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Biomedical subjects

A D Donnenberg

Publications and source records attributed to A D Donnenberg.

At least 55 records · Page 3Linked to original sources
PubMed1992

Pathogenesis of acute infection in rhesus macaques with a lymphocyte-tropic strain of simian immunodeficiency virus.

The simian immunodeficiency virus, SIVmac, causes disease affecting multiple organ systems in macaques similar to human immunodeficiency virus infection in humans. Molecularly cloned SIVmac with a strong lymphocyte tropism was used in pathogenesis experiments to correlate viral cell tropism with disease. In 5 animals, exhaustive analyses on viruses from tissues and identification of infected precursor cells were done at multiple times during infection to ensure the virus had not mutated into a macrophage-tropic variant. Viral replication was measured by infectivity, infectious center assays, and in situ hybridization. Lymphocytes produced most virus in tissues, indicating the virus maintained its cell tropism in vivo. Lymphocytes in bone marrow were latently infected and those in the spleen and lymph nodes were productively infected. The virus failed to replicate in the brain after intracerebral inoculation. SIVmac that maintained a strong tropism for lymphocytes and a corresponding poor tropism for macrophages can cause persistent infection and AIDS but not other diseases such as primary pneumonia and encephalitis in rhesus macaques.

Acute Disease↗
PubMed1992

Clinical, laboratory, and histopathologic indicators of the development of progressive acute graft-versus-host disease.

Graft-versus-host disease (GvHD) is the major cause of morbidity and mortality following bone marrow transplantation (BMT). The goal of this study of 69 cyclosporin-treated, allogeneic BMT patients was to identify early clinical, laboratory, or histopathologic indicators of the development of progressive, fatal GvHD. Peak values within 100 d of allogeneic BMT for total bilirubin, stool volume in a day, clinical stage of cutaneous GvHD (based on extent of rash), and overall clinical stage of GvHD (based on a combination of graft-versus-host reactions in the skin, liver, and gastrointestinal tract) were most useful (p less than 0.05, by logistic regression) in identifying those patients with clinically progressive and fatal GvHD. Peak values for each of these parameters were reached an average of 40 d or less after BMT. Each unit increase in peak clinical stage of rash (e.g., stage 2 versus stage 3) was associated with an odds ratio incremental risk of 5.8 for clinical progression of GvHD, and each tenfold increase in peak total bilirubin (e.g., 2 mg/dl versus 20 mg/dl) or stool output in a day (e.g., 100 cm3/d versus 1000 cm3/d) was associated with an incremental risk of 8.4 and 10.6, respectively, for a fatal outcome from GvHD. Number of exocytosed lymphocytes and dyskeratotic epidermal keratinocytes (DEK) per linear millimeter of epidermis, the presence of follicular involvement, and the degree of dermal perivascular lymphocytic infiltration in 121 skin biopsy specimens were not associated with the development of progressive or fatal GvHD. Pretransplant total body irradiation was associated (p = 0.03, by Mann-Whitney U testing) with an increased number of DEK in skin biopsy specimens taken less than 20 d after BMT. This study demonstrates that monitoring of total bilirubin, stool output, extent of rash, and overall clinical stage of GvHD is most useful during the first 40 d after BMT in formulating the prognosis of early acute GvHD in allogeneic BMT patients receiving cyclosporin.

Acute Disease↗
PubMed1992

Effect of donor and recipient immunization protocols on primary and secondary human antibody responses in SCID mice reconstituted with human peripheral blood mononuclear cells.

We have examined the ability of mice with severe combined immunodeficiency (SCID mice) reconstituted with human peripheral blood mononuclear cells (PBMC) to generate human antibody responses after specific immunization. SCID mice reconstituted with cells from a keyhole limpet hemocyanin (KLH)-naive donor are unable to generate specific human antibody responses after immunization with that antigen. After KLH immunization, SCID mouse recipients of human PBMC from a KLH-immune subject develop specific human antibody levels exceeding those of the donor. Human antitetanus antibody titers in reconstituted, immunized mice are also equivalent to those of the donor, provided that the mice are immunized within days of human cell transplantation. The ability of reconstituted mice to generate high titers of specific human antibody is lost within 35 days of human cell reconstitution, even though titers of total human immunoglobulin (Ig) are preserved. SCID mice reconstituted with tetanus-immune donor cells fail to generate IgA responses after booster immunization, and IgM responses are low or nonexistent. These data indicate that early exposure of the adoptive recipients of human cells to antigen is required to transfer specific human humoral responses. These findings are also consistent with a requirement for persistence of antigen for the maintenance of B-cell memory. The ability to achieve specific human antibody levels equivalent to those obtained with humans indicates that reconstituted mice may be useful for the evaluation of human antibody-mediated mechanisms of resistance to infection. The data indicate, however, that cells from immunized donors will have to be used for such studies.

Animals↗
PubMed1991

Recovery of the simian immunodeficiency virus (SIV) and depression of colony formation in in vitro infected progenitor cell-enriched rhesus bone marrow (BM).

Rhesus progenitor-enriched BM was exposed overnight to SIV and cultured in a limiting dilution assay where the potential for progenitor interaction with lymphocytes or macrophages was low. Virus was consistently isolated late in culture, detection being aided by coculture with CEM174 lymphoblasts. Although infected cells had reduced clonogenic activity, colonies were indistinguishable from those derived from uninfected BM with respect to proliferative potential, morphology, and longevity in culture. Primate immunodeficiency viruses, therefore, may infect immature BM populations, directly affecting hematopoietic activity.

Animals↗
PubMed1990

Isolation of cell cycle fractions by counterflow centrifugal elutriation.

Counterflow centrifugal elutriation (CCE) has been used to fractionate cell populations on the basis of sedimentation properties, with minimal perturbation of metabolic function. Therefore, it is an ideal method for the isolation of cell cycle phase specific populations. We present modifications of the standard Beckman centrifugal elutriation system which permit standardization of the elutriation procedure and eliminate inter-run variability. We provide elutriation parameters for the cell cycle fractionation of a variety of cultured cell lines and suggest ways to improve the quality of the cell separations. In addition, we describe protocols for the fractionation of up to 3.50 X 10(8) cells in the small (JE-6B) Beckman elutriation system. This represents a four- to eight-fold increase in cell numbers over current cell fractionation procedures. Cell cycle populations containing greater than 95% G1, greater than 80% S, and greater than 70% G2/M were consistently obtained using these protocols. Finally, we analyzed phase-enriched fractions from several cultured cell lines for the cell cycle regulation of the enzyme thymidine kinase. The data confirm previous findings that CCE is an excellent means of obtaining physiologically unperturbed cell cycle phase specific fractions.

Animals↗
PubMed1990

Reconstitution of antibody response after allogeneic bone marrow transplantation: effect of lymphocyte depletion by counterflow centrifugal elutriation on the expression of hemagglutinins.

The generation of ABO hemagglutinins was used as a model to assess the tempo of reconstitution of antibody responses in recipients of elutriated (CCE) and nonelutriated (nonCCE) HLA matched bone marrow allografts. The study included 29 CCE recipients (10 major, 6 minor, and 1 major/minor ABO-mismatched, and 12 ABO-matched) and 40 nonCCE recipients (14 major, 12 minor, 2 major/minor, and 12 matched). Plasma volume in the graft and in blood product transfusions was uncorrelated with changes in hemagglutinin titers and therefore was excluded as a significant source of antibody. Removal of graft lymphocytes by CCE did not result in prolongation of host-derived hemagglutinins in recipients of major ABO-mismatched grafts. However, CCE resulted in a complete abrogation of the adoptive transfer of donor-derived antibody as detected in recipients of minor ABO-mismatched grafts. Despite the absence of adoptively transferred donor immunity in recipients of CCE grafts, they had hemagglutinin levels comparable with those of recipients of nonCCE grafts by 6 months after transplantation. This demonstrates that recipients of elutriated marrow were competent to mount de novo responses at that time. The strong correlation between donor pretransplant hemagglutinin titer and recipient titer 1 year after bone marrow transplantation in recipients of nonCCE grafts suggests that even late after transplant, antibody remains the product of adoptively transferred memory cells in recipients of grafts containing large numbers of mature lymphocytes.

ABO Blood-Group System↗
PubMed1990

Bone marrow graft engineering by counterflow centrifugal elutriation: results of a phase I-II clinical trial.

In an attempt to reduce the incidence and severity of acute graft-versus-host disease (GVHD), we have decreased the number of bone marrow (BM) lymphocytes in the donor marrow graft before bone marrow transplantation (BMT) using counterflow centrifugal elutriation (CCE). In a phase I-II clinical trial, 23 patients received lymphocyte-depleted BM allografts from their HLA-identical, mixed lymphocyte culture (MLC)-nonreactive sibling donors. The patients entered in the study were deemed to be at high risk for treatment failure on the basis of age (greater than 30 years; median, 39 years) and the result of our skin explant assay predictive of acute GVHD. Patients predicted not to develop acute GVHD by this assay were excluded from this study. All patients received a standard lymphocyte dose of 0.5 x 10(6) morphologic lymphocytes per kilogram ideal body weight (IBW) in the marrow graft and were maintained on cyclosporine A (CsA) immunosuppression for 170 days after BMT. Prompt hematopoietic recovery occurred in 22 of 23 patients with a median time to an absolute neutrophil count (ANC) greater than or equal to 500/microL of 21 days. Donor cell engraftment was subsequently verified by cytogenetic and/or DNA analysis in all of 21 evaluable patients. No patient developed systemic acute GVHD. Only five (22%) developed cutaneous GVHD (clinical stage 1) that required steroid treatment, including one patient who failed to engraft. The median follow-up of the patients enrolled in this study is 14 months (range, 5 to 20 months). Actuarial survival 1 year after BMT is 83%. Thus, in two consecutive clinical trials using CCE to deplete donor BM of alloreactive lymphocytes (1.0 x 10(6) versus 0.5 x 10(6) lymphocytes/kg), we have demonstrated that the procedure does not interfere with BM engraftment and is effective in decreasing the incidence and severity of acute GVHD. Furthermore, comparison of these studies has revealed a differential dose response relationship between the number of graft lymphocytes, protection of engraftment, and induction of acute GVHD. Although there appears to be a modest relationship between lymphocyte dose and time to hematopoietic recovery, the 50% reduction in lymphocyte dose from that used in our previous trial resulted in a marked decrease in acute GVHD without compromising engraftment.

Adult↗
PubMed1990

Using elutriation to engineer bone marrow allografts.

We have used elutriation to deplete lymphocytes from the marrow allografts of 64 patients to date. The first phase I trial (1 x 10(6) lymphocytes/kg IBW) was designed to test the procedure for potential toxicities, most notably, graft failure. Study 2 (1 x 10(6) lymphocytes/kg, no CsA) was expected to reduce potential toxicity incurred from long term immunoprophylaxis while study 3 was aimed at reducing the incidence of GVHD by further reducing lymphocyte dose (5 x 10(5)/kg). Graft lymphocyte dose was based on morphologic determination and was subsequently confirmed by limiting dilution analysis and flow cytometry. Although grafts were standardized solely by lymphocyte dose, the product was more uniform than the original harvested BM with respect to other cell populations. Nearly all study I (n = 40) and study III (n = 20) patients engrafted with a median time to ANC greater than 500/ul of 19 days. Three of the 4 patients consecutively enrolled in study II failed to engraft, thus terminating the trial. While a moderate proportion of study I patients had AGVHD (44%) with attendant morbidity, only 20% of study III patients were found to have mild AGVHD (less than or equal to stage I). To date, this cohort has no organ or chronic GVHD and no GVHD-associated morbidity. Median follow-up times for patients in studies I and III are 27 and 11 months, respectively. Overall actuarial survival (n = 60) is 42% at 38 months (38% study I, 80% study III). Good prognosis study I patients experienced 45% actuarial survival versus 9% in the poor prognostic group. While lymphocyte depletion has been effective in reducing the incidence and severity of AGVHD, new strategies are needed to address the issue of disease relapse. As with other methods, lymphocyte depletion by elutriation caused an increased rate of leukemia relapse. The actuarial probability of remaining in remission for recipients of elutriated marrow containing 1 x 10(6) and 5 x 10(5) lymphocytes/kg, respectively, were 60% and 46% at 16 months. Elutriation provides a rapid, reproducible and flexible methodology for graft manipulation which has been effective in reducing the incidence and severity of AGVHD. However, if lymphocyte depletion is to fulfill its promise as a means of reducing the overall morbidity of allogeneic BMT, new strategies may be needed to address the issue of relapse. These may include changes in marrow ablative therapy and post-graft immunosuppression. Equally as important may be the ability to further manipulate accessory cells and lymphoid populations presently excluded from the graft.

Adult↗
PubMed1990

Elutriation of bone marrow delineates two distinct natural suppressor cell populations.

It appears that part of the confusion surrounding the lineage of NS cells could be due, in part, to the presence of more than one cell population in normal BM. Whether other cell populations exist in other organ compartments, or can be induced, is presently unknown. This is of particular interest in allogeneic BMT where various lymphocyte depletion techniques have been employed to reduce the incidence of AGVHD. When CCE is used for depletion, the NS lymphocyte component is entirely removed. Since the incidence of AGVHD is significantly reduced with CCE lymphocyte-depleted rat and human BM, it appears that this subpopulation need not be present to abrogate AGVHD. Quite surprisingly, preliminary studies in rats indicates that this lymphocyte subpopulation may actually induce acute syngeneic GVHD (Fischer et al., 1989). That a cell(s) in the clonogenic compartment has the ability to suppress or down-regulate a variety of immune responses is not altogether surprising. This cell is better thought of as an auto-regulatory cell which has the ability to control the cellular interactions in its immediate micro-environment. Indeed, R/O NSCA can be augmented by GM-CSF, IL-3, and CsA (NoGa et al., 1988a). In vitro, this cell differentiates into the mono-myeloid series using a variety of stimulatory agents and can acquire tumoricidal activity. The ability to express NSCA is lost however, being present only during a brief window of early maturation. Only IL-3 can sustain NSCA in culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1989

Allogeneic bone marrow transplantation, zidovudine, and human immunodeficiency virus type 1 (HIV-1) infection. Studies in a patient with non-Hodgkin lymphoma.

Human immunodeficiency virus type 1 (HIV-1)-infected patients with non-Hodgkin lymphoma are classified as having the acquired immunodeficiency syndrome (AIDS). Allogeneic bone marrow transplantation is a successful therapy for patients with lymphoma who have a poor prognosis. Combined therapy with allogeneic bone marrow transplantation and the antiviral drug zidovudine has the potential advantage of protecting the new donor hematopoietic-lymphoid and monocyte-macrophage cells from HIV-1 infection. A 41-year-old man infected with HIV-1 who had lymphoma was treated with high-dose cyclophosphamide and total body irradiation followed by allogeneic bone marrow transplantation. Before transplantation he received high-dose zidovudine for 2 weeks (5 mg/kg body weight intravenously every 4 hours) and after transplantation he received a lower maintenance dose (1.33 mg/kg body weight intravenously every 4 hours). No untoward toxicities attributable to zidovudine were observed. Bone marrow engraftment occurred on day 17. Chromosome and restriction fragment length polymorphism analyses demonstrated complete chimerism. Peripheral blood mononuclear cells and bone marrow samples were negative for HIV-1 by culture and polymerase chain reaction gene amplification 32 days after transplantation. The patient died 47 days after transplantation because of tumor relapse. Analysis of autopsy tissue showed no evidence of HIV-1 by either culture (brain, bone marrow, lymph node, and tumor specimens) or by polymerase chain reaction gene amplification for HIV-1 RNA and DNA sequences (brain, bone marrow, heart, kidney, liver, lung, rectosigmoid, spleen, and tumor specimens). Immunologic monitoring showed loss of HIV-1 antibody. Adoptive immunologic transfer was shown to be present to both tetanus and diphtheria antigens. Our case suggests that the HIV-1-infected recipient cells may have been eradicated secondary to the bone marrow ablative chemo-radiotherapy and that zidovudine may be able to prevent the establishment of HIV-1 infection in donor hematopoietic-lymphoid cells.

Adult↗
PubMed1989

Qa-2 expression in the adult murine thymus. A unique marker for a mature thymic subset.

The MHC Ag, Qa-2, is expressed on all peripheral T cells, a subset of bone marrow cells, and to a lesser extent on B cells. The Qa-2 Ag is also expressed on 5 to 6% of normal adult murine thymocytes. Through the use of flow cytometry, counterflow centrifugal elutriation and acridine orange staining, we have analyzed the cell surface phenotype, cell size, and cell cycle status of this thymic population. Our studies indicate that Qa-2+ thymocytes are large, non-mitotic, G1 cells which have the cell surface phenotype of CD5+, CD3+, J11dLO and lack receptors for peanut agglutinin. This population can be further subdivided into three categories; CD4+/CD8-, CD4-/CD8+, and CD4-/CD8-. These data indicate that Qa-2 surface expression can only be detected on thymocytes in the final stages of differentiation. The Qa-2 Ag can be used as a cell surface marker to identify a unique subset of mature thymocytes.

Animals↗
PubMed1989

Limiting dilution analysis of in vivo-activated (IL-2 responsive) peripheral blood lymphocytes in HIV-1-infected subjects.

The progression of infection with human immunodeficiency virus, type 1 (HIV-1), is associated with a loss of helper T cell function, but the mechanism for this loss (e.g., decreased absolute number of helper cells, altered function of helper cells, or both) has not been delineated. Many studies have suggested that T-cell production of and/or responsiveness to the T cell growth factor interleukin-2 (IL-2) declines over the course of HIV-1 infection. Using a highly quantitative 6-day limiting dilution assay (LDA), we investigated whether the number and the proliferative capacity of circulating IL-2 responsive cells in patients with AIDS differ from those in patients in earlier stages of HIV-1 infection (asymptomatic or AIDS-related complex) and healthy seronegative individuals. The frequency of IL-2 responsive cells declined progressively in asymptomatic seropositive subjects, those with ARC, and those with AIDS. In contrast, the proliferative capacity of individual IL-2 responsive cells, as reflected by the magnitude of thymidine uptake per precursor, was reduced only in patients with frank AIDS and was normal in asymptomatic subjects and in those with ARC. These results suggest that the development of AIDS in the setting of HIV-1 infection may reflect a combination of qualitative as well as quantitative changes in lymphocyte function. They also suggest that analysis of lymphocyte responsiveness to IL-2 may provide a useful approach to prediction of the development of AIDS in individuals infected with HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Characterization of the natural suppressor cell population in adult rat bone marrow.

Natural suppressor cell activity (NSCA) has been ascribed to a subset of cells present in human and murine hematopoietic tissues which can suppress a variety of lymphocyte responses without MHC restriction. We investigated NSCA in lymphocyte-depleted rat bone marrow (BM) which is used as a model for prevention of graft vs host disease (GVHD) following allogeneic BM transplantation (BMT). The T-cell depleted fraction obtained after elutriation contained higher levels of NSCA than the unseparated BM. Further separation of this graft fraction by discontinuous Percoll gradient centrifugation revealed high levels of radiosensitive NSCA in the low density (less than 1.070) fraction which represented 0.5% of the original BM population. These cells were of blast morphology, stained intensely with a dansylated derivative of cyclosporine A (dans CsA) and weakly expressed macrophage/granulocyte antigens and non-specific esterase (NSE). These cells were initially non-adherent but proliferated in culture to produce intensely NSE positive, adherent, phagocytic cells of macrophage morphology. We conclude that the highly suppressive, radiosensitive cell present in rat BM may be of early progenitor or monocyte lineage. The grafting of natural suppressor (NS) cells and progenitor cells may affect graft/host immunoregulation and their characterization may provide insight into GVH biology and graft rejection.

Animals↗
PubMed1988

Selective differentiation and proliferation of hematopoietic cells induced by recombinant human interleukins.

Effects of recombinant human interleukins on hematopoiesis were explored by using suspension cultures of mononuclear cells of human umbilical-cord blood and bone marrow. The results showed that interleukin 5 induced the selective differentiation and proliferation of eosinophils. After 3 weeks in culture with interleukin 5, essentially all nonadherent cells in both bone marrow and cord blood cell cultures became eosinophilic myelocytes. Culture of the same cells with interleukin 4 resulted in the selective growth of OKT3+ lymphocytes. However, OKT3+ cells did not develop if the bone marrow cells were depleted of OKT3+/OKT11+ cells prior to the culture, indicating that interleukin 4 induced the proliferation of a subpopulation of resting T cells present in cord blood and bone marrow cell preparations. In suspension cultures of bone marrow cells and cord blood cells grown in the presence of interleukin 3, basophilic, eosinophilic, and neutrophilic myelocytes and macrophages developed within 2 weeks. By 3 weeks, however, the majority of nonadherent cells became eosinophilic myelocytes. In contrast to mouse bone marrow cell cultures, neither interleukin 3 nor a combination of interleukins 3 and 4 induced the differentiation of mast cells in human bone marrow or cord blood cell cultures.

Bone Marrow Cells↗
PubMed1988

Immunoglobulin E levels following allogeneic, autologous, and syngeneic bone marrow transplantation: an indirect association between hyperproduction and acute graft-v-host disease in allogeneic BMT.

Markedly elevated serum IgE levels have been noted following allogeneic bone marrow transplantation (BMT) and have been correlated with graft-v-host disease (GVHD) in several studies. To investigate this phenomenon, we measured serum IgE levels in 387 allogeneic, 143 autologous, and 21 syngeneic BMT recipients before and at intervals after BMT. As a population, allogeneic BMT recipients displayed a biphasic elevation in IgE levels, with peak levels occurring either early (days 15 to 19) or late (days 80 to 89) posttransplant. Only in individuals in whom peak levels occurred early did IgE level correlate with liver disease, histological changes, and overall clinical stage of GVHD. The association of IgE elevation and GVHD does not appear to be direct since recipients of syngeneic (monozygotic twin) grafts had the highest incidence of IgE hyperresponsiveness as well as the highest absolute IgE levels. Similarly, 22 recipients of autologous marrow not treated with 4-hydroperoxycyclophosphamide had elevated IgE levels comparable to those seen in allogeneic graft recipients. We hypothesize that augmented IgE synthesis and its subsequent resolution is the natural consequence of immune reconstitution in the presence of potentially reaginic agents such as antibiotics and infectious agents. As such, IgE hyperresponsiveness in syngeneic graft recipients may reflect the maturational sequence of IgE regulatory elements in the absence of interference by GVHD, GVHD therapy, or minor histocompatibility disparities. The cell populations required for IgE response (T cells, B cells, and antigen-presenting cells) may be reconstituted in advance of the regulatory elements that limit IgE production in healthy subjects. Although this temporal relationship does not appear to hold in allogeneic BMT, the balance between positive and negative factors, which determines the rates of IgE synthesis and catabolism, may be altered by GVHD, infection, and liver dysfunction acting alone or in combination.

Alanine Transaminase↗
PubMed1988

Lymphocyte depletion of donor bone marrow by counterflow centrifugal elutriation: results of a phase I clinical trial.

We report here the results of a phase I clinical trial using counterflow centrifugal elutriation (CCE) for the removal of donor T lymphocytes before allogeneic bone marrow transplantation (BMT). Thirty-eight patients received lymphocyte-depleted allografts from HLA-identical, MLR-nonreactive sibling donors. The patients entered onto the study were either at high risk on the basis of age (median, 39 years) or disease status (acute leukemia in early relapse [ER], chronic myelogenous leukemia [CML] in accelerated phase [AP], or therapy resistant [RES] lymphoma). All patients received a standard lymphocyte dose of 1 x 10(6) morphologic lymphocytes per kilogram ideal body weight (BW) and were maintained on cyclosporine A (CsA) for 170 days after BMT. Prompt engraftment occurred in 37 of 38 patients with a median time to absolute neutrophil count (ANC) greater than 500/microL of 18 days. Although acute graft-v-host disease (GVHD; clinical stage I or greater) was observed in 45%, it was limited to the skin in all but five patients. Survival was related to disease status at the time of BMT. Among patients with acute leukemia in first or second remission, CML in chronic phase (CP) or lymphoma in partial remission (PR), 64% are currently alive, in contrast to 31% of patients with acute leukemia in third remission or early relapse, CML in second CP or AP, or RES lymphoma. Median follow-up for all patients was 351 days (range, 105 to 711 days). We conclude that this procedure is safe and warrants further evaluation in a randomized efficacy trial.

Acute Disease↗
PubMed1988

Separation of rat bone marrow cells by counterflow centrifugal elutriation: a model for studying the effects of lymphocyte depletion.

We have developed a simple three flow-rate, fixed rotor speed, counterflow centrifugal elutriation (CCE) procedure that permits the isolation of an engraftable lymphocyte-depleted (greater than 98%) fraction from ACI rat bone marrow. The different cell fractions were characterized by morphology, alloreactivity in mixed lymphocyte culture and limiting dilution analysis, colony-forming capacity, and their capacity to reconstitute hematopoiesis and effect a graft-versus-host reaction in lethally irradiated allogeneic hosts. After CCE fractionation of ACI rat marrow, transplantation of the lymphocyte-depleted marrow fraction resulted in sustained engraftment without evidence of clinical or histologic acute graft-versus-host disease (GVHD). CCE fractionation of rat bone marrow may be a useful preclinical model for studying lympho-hematopoietic and immune reconstitution after transplantation with lymphocyte-depleted donor marrow, as well as for studying the role of lymphocyte subpopulations on engraftment, acute GVHD, and leukemia relapse in syngeneic and allogeneic bone marrow transplantation.

Animals↗