in that it suppressed the maturation of T lymphocytes responding to both, the appropriate H‐Y antigen as well as to unrelated H‐2dalloantigens or to the hapten 2,4,6‐trinitrophenyl (TNP). The effect of SF on CTL responses was most pronounced in early phases of primary or secondary MLC. When analyzed for its inhibitory activity on precursor cells in populations selected for either Lyt‐2−or L3T4−lymphocytes, it was found that SF interfered with the maturation of both subsets. The inhibition of CTL responses elicited by SF could not be reversed by the addition of exogenous interleukin 2. The finding that SF also inhibited the proliferation of some but not all antigen‐dependent cloned T cells with helper or cytotoxic potential provides evidence that the factor also may regulate effector lymplrc∼cytes. In addition, the results support the assumption that SF exerts its effect directly on the responder rather than the stimulator population, and demonstrate that the development of CTL from their precursor cells is controlled at least in part by the cytotoxic effector cells themselves via a soluble factor(s) that interferes with distinct stages of T cell maturation. These findings again emphasize the expression of multiple functions by CTL and indicate their possible role during the course of an immune response by their capability to eliminate target cells and to secrete a soluble produc

ISSN:0014-2980    

DOI:10.1002/eji.1830150807

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractThe T cell mitogens, concanavalin A and the monoclonal antibody OKT3, cause a rapid activation of ornithine decarboxylase (ODC) activity in human T lymphocytes, maximal within 10 min of mitogen addition. Nonmitogenic ligands to T cell surface structures do not induce ODC. The enzyme induction is dependent upon an intact mobility of ligand‐receptor complex, requires a functioning energy metabolism, but is independent ofde nuvoprotein synthesis. The early induction of pre‐existing ODC molecules appears to be specifically linked to the initiation of T lymphocyte proliferat

ISSN:0014-2980    

DOI:10.1002/eji.1830150808

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractThe requirements for interleukin 2 (IL 2) and other T cell‐derived helper factors in the responses of unprimed and antigen‐primed B cells to sheep erythrocytes were investigated. Unprimed B cells required both IL 2 and additional factor(s), hereafter referred to as T cell‐replacing factor (TRF), in addition to specific antigen, for antibody production. IL2 was required only during the early stages (⋍24 h) of culture while TRF was necessary only after this time and was then required throughout the remaining culture period. IL2 stimulated the appearance of Thy‐1+cells in unprimed “B cell” populations which could substitute for the function of IL2, implicating an indirect role, at least in part, for IL2 in the TRF assay. Furthermore, in contrast to the results with unprimed B cells, primed B cells required only late‐acting TRF for optimal antibody responses. We suggest that IL2 activates residual T cells or precursors of T cells in B cell populations which then function, in the presence of specific antigen, to render B cells receptive to T cell‐derived factors which promote B cell growth an

ISSN:0014-2980    

DOI:10.1002/eji.1830150809

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractIsologous IgG2a, and IgG2banti‐hapten antibodies injected along with trinitrophenylated or fluoresceinated keyhole limpet hemocyanin (KLH) were found to considerably stimulate primary IgG responses to the carrier protein in mice. No such stimulation was observed with IgG1, IgM and IgA anti‐hapten antibodies. Depending on the antigen antibody combination, the amplification obtained after a single injection of IgG2‐complexed haptenated KLH ranged from 20‐ to 1000‐fold. By comparison, secondary responses were only marginally enhanced (≈ 3‐fold) when IgG2‐complexed rather than free antigen was used to boost irradiated recipients previously reconstituted with primed spleen cells. The IgG2‐mediated enhancement was effective over a wide range of antigen/antibody ratios, did not require the use of high affinity antibodies and occurred whatever the route of injection. The stimulation was specific for the complexed antigen and developed to the same extent whether complexes were formedin vitro or in vivo. A comparable stimulation of the anti‐carrier response was obtained with several other haptenated proteins but with formaldehyde‐treated diphtheria and tetanus toxoids inhibition rather than sti

ISSN:0014-2980    

DOI:10.1002/eji.1830150810

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractMinimal requirements for growth and acquisition of cytolytic activity by alloantigenstimulated cytolytic T lymphocyte precursors (CTL‐P) have been investigated. CTL‐P from C57BL/6 spleen were purified by staining with monoclonal anti‐Lyt‐2 antibodies followed by positive selection on a fluorescence‐activated cell sorter. Microcultures containing 2000 purified Lyt‐2+cells were set up with irradiated P815 (DBA/2 mastocytoma) stimulating cells and pure interleukin 2 obtained by recombinant DNA technology (rIL 2). Proliferation and generation of antigen‐specific cytolytic activity were observed to be both antigen and IL2‐dependent in such microcultures. Furthermore, P815 stimulating cells could be replaced by 5 other H‐2dcell lines of differing tissue origin. In limiting dilution studies, 1–2% of Lyt‐2+CTL‐P (contaminated by<0.2% macrophages) could be induced to grow and express cytolytic activity in the presence of irradiated P81S and rIL 2. Taken together, these data indicate that neither accessory cells nor differentiation factors (other than IL 2) are absolutely required for alloantigen‐induced growth and

ISSN:0014-2980    

DOI:10.1002/eji.1830150811

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY