摘要:

SUMMARYThis study investigates the possibility that the active enhancing properties of bone marrow (BM) cells may be related to la-like determinants on their surface membranes. Less chromium was released on a cell per cell basis from nucleated baboon BM cells used as targets in complement-dependent cytotoxicity than from labelled lymph node lymphocytes. On the other hand, BM cells stimulated allogeneic lymphocytes in culture more vigorously than lymph node lymphocytes. BM cells with lymphocyte-activating properties could be enriched by fractionation on a discontinuous bovine serum albumin gradient. BM cells responded poorly to allogeneic cell stimulation in mixed culture. Platelet absorption studies of an alloan-tiserum supported the conclusion that nucleated BM cells, and particularly BM fractions collected from the less dense interfaces of a bovine serum albumin gradient, express relatively more lymphocyte-activating or la-like determinants than “serologically defined” determinants.We have previously reported highly significant prolongation of liver allograft survival in chacma baboons following the administration of a polyspecific alloantiserum (PSS) and a single injection of 25 × 106donor bone marrow (BM) cells at the time of transplantation (7). Graft survival was also significantly longer than that seen in a group of animals passively enhanced with PSS alone. All eight of the animals tested in the PSS + BM group formed alloantibodies detected by mixed cell agglutination against the lymphocytes of a random panel of 10 baboons. The effect of the BM was abrogated (7) or lessened (8) by coincident administration of cyclophosphamide or anti-lymphocyte serum and azathioprine and prednisolone, respectively. The studies reported here investigate the possibility that the active enhancing properties of BM cells may be related to la-like determinants on their surface membranes, and show that nucleated BM cells are rich in lymphocyte-activating (Ia-like) determinants, and relatively poor in serologically defined (SD) determinants. The accompanying paper gives the results of active immunization with whole suspensions and fractions of nucleated BM cells.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYOutbred chacma baboons were preimmunised with donor-specific bone marrow (BM) fractions obtained from the less dense interfaces of a bovine serum albumin gradient, and shown to be relatively rich in Ia-like determinants. One group received the BM cells i.v. 1 day after the administration of 50 mg of cyclophosphamide per kg, and another group was immunised with BM cells suspended in incomplete Freund's adjuvant. Both these protocols resulted in a predominantly antidonor B cell antibody response, and survival of orthotopic liver transplants from the BM donors was significantly prolonged. One animal is still alive more than 1 year after transplantation. Two other groups of baboons were preimmunised by similar protocols but with spleen cells instead of BM cells. The antibody response in all animals tested was against both B and T cells. Liver allograft survival was prolonged, not quite as much as that seen following BM preimmunisation, but still significantly so in comparison with untreated controls. Positive lymphocyte-mediated cytotoxicity developed in some animals. This may be avoidable by modification of the preimmunisation protocol. These studies indicate therefore that liver allograft survival in the primate can be enhanced by preinduction of donor-specific B cell alloantibodies. However, in this model enhancement is not solely the property of antibodies with B cell specificity.Previous studies in our laboratories have demonstrated highly significant enhancement of baboon liver allograft survival by a single injection of donor bone marrow (BM) at the time of transplantation and the administration of a polyspecific baboon alloantiserum three times a week for 2 weeks thereafter (12). In the preceding paper, we have shown that BM cells are relatively rich in lymphocyte-activating (Ia-like) determinants and relatively poor in serologically defined determinants when compared with lymph node lymphocytes on a cell per cell basis (14). The possibility was raised that the enhancing properties of BM may be attributable to the induction of B cell alloanti-bodies. In the studies reported here, we demonstrate that preimmunisation of baboons with donor-specific BM fractions does indeed induce antibodies with a predominant anti-B cell pattern, and that the survival of subsequently transplanted liver allografts from the BM donors is significantly prolonged.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYThe alloantigenic reactivity of hamster spleen cells from unsensitized animals was analyzed in vitro. When compared with normal MHA cells, MHA anti-CB spleen cells responded better or to the same degree in mixed lymphocyte reaction (MLR) during the first 3 days after alloantigenic exposure. However, by day 5 postsensitization there was a significant reduction in spleen cell MLR activity, which returned to normal or even an exaggerated response 7 days following immunization.We examined the possibility that the reduction in MLR responsiveness 5 days following immunization might be attributable to the generation of splenic suppressor cells. Irradiated spleen cells from unsensitized and from MHA anti-CB donors were cocultured with normal responder MHA lymph node cells stimulated by (MHA x CB)F, hybrid lymph node cells in MLR. No regulatory effect of either cell population was seen, indicating that even hamster spleen cells from alloimmune donors fail to suppress the mitotic response of normal lymph node cells to allogeneic targets.In recent years information has accumulated, especially in the transplantation literature, that ascribes regulatory control of various immune responses to subpopulations of lymphocytes and/or their secretory factors. On the one hand, cellular interactions of distinct subpopulations of thymus-derived lymphocytes allow enhanced immune responsiveness in graft-versus-host reactions (1,2), mixed lymphocyte reactions (3, 6, 21), and the effector phase of the cytotoxic allograft response (16, 22). On the other hand, at other times during the course of allogeneic cell interactions, specific and nonspecific mechanisms of control are evoked which suppress immune expression (12).The majority of data concerning suppression in allograft responses has been obtained from model systems utilizing rats and mice. Although the precise mechanisms by which the immune response is thus regulated remain to be elucidated, information as to the nature of the cell type(s) involved is more substantive: antigen-specific suppressor cells appear to be of thymic origin, localizing primarily in the spleen (13, 14, 24) and possessing a distinct Ly antigen phenotype (7).Recent evidence concerning alloantigenic responses of Syrian hamsters thought to be major histocompatibility complex disparate suggests that, unlike rats and mice, hamsters fail substantially to generate a mechanism that limits clonal expansion following an alloantigenic stimulus both in vivo and in vitro. Early studies of systemic graft-versus-host reactions induced in (MHA × CB)F1hybrid hosts, by normal and specifically sensitized parental lymphoid cells, suggested that the latter donors were more potent on a cell for cell basis (78). As a recent extension of these studies, we have reported that local graft -versus-host reactions (popliteal lymph node hypertrophy) and mixed lymphocyte reactions (MLRs) comparing alloimmune and normal spleen and lymph node cells (9) similarly demonstrate a superior response on the part of the specifically sensitized cells. However, as was shown in that report, during an early phase after alloimmunization, the MLR of hamster spleen cells appeared to be reduced compared with unsensitized cells. This was the first time in hamsters that we had ever seen this reversal in MLR potential of normal and sensitized cells. In this report we have examined the development of alloimmunity in hamsters by using in vitro methods in an attempt to document whether this species can and does generate suppressor cells under these conditions, and whether these cells could account for the early reduction in reactivity shortly after alloantigenic sensitization.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYCadaveric renal transplants were performed despite a positive conventional crossmatch (usually intermediate positive) resulting from donor-specific B cell lymphocytotoxins (both IgG and IgM) or IgM cold-reactive T cell lymphocytotoxins. Graft survival at 2 months was 72% in the 14 patients with B cell-specific antibodies and 71% in the 7 recipients with T cell antibodies. No correlation was observed between graft rejection and warm (mainly IgG) or cold (IgM) B cell-specific antibodies. These results indicate that not all positive crossmatches are a contraindication to transplantation. Attempts should be made to study the nature of the lymphocytotoxins before withholding the allograft from the recipient.Until recently, transplantation across positive crossmatches was felt to be improper or even unethical, mainly because of the increased risk of hyperacute and accelerated graft rejections (1–3). Several centers, including ours, have now demonstrated that donor-specific lymphocytotoxins directed against B lymphocytes and not T lymphocytes are harmless (4–7). A positive crossmatch for donor T lymphocytes is still felt to be an absolute contraindication to transplantation ( 7).Two main types of lymphocytotoxins have recently been described: (1) those active against HLA antigens, and (2) those active against non-HLA antigens.2Research in certain disease states has demonstrated the existence of IgM lymphocytotoxins, which as a rule are cold-reactive and reactive against non-HLA antigens present on both B and T cells (8). Investigations in our laboratory, utilizing a modified indirect immunofluores-cent technique to study lymphocytotoxins, have demonstrated that sera from potential recipients with nephritis or on hemo-dialysis commonly have cold-reactive IgM lymphocytotoxins reactive against T and B cells (9). Furthermore, by absorbing these sera against pooled platelets and red blood cells, no appreciable decrease in reactivity was observed, indicating that these IgM lymphocytotoxins were reactive against non-HLA determinants. The important observation that B cell-specific lymphocytotoxins are reactive against non-HLA antigens led us to reexamine the outcome of transplants across a positive T cell crossmatch,3resulting from such IgM non-HLA-reactive antibodies (10). Second, because of certain controversies regarding the harmfulness of warm (and not cold-reactive) B cell antibodies ( 7), we present data reexamining this issue as well.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYImmunological mechanisms of increased graft survival in “immunologically privileged” sites were defined by comparing host responses against orthotopic and alymphatic skin allografts in rats. The conventional skin grafts reject by day 8; grafts placed on alymphatic skin pedicles heal in normally, but begin by day 16 to 18 to contract inexorably until only a scar remains by day 35 to 40. Lymphocyte-mediated cytotoxicity rose significantly in spleen and draining lymph nodes 8 to 10 days after orthotopic grafting, but was absent as long as 35 days after skin transplantation to alymphatic pedicles. No significant activity in antibody-dependent lymphocyte-mediated cytotoxicity was noted in either recipient group, while complement-dependent cytotoxicity was slightly elevated 8 to 10 days postoperatively in both groups. Passive transfer of serum from recipients of alymphatic skin grafts, taken 8 and 12 days after grafting, prolonged survival of test cardiac allografts significantly, although neither control serum from recipients of orthotopic skin allografts, or serum taken 28 days after alymphatic skin grafting increased test heart survival. We conclude that prolonged survival of skin grafts on alymphatic sites may be based, at least partially, on the development of host humoral factors.The anatomical defect common to most “immunologically privileged” sites is the absence of lymphatic drainage. When an allograft is transplanted to the hamster cheek pouch, anterior chamber of the eye, or the central nervous system, host sensi-tization is delayed and graft survival prolonged (4, 6, 12). Both afferent and efferent limbs of the immune response remain at least partially intact in these sites, since eventual rejection does occur while sensitization of the host by a conventional route leads to accelerated rejection of the protected graft (2, 10, 11, 13). Skin allografts on alymphatic skin pedicles in the rat survive longer than orthotopic grafts (1, 16). The inexorable chronic rejection, which they ultimately experience, suggests that recipient sensitization must occur in areas other than the regional draining lymph nodes. Thus, in contrast to the cellular reaction to conventional grafts noted in thymus-dependent areas of regional lymph nodes and spleen ( 75), cell proliferation in response to alymphatic grafts occurs primarily in splenic B cell areas. In this study, we present evidence that prolongation of survival of alymphatic grafts may be attributable, at least in part, to enhancing activity.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYBiopsy specimens were obtained from 43 transplanted kidneys at the time of excision from the donor but prior to revascularization, and 1 hr after revascularization. Two independent laboratories evaluated specimens by immunofluores-cent techniques for the presence of IgM, IgA, IgG, C'3, and fibrin. Results from the two laboratories were examined for reproducibility and immunological specificity, and correlated with clinical course. Results show that immunoglobulin deposition seen in the 1-hr renal biopsy specimens is of little significance, because: (1) immunoglobulin deposition was difficult to quantitate reliably, (2) the presence of immunoglobulins did not correlate with clinical course, and (3) the majority of immunoglobulin deposition detected was not immunologically specific, since it was most often either present prior to vascularization or disappeared with vascularization.The morphological changes that are associated with renal allograft rejection are well documented (3, 8, 10, 13). Immuno-fluorescent and electron microscopic techniques have shown that both accelerated and chronic rejections are characterized by immunoglobulin deposition (especially IgG), as well as complement (C'3) and fibrin deposition and polymorphonuclear infiltration of vessels and glomeruli (12). The use of the 1-hr postvascularization renal biopsy as an index for both the prognosis and diagnosis of allograft rejection is based on the assumption that these histopathological changes can be quantitatively and qualitatively assessed at 1-hr post-transplantation, and that they are immunologically specific. It was the objective of this investigation to test these basic assumptions in order to evaluate the significance of the 1-hr biopsy in renal transplantation.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYThree protocols of blood transfusion were evaluated in a canine model for (1) the strength and breadth of leukocytotoxin induction, (2) the induction of cell-mediated immunity against the blood donors, (3) haemagglutinin production, and (4) any effect on kidney graft survival. At the end of the transfusion schedule, each dog received a kidney graft and was given azathioprine and prednisolone postoperatively. All dogs were unrelated and blood donors were not used as kidney donors. All three transfusion protocols, comprising i.v. injections of blood twice weekly or every 2 weeks from one or three donors, induced unacceptably strong and broad leukocytotoxins. All transplants performed across a positive crossmatch failed to function. However, where a negative crossmatch was available, the trend of results was that the transfused dogs had better graft survival than nontransfused animals similarly treated with azathioprine and prednisolone. Only one dog produced haemagglutinins. Several animals had positive cell-mediated immunity against the blood donors, but the response was not strong and was frequently not sustained.The problems posed by blood transfusions in clinical renal transplantation are complex, and have been a subject of debate from the time of the earliest transplants. A number of early studies comparing graft survival in patients, who had received few transfusions with those that had received many before transplantation, showed that graft outcome either was not different in the two groups (19) or that it might have been better in the patients given the most transfusions (7). That blood transfusions before transplantation could induce a state of specific unresponsiveness to a subsequent organ allograft was clearly demonstrated in the rat by a number of groups ( 10, 17, 18).The more exacting clinical comparison of a group of nontransfused patients with a transfused group was not made until 1974 when Opelz and Terasaki (21) published data showing that graft survival was substantially worse in nontransfused patients. Their work has been supported by further clinical reports ( 14, 15, 22, 27) and by experimental work in the rhesus monkey (26) and the dog (1). Although the clinical results from our unit show that nontransfused and transfused patients have essentially similar and excellent graft survival (P. J. Morris et al., in preparation), the retrospective studies from most, but not all, units suggest that blood transfusions before transplantation do lead to better graft survival in those patients that receive a transplant.The problem that arises in patients given transfusions before transplantation is that any beneficial effect in terms of graft protection for those that come to transplantation might be offset by the relegation to life-long dialysis of those that become highly sensitized (3, 24). The clinical problem, then, is the choice of a protocol for transfusion that is most likely to result in graft protection and least likely to result in the production of lymphocytotoxins to HLA-A, B, and C antigens. The balance between an overall harmful or beneficial effect of transfusions almost certainly depends on a number of variables, such as the number of different blood donors, the frequency of transfusion, the volume of blood transfused, the use of frozen blood, the age of the blood, the interval between the last transfusion and transplantation, the degree of histocompatibility between blood donor and recipient, the genotype of the recipient, and the degree of nonspecific immunosuppression induced by chronic renal failure. The experiments reported in this paper attempt to evaluate some of these factors in the dog.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYCell-mediated immunity to cytomegalovirus (CMV) was studied in a bone marrow transplant patient with evidence of active CMV infection. The lymphocytes from this patient were found to specifically recognize and respond in vitro by transformation to CMV-infected Wistar-38 fibroblasts and by production of macrophage migration inhibition factor to CMV antigen. In addition, plasma and spinal fluid from the patient were found to contain blocking factor that specifically inhibited the lymphocyte response in the above assays. Biochemical, biophysical, and immunological studies indicate that the blocking factor may be an antigen-antibody complex.The immunosuppression required for bone marrow transplantation results in an increased number of severe and often life-threatening viral infections (4, 11). Immunosuppressive regimens utilized in patients undergoing renal transplantation also result in a high incidence of viral infections, particularly infection with cytomegalovirus (CMV) (3, 8). Increasing complement-fixing antibody titers to CMV have been reported in both renal and bone marrow transplant recipients with clinical evidence of CMV infection (3, 4, 8, 9, 11). Thus, despite immunosuppression, a specific antibody response is seen and a vigorous serological response may indicate a more favorable prognosis (11). Depression of cellular immunity, as measured by blasto-genic response to phytohemagglutinin, has been described in renal transplant patients infected with CMV (9). However, the presence of specific cellular immune response to CMV in infected patients is poorly documented. This report characterizes the cell-mediated immune response to CMV in a patient who developed evidence of acute CMV infection following bone marrow transplantation. Lymphoid cells from this patient were found to specifically recognize and respond in vitro by transformation to a CMV-infected cell line and by production of macrophage migration inhibition factor (MIF) to CMV antigen. Furthermore, plasma and spinal fluid from this patient were found to contain blocking factor that specifically inhibited lymphocyte transformation and MIF production in response to CMV antigen. Partial characterization of the blocking factor indicates that it may be an antigen-antibody complex.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYTo test the association of small bile duct destructive lesions in the liver with acute graft-versus-host disease, a blind (coded) histological study was done comparing liver tissue from three groups of dogs given 1,200 R of total-body irradiation: one not given marrow infusions after irradiation, another given autolo-gous hemopoietic grafts, and a third given marrow grafts from DLA-nonidentical unrelated donors. The dogs with unrelated grafts all developed graft-versus-host disease, and their liver histology was distinguished from that of the dogs in the other two groups by three findings: (1) extensive small bile ductule necrosis and atypia; (2) infiltrates of mononuclear cells around and in ductules; and (3) individual hepatocyte necrosis scattered throughout the lobules. Thus, bile duct lesions appear to be a good marker for assessing the presence and severity of hepatic graft-versus-host disease in dogs.Small bile duct proliferation was first reported by de Vries and Vos (2) in mice as a feature of the graft-versus-host reaction of the liver. Subsequent studies in animals showed eosinophilic change, necrosis, and marked atypia of the epithelium of small bile ducts in addition to necrosis of hepatocytes (3, 4, 11, 14, 18). Similar small bile duct lesions have been described in human patients with acute graft-versus-host disease (GVHD) after allogeneic marrow transplantation. Since they seemed to be the only changes distinguishing liver GVHD from other types of hepatitis, small bile duct lesions have been proposed as the basis of a graded assessment of the severity of hepatic GVHD involvement (6, 17). Woodruff et al. (22) have noted bib duct changes in some human marrow graft recipients, but have been reluctant to assign a relationship to graft-versus-host reaction because of concurrent viral infection, especially cyto-megalovirus (CMV).Dogs that are specifically immunized provide a model in which hepatitis is distinctly unusual even after marrow transplantation (8, 10, 11, 13–15). Also, interstitial pneumonia is rare and CMV infection has not been described. This allows one to study the hepatic changes in GVHD under better controlled conditions.In this study we describe the hepatic histology in three groups of dogs given 1,200 R of total-body irradiation (TBI): one given no marrow infusions after irradiation, another given autologous hemopoietic grafts, and a third given marrow grafts from DLA-nonidentical unrelated donors.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYPapain solubilization enables two molecular models to be obtained according to which SLA specificity is studied. The SLA 1 antigen in the soluble state is a molecule having an apparent molecular weight of about 40,000 daltons. It is composed of two polypeptide subunits with molecular weights of 28,000 and 12,000 daltons. The molecular weight of papain-solubilized SLA 7 antigen is twice that of the SLA 1 antigen. Partial dissociation of the SLA 7 antigen produces 42,000-dalton structures, while total dissociation yields polypeptides having molecular weights similar to those polypeptides constituting the SLA 1 antigen. All of these facts indicate that the soluble form of the SLA 7 antigen is a tetracatenary structure including two of each polypeptide.The SLA antigen light chain is shown to be a β2-micro-globulin. A strong cross-reaction between pig and human β2-microglobulins is demonstrated in this respect.The genetic organisation of the major histocompatibility complex in the pig fits the model generally accepted for HLA (28). The classical SLA histocompatibility antigens are under the control of at least three tightly linked genes situated about 0.5 centimorgans distant from a region controlling mixed lymphocyte reactions and from genes coding for Ia-like structures (26, 29, and manuscript in preparation).Papain solubilised SLA 1 and SLA 7 antigens have apparent molecular weights (mol wt) of 40,000 and 85,000 daltons, respectively. Under dissociating conditions both dissociate into 30,000-mol wt heavy and 12,000-mol wt light chains. These results suggest that SLA 7 may be a tetracatenary structure composed of two heavy and two light chains (1). Classical human HLA and murine H-2 antigens are composed of a heavy chain carrying the alloantigenic determinants (12, 24) and a smaller chain apparently identical to β2-microglobulin (4, 7,17). Dimerised 4 chain structures have been reported for HLA and H-2 antigens (2, 15, 18, 22), but their existence has yet to be unequivocally established (8, 19).We report here detailed structural studies of the SLA antigens, SLA 1 and SLA 7, with special reference to the characterisation of their light chain component.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID