Successful prevention of autoimmune disease by transplantation of adequate number of fully allogeneic hematopoietic stem cells

Allogenic hematopoietic stem cell transplantation in pemphigus vulgaris: a single-center experience

Background:

Pemphigus vulgaris (PV), an autoimmune disorder characterized by blistering skin/mucus membrane lesions, is mediated by desmoglein-3 autoantibodies. We carried out a prospective clinical trial of hematopoietic stem cell transplantation (HSCT) in thymus, bone marrow (BM) and periphery to reconstitute central and peripheral arms of self-tolerance.

Materials and Methods:

Eleven (M:F=5:6) patients with mean age 33.5 years and mean duration of disease 22.8 months, having painful pruritic blisters and ulcers resistant to corticosteroids, were treated with cytokine-stimulated allogeneic HSCT (mean dose: 21.8 × 10⁸ cells/kg BW) from blood group-matched related donors. BM with mean CD34+ count 1.1% was inoculated into thymus, marrow and periphery, followed by two peripheral blood stem cell (PBSC) infusions.

Results:

Recovery began within 24 hours of HSCT and new lesions stopped after 6 months. No graft versus host disease (GvHD)/adverse effect was observed in any patient/donor. Over a mean follow-up of 8.02 years, all patients were well without recurrence/new lesions.

Conclusion:

Drug-resistant PV can be successfully and safely treated by allogeneic HSCT.

Autoimmune disease: is it a disorder of the microenvironment?

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disease that involves several vital organs including the cardiovascular system, joints, and kidneys. The pathology is characterized by accumulation of autoreactive lymphocytes that attack the patients' own tissues, secretion of autoantibodies and deposition of immune complexes in vital organs. Chronic widespread inflammation is the hallmark of SLE and the target of current therapy. According to recent theories, intonating immune circuits of inflammatory cytokines and immune cells constitute highly specialized targets for SLE therapy, which nonetheless consists for the most part of anti-inflammatory medications and cytotoxic drugs. For advanced autoimmune disorders, cell therapy aiming at introducing "healthy" stem cells has been promising, keeping in mind that in its current state, stem cell therapy is reserved for the most advanced diseases refractory to traditional therapy. Ongoing studies in our laboratories examined the role of the bone marrow microenvironment, in particular, mesenchymal stem cells (MSCs) in the etiopathogenesis of SLE. Specifically, we are testing the hypothesis that, in human SLE mouse model, marrow MSCs are defective structurally and functionally. Preliminary data indicate that structural and functional defects in MSC population from an autoimmune mouse model for human SLE may contribute to this pathology and consequently present a target for cell therapy.

Reversal of autoimmune disease in lupus-prone New Zealand black/New Zealand white mice by nonmyeloablative transplantation of purified allogeneic hematopoietic stem cells

Patients with severe systemic lupus erythematosus (SLE) refractory to conventional treatment are candidates for autologous hematopoietic stem cell (HSC) transplantation if the intent is to reset the immunologic clock. These patients might be candidates for allotransplantation with (SLE)-resistant major histocompatibility complex (MHC) haplotype-matched HSC if partial or complete replacement of an autoimmune-prone system is the intent. Using lupus-prone New Zealand black x New Zealand white (NZBW) mice, we investigated the use of highly enriched, haplomismatched, allogeneic HSC to prevent development of or to treat established autoimmune pathology. Young NZBW mice receiving purified allogeneic HSC transplants had improved survival, decreased proteinuria, circulating immune complexes, and autoantibodies to nuclear antigens than did untreated mice or mice given NZBW HSCs. NZBW mice with established lupus-like disease that received nonmyeloablative conditioning and transplants of (MHC) haplomismatched allogeneic HSCs also had greatly increased overall survival. Mice that received transplants exhibited stabilization or reversal of their lupus symptoms; stabilized or decreased proteinuria, and a lower frequency of elevated circulating immune complexes or autoantibodies than did control mice. Induction of durable mixed chimerism by transplantation of purified allogeneic HSCs after nonmyeloablative conditioning has the potential to reverse symptoms of established NZBW lupus.

Hematopoietic Stem Cell Transplantation in Autoimmune Diseases: The Ahmedabad Experience

INTRODUCTION

Autoimmune disease represents a (AD) breakdown of natural tolerance against autoreactive antigens leading to a high mortality and morbidity. The reaction is usually polyclonal; T- and B-cell components of the hematopoietic system are responsible for disease progression. Allogeneic/autologous hematopoietic stem cell transplantation (HSCT) are the current modalities for treating drug-resistant AD.

PATIENTS AND METHODS

We present a single-center retrospective evaluation of allogeneic HSCT with nonmyeloablative, low-intensity conditioning in nine patients (five males, four females) with pemphigus vulgaris (PV) and 27 patients with systemic lupus erythematosus (SLE; 3 males, 24 females). The mean follow-up period was 4.24 years for PV and 4.9 years for SLE. Cytokine-mobilized HSC from unmatched related donors, with mean dose of 21.3 x 10(8) nucleated cells/kg body weight (BW; mean CD34(+) count, 6 x 10(6)/kg BW) was administered in to the thymus as well as the portal and peripheral circulations of recipients. Cyclosporine (4 +/- 1 mg/kg BW per day) and prednisolone (10 mg/kg BW per day) were administered for 6 months to protect mixed chimerism. A subset of patients with cross-gender donors were analyzed for peripheral blood chimerism at 1 month post-HSCT and every 3 months thereafter.

RESULTS

Sustained clinical remission with peripheral lymphohematopoietic chimerism of 0.7 +/- 0.3% was observed in PV, whereas SLE relapsed after mean of 7.35 months of disease-free interval associated with fall in chimerism from 5 +/- 3% to < or =0.08 +/- 0.03%.

CONCLUSION

HSCT was effective to achieve early clinical remission of PV; and in SLE relapsed after a 7.35-month disease-free interval accompanied by a fall in mixed lymphohematopoietic chimerism.

Mesenchymal stem cells in autoimmune disease

Autoimmune diseases afflict more than 3% of the U.S. population. Current therapy for mild to moderate cases is symptomatic, however advanced cases suffer high morbidity and mortality. Advanced patients have benefited from stem cell therapy in the form of bone marrow transplantation in conjunction with high-dose cytotoxic therapy. Broader application of stem cell therapy requires better understanding of how adult stem cells affect development and foster treatment of autoimmune pathologies, and of better ways to manipulate the host immune responses. While extensive research documents the role of hematopoietic stem cells (HSCs) in autoimmune disease, few studies have addressed if and how mesenchymal stem cells (MSCs) contribute to their etiopathology. Recent characterization of MSCs and their role in hematopoiesis and immune modulation suggest that their potential for cell therapy extends beyond their traditional accessory function in HSC engraftment. MSCs contribute significantly to tissue restructuring and immune functioning, in addition to facilitating durable, long-lasting stem cell engraftment. MSCs are relatively easy to obtain and expand in in vitro cultures, rendering them a prime candidate for genetic manipulations for stem cell therapy. They have the potential to differentiate into multiple lineages such as osteoblasts, adipose tissue, cartilage, tendon, and stromal cells. The role of MSCs for autoimmune disease therapy could thus be based both on immune function modulation and contribution to hematopoiesis. In this review, we examine the biology of MSCs, and their potential for cell therapy of autoimmune disease.

Transplanted bone marrow cells repair heart tissue and reduce myocarditis in chronic chagasic mice

A progressive destruction of the myocardium occurs in approximately 30% of Trypanosoma cruzi-infected individuals, causing chronic chagasic cardiomyopathy, a disease so far without effective treatment. Syngeneic bone marrow cell transplantation has been shown to cause repair and improvement of heart function in a number of studies in patients and animal models of ischemic cardiopathy. The effects of bone marrow transplant in a mouse model of chronic chagasic cardiomyopathy, in the presence of the disease causal agent, ie, the T. cruzi, are described herein. Bone marrow cells injected intravenously into chronic chagasic mice migrated to the heart and caused a significant reduction in the inflammatory infiltrates and in the interstitial fibrosis characteristics of chronic chagasic cardiomyopathy. The beneficial effects were observed up to 6 months after bone marrow cell transplantation. A massive apoptosis of myocardial inflammatory cells was observed after the therapy with bone marrow cells. Transplanted bone marrow cells obtained from chagasic mice and from normal mice had similar effects in terms of mediating chagasic heart repair. These results show that bone marrow cell transplantation is effective for treatment of chronic chagasic myocarditis and indicate that autologous bone marrow transplant may be used as an efficient therapy for patients with chronic chagasic cardiomyopathy.

Transfer of hematopoietic stem cells encoding autoantigen prevents autoimmune diabetes

Bone marrow or hematopoietic stem cell transplantation is a potential treatment for autoimmune disease. The clinical application of this approach is, however, limited by the risks associated with allogeneic transplantation. In contrast, syngeneic transplantation would be safe and have wide clinical application. Because T cell tolerance can be induced by presenting antigen on resting antigen-presenting cells (APCs), we reasoned that hematopoietic stem cells engineered to express autoantigen in resting APCs could be used to prevent autoimmune disease. Proinsulin is a major autoantigen associated with pancreatic beta cell destruction in humans with type 1 diabetes (T1D) and in autoimmune NOD mice. Here, we demonstrate that syngeneic transplantation of hematopoietic stem cells encoding proinsulin transgenically targeted to APCs totally prevents the development of spontaneous autoimmune diabetes in NOD mice. This antigen-specific immunotherapeutic strategy could be applied to prevent T1D and other autoimmune diseases in humans.

Mixed bone marrow or mixed stem cell transplantation for prevention or treatment of lupus-like diseases in mice

Scientific analyses fortified by interpretations of immunodeficiency diseases as 'experiments of nature' have revealed the specific immune systems to be comprised of T cells subserving cell-mediated immunities plus B cells and plasma cells which produce and secrete antibodies. These two separate cellular systems regularly interact with each other to produce a coordinated defense which permits mammals to live within a sea of microorganisms that threaten the integrity and the survival of individuals. We have shown that bone marrow transplantation (BMT) can be used as a form of cellular engineering to construct or reconstruct the immune systems and cure otherwise fatal severe combined immunodeficiency. When severe aplastic anemia complicated the first BMT which was performed to cure a fatal severe combined immunodeficiency, a second BMT cured for the first time a complicating severe aplastic anemia. Subsequently, BMT has been used effectively to treat some 75 otherwise fatal diseases such as resistant leukemias, lymphomas, inborn errors of metabolism, and genetic anomalies of the hematopoietic development such as sickle cell anemia, thalassemia, congenital neutropenias, and many other diseases. More recently, we have employed BMT in mice both to cure and cause autoimmunities, and, together, these experiments showed that autoimmunities actually reside in the hematopoietic stem cells. We have also found that mixed BMT or mixed hematopoietic stem cell transplantation (HSCT) can be used to prevent and cure the most complex autoimmunities such as those occurring in BXSB mice and in (NZW x BXSB)F1 W/BF1 mice. Untreated, the former develop fulminating lethal glomerulonephritis plus numerous humoral autoimmunities. Mice of the (W/B)F1 strain develop autoimmune thrombocytopenic purpura, coronary vascular disease with myocardial infarction, glomerulonephritis, and numerous autoantibodies. All of these abnormalities are prevented or cured by mixed syngeneic (autoimmune) plus allogeneic (normal healthy) BMT or mixed peripheral blood HSCT. Thus, the most complex autoimmune diseases can be prevented or cured in experimental animals by mixed syngeneic plus allogeneic BMT or HSCT which produce stable mixed chimerism as a form of cellular engineering.

Induction of tolerance in autoimmune diseases by hematopoietic stem cell transplantation: getting closer to a cure?

Hematopoietic stem cells (HSCs) are the earliest cells of the immune system, giving rise to B and T lymphocytes, monocytes, tissue macrophages, and dendritic cells. In animal models, adoptive transfer of HSCs, depending on circumstances, may cause, prevent, or cure autoimmune diseases. Clinical trials have reported early remission of otherwise refractory autoimmune disorders after either autologous or allogeneic hematopoietic stem cell transplantation (HSCT). By percentage of transplantations performed, autoimmune diseases are the most rapidly expanding indication for stem cell transplantation. Although numerous editorials or commentaries have been previously published, no prior review has focused on the immunology of transplantation tolerance or development of phase 3 autoimmune HSCT trials. Results from current trials suggest that mobilization of HSCs, conditioning regimen, eligibility and exclusion criteria, toxicity, outcome, source of stem cells, and posttransplantation follow-up need to be disease specific. HSCT-induced remission of an autoimmune disease allows for a prospective analysis of events involved in immune tolerance not available in cross-sectional studies.

Cellular immunology in a historical perspective

Bruton's XLA and DiGeorge syndrome patients show that two basic immune systems are distinct from each other in humans - thymus-dependent cell-mediated immunodeficiencies vs. antibody-based immunodeficiencies. The appendix-sacculus lymphoid organ of rabbits, like the bursa of Fabricius, represents a central lymphoid organ. Chronic granulomatous disease of childhood (CGD) revealed that phagocytosis killing of catalase-positive microorganisms employ oxidative burst. Bone marrow transplantation (BMT) proved life saving in severe combined immunodeficiency (SCID). The first BMT cured XSCID and the second BMT cured a complicating aplastic anemia launching BMT as a treatment of many diseases. Now 75 fatal diseases have been cured by myeloablative BMT. BMT also cured experimental autoimmune diseases. BMT alone did not cure lupus with polyarthritis in MRL/lpr mice or polyarthritis in NZB/KN mice, but BMT plus bone (stromal cell) transplants cured these diseases. Autoimmune diseases and lethal glomerulonephritis were prevented or cured in BXSB mice by mixed allogeneic plus syngeneic BMT. X-linked Hyper IgM syndrome (XHIM) was also cured by BMT from a 2-year-old MHC-matched sibling donor. Nonmyeloablative BMT plus mesenchymal stem cells (stromal cells) was effective treatment for a form of collagen-vascular disease and also a lethal form of hypophosphatasia. Mannan-binding lectin, an opsonin that activates the complement system when mutated and at low levels in blood, opens a door to frequent infections throughout childhood and adult life. This new immunodeficiency is based on genetic mutations that involve a native defense system.