ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01983.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01984.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

We have studied the interaction of mitogenic lectins such as phytohaemagglutinin (PHA) and concanavalin A (Con A) with both surface molecules which, by the use of monoclonal antibodies, are known to trigger T‐cell mitogenesis. Monoclonal antibodies recognizing the T‐lymphocyte receptor for antigen (Ti) and/or its associated structure, CD3, activate T cells. More recently, a second pathway of activation has been described which involves the sheep erythrocyte binding glycoprotein CD2. a surface molecule distinct from Ti‐CD3. Lysates from surface‐iodinated T‐leukaemia cell lines were treated with lectin and affinity purified anti‐lectin antibodies coupled to protein A‐Sepharose. We have shown that eluatcs from Con A/anti‐Con A or PHA/anti‐PHA immunoprecipitates contained Ti. since;a rabbit anti‐Tα serum, which recognises the native and denatured forms of the constant region of the α chain, immuno‐precipitated Ti from these eluates. Furthermore, Ti immunoprecipitalcd bv anti‐Tα serum from lysates of surface iodinated E lymphocvtes was binding to PHA after elution from the immunoprecipitate. When the purified Ti molecule was reduced and alkylated, allowing the permanent dissociation of its α and β subunits, PHA interacted with both chains, whereas anti‐Tα serum immunoprecipitalcd the α chain onlv. Altogether, these results demonstrate that PHA interacts with both chains of the T cell receptor for antigen on human peripheral T lymphocytes. With the HPB‐ALL tumour line, a similar approach showed that both α and β chains of Ti bind to Con A andUlex europtaeus‐ 1 but notHelix pomatia.Affinity chomatographv on immobilized lectins and immunoprecipitation with lectin/anti‐leelin antibodies were employed to test whether CD2 binds to PHA and Con A. The results show that CD2 from human peripheral T lymphoevtes binds both lectins bu

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01985.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The circulatory pool of B cells, from donors immune lo hepatitis B (HB) through natural infection, contained sensitized B cells with the capacity to secrete antibodies with specificity for human serum albumin (USA) when stimulated with purified hepatitis B surface antigen (HBsAg) in vitro The immunoglobulin secretion was dependent upon and regulated by T cells and specifically induced, since it was not obtained in cell cultures from HB‐susceptible donors. Culture supernatants with anti‐USA reactivity also contained specific antibodies to HBsAg (anti‐HBs). indicating that the outer coat of HBV normally provokes an immune response to both the viral antigen and a self component. Perturbation in the regulation of the immune response triggered by USA in association with HBV/HBsAg particles may involve a putative risk for development of chronic HBsAg carrie

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01986.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

We have tested the ability of trinitrophenyl (TNP)‐labelled antigen‐presenting cells (Langerhans cells (LC) and peritoneal macrophages (Mø)) administered intravenously to induce cells that mediate and regulate contact sensitivity. TNP‐Mφ fail to induce contrasuppressor cells (Tcs) but activate efferent T suppressor (Ts) cells. However, the activity of immune cells can be recovered after removal of Ly 2 Ts cells. In sharp contrast, TNP‐substituted purified LC produced a significant contact sensitivity reaction, which is roughly equivalent to that achieved by skin sensitization with picryl chloride. Immune cells from these animals were relatively resistant to suppression by antigen‐specific Ts cells, and we have found that their resistance is due to the presence of Ly 1,Vicia villosalectin adherent, I‐J+cells. The Tcs cell induced by TNP‐LC is indistinguishable by surface markers and function from Tcs cell found in mice injected with antigen‐antibody complexes. Both these Tcs cells are capable of protecting immune cells from the effects of suppression by antigen‐specific Ts cells if added in the proper sequence. Although they have identical surface phenotypes, it is not known at present whether or not Tcs cells induced by two different antigen presentations are identical. The possible reasons why LC are such potent inducers of contrasuppre

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01987.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The thymic microesnvironment is known to play a key role in T‐cell differentiation, but the exact nature of the interactions between epithelial and lymphoid cells has not been fully elucidated, With a monoclonal antibody to a thymic epithelial glycoprotein, we report the localization of an antigen specific for medullary epithelial cells of the mouse thymus. This antigen is found in the Golgi apparatus of epithelial cells, and on their borders with adjoining lymphocytes. This location is compatible with the previously reported observation that differentiation signals transmitted to thymic lymphocytes by thymic epithelial cells require actual contact between these two cell type

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01988.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Peritoneal cells from untreated mice secrete autoantibodies after 3–4 days of in vitro culture, although the cells do not divide. Here, peritoneal cells enriched for B cells to contain 95% surface Ig‐bearing cells, did not secrete autoantibodies after 3 days of in vitro culture unless plastic‐adherent cells derived from the peritoneal cavity were cultured with the B cells. Cell‐free media, taken from peritoneal adherent cells that had been cultured for 3 days in vitro, when added at a final concentration of 50% in fresh culture medium to purified B cells, substituted for the presence of accessory cells. In contrast to cultures of unfractionated peritoneal cells, little increase in precursor frequency was detected when enriched B cells were cultured in the presence of LPS/DXS. However, the addition of adherent cells, supernatants derived from adherent cells, or cytokines produced by a T‐cell hybrid EL4, resulted in an increased precursor frequency when LPS/DXS was added to the culture medium. Three macrophage cell lines. P3788‐D1. J774. and PU‐5‐IR, when added to purified B cells, augmented the autoantibody precursor frequency detected in vitro. This is strong evidence that potentially autoreactive B cells require one or more types of accessory cells in order to differentiate into autoantibody secretors during culture in vitro. Further, the results provide indirect evidence that interleukin 1 may be a crucial molecule in the differentia

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01989.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

B lymphocytes, preactivated by lipopolysaccharide (LPS), could he triggered to growth by a strain ofMycoplasma arginini, while the level of immunoglobulin (Ig) secretion, quantitatesd as the number of plaque‐forming cells (PFC). was low. The PFC response could be increased by the addition of conditioned media (CM) from lectin‐activated spleen cells or T cell tumour EL.‐4 to the culture of preactivated B cells. CM did not by itself induce a significant amount of PFC in the cultures of LPS‐preactivated B cells. The maturation enhancing activity was distinct from 1L‐2 and B cell growth factor as judged by gel exclusion chrom

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01990.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Expression of C1q receptors on the plasma membrane of thioglycollate‐stimulated guinea pig peritoneal exudate macrophages increased 1.54 times as compared to unstimulated controls. A Scatchard plot of the binding of125I‐C1q to the cells revealed that the binding is a result of an increase in the number of receptors and not to an increased affinity of the receptors. Thioglycollate‐.activated macrophages were found to be 1.6 times more active than non‐activated macrophages in the binding of125I‐C1q at 4°C. The enhanced binding of125I‐C1q by activated peritoneal macrophages was reflected in an increase in the amount of125I‐C1q degraded by these tells as compared to resident peritoneal macrophages. This suggests that stimulation of phagocytic cells leads to an increase in the expression of C1q receptors and to a concomittant increase in the uptake and degr

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01991.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

We have examined the cellular changes taking place in rat popliteal lymph nodes undergoing a graft‐versus‐host (GvH) reaction. Lamination of immunoperoxidase‐stain lymph node sections, using a panel of mouse monoclonal antibodies directed against different rat lymphoid cell subsets, revealed a disorganization of the lymph node architecture with disappearance of the follicles, and an intermingling of T and B cells, so that no distinct T ‐ and B‐cell areas were visible any more. Since the GvH nodes showed a preferential accumulation of host B cells over host T cells (particularly over the W 3/25’T helper cell subset), we also investigated the requirements for host B cell activation. The popliteal lymph node GvH reaction was induced in (PVG x DA)F1rats by the injection of PVG cells into one foot and by DA cells into the other foot, and then immunoglobulin kappa allotype marked PVG B cells from athymic donors were injected intravenously. The allotype marked B cells proliferated vigorously in response to the DAT cells, but much less in response to the PVG T cells. These results indicate that the massive B‐cell activation taking place in GvH reactions may require an alloantigen incompatibility between donor T cells and host B cells, and argue against non‐specific mitogenic induction

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1986.tb01992.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY