摘要:

The genetic region that influences graft rejection in animals and man is known as the major histocompatibility complex (MHC). The gene products of this complex (15) exert a profound influence on the activation of T lymphocytes. At least three effects of the MHC on T cells deserve special mention. First, the frequency of T lymphocytes that respond to cell surface alloantigens coded by the MHC is 100 to 1000 times greater than the frequency of T cells that respond to other antigens (27, 35). Second, the extent of a T‐cell response to certain antigens is controlled by genes that have been mapped in the I region of the MHC (3). Third, it has recently been shown that the MHC imposes constraints on the activities of sensitized T cells (7). The aim of this article is to review briefly some of the recent work performed in mice which allows the formulation of a model that may be used to explain tentatively the relationship between MHC gene products, T‐lymphocyte activation, and immune reactiv

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02150.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The proliferative response of immune human T lymphocytes to low concentrations of purified protein derivative (PPD) in vitro was found to require the presence of macrophages. By coculturing different combinations of immune T lymphocytes and allogeneic macrophages with PPD in low concentration, optimal stimulation (that is, as efficient as the autologous combinations) was shown to require HLA‐D identity between the macrophages and responding T cells. Identity for HLA‐A and ‐B appeared to be of less or no importance. It is concluded that membrane structures encoded by HLA‐D or closely linked loci are involved in the human macrophage/T‐lymphocyte interaction in the proliferative response to PPD, much in the same way as the Ia antigens o

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02151.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Upon in vivo alloactivation of Ig‐anti‐Ig column‐purified splenic ‘T’ cells in lethally irradiated allogeneic recipients, a variable proportion of donor‐derived cytotoxic T lymphocytes (CTLs) are able to bind IgG antibody‐coated erythrocytes through surface Fc receptors (FcR) and form rosettes. The use of fractionation procedures based on the ability of these cells to form rosettes has enabled us to separate FcR‐positive CTLs from FcR‐negative CTLs and to examine the ability of these two cell populations to perform as effector cells in direct T‐cell‐mediated killing and in antibody‐dependent cellular cytotoxicity. A series of experiments, either by direct isolation of the two cell populations or by deletion of the FcR‐positive population by filtration through complexed immunoglobulin columns (Ig‐anti‐Ig), has shown both populations to be efficient in direct T‐cell mediated cytotoxicity against the relevant target cell. The striking difference between the two populations is the exclusive ability of the FcR‐positive population to function as effector cells in antibody‐dependent cellular cytotoxicity (ADCC). Purification steps before in vivo alloactivation of our responding cells for the removal of ‘B’ cells and FcR‐bearing cells with‘K’‐cell activity, followed by procedures to remove phagocytic and adherent cells in the resulting immune spleen cell preparation and, finally, by velocity sedimentation of the rosetting and nonrosetting blasts from the small lymphocyte population, has resulted in a population of FcR‐positive cells 98% positive for the Thy 1.2 alloantigen. These fractionation steps and immnunofluorescence criteria of purity strongly favor the contention that the ADCC activity within the FcR‐positive T‐c

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02152.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Mouse macrophages, activated in vivo or in vitro, were made to internalize sheep erythrocytes opsonized with IgG or IgM and complement. Scanning electron microscopy and transmission electron microscopy were performed ac various times after the transfer of the cultures from conditions favoring attachment to conditions favoring internalization. The receptors for Fc and C3 were distributed randomly over the macrophage surface with the exception of the extreme periphery, were Fc receptors were more abundant. The E‐IgG were ingested by means of thin membrane extensions rising from the macrophage surface and enclosing the opsonized particles tightly in a cup‐like structure protruding from the macrophage surface. Only afterwards were the covered particles drawn into the cell body proper. The E‐IgMC were seen to sink directly into the macrophage cytoplasm without apparent involvement of membrane extensions. Experiments with cytochalasin B suggested that microfilaments were essential for the phagocytosis by Fc but much less important with the C3 rec

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02153.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Lymphocytes transferred from 6‐day‐old human mixed lymphocyte cultures (MLC) inhibited the response to allogeneic cells of freshly taken lymphocytes autologous to the transferred MLC‐responding cells. No specificity for this cell‐dependent suppression could be determined. The inhibitory effects of the suppressing cells could be abrogated by moderate X‐ray irradiation and significantly reduced by pretreating them with an anti‐Ia‐like antiserum and complement, Tin‐human suppressor cell responsible for the observed effects therefore appears to carry determinants equivalent to the murine

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02154.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Rat blastocysts were transferred to the uteri of either immunodeficient, congenitally athymic (nu/nu) ‘nude’ mice or immunocompetent, heterozygous (nu/+) mice. Histological analysis showed that there was a similar frequency of implanted blastocysts in the two types of mice, that blastocysts transferred to nude athymic mice outlived those in heterozygous controls by at least 3 days, and that blastocysts in nude mice showed delayed and abnormal development and were eventually rejected. These findings suggest that the T‐cell deficiency in nude mice may prolong the survival of implanting blastocyst but that other immune or non‐immune factors still limit their deve

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02155.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

IgD was detected in 84% of cord sera at term by an inhibition‐of‐hemagglutination test, in contrast to low incidences reported earlier. Cord blood IgD and maternal serum IgD values were unrelated to each other, consistent with a fetal origin of the IgD. The cord blood IgD failed to correlate, either directly or inversely, with cord blood IgA or IgM, suggesting that its presence does not reflect fetal synthesis of specific antibody but rather may be developmen

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02156.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

By using chicken antibodies and chicken lymphoid cells, we could demonstrate antibody‐dependent cytotoxicity (ADCC) against haptenated chicken erythrocytes. ADCC could be demonstrated either by treating the target cells with antibody (sensitization) or by treating the effector cells (arming). Approximately ten times higher antibody concentrations were required for arming than for sensitization. Chicken lymphoid cells did not co‐operate with mammalian antibodies in either type of ADCC, and thus the situation was reciprocal to that observed earlier with mammalian lymphoid cells. In a further attempt to characterize the arming phenomenon we used biofiltered (aggregate‐free) mouse antibodies for the arming of rat spleen cells. They were as efficient as nonfiltered antibodies, and this confirms that individual antibody molecules are efficient in a

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02157.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Block neutralization data since 1949 for the foot‐and‐mouth disease virus system have been analyzed in terms of a unified mass‐action theory for computing the amounts of infectious complexes. Proof that infectious complexes contribute considerably to the assays was obtained by demonstrating a reduction in titer after an additional reaction with anti‐Ig antibody before the assay. In the suckling mice assay with intraperitoneal inoculation, both the data of others and our own on several types indicate that for IgG probably three of the unknown total number of critical sites on the virion must be available for infectivity and death. For IgM, just one of an unknown different total number of critical sites on the virion must be available. In tissue culture infectivity assays the minimum number is two or three, whereas in the bovine tongue assay it could be one or two, but probably two. The difficulties in establishing the at present unknown total numbers of neutralization sites to both IgG and IgM are considerable. However, by the simplest interpretation of the data, the number is estimated to be between 5 and 10 for IgG and perhaps just 1 for IgM. A speculation, consistent with the known virion architecture, is that just 1 of the 12 vertices is uniquely involved in infectivity and death, at least in the suckling‐m

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02158.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Rabbit anti‐rat brain synaptic membrane and anti‐rat thymocyte antisera were used in cytotoxicity, immunofluorescence, and absorption assays to define the antigenic relationship between the rat brain and thymocytes, and the localizing properties of antibodies. Both antisera cross‐reacted with brain tissue and thymocytes. However, anti‐synaptic membrane and anti‐thymocyte antisera also contained antibodies specific for neurons and thymocytes, respectively, Immunofluorescence showed that antibodies from anti‐thymocyte antiserum reacted with antigenic determinants situated on the surface membrane of

ISSN:0300-9475    

DOI:10.1111/j.1365-3083.1977.tb02159.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY