摘要:

In an attempt to obtain pure populations of nonlymphoid thymic cells, monolayers of thymic cells enriched for low‐density cells were transformed with SV40. This paper describes the characteristics of the initial cell lines which resulted from this approach. These cell lines appeared to be of epithelial origin by morphologic criteria (extensive surface microvilli and pronounced intercellular tight functions) and by biochemical analysis, since they possessed mouse keratin proteins. They did not possessI‐region‐associated antigens on their surface, markers that have been detected on normal thymic epithelium. Functionally, these transformed cell lines secreted a factor capable of inducing thymocytes to mature to functional cytotoxic effector cells directed against allogeneic stimulators. This factor did not appear to be interleukin 1, interleukin 2, or colony‐stimulating factor; did not result in thymocyte proliferation; and did not affect peripheral T cells. The cell lines described in this report should prove useful in delineating the steps by which immature T cells acquire their immunocompetence in the

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb00759.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb03996.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

IgE antibodies against trinitrophenylated ovalbumin (TNP‐OVA) were raised in Brown Norway rats by a highly reproducible immunization procedure. With these rats, the kinetics of the IgE response was studied, both for free circulating and cell‐bound IgE. Cell‐bound IgE was dissociated from peritoneal cell suspensions at acid pH; TNP‐specific and total IgE in serum and in eluates of peritoneal cells were determined by radioimmunoassay. Both for total and TNP‐specific IgE, a significant correlation was found between the serum IgE level and the amount of IgE molecules per mast cell. One day before TNP hapten could induce histamine release from mast cells, TNP‐specific IgE appeared in the circulation and on the cells. These results suggest that also in active sensitization, there is a lag time for sensitization of

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb00760.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Spleen effector cells for IgG‐ and IgM‐induced antibody‐dependent cellular cytotoxicity (ADCC) were characterized with respect to density and cell surface markers by using sheep erythrocytes (SRBC) coated with hybridoma‐derived monoclonal anti‐SRBC IgG or anti‐SRBC IgM antibodies as targets. While basically the same effector celts are cytolytic for IgG and IgM antibody‐coated SRBC, they differ with respect to their relative killing capacity for IgG‐ versus IgM‐coated target cells. On the basis of physical and biochemical properties three populations with cytolytic capacity could be separated: (I) A light fraction of large cells had high cytolytic potential for both IgG‐ and IgM‐coated SRBC. The cells were negative for the Fc receptor for IgG (Fcy‐R−) and the C3‐receptor (C3‐R−), they carried the receptor forHelix pomatiaA agglutinin (HP‐A+), and reactivity was strongly reduced after treatment with anti‐Thy‐1 and complement (C). (II) High activity was also observed with a medium‐dense fraction, preferably lysing IgG antibody‐coated cells. The cells were Fcy‐R+, partly C3‐R+, mostly HP‐A−, and only a minor portion of the cells were Thy‐1+. (Ill) A dense fraction, displaying on a percell basis low cytolytic potential, was more active in IgM than IgG ADCC. The cells were Fcy‐R+, HP‐A+and Thy‐1+. All three effector cell populations were non‐adherent,

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb00761.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb03997.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Lymphocytes isolated from human tonsils are capable of lysing cells or the natural killer (NK)‐susceptible line K562. Although weak compared with that of autochthonous peripheral lymphocytes, cytotoxicity is invariably manifest at high effector‐to‐target ratios. Like peripheral NK cells, tonsillar cytotoxic lymphocytes possess a low buoyant density, which makes possible their partial enrichment from non‐cytotoxic cells by centrifugation on discontinuous Percoll gradients. However, examination of cytotoxic fractions indicates that, unlike blood lymphocyte‐mediated cytotoxicity, effector function is not associated with the presence of large granular lymphocytes. Furthermore, a functional distinction from classical NK cells is apparent since, although tonsillar cytotoxicity is significantly enhanced after exposure to supematants from polyclonally activated allogeneic tonsils, pretreatment with lymphobtastoid (Namalva) interferon (IFN‐α) at doses shown to potentiate maximally the cytotoxicity of peripheral blood lymphocytes fails to influence reactivity. These data provide preliminary evidence for the existence of, at least limited, heterogeneity among hu

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb00762.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb03998.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Serum complement profile studied in 50 lepromatous leprosy patients with various bacillary loads demonstrated significantly decreased C3 levels in patients with high bacteriological index (2+ to 4 +) as compared with those with lesser bacterial load. In contrast, mean serum levels of Cl q and C4 components remained unchanged. The concentration of factor B breakdown product (Ba) and its ratio to factor B increased with the bacterial density and more so in patients with erythema nodosum leprosum. A significant negative correlation was found between serum C3 and Ba levels in most lepromatous patients. Analysis of the data suggested the alternative pathway as the possible mechanism of complement activation in lepromatous leprosy.

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb00763.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb03999.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The synthesis of factors that monitor the expression of the Thy‐l cell surface component by marker‐negative precursor cells requires an intact left cerebral cortex, whereas the activity of sodium diethyldithiocarbamate, an immunopotentiator that increases this synthesis, seems to require an intact right neocortex. These results suggest a role for the cerebral cortex in the coordinated interregulation of lymphocyte subclasses. The finding extends previous information suggesting relationships between the central nervous system and the T‐cell arm of the immune s

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1983.tb00764.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY