摘要:

The aim of these studies was to characterize the (H‐2b× H‐2k)F1‐unique restriction element(s) responsible for presentation of bovine insulin (BI) to a long‐term cultured T‐cell line (BK‐BI‐1.2). (B10.BR × bm12)F1spleen cells, which express a normal AbαAkβmolecule but a mutated AkαAAbm12βproduct on their cell surface, were perfectly able to act as BI‐presenting cells. Antibody inhibition experiments with antibodies directed at I‐Akproducts revealed that monoclonal antibody 10–2.16, which reacts with the Akβpolypeptide chain, abrogated BI‐directed T‐cell proliferation, whereas antibody H116–32.R5 with specificity for the Akαchain was not inhibitory. These results identified the AbαAkβcomplex as restriction structure. Recognition of BI in the context of the AbαAkβmolecule depended on the glutamic acid residue in position 4 of the A chain of bovine insulin. Twenty to twenty‐five percent of the secondary proliferative response of (B10 × B10.BR)F1lymph node T cells primed with BI in vivo was directed at the A4 determinant, suggesting that BK‐BI‐1.2 T blasts are representative of T‐cell clones with measurable frequency. In (B10.BR × bm12)F1mice, which lack a functional AbαAbβrestriction element, up to 80% of the proli

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00982.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The modulatory effect of human heat‐aggregated IgG on human B‐cell differentiation induced by pokeweed mitogen was investigated with three experimental protocols. Pulse exposure to aggregated IgG, followed by extensive washings before culture, of peripheral blood mononuclear cell suspensions rigorously depleted of platelets and containing less than 4% monocytes resulted in a selective decrease of the numbers of IgG‐containing cells and IgG‐secreting cells, whereas a simultaneous decrease of the numbers of cells producing IgG and, to a lesser extent, of those producing IgM or IgA was observed when the pulsed suspensions contained platelets and more than 4% monocytes. This non‐isotype‐specific suppression was shown to be more pronounced when aggregated IgG and platelets were present in the cell suspensions throughout the cultures. The results suggest that two distinct suppressor pathways can be triggered by aggregated IgG. The first one is restricted to cells producing the matching isotype, in the absence of platelets, with few monocytes in the cell suspensions. The second one leads to a nonspecific suppression of the three major Ig classes. It requires the presence of platelets and/or a high percentage of monocytes and, although it remains to be demonstrated, is probably mediated by prost

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00983.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Hybridomas obtained by fusion of lactute dehydrogenase B (LDHB)‐aciivatcd suppressor T (Ts) cells with the BW5147 thymoma produce a suppressor factor (TsF) that inhibits the proliferation of LDHB‐activated helper T (Th) cells. A similar factor (TsE) is contained in the extract of suppressor hybridomas. Both TsF and TsE are specifically retained by LDHB‐immunoadsorbent columns. Both consist of two components, an antigen‐binding component (ABC) and possibly a major histocompatibility complex (MHC) component. The latter reacts with certain monoclonal antibodies specific for MHC determinants. The two components arc covalently associated in the IsF and noncovalcntly associated in TsE. Mixing of the two components reconstitutes the activity of the TsF or TsE. Disruption of the ABC's tertiary structure results in its inability to reconstitute suppressive activity on mixing with the MHC components. The ABC may contain an intrachain disulphide hond(s). Suppression is obtained when Th cells are incubated first with the ABC and then with the MHC component or vice versa, provided that the incubation period is at least 4 h. The MHC component is also produced by nonsuppressor hybridomas but not by mitogen‐stimulated blasts or by the parental thymoma. The TsF is a glyeoprotein with a molecular weight ot about 120.000 to 160.000. The molecular weight of the ABC is about 76,000–86,000 and of the MHC component about 30

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00984.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

On activation of cells membrane‐associated proteases—including serine esterases known to cleave the third component of complement (C3)—become expressed. In this paper it is shown that as a consequence of this enzyme activity isolated native human C3 added to concanavalin A (Con A)‐activated human lymphocytes is cleaved on the surface of the blast cell. This enables the immediate fixation of nascent C3b (C3bx) through its short‐lived metastable biinliniisite to Oh acceptors (C3bA's) newly expressed on Con A‐stimulaled cells. Aeceptor‐bound C3b is detected by the immune adherence rosette formation of the O‐treated Con A blasts with the C3b receptor (C3bR)‐bearing O. Rh+ erythroeytes (32 ± 4%). The cleavage of C3 and the covalent fixation of C3b are shown to he inhibited hy phenylmethylsulphonyl fluoride and methylamine, respeclively. As a functional consequence of the covalent fixation of C3b to the mitogen‐activatcd lymphocytes it is demonstrated that the antibody‐dependent cellular cytotoxicity (ADCC) of these cells against O. Rh erythrocytes sensitized with anti‐D IgG is significantly enhanced. The C3 specificity of the process and the role of C3bR's of the target cells: are proved. It is postulated that effector cell‐bound C3b amplifies ADCC by improving effecto

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00985.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Spleen cells of various mouse strains (e.g. BALB/c, C3H, and CBA) reacted towards MAS (a mitogen derived from supernatants of culturedMycoplasma arthritidis) with a marked lymphoproliferative response. This reactivity was T‐cell‐dependent. It was reduced by 90% after removal of macrophages by passage of the spleen cells through Sephadex G‐10 columns. Addition of 2‐mercaptoethanol (2‐ME) to macrophage‐depleted CBA spleen cells completely restored the response to MAS. Spleen cells of C57BL/6 and C57BL/10 mice were unreactive to MAS, even in the presence of macrophages, and this non‐reactivity was controlled by the I‐region of H‐2. Other mouse strains that, similarly to C57BL/6, lack the expression of I‐E on the cell surface (that is, mice of the haplotype H‐2f, H‐2q, and H‐2s) were also non‐responsive to MAS. However, the addition of 2‐ME to spleen cells of non‐responder mice resulted in high lymphoproliferative responses to MAS, which were as high as those of CBA spleen cells. The reaction of C57BL/6 spleen cells to MAS in the presence of 2‐ME again was T‐cell‐dependent, as shown by data with spleen cells of homozygous nude mice and spleen cells treated by anti‐thy‐1 and C. A macrophage dependency of this response was also evident. When C57BL/6 spleen cells were vigorously freed of accessory cells by the use of nylon wool columns, the MAS res

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00986.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Activation of T lymphocytes by an antigen requires joint recognition of the‐ antigen and the class‐H HLA determinants on the membrane of the antigen‐presenting cells (APC). Patients with reactive arthritis exhibit a depressed lymphocyte transformation response 10Yersinia, suggesting a possible immunoregulatory disturbance in these patients. In this study the role of Ia (dass‐II HLA antigen)‐positive APC in the lymphocyte response to a complex antigen, wholeYersiniabacterium, was evaluated. The results demonstrate that Ia‐positive cells are necessary for the T‐lymphocyte response toYersinia. The role of APC in the pathogenesis of reactive arthritis

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00987.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The influence of murine alpha/beta‐interferon (Mu IFN‐α/β) and murine gamma‐interferon (Mu IFN‐γ) preparations on the attachment and ingestion phase of phagocytosis by mouse peritoneal macrophages (MPM) was studied. A non‐opsonized strain ofEscherichia coli, IgG‐opsonizedE. coli, and sheep erythrocytes opsonized with IgG (E‐IgG) and IgM plus complement factor C3b (E‐IgMC) were used as test particles. Pretreatment of MPM with 102‐103U/ml of Mu IFN‐α/β for 24 h enhanced both attachment and ingestion of bacteria or erythrocytes mediated by the non‐specific receptor, the Fc receptor, or the C3b receptor. Higher concentrations had no such effects. In contrast, treatment of MPM with 101‐102U/ml of Mu IFN‐γ suppressed attachment and ingestion of non‐opsonized and IgG‐opsonizedE. coliand of E‐IgG by 10–40%. Mu IFN‐γ did not influence attachment and ingestion of E‐IgMC. The effects were neutralized by specific anti‐IFN antiserum. The data indicate that the IFN effect on phagocytic activity is, at least to a large extent,

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00988.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

An enzyme‐linked immunosorbent assay for detection and quantification of the terminal complexes (SC5b‐9 and membrane attack complex) of human complement is described. We separate the complex from the native complement components, to use antibodies against the native components in a ‘double‐antibody sandwich’ technique. It is thereby possible to detect the terminal complement complex in solution without the requirement of specific antibodies against the neoantigens. The results show that the assay is both sensitive and specific. Evidence is presented that a terminal complement complex occurs in a normal plasma pool. The terminal complement complex may be valuable for evaluating both the physiology and palhophysiology of the complement syste

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00989.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00990.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1984.tb00991.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY