摘要:

SummaryTolerance to soluble antigens has previously been shown to occur in mice if anti‐L3T4 monoclonal antibody (MoAb) is administered al the time of antigen exposure. The process of tolerance induction may require the depletion of L3T4+cells or it may be due to down‐regulation or negative signaling of L3T4+cells. We compared the effects of L3T4+cell depletion and L3T4 antigen blockade at the time of primary antigen challenge on long‐term humoral responses. Anti‐L3T4 MoAb GK1·5 (IgG2b) and H129·19 (IgG2a) were used to deplete or block, respectively. L3T4+cells.Following a short course of MoAb and antigen challenge with both aggregated human IgG (ag‐HGG) and ovalbumin (OVA) in each mouse, primary response titres to each antigen in both MoAb treated groups were ∼1:102compared with ∼1:105in control mice. Repeated antigen challenge significantly increased the anti‐OVA titre in both MoAb treated groups and by 150 days they were similar to controls. However, anti‐HGG titres did not increase significantly in either of the MoAb treated groups.Thus either depletion of peripheral L3T4+cells, or blockade of the L3T4 antigen without depletion of peripheral L3T4+cells, can invoke a state of long‐term antigen‐specific tolerance to some antigens. Why the effect is restricted to particular antigens, and the exact mechanisms of tolerance induction remain to be determined.

ISSN:0004-945X    

DOI:10.1038/icb.1989.1

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryPolymorphonuclear leucocytes (PMN) were assessedin vitrofor their ability to synthesize and secrete proteoglycans. The PMN were isolated from human peripheral blood and were found to contain<5% mononuclear cells. Following 24 h incubation in the presence of (35S)‐sulfate, significant quantities of35S‐labelled macromolecules were detected both within the culture medium and cells. Although the PMN preparations contained some platelets (approximately five platelets: one PMN), culture of platelets alone did not result in the detection of any35S‐labelled macromolecules in either the medium or platelets.35S/3H‐labelled macromolecules from the PMN cultures were identified as proteoglycans on the basis of their degradation by papain, alkaline sodium borohydride, chondroitinase ACII, chondroitinase ABC and nitrous acid. The labelled proteoglycans isolated from the medium and cells eluted from Sepharose CL‐4B with a Kavof 0·63; this indicated a small size compared with many other proteoglycans. The glycosaminoglycans associated with the proteoglycans were identified as heparan sulfate, chondroitin sulfate and dermatan sulfate, with chondroitin sulfate being the principal component. The average molecular weight of the glycosaminoglycans was determined to be 16 000. Therefore, the data from this study demonstrate the ability of human PMN to synthesize and secrete proteoglycansin vitrowhich appear to differ from those synthesized by mesenchymal cells with respect to molecular size and glycosaminoglycan composition

ISSN:0004-945X    

DOI:10.1038/icb.1989.2

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryIntraperitoneal injection of (BALB/c × C57BL/6) F1 mice with live, but not killedSalmonella enteritidis11RX (11RX) induced T cells in the spleen and peritoneal cavity which were able to proliferatein vitroin response to two different forms of 11RX antigens. The majority of cells which proliferated were L3T4+T cells and most of the response was restricted by theI‐Alocus of theH‐2major histocompatibility complex, although a smallerKregion restricted response was also detected. T cells able to respond to 11RX antigens could only be demonstrated when non‐adherent lymphoid cell suspensions from immunized mice were used, and usually a limited response was obtained unless small numbers of adherent cells present in normal peritoneal cell suspensions were added. Cells culturedin vitrofor 3 days were able to mediate local transfer of delayed type hypersensitivity and secondary immunization did not enhance the reactivity of responding cells to 11RX antigens.

ISSN:0004-945X    

DOI:10.1038/icb.1989.3

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryWe have characterized the cellular immune response to human adenovirus 5 (Ad‐5) in mice, as a basis for future study of responses to foreign antigens in recombinant adenoviruses. Primaryin vivolytic effector cells contained both virus immune cytolytic T (Tc) cells and natural killer cells. The Tc effectors could be boostedin vitroto give a secondary Tc cell response. The Tc cell response to Ad‐5 was major histocompatibility complex (MHC) restricted, and in CBA/H (H‐2k) mice mapped to the K end of MHC. Kinetic experiments suggested the Tc cell response was directed against early rather than late viral proteins. Experiments with viral mutants showed that the main responses were to the E1A and E1B proteins, with some involvement of E2. Expression of E3 and E4 in infected targets was not required, in fact lysis of target cells infected by viruses with a deletion in E3 was augmented.

ISSN:0004-945X    

DOI:10.1038/icb.1989.4

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryHuman α‐lactalbumin (α‐LA), a milk protein normally produced by, and restricted to, functionally differentiated breast epithelial cells has been shown immunohistochemically to be a good marker for breast cancer. Antibodies with specificity only for human α‐LA have not previously been reported. The present study documents the production and characterization of an IgG1murine monoclonal antibody with specificity restricted only to human α‐LA. This monoclonal antibody, designated ET‐1, was purified by affinity chromatography using human α‐LA. Specificity of ET‐1 for human α‐LA was established by enzyme linked immunosorbent assay (ELISA), absorption studies, immunoprecipitation and by immunoblotting. ET‐1 binds to human α‐LA with a KDof 7·41 × 10‐8mol/l and does not cross‐react with bovine α‐LA. This unique reactivity of ET‐1, which is not inherently shared by polyclonal antisera, should enable the antibody to be used for the development of a sensitive immunoassay for circulating human α‐LA.

ISSN:0004-945X    

DOI:10.1038/icb.1989.5

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryThe addition of interleukin‐2 (IL‐2) to lymphocyte cultures from acute infectious mononucleosis (IM) donors dramatically increased the incidence of regression in such cultures and resulted in the emergence of an IL‐2 dependent, CD3 Epstein‐Barr virus nuclear antigen (EBNA)‐negative cell population. Corresponding cultures seeded in the absence of IL‐2 rarely regressed and were quickly dominated by IL‐2 independent, CD3‐negative, EBNA‐positive cells. Lymphocyte cultures from Epstein‐Barr virus (EBV) seropositive donors showed enhanced regression in the presence of IL‐2 but failed to regress after the removal of the E‐rosetting population. Cultures from EBV‐seronegative donors showed no evidence of regression in the presence or absence of IL‐2. E‐rosetting cells isolated from cultures from acute IM donors that had been cultured in the presence of IL‐2 lysed autologous and allogeneic lymphoblastoid cell lines.

ISSN:0004-945X    

DOI:10.1038/icb.1989.6

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryImmunoglobulin and T cell receptor gene probes have been used to investigate cell lineage and monoclonality in lymphoid malignancies. In the present study we have used T cell receptor β‐and γ‐chain gene probes to screen for abnormal rearrangements of these genes in B lymphoblastoid cells from patients with ataxia‐telangiectasia (A‐T). No rearrangement of either gene was observed but deletion of a β‐chain gene allele is described for one A‐T cell line. Expression of mRNA hybridizing to the β‐chain gene probe was demonstrated for two A‐T homozygotes (brother and sister) as well as for their mother (heterozygote). This transcript was found to be truncated in all three cases.

ISSN:0004-945X    

DOI:10.1038/icb.1989.7

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryMonoclonal antibodies of the CD9 cluster recognize a 24 kD protein (p24) found on platelets and endothelium, and expressed by lymphocytes at restricted stages of maturation and activation. In this study, we explore the possibility that p24 is involved in the response of lymphocytes to signals delivered by lymphokines. p24 is expressed only very weakly by resting B lymphocytes. We found no increase in expression when cells were activated with anti‐immunoglobulin together with interleukin‐4, or induced to proliferate by low‐molecular weight B cell growth factor (LMW‐BCGF). Culture of activated B cells with B cell differentiation factor was associated with an increased mean expression of p24. In cells from a patient with chronic lymphocytie leukaemia (CLL), culture with LMW‐BCGF up‐regulated p24 expression. Resting T cells (p24‐negative) were induced to express p24 strongly when activated with antibody against CD3. CD9 antibody did not modulate B or T cell responses to activation stimuli. The results suggest that the p24 molecule is not involved in the primary interaction of cells with lymphokine, but rather may be involved in a secondary reaction, such as ion flux, which follows as a consequence of the action of lymphokines on cells.

ISSN:0004-945X    

DOI:10.1038/icb.1989.8

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

摘要:

SummaryA total of 17 monoclonal antibodies (MoAb) were used to analyse the antigenic structure of pilus protein from three serogroups ofBacteroides nodosus.The four MoAb which agglutinated pili were serogroup (and subgroup) specific, and the agglutinating epitope was present on the pili monomer and dependent on the intra‐chain disulfide bond.Non‐agglutinating MoAb identified two further non‐linear and serogroup‐restricted epitopes on strain 198 (A1) pili and two linear epitopes on 336 (F1) and 265 (H1) pili. Three MoAb cross‐reacted with pili from six of the eight major serogroups and recognized an epitope in theN‐terminal region of the molecule. This panel of MoAb has therefore identified at least four epitopes on pilus protein and will facilitate serotopic analyses of the immunogenicity of each epitope in sheep during vaccination against footrot.

ISSN:0004-945X    

DOI:10.1038/icb.1989.9

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY

ISSN:0004-945X    

DOI:10.1038/icb.1989.10

出版商:Nature Publishing Group    

年代:1989

数据来源: WILEY