asialo-gm1-ganglioside and Graft-vs-Host-Disease

A chimeric severe combined immunodeficient mouse engrafted with human peripheral blood (hu-PBL-SCID) model has been developed to test anti-T-cell monoclonal antibody (mAb) effects on systemic symptoms of the host and the survival of human skin grafts. To obtain consistent engraftment without lethal acute graft-versus-host disease (GVHD), SCID mice were pretreated with a combination of total body irradiation (2.5 Gy, day 0) and anti-asialo GM1 (anti-mouse natural killer cell) antiserum (50 micrograms i.p., day 3) before the intraperitoneal injection of 40-50 X 10(6) human PBL on day 4. With this protocol, the engraftment rate was 82% with 5-98% human CD45-positive cells in the peripheral blood. Mortality at 30 days was 0% in the mice bearing 5-50% human cells compared with 70% in those with more than 50%. Using hu-PBL-SCID mice with 5-50% human cells in their peripheral blood, we demonstrated the following results: 1) Human T cells isolated from these mice proliferated in response to immobilized OKT3 stimulation in vitro. 2) Hu-PBL-SCID mice but not normal SCID mice were able to reject human skin grafts in vivo 16-21 days after grafting. 3) Both OKT3 (anti-human CD3 mAb) and T10B9 (anti-human alpha beta T-cell receptor mAb) treatment prevented human skin graft rejection in hu-PBL-SCID mice. 4) OKT3 but not T10B9 induced first dose reactions characterized by hypothermia and hypoactivity which were consistently observed within 90 min of intravenous injection into hu-PBL-SCID mice. 5) Human cytokines were detected in the serum of the hu-PBL-SCID mice treated with anti-T-cell mAbs. The close similarity of these responses to human clinical mAb immunosuppressive therapy suggests that the hu-PBL-SCID mouse model may be an excellent tool for investigating the immunosuppression, side effects, and mechanism of action of agents that are specific for human and higher apes and not reactive with lower animals.

Topics: Acute Disease; Animals; Antibodies, Monoclonal; Cell Division; Cytokines; Disease Models, Animal; G(M1) Ganglioside; Graft Survival; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Hypothermia; Immune Sera; Immunoglobulin M; Immunosuppressive Agents; Leukocytes; Lymphocyte Activation; Mice; Mice, SCID; Muromonab-CD3; Receptors, Antigen, T-Cell, alpha-beta; Skin Transplantation; Survival Rate; T-Lymphocytes; Transplantation, Heterologous; Whole-Body Irradiation

Studies were performed to examine whether, in addition to T cells, there might be other immune cells also capable of exerting a graft-versus-leukemia (GVL) response following allogeneic marrow transplant. Using an MHC-matched mouse model, consisting of normal B10.S donors and SJL/J Rauscher-retroviral-leukemic recipients, the donor cells were selectively depleted of their Asialo-GM1+ component prior to being infused into the leukemic recipients. The incidence of relapse was then compared against that for matched leukemic control recipients of undepleted cells from the same donors. FCM analysis of the depletion protocol indicated that exposure to anti-Asialo-GM1 antibody eliminated more than half of the donor NK1.1+ cells, but caused no significant losses among the Thy-1+, CD3+, or CD8+ cells. Nevertheless, fatal relapse among the leukemic recipients of the depleted cells was nearly double that found among the leukemic control recipients of undepleted cells, 47.5 vs 25.4% (P = 0.01). In a parallel study, using normal SJL/J recipients, this same depletion protocol was found to have no significant effect on the incidence of graft-versus-host disease (GVHD). These results therefore suggest that Asialo-GM1+ NK cells may be capable of contributing to the suppression of relapse in this type of leukemic recipient of allogeneic marrow, and that this suppression may occur independently of GVHD.

Topics: Animals; Antibodies; Bone Marrow Transplantation; G(M1) Ganglioside; Graft Rejection; Graft vs Host Disease; Killer Cells, Natural; Leukemia, Experimental; Mice; Mice, Inbred Strains; Recurrence; Retroviridae

The severe combined immunodeficient (SCID) mouse engrafted with human peripheral blood lymphocytes (PBLs) is a potentially useful model for the study of cancer immunotherapy. For this application, rapid, consistent, and high level engraftment of SCID mice with functional human cytotoxic effector cells is necessary. To date, short term human lymphoid cell engraftment in SCID mice has generally been low and variable. Further, most of the human cells detected within the first 30 days are found in the peritoneal cavity. The purpose of the present study was to improve short term reconstitution of human PBLs in the SCID mouse. When untreated SCID mice were injected with human PBLs, the mean level of CD3+ cells in the spleens was < 5% on days 6-32 after injection, as determined by flow cytometry (FCM). Depletion of SCID mouse natural killer (NK) cells with anti-asialo GM1 only marginally improved short term reconstitution with human CD3+ cells. Preirradiation of SCID mice with 3 Gy improved reconstitution to over 16% CD3+ cells on days 12-14 following engraftment. However, the combination of pretreatment with anti-asialo GM1 plus radiation, significantly increased the mean percentage of human CD3+ cells in the spleen to 40% within 2 weeks following injection of PBLs. Human T cells positive for CD4, CD8, TcR alpha beta, and TcR gamma delta, and human NK and B cells were detected in the spleens of irradiated plus anti-asialo GM1 pretreated SCID mice. The presence of human lymphoid cells was confirmed by immunohistologic staining. The human immune cells in these mice were shown to be functional by the in vivo demonstration of an appropriate secondary immune response to the injection of tetanus toxoid and by an in vivo proliferative response to phytohemagglutinin. Human NK cells could be found in the spleens and peripheral blood of irradiated plus anti-asialo GM1 pretreated mice. These cells were also shown to be competent by their ability to lyse the human NK sensitive tumor targets K562 and MOLT-4 in 51Cr release assays. Thus, pretreatment of SCID mice with radiation plus anti-asialo GM1 significantly improves short term human PBL engraftment and provides a potentially useful model for the study of cancer immunotherapy.

Topics: Animals; CD4-Positive T-Lymphocytes; G(M1) Ganglioside; Graft vs Host Disease; Humans; Immunoglobulin G; Killer Cells, Natural; Lymphocyte Transfusion; Mice; Mice, SCID; Severe Combined Immunodeficiency; Spleen; T-Lymphocytes, Regulatory; Transplantation, Heterologous

The nature of the effector cell(s) responsible for the depression of B-cell genesis in the bone marrow of mice undergoing systemic graft-versus-host disease (GVHD) has been examined. Donor C57BL/6 (B6) mice were treated in vivo with either a single injection of anti-asialo GM1 antibody (anti-ASGM1) to eliminate naturally occurring (endogenous) ASGM1+ cells or B6xAF1 (B6AF1) lymphoid cells followed by anti-ASGM1 to eliminate both endogenous and "induced" ASGM1+ cells. Lymphoid cells from donor mice after the elimination of endogenous ASGM1+ cells produced severe GVHD and concomitant depression of B-cell genesis when injected into B6AF1 recipients. In contrast, cells from donors depleted of both the endogenous and inducible ASGM1+ populations did not cause GVHD or depletion of B lineage cells in B6AF1 recipients but did depress B-cell genesis in B6C3F1 mice. The "induced" ASGM1+ cells were Thy 1+, but their elimination did not significantly alter either overall T-cell function or specific cytotoxic T-cell (CTL) reactivity against the sensitizing (B6AF1) strain. The results suggest that the effector cell responsible for the depression of B-cell genesis during systemic GVHD can be induced to express ASGM1, is strain-specific and Thy 1+; but is not a conventional CTL.

Topics: Animals; Antibodies, Monoclonal; B-Lymphocytes; Bone Marrow Transplantation; Female; G(M1) Ganglioside; Graft vs Host Disease; Hematopoiesis; Killer Cells, Natural; Lymph Nodes; Male; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred CBA; Spleen; T-Lymphocyte Subsets

Topics: Animals; Antibodies; G(M1) Ganglioside; Graft vs Host Disease; Immunization; Intestine, Small; Lymphocyte Transfusion; Rats; Rats, Inbred Lew; Rats, Inbred Strains; Transplantation, Homologous

Topics: Animals; Antibodies, Monoclonal; Bone Marrow Transplantation; Cytotoxicity, Immunologic; G(M1) Ganglioside; Graft Survival; Graft vs Host Disease; Immunotherapy; Killer Cells, Natural; Lymphocytes; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Whole-Body Irradiation

We have recently demonstrated that high-dose IL-2, when begun on the day of bone marrow transplantation, has a potent protective effect against graft-vs.-host disease mortality, especially when coadministered with T cell-depleted syngeneic bone marrow cells. Because several groups of investigators have demonstrated that lymphokine-activated killer cells can mediate GVHD protection, we hypothesized that the mechanism of protection by IL-2 administration might involve the in vivo activation of natural killer and/or LAK cells. In order to test this hypothesis, we evaluated the effect of IL-2 administration on the number of NK1+ cells and on NK-mediated cytotoxic activity in recipients of GVHD-producing inocula. Furthermore, we evaluated the effects on IL-2-induced GVHD protection of depleting NK cells and LAK precursor cells in vivo with mAb against NK1.1 or antiserum against asialo GM1. The results demonstrate that: (1) The number of NK1+ cells is not increased in spleens of IL-2-treated compared with control recipients of GVHD-producing inocula; (2) NK activity is not increased in IL-2-treated compared with control recipients of GVHD-producing inocula during or immediately following the period of IL-2 administration; (3) depletion of NK cells and LAK precursors from the donor and host influenced the time course of GVHD-related mortality in a complex fashion; and (4) IL-2-induced GVHD protection is largely independent of the activity of an NK or LAK cell population of donor or host origin. IL-2-induced GVHD protection therefore reflects primarily the activity of non-LAK protective cell populations, or it may be a direct inhibitory effect on responding donor cell populations as they encounter host antigen.

Topics: Animals; Antibodies; Bone Marrow Transplantation; Cytotoxicity, Immunologic; Female; G(M1) Ganglioside; Graft vs Host Disease; Interleukin-2; Killer Cells, Lymphokine-Activated; Killer Cells, Natural; Leukocyte Count; Lymphocyte Depletion; Male; Mice; Mice, Inbred A; Mice, Inbred BALB C; Receptors, Antigen, T-Cell, alpha-beta; Spleen; Time Factors

Topics: Animals; Bone Marrow Transplantation; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Immunization, Passive; Immunosuppression Therapy; Lymphoid Tissue; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; T-Lymphocytes, Regulatory; Whole-Body Irradiation

In three different murine models of bone marrow (BM) transplantation the capacity of asialo GM1+ cells to suppress graft-vs-host disease (GVHD) was investigated. In a first model, total lymphoid irradiation (TLI)-treated BALB/C mice were given 1 mg of anti-asialo GM1 antibody. This led to the disappearance of functional suppressor cells after TLI. Injections of anti-asialo GM1 into TLI-treated BALB/C mice before infusion of 30 x 10(6) fully allogeneic (C3H) BM cells, led to a significantly decreased survival rate as compared to TLI-treated mice injected with control serum before BM transplantation (survival 29 and 83%, respectively, at 120 days after transplantation, p = 0.0032 log rank). The mortality of the former group was due to GVHD as 1 degree all dying animals showed clinical and histologic signs of GVHD, 2 degrees all animals were chimeric and 3 degrees mice receiving no or syngeneic BALB/C BM had excellent survival rates excluding BM aplasia or increased susceptibility for infections as reason for the mortality of the allogeneic BM recipients. In a second model, asialo GM1+ cells were removed in vitro from the C3H BM inoculum before injection into lethally irradiated (9 Gy) BALB/C recipients. In mice kept in specific pathogen-free conditions, this procedure resulted into a significant mortality (12/12) as compared to mice receiving BM pretreated with control serum (1/12, p = 0.0001 log rank). When kept in conventional housing, GVHD occurred in both groups but much earlier in the group receiving anti-asialo GM1-treated BM (median survival time 6 vs 46 days for the control mice, p = 0.001 log rank). No animal receiving anti-asialo GM1 and treated with syngeneic BM died, thus excluding toxicity, increased susceptibility to infections, or decreased graft take as a cause of mortality. In a last model, asialo GM1 cells were removed from syngeneic BM in a BM transplantation model in which T cell-depleted syngeneic (BALB/C) and non-T cell-depleted allogeneic (C3H) BM was administered to lethally irradiated (9 Gy) BALB/C mice. Also in this model GVHD-related mortality only occurred in the group of mice receiving syngeneic BM from which asialo GM+ cells were depleted before infusion (3/12). Our experiments thus clearly show that asialo GM1+ cells from both recipient (the TLI model) as well as donor origin (the TBI experiments) can suppress the occurrence of GVHD.

Topics: Animals; Bone Marrow Transplantation; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Killer Cells, Lymphokine-Activated; Killer Cells, Natural; Lymphoid Tissue; Male; Mice; Mice, Inbred BALB C; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Regulatory

In previous studies we demonstrated that an induced asialo-GM1 positive (ASGM1+) cell of donor origin that exerts natural killer cell-like activity (NK activity+) plays a crucial role in the development of graft-versus-host (GVH)-associated tissue damage and severe immunosuppression. This study examined whether the ASGM1+ (NK activity+) GVH effector cells were activated by non-specific signals or whether these cells were triggered by specific alloantigens and displayed antigenic specificity. C57B1/6 (B6) donor mice were treated with either B6 x AF1 (B6AF1) lymphoid cells and anti-asialo GM1 antibodies (anti-ASGM1) to induce and eliminate specifically activated B6-anti-B6AF1 ASGM1+ (NK activity+) cells or with polyinosinic: polycytidylic acid (poly I:C), and anti-ASGM1 to eliminate non-specifically activated ASGM1+ (NK activity+) cells. Donor spleen and lymph node cells depleted of the specific allo-induced ASGM1+ NK reactive cells showed near normal numbers of L3T4+ and Lyt-2+ cells and retained T- and B-cell functions as measured by mitogen responses (to PHA, Con A and LPS), mixed lymphocyte responses (MLR) (to B6AF1) and the generation of cytotoxic T cells (CTL) (to B6AF1 blasts). Anti-ASGM1 treatment almost completely abrogated NK activity in all donor inocula. GVH reactions were induced by injecting treated donor cells into B6AF1, B6 x C3HejF1 (B6C3HF1) and B6 x SJLF1 (B6SJLF1) hybrids and monitored by splenomegaly, suppression of T-cell mitogen responses and the development of histopathological lesions in the thymus, liver and pancreas. Cells from donors depleted of non-specifically (poly I:C) induced ASGM1+ cells induced severe histological lesions, marked immunosuppression and splenomegaly in all three F1 hybrid combinations. When the donor cells were depleted of specifically induced (B6-anti-B6AF1) ASGM1+ cells and injected into the three F1 combinations they induced splenomegaly in all three but caused severe tissue injury and intense immunosuppression only in B6C3HF1 and B6SJLF1 mice and not in B6AF1 mice. Genetic analysis suggests that the H-2D (or a closely related) region of the H-2 complex plays an important role in the activation of the specific GVH effector cells. These results suggest that the cell(s) responsible for splenomegaly are different from the ones that cause severe GVH-associated tissue damage and immunosuppression although there may be cells and/or lymphokines common to both processes.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Animals; Antibody Specificity; Cell Division; Cytotoxicity, Immunologic; Female; Flow Cytometry; Fluorescent Antibody Technique; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Immune Tolerance; Killer Cells, Natural; Lipopolysaccharides; Lymph Nodes; Lymphocyte Culture Test, Mixed; Male; Mice; Mice, Inbred C57BL; Poly I-C; Spleen

Topics: Acute Disease; Alopecia; Animals; Chronic Disease; Dermatitis; Female; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Mice; Mice, Inbred C57BL; Mice, Inbred DBA

The purpose of this study was to begin to dissect the mechanism whereby anti-asialo GM1 (alpha ASGM1) prevents otherwise lethal graft-vs-host disease (GVHD) across multiple minor histocompatibility barriers in mice. Phenotypic characterization of cells from the peak proliferative time of the graft-vs-host reaction (C57BL/6J lymph node cells----irradiated LP/J, days 5-7) revealed the alpha ASGM1 and alpha Thy 1.2 identified cells with an approximate 80% concordance and that NK-1.1 staining was negligible. Because resting T cells do not label with alpha ASGM1, the epitope recognized by alpha ASGM1 on GVHR T cells is an activation antigen. Because asialo GM1 has been previously found on the surface of activated macrophages, we wanted to distinguish between the two most likely targets for the in vivo effect of alpha ASGM1 infusions (T cells or macrophages). We compared the effects of alpha ASGM1 infusions on alloantigen-stimulated T-cell proliferation versus antigen presentation: T-cell proliferation was markedly reduced by alpha ASGM1 infusions, whereas antigen presentation function was not diminished. We conclude that the mechanism whereby alpha ASGM1 prevents GVHD does not involve NK cells or antigen presenting cells, but does involve activated donor T cells. The potential therapeutic advantage of such an antibody for use in human disorders compared to pan-immunosuppression lies in its ability to eliminate selectively those T cells involved in the immunologic process (i.e. activated T cells) while sparing the remainder of the T-cell repertoire.

Topics: Animals; Antigens, Surface; Female; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Isoantigens; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Phenotype; T-Lymphocytes

In this study anti-asialo GM1 antibodies (anti-ASGM1) were used to further characterize the effector cells responsible for graft-versus-host (GVH)-induced histopathological lesions: Two different types of ASGM1+ cells were identified: an endogenous ASGM1+ population and an induced ASGM1+ population. Both of the ASGM1+ cell populations exhibited natural killer (NK) cell activity, as assessed by their ability to lyse YAC tumor targets in vitro. Donor C57BL/6 (B6) mice were treated in vivo with anti-ASGM1 to eliminate endogenous ASGM1+ cells. ASGM1+ cells were induced in B6 donor mice by treating the animals with 15 x 10(6) B6 x AF1 (B6AF1) lymphoid cells for 44-48 hr. The induced ASGM1+ cells were eliminated by in vivo treatment with anti-ASGM1. GVH reactions were induced by injecting B6 lymphoid cells into B6AF1 mice. Prior to GVH induction the B6 donor cells were tested for NK cell activity against YAC tumor target cells in vitro and for T and B cell functions by mitogen responses in vitro. GVH reactions were determined by splenomegaly, suppression of the plaque-forming cell (PFC) response to sheep red blood cells (SRBC), suppression of the T and B cell mitogen responses, and the development of GVH-associated histopathological alterations in the thymus, liver, and pancreas. Donor lymphoid cells depleted of endogenous ASGM1+ cells were effective at inducing splenomegaly, severe suppression of immune functions, and histopathological lesions. Donor lymphoid cells depleted of both the endogenous and induced ASGM1+ cells displayed normal T cell mitogen responses and were capable of inducing splenomegaly and partial suppression of the PFC response to SRBC when injected into B6AF1 recipients, however, these lymphoid cells failed to induce both GVH-associated histopathological lesions and severe suppression of T and B cell mitogen responses. These results suggest that semiallogeneic stimulation induces an ASGM1+ population in the donor inoculum that displays NK cell-like function (YAC killing) and that plays a crucial role in inducing GVH-mediated histopathological lesions and severe immunosuppression of both T and B cell responses.

Topics: Animals; Antigens, Surface; Female; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Killer Cells, Natural; Mice; Mice, Inbred Strains; Splenomegaly

Topics: Animals; Antibodies; Cytotoxicity, Immunologic; Disease Models, Animal; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Killer Cells, Natural; Mice; Mice, Inbred CBA; Mice, Inbred Strains; Reference Values; Spleen; T-Lymphocytes, Cytotoxic

Graft-versus-host disease (GVHD) was induced in irradiated (750 rad) (CBA x C57BL/6)F1 hybrid mice by an intravenous injection of 30 x 10(6) CBA spleen cells and 5 x 10(6) syngeneic F1 bone marrow cells. The GVHD resulted in the death of 80% of recipients within 9 days. However, when radioresistant Asialo-GM1+ cells were depleted from the recipients with a single injection of anti-Asialo-GM1 antibody 2 days before irradiation and transplantation, mortality decreased significantly (to 11%). During the GVHD, anti-host specific cytotoxic T cell (CTL) activity could be shown in vitro in the spleens of mice suffering from the GVHD if suppressor activity was first abolished by in vitro culture procedures. This CTL activity, however, was not detectable in the spleens of anti-ASGM1 antibody pretreated hosts. The results indicate that radioresistant ASGM1+ cells of host origin are necessary for the induction of both anti-host CTL and lethal GVHD.

Topics: Acute Disease; Animals; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Immune Sera; Killer Cells, Natural; Lymphocyte Depletion; Mice; Mice, Inbred CBA; Species Specificity; Spleen; T-Lymphocytes, Cytotoxic

Graft-versus-host disease (GVHD) was induced in (CBA X C57BL/6) F1 mice by i.v. injection of 50 X 10(6) parental spleen cells. The GVHD induced an enhanced NK (anti-YAC-1) cytotoxicity during the first 2 weeks after the spleen cell transfusion. This cytotoxic activity was shown to be mediated by asialo GM1-positive, partially Thy-1-positive and nylon-wool (NW) non-adherent cells, thus being classical NK cells. Depletion of NK-cell activity from donor and/or recipient mice with anti-asialo GM1 antibody prior to the spleen cell transfer did not prevent the GVHD as judged by the splenomegaly assay. Also, when NK activity was potentiated with polyinosinic-polycytidylic acid (pIC), no effect on the GVHD was seen. These data suggest that NK cells are not crucial for the development of GVHD in this model.

Topics: Animals; Antibodies; Cytotoxicity, Immunologic; Disease Models, Animal; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Killer Cells, Natural; Leukocyte Count; Male; Mice; Poly I-C

In mice, as in humans, lethal graft-versus-host disease (GVHD) with skin involvement often occurs in immunoincompetent recipients of donor hematopoietic cells in spite of matching at major histocompatibility loci and nonreactivity in mixed lymphocyte culture, if donor and recipient are disparate at several minor histocompatibility loci. In mice, both death and skin disease can be prevented by the use of an antiserum containing antibodies to a cell surface glycolipid, asialo GM1 (ASGM1). Because treatment of only the recipients with anti-asialo GM1 substantially reduces the subsequent proliferation of infused donor lymphoid cells, we infer that anti-asialo GM1 interferes with a host minor-antigen-presenting cell, so that donor lymphocytes fail to see minor host antigens as immunogenic. Of the tissues examined by immunofluorescence microscopy, ASGM1 was found on the epidermal Thy-1+ dendritic cell, on dendritic cells in the thymus, and as has been previously described, on lung and spleen cells. Following the intravenous administration of anti-asialo GM1, only the spleen showed an obvious change, losing approximately 80% of its ASGM1 + cells. Further analysis of spleen cells bearing ASGM1 may better define the phenotype of the inferred minor antigen-presenting cell and lead to a method of improving the outcome of human bone marrow transplantation.

Topics: Animals; Antibodies; Cell Division; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Histocompatibility Antigens; Humans; Killer Cells, Natural; Lymphoid Tissue; Mice

Graft-vs-Host disease (GVHD) remains a devastating problem in human bone marrow transplantation (1, 2). Because removal of Thy-bearing cells from the donor inoculum has prevented GVHD in murine models (3, 4), it has been hoped that a similar cell surface antigen or combination of antigens could be found in humans. Unfortunately, treatment of human donor cells with various T cell antisera has not yet been successful in preventing GVHD (5). Encouraging results have been reported in five patients who received bone marrow depleted of T cells by the sequential use of soybean agglutinin and the differential sedimentation of cells forming rosettes with sheep red blood cells (6). Although donor T cells are thought to be necessary for initiating GVHD, the immunopathogenesis of GVHD is still not understood. Because donors and recipients are routinely major histocompatibility complex matched and chosen to be nonreactive in mixed lymphocyte cultures human GVHD is thought to result from minor histocompatibility antigen disparities. Lopez and coworkers (7, 8) found a strong association between the incidence of human GVHD and the pretransplant levels of natural killer (NK) activity of the recipients; when the recipient NK activity was low, GVHD rarely developed. They speculated that the NK cell lineage is serving as an important stimulator-inducer. We therefore examined the in vivo effects of anti-asialo GM1 on a murine model of GVHD based on minor antigen disparity. This antiserum has several immunologic effects, including a profound NK suppression. We found that the mice treated with this antibody have normal survival rates, even though they do develop histologic GVHD in the skin. This finding suggests the possibility of a new prophylactic approach to human GVHD and raises many questions regarding the function of asialo GM1-bearing cells in immune regulation.

Topics: Animals; Bone Marrow; Bone Marrow Transplantation; G(M1) Ganglioside; Glycosphingolipids; Graft vs Host Disease; Immune Sera; Killer Cells, Natural; Mice; Mice, Inbred C57BL; Minor Histocompatibility Loci; Skin; Spleen