1
|
Nelsen MK, Beard KS, Plenter RJ, Kedl RM, Clambey ET, Gill RG. Disruption of Transplant Tolerance by an "Incognito" Form of CD8 T Cell-Dependent Memory. Am J Transplant 2017; 17:1742-1753. [PMID: 28066981 PMCID: PMC5489385 DOI: 10.1111/ajt.14194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/27/2016] [Accepted: 12/29/2016] [Indexed: 01/25/2023]
Abstract
Several approaches successfully achieve allograft tolerance in preclinical models but are challenging to translate into clinical practice. Many clinically relevant factors can attenuate allograft tolerance induction, including intrinsic genetic resistance, peritransplant infection, inflammation, and preexisting antidonor immunity. The prevailing view for immune memory as a tolerance barrier is that the host harbors memory cells that spontaneously cross-react to donor MHC antigens. Such preexisting "heterologous" memory cells have direct reactivity to donor cells and resist most tolerance regimens. In this study, we developed a model system to determine if an alternative form of immune memory could also block tolerance. We posited that host memory T cells could potentially respond to donor-derived non-MHC antigens, such as latent viral antigens or autoantigens, to which the host is immune. Results show that immunity to a model nonself antigen, ovalbumin (OVA), can dramatically disrupt tolerance despite undetectable initial reactivity to donor MHC antigens. Importantly, this blockade of tolerance was CD8+ T cell-dependent and required linked antigen presentation of alloantigens with the test OVA antigen. As such, this pathway represents an unapparent, or "incognito," form of immunity that is sufficient to prevent tolerance and that can be an unforeseen additional immune barrier to clinical transplant tolerance.
Collapse
Affiliation(s)
- M. K. Nelsen
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - K. S. Beard
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - R. J. Plenter
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - R. M. Kedl
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - E. T. Clambey
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - R. G. Gill
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO
| |
Collapse
|
2
|
Abstract
The goal of cellular transplantation is to allow long-term function of the grafted cells using minimal host immunosuppression. To this end, the major strategies to implant cells and tissues are through: (i) the pretreatment of the graft to reduce tissue immunogenicity; (ii) the application of immunoisolation technologies to prevent host sensitization to implanted cells; and (iii) the induction of immunological tolerance to the donor tissues. Further, a major dilemma facing clinical tissue grafting is the shortage of donor tissue for transplantation. This problem requires the consideration of tissues from other species (xenografts) as a potential source of donor material. In light of these issues, the focus of this discussion is on the T cell-dependent response to allogeneic and xenogeneic transplants and the implications of this reactivity on the field of cellular replacement therapy.
Collapse
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | |
Collapse
|
3
|
Lin CM, Plenter RJ, Coulombe M, Gill RG. Interferon Gamma and Contact-dependent Cytotoxicity Are Each Rate Limiting for Natural Killer Cell-Mediated Antibody-dependent Chronic Rejection. Am J Transplant 2016; 16:3121-3130. [PMID: 27163757 PMCID: PMC5083186 DOI: 10.1111/ajt.13865] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/26/2016] [Accepted: 05/02/2016] [Indexed: 01/25/2023]
Abstract
Natural killer (NK) cells are key components of the innate immune system. In murine cardiac transplant models, donor-specific antibodies (DSA), in concert with NK cells, are sufficient to inflict chronic allograft vasculopathy independently of T and B cells. In this study, we aimed to determine the effector mechanism(s) required by NK cells to trigger chronic allograft vasculopathy during antibody-mediated rejection. Specifically, we tested the relative contribution of the proinflammatory cytokine interferon gamma (IFN-γ) versus the contact-dependent cytotoxic mediators of perforin and the CD95/CD95L (Fas/Fas ligand [FasL]) pathway for triggering these lesions. C3H/HeJ cardiac allografts were transplanted into immune-deficient C57BL/6 rag-/- γc-/- recipients, who also received monoclonal anti-major histocompatibility complex (MHC) class I DSA. The combination of DSA and wild-type NK cell transfer triggered aggressive chronic allograft vasculopathy. However, transfer of IFN-γ-deficient NK cells or host IFN-γ neutralization led to amelioration of these lesions. Use of either perforin-deficient NK cells or CD95 (Fas)-deficient donors alone did not alter development of vasculopathy, but simultaneous disruption of NK cell-derived perforin and allograft Fas expression resulted in prevention of these abnormalities. Therefore, both NK cell IFN-γ production and contact-dependent cytotoxic activity are rate-limiting effector pathways that contribute to this form of antibody-induced chronic allograft vasculopathy.
Collapse
Affiliation(s)
- C M Lin
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, CO.
| | - R J Plenter
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, CO
| | - M Coulombe
- Department of Surgery, University of Colorado, Aurora, CO
| | - R G Gill
- Department of Surgery, University of Colorado, Aurora, CO
| |
Collapse
|
4
|
Levitsky J, Gill RG. What's Hot, What's New From the 2016 American Transplant Congress. Am J Transplant 2016; 16:3105-3114. [PMID: 27516154 DOI: 10.1111/ajt.14010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/07/2016] [Accepted: 08/08/2016] [Indexed: 01/25/2023]
Abstract
From June 11-15, 2016 the American Transplant Congress, the joint meeting of the American Society of Transplantation and the American Society of Transplant Surgeons, held its annual meeting in Boston, MA. The meeting, attended by 5200 registrants, included pre-meeting conferences, focused topic sessions, and hundreds of high-quality presentations from the transplant field. This meeting report highlights key findings from specific basic science, translational, and clinical research presentations deemed to have notable impact in thematic areas. In particular, there were a number of transformative studies indicating important advances in the understanding of alloimmunity, chronic rejection, tolerance, and organ-specific outcomes. Many of these results are discussed in the context of the published literature to showcase rapid advances in the transplant field.
Collapse
Affiliation(s)
- J Levitsky
- Division of Gastroenterology and Hepatology, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL.
| | - R G Gill
- Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO.
| |
Collapse
|
5
|
Bishop NH, Beard KS, Gill RG. Resistance of spontaneously diabetic Ins2(akita) mice to allograft tolerance induced by anti-CD154 therapy. Transplant Proc 2015; 46:2007-9. [PMID: 25131095 DOI: 10.1016/j.transproceed.2014.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Despite ongoing advances in the clinical islet transplant field, progressive decline in graft function continues to reduce the long-term success of islet transplantation for restoring euglycemia in type 1 diabetic recipients. To preserve graft function and avoid the use of chronic immunosuppressive drug therapy, a key goal is to induce donor-specific immune tolerance to islet transplants. Preclinical rodent studies of islet transplantation largely utilize models of diabetes either induced experimentally with beta cell toxins or spontaneously occurring in strains genetically prone to autoimmune diabetes. In this study, we sought to determine if chronic, severe hyperglycemia itself, independent of both beta cell toxins and host autoimmunity, influenced acute allograft rejection and/or the capacity to induce allograft tolerance. METHOD To this end, we studied the response to islet allografts in severely diabetic, non-autoimmune C57Bl/6 Ins2(akita) recipients. RESULTS Results indicate that diabetic Ins2(akita) mice display higher levels of blood glucose, show more rapid acute islet allograft rejection, and are resistant to allograft prolongation induced with anti-CD154 therapy relative to wild-type littermates rendered diabetic with streptozotocin. As such, results suggest that severe hyperglycemia may be an independent risk factor impacting the capacity to induce tolerance to islet allografts. Thus, Ins2(akita) mice represent a stringent model for evaluating anti-rejection strategies in the setting of severe metabolic demand on islet transplants.
Collapse
Affiliation(s)
- N H Bishop
- Integrated Department of Immunology, University of Colorado Denver, Aurora, Colorado
| | - K S Beard
- Department of Surgery, University of Colorado Denver, Aurora, Colorado
| | - R G Gill
- Integrated Department of Immunology, University of Colorado Denver, Aurora, Colorado; Department of Surgery, University of Colorado Denver, Aurora, Colorado.
| |
Collapse
|
6
|
Gill RG. An orchestrated dance between differing regulatory T cell phenotypes in allograft tolerance. Am J Transplant 2013; 13:1945-6. [PMID: 23890281 DOI: 10.1111/ajt.12336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 04/27/2013] [Accepted: 05/06/2013] [Indexed: 01/25/2023]
|
7
|
Mirski MM, Lewin JL, Ledroux SL, Shermock KS, Thompson CT, Goodwin HG, Mirski EM, Gill RG. Validity and reliability of the Johns Hopkins Adapted Cognitive Exam for critically ill patients. Crit Care 2011. [PMCID: PMC3067036 DOI: 10.1186/cc9782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
8
|
Mirski MM, Gill RG, Murakami PM, Thompson CT, Lewin JL. Dexmedetomidine improves attention and recall in agitated critically ill patients. Crit Care 2011. [PMCID: PMC3067029 DOI: 10.1186/cc9775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
9
|
|
10
|
Ramirez-Victorino F, Ramirez-Victorio F, Beilke JN, Gill RG. Both innate and adaptive major histocompatibility complex class I-dependent immunity impair long-term islet xenograft survival. Transplant Proc 2008; 40:557-8. [PMID: 18374128 DOI: 10.1016/j.transproceed.2008.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Natural killer (NK) cells have long been appreciated for their rapid, proinflammatory contribution to host defense. However, more recent studies show an unexpected regulatory role for host major histocompatibility complex (MHC) class I-dependent immunity and NK cells in promoting tolerance induction to islet allografts. It is unclear whether the potential tolerance induction to islet xenografts follows similar requirements to those found in allograft tolerance. In this study, we determined whether induced islet xenograft prolongation also showed a reliance on MHC class I-dependent immune pathways. In particular, we tested whether NK1.1+ cells and/or CD8 T cells were required for the long-term islet xenograft survival in a rat-to-mouse transplant model. Short-term host treatment with combined anti-CD154 plus anti-LFA-1 (CD11a) resulted in prolonged, but not indefinite, survival of WF rat islet xenografts in C57BI/6 mouse recipients. In stark contrast with similar islet allograft studies, adjunct treatment with anti-NK1.1 therapy combined wither anti-CD154/anti-LFA-1 treatment led to long-term (>100 days) survival of the majority of islet xenografts. In parallel studies, we determined whether CD8 T cells also contributed a barrier to xenograft survival. Similar to results found in anti-NK1.1-treated animals, CD8-deficient (knockout) recipients also demonstrated augmented xenograft prolongation after combined anti-CD154/anti-LFA-1 therapy. Taken together, NK1.1+ cells (NK/NKT cells) and CD8 T cells constitute differing MHC class I-dependent immune pathways forming a significant barrier to xenograft prolongation.
Collapse
Affiliation(s)
- F Ramirez-Victorino
- University of Colorado Health Sciences Center, Aurora, Colorado, California, USA
| | | | | | | |
Collapse
|
11
|
Sarkar SA, Gunter J, Bouchard R, Reusch JEB, Wiseman A, Gill RG, Hutton JC, Pugazhenthi S. Dominant negative mutant forms of the cAMP response element binding protein induce apoptosis and decrease the anti-apoptotic action of growth factors in human islets. Diabetologia 2007; 50:1649-59. [PMID: 17593347 DOI: 10.1007/s00125-007-0707-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 04/03/2007] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS Transplantation of islets is a viable option for the treatment of diabetes. A significant proportion of islets is lost during isolation, storage and after transplantation as a result of apoptosis. cAMP response element binding protein (CREB) is an important cell survival factor. The aim of the present study was to determine whether preservation of CREB function is needed for survival of human islets. MATERIALS AND METHODS To determine the effects of downregulation of CREB activity on beta cell apoptosis in a transplantation setting, adenoviral vectors were used to express two dominant negative mutant forms of CREB in human islets isolated from cadaveric donors. Markers of apoptosis were determined in these transduced islets under basal conditions and following treatment with growth factor. RESULTS Expression of CREB mutants in human islets resulted in significant (p < 0.001) activation of caspase-9, a key regulatory enzyme in the mitochondrial pathway of apoptosis, when compared with islets transduced with adenoviral beta galactosidase. Immunocytochemical analysis showed the activation of caspase-9 to be predominantly in beta cells. Other definitive markers of apoptosis such as parallel activation of caspase-3, accumulation of cleaved poly-(ADP-ribose) polymerase and nuclear condensation were also observed. Furthermore, the anti-apoptotic action of growth factors exendin-4 and betacellulin in human islets exposed to cytokines was partially lost when CREB function was impaired. CONCLUSIONS/INTERPRETATION Our findings suggest that impairment of CREB-mediated transcription could lead to loss of islets by apoptosis with potential implications in islet transplantation as well as in the mechanism of beta cell loss leading to diabetes.
Collapse
Affiliation(s)
- S A Sarkar
- Barbara Davis Center for Childhood Diabetes and Rocky Mountain Islet Transplantation Program, Aurora, CO, USA
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
Though CD8(+) T lymphocytes are important cellular mediators of islet allograft rejection, their molecular mechanism of rejection remains unidentified. Surprisingly, while it is generally assumed that CD8(+) T cells require classic cytotoxic mechanisms to kill grafts in vivo, neither perforin nor FasL (CD95L) are required for acute islet allograft rejection. Thus, it is unclear whether such contact-dependent cytotoxic pathways play an essential role in islet rejection. Moreover, both perforin and CD95L have been implicated in playing roles in peripheral tolerance, further obscuring the role of these effector pathways in rejection. Therefore, we determined whether perforin and/or FasL (CD95L) were required by donor MHC-restricted ('direct') CD8(+) T cells to reject islet allografts in vivo. Islet allograft rejection by primed, alloreactive CD8(+) T cells was examined independently of other lymphocyte subpopulations via adoptive transfer studies. Individual disruption of T-cell-derived perforin or allograft Fas expression had limited impact on graft rejection. However, simultaneous disruption of both pathways prevented allograft rejection in most recipients despite the chronic persistence of transferred T cells at the graft site. Thus, while there are clearly multiple cellular pathways of allograft rejection, perforin and FasL comprise alternate and necessary routes of acute CD8(+) T-cell-mediated islet allograft rejection.
Collapse
Affiliation(s)
- M Sleater
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Department of Medicine, USA
| | | | | |
Collapse
|
13
|
Gianani R, Putnam A, Still T, Yu L, Miao D, Gill RG, Beilke J, Supon P, Valentine A, Iveson A, Dunn S, Eisenbarth GS, Hutton J, Gottlieb P, Wiseman A. Initial results of screening of nondiabetic organ donors for expression of islet autoantibodies. J Clin Endocrinol Metab 2006; 91:1855-61. [PMID: 16478822 DOI: 10.1210/jc.2005-1171] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Type 1A diabetes is characterized by a long prodromal phase during which autoantibodies to islet antigens are present. Nevertheless, we lack data on the pancreatic pathology of subjects who are positive for islet autoantibodies (to islet autoantigens GAD65, insulin, and ICA512). OBJECTIVE In this manuscript, we describe a novel strategy in obtaining pancreata and pancreatic lymph nodes from islet autoantibody-positive organ donors that involves careful coordination among the laboratory and the organ donor provider organization. DESIGN We developed a rapid screening protocol for islet autoantibodies measurement of organ donors to allow identification of positive subjects before organ harvesting. In this way we were able to obtain pancreata and pancreatic lymph nodes from subjects with and without islet autoimmunity. SETTING The organ donors used in this study were obtained from the general community. SUBJECTS The population studied consisted of 112 organ donors (age range 1 month to 86 yr, mean age 39 yr). MAIN OUTCOME MEASURE The main outcome measure of this study consisted of evaluating the pancreatic histology and identify T cells autoreactive for islet antigens in the pancreatic lymph nodes. RESULTS To date we have identified three positive subjects and obtained the pancreas for histological evaluation from one of the autoantibody-positive donors who expressed ICA512 autoantibodies. Although this subject did not exhibit insulitis, lymphocytes derived from pancreatic lymph nodes reacted to the islet antigen phogrin. CONCLUSION In summary, these results indicate that it is possible to screen organ donors in real time for antiislet antibodies, characterize pancreatic histology, and obtain viable T cells for immunological studies.
Collapse
Affiliation(s)
- R Gianani
- The Barbara Davis Center, Department of Pathology, University of Colorado at Denver and Health Science Center, Aurora, Colorado 80010, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Beilke JN, Kuhl NR, Van Kaer L, Gill RG. Erratum: Corrigendum: NK cells promote islet allograft tolerance via a perforin-dependent mechanism. Nat Med 2006. [DOI: 10.1038/nm0306-367b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
15
|
Abstract
Leukocyte function associated antigen-1 (LFA-1) was one of the earliest of cell-surface molecules identified by monoclonal antibodies generated against leukocyte immunogens. This integrin heterodimer is perhaps best known as a classic adhesion molecule facilitating the interaction between T cells and antigen-presenting cells. However, varied studies indicate that LFA-1 has multi-faceted roles in the immune response including adhesion, activation and trafficking of leukocyte populations. While there has been long-standing interest in LFA-1 as a therapeutic target for regulating immunity, anti-LFA-1 therapy is still not a first-line indication for any clinical condition. Antagonism of LFA-1 with monoclonal antibodies, either alone or in combination with other agents, can result in regulatory tolerance in vivo. Furthermore, new generation humanized anti-LFA-1 monoclonal antibodies (Efalizumab) show at least modest promise for continued application in clinical trials. Thus, anti-LFA-1 forms a potential, but still largely unexploited, immunotherapy which may find its greatest application as an agent which augments other therapies.
Collapse
Affiliation(s)
- M R Nicolls
- Department of Medicine, University of Colorado Health Science Center, Denver, Colorado, USA.
| | | |
Collapse
|
16
|
Johnson Z, Beilke J, Pietra B, Kelly B, Gill RG. Distinct requirements for host CD80/CD86 costimulatory molecules in cardiac versus islet rejection. Transplant Proc 2004; 36:1171-2. [PMID: 15194405 DOI: 10.1016/j.transproceed.2004.04.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The role of B7 family members CD80 and CD86 in providing costimulatory signals to T cells is well established. Interestingly, previous studies show that host CD80/CD86 expression is required for cardiac allograft rejection. However, the role for host costimulation by CD80/CD86 molecules for the rejection of neovascularized islet allografts and xenografts is unknown. The purpose of this study was to determine whether islet allografts and/or rat islet xenografts required host CD80/CD86 molecules for acute rejection. Streptozotocin-induced diabetic C57Bl/6 (B6, H-2(b)) or B6 CD80/CD86 double-deficient mice were grafted with allogeneic BALB/c (H-2(d)) islet allografts or with WF (RT1(u)) islet xenografts. Nondiabetic B6 mice were grafted with BALB/c heterotopic cardiac allografts. Consistent with previous reports, BALB/c islet allografts were acutely rejected in wild-type B6 mice could survive long-term (>100 days) in B6 CD80/CD86-deficient animals. In stark contrast, both islet allografts and WF rat islet xenografts demonstrated acute rejection in both control B6 and in B6 CD80/CD86 deficient hosts. In conclusion, varied studies imply that the inherent pathways for rejecting primarily vascularized versus cellular allografts or xenografts may be distinct. The present study illustrates this concept by showing a marked difference in the role of host-derived CD80/CD86 costimulatory molecules for cardiac allograft versus islet allograft/xenograft rejection in vivo. Although such costimulation is rate limiting for cardiac allograft rejection, these same molecules are not necessary for acute rejection of either islet allografts or xenografts.
Collapse
Affiliation(s)
- Z Johnson
- The Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver, 80262, USA
| | | | | | | | | |
Collapse
|
17
|
Abstract
The purpose of this study was to determine the role for CD8 T cells versus generalized MHC class I-restricted antigen presentation in islet allograft rejection and tolerance. Diabetic C57BI/6 (B6, H-2(b)) controls, C57BI/6 CD8-deficient (CD8 KO), or MHC class I-deficient C57BI/6 (beta 2m KO) recipients were grafted with allogeneic BALB/c (H-2(d)) islets. Islet allografts were acutely rejected in untreated B6, CD8 KO, and in beta 2m KO mice, indicating that neither CD8 T cells nor host MHC class I is required for allograft rejection. We then determined the efficacy of costimulation blockade in these same strains. Costimulation blockade with anti-CD154 therapy facilitated long-term islet allograft survival in both B6 and in CD8 KO recipients. However, anti-CD154 treated beta 2m KO recipients were completely refractory to anti-CD154 therapy; all treated animals acutely rejected islet allografts with or without therapy. Also, anti-NK1.1 treatment of wild-type B6 mice abrogated graft prolongation following anti-CD154 therapy. Taken together, results show a dramatic distinction between two forms of MHC class I-restricted pathways in allograft prolongation. Although anti-CD154-induced allograft survival was CD8 T-cell independent, an intact host MHC class I-restricted (beta 2m-dependent) pathway is nevertheless necessary for allograft survival. This pathway required NK1.1+ cells, implicating NK and/or NKT cells in promoting allograft prolongation in vivo.
Collapse
Affiliation(s)
- J Beilke
- The Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver, 80262, USA
| | | | | | | |
Collapse
|
18
|
Nicolls MR, Coulombe M, Gill RG. The basis of immunogenicity of endocrine allografts. Crit Rev Immunol 2002; 21:87-101. [PMID: 11642616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Two signals are required for optimal T-cell activation: the engagement of the antigen-specific receptor and the provision of a second non-antigen-specific inductive signal, or costimulator (CoS). Regarding allograft immunity, two primary pathways of donor antigen presentation can fulfill this two-signal requirement, resulting in cellular immunity to a transplant: (1) "direct" (donor MHC-restricted) presentation in which the antigen-presenting cells (APCs) resident within the transplant directly activate host T lymphocytes and (2) "indirect" (host MHC-restricted) presentation in which host-derived APCs acquire donor antigens that are then presented to host T lymphocytes. It appears that endocrine allografts, such as pancreatic islets and thyroid, are highly dependent on donor-derived APCs, or "passenger leukocytes," to trigger acute graft rejection. Tissue pretreatment aimed at selectively eliminating APCs within endocrine tissues can result in indefinite allograft survival in immune-competent recipients. Although such results implicate the "direct" pathway as the predominant route of host sensitization, the role of donor APCs in rejection appears to be more complex. Recently, we have found that indirect, CD4 T-cell-dependent reactivity can contribute to islet allograft rejection. However, such indirect recognition nevertheless requires donor-derived APCs as a source of antigen. Thus, whereas the donor-type APC is a critical limiting step for initiating islet allograft rejection, such cells can trigger both direct and indirect forms of immune responses that can result in graft rejection. That is, donor hematopoietic cells, rather than tissue parenchymal cells, probably play a major role in providing antigens that stimulate cellular immunity.
Collapse
Affiliation(s)
- M R Nicolls
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | |
Collapse
|
19
|
Pietra BA, Gill RG. Immunobiology of cardiac allograft and xenograft transplantation. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2002; 4:123-57. [PMID: 11460981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Heart transplantation has been performed clinically for four decades, and has become the standard of care for end-stage heart disease. Our understanding of the immunobiology of transplantation has made tremendous strides, but our knowledge still lags behind the clinical use. As a result, nonspecific immunosuppression remains the standard therapy. This chapter is a review of our present knowledge of the immunobiology of allotransplantation and xenotransplantation with emphasis on antigen presentation, costimulation, and T-cell activation in the context of transplantation. The molecular events of T-cell activation, with some emphasis on the sites of action of present day immunosuppression, are reviewed. Basic aspects of immunosuppression are reviewed elsewhere in this edition. Given the paucity of allografts, xenografts are being considered as an alternative donor source. This being the case, cellular and humoral response to xenografts is considered and contrasted with our understanding of allograft immunity. Basic mechanisms of tolerance are discussed, with examples of experimental tolerance induction in small and large animals. A brief description of special considerations for the immunology in human neonate/infant recipients is mentioned. Understanding the immunobiology of transplantation is key to making decisions regarding heart transplant recipients today, in addition to developing better protocols and the induction of tolerance in the future.
Collapse
Affiliation(s)
- B A Pietra
- Department of Pediatrics, The Children's Hospital, Denver, CO 80212, USA
| | | |
Collapse
|
20
|
Abstract
It has been recognized for many years that immunoisolation strategies form an attractive approach to preventing the rejection of cellular allografts and xenografts. Although immunoisolation has proven dramatically successful in some cases, the results have tended to be somewhat variable. Although many advances have been made in the development of biocompatible materials for separating host immune cells from the transplanted tissues, much of the experimentation in this area has been outcome driven. That is, the nature of host reactivity and/or biomaterial design resulting in the failure of some immunoisolation strategies has mostly been undefined. A first premise of this discussion is that immunoisolation is primarily cell isolation and not antigen isolation, per se. That is, although varied membrane barriers are designed to prevent cell-cell contact between host and donor cells, soluble antigens derived from the transplant are likely to gain access to the host immune system. A key question centers on the degree and consequence of this type of antigen presentation in the host to the immunoisolated transplant. To address this and related concerns, this overview presents a simple paradigm for using defined rodent (mouse) models for systematically screening the efficacy of immunoisolated cellular transplants. The proposition is made that understanding the basis of graft failure will aid in the design of future immunoisolation technologies.
Collapse
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA.
| |
Collapse
|
21
|
Wiseman AC, Pietra BA, Kelly BP, Rayat GR, Rizeq M, Gill RG. Donor IFN-gamma receptors are critical for acute CD4(+) T cell-mediated cardiac allograft rejection. J Immunol 2001; 167:5457-63. [PMID: 11673565 DOI: 10.4049/jimmunol.167.9.5457] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent studies using mouse models demonstrate that CD4(+) T cells are sufficient to mediate acute cardiac allograft rejection in the absence of CD8(+) T cells and B cells. However, the mechanistic basis of CD4-mediated rejection is unclear. One potential mechanism of CD4-mediated rejection is via elaboration of proinflammatory cytokines such as IFN-gamma. To determine whether IFN-gamma is a critical cytokine in CD4-mediated acute cardiac allograft rejection, we studied whether the expression of IFN-gamma receptors on the donor heart was required for CD4-mediated rejection. To investigate this possibility, purified CD4(+) T cells were transferred into immune-deficient mice bearing heterotopic cardiac allografts from IFN-gamma receptor-deficient (GRKO) donors. While CD4(+) T cells triggered acute rejection of wild-type heart allografts, they failed to trigger rejection of GRKO heart allografts. The impairment in CD4-mediated rejection of GRKO hearts appeared to primarily involve the efferent phase of the immune response. This conclusion was based on the findings that GRKO stimulator cells provoked normal CD4 proliferation in vitro and that intentional in vivo challenge of CD4 cells with wild-type donor APC or the adoptive transfer of in vitro primed CD4 T cells failed to provoke acute rejection of GRKO allografts. In contrast, unseparated lymph node cells acutely rejected both GRKO and wild-type hearts with similar time courses, illustrating the existence of both IFN-gamma-dependent and IFN-gamma-independent mechanisms of acute allograft rejection.
Collapse
Affiliation(s)
- A C Wiseman
- Division of Nephrology, Department of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA
| | | | | | | | | | | |
Collapse
|
22
|
Abstract
BACKGROUND Adhesion molecules are involved in multiple steps of the continuum of allograft rejection. We studied the effects of blockade of the interactions between alpha4 integrin and its ligands, vascular cell adhesion molecule-1 (VCAM-1) and fibronectin, on allograft survival. METHODS Streptozotocin-induced diabetic CBA (H-2k) mice received islet transplants from BALB/c (H-2d) donors. Recipient mice were treated with antibodies against alpha4 integrin (PS/2), VCAM-1 (MK 2.7), and a peptide corresponding to the binding site of alpha4 integrin on fibronectin (connecting segment 1 peptide, CS1-peptide). Graft function was measured by daily tail vein blood glucose levels, with rejection defined as the return of hyperglycemia. Graft-bearing kidneys were removed for immunohistochemical analysis. RESULTS Treatment with anti-alpha4 integrin antibody, anti-VCAM-1 antibody, or with CS1-peptide led to long-term survival of islet allografts. Recipients with long-surviving islet grafts did not show tolerance, in that they rejected a second donor-type islet allograft. Although both anti-alpha4 integrin antibody and CS1-peptide completely abolished cellular infiltration of the islet graft 7 days after transplantation, anti-VCAM-1-treated recipients showed a dense peri-islet infiltrate of activated, alpha4 integrin+, cytotoxic T cells. CONCLUSIONS These data show that alpha4 integrin is critically important to allograft rejection. Anti-VCAM-1 antibody appears to prevent rejection without qualitatively affecting either T cell activation or migration to the graft. Conversely, anti-alpha4 integrin antibody and CS1-peptide may prevent islet allograft rejection by altering either T cell activation or lymphocyte trafficking. Blocking interactions between alpha4 integrin and its ligands may provide novel forms of immunosuppression.
Collapse
Affiliation(s)
- M D Stegall
- The Transplantation Research Laboratory, Department of Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA
| | | | | | | | | | | | | |
Collapse
|
23
|
Pietra BA, Wiseman A, Bolwerk A, Rizeq M, Gill RG. CD4 T cell-mediated cardiac allograft rejection requires donor but not host MHC class II. J Clin Invest 2000; 106:1003-10. [PMID: 11032860 PMCID: PMC314344 DOI: 10.1172/jci10467] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Numerous studies indicate that CD4 T cells are required for acute cardiac allograft rejection. However, the precise role for CD4 T cells in this response has remained ambiguous owing to the multipotential properties of this T-cell subpopulation. In the current study, we demonstrate the capacity of CD4 T cells to serve as direct effector cells of cardiac allograft rejection. We show that CD4 T cells are both necessary and sufficient for acute graft rejection, as indicated by adoptive transfer experiments in immune-deficient SCID and rag1(-/-) recipients. We have analyzed the contribution of direct (donor MHC class II restricted) and indirect (host MHC class II restricted) antigen recognition in CD4-mediated rejection. Acute CD4 T cell-mediated rejection required MHC class II expression by the allograft, indicating the importance of direct graft recognition. In contrast, reciprocal experiments indicate that CD4 T cells can acutely reject allogeneic cardiac allografts established in rag1(-/-) hosts that were also MHC class II deficient. This latter result indicates that indirect presentation of donor antigens by host MHC class II is not required for acute CD4-mediated rejection. Taken together, these results indicate that CD4 T cells can serve as effector cells for primary acute cardiac allograft rejection, predominantly via direct donor antigen recognition and independent of indirect reactivity.
Collapse
Affiliation(s)
- B A Pietra
- Division of Cardiology, The Children's Hospital, Barbara Davis Center for Childhood Diabetes, Denver, CO 80262, USA
| | | | | | | | | |
Collapse
|
24
|
Abstract
CD8+ T cells have long been considered to be the prototypical cytotoxic lymphocyte subpopulation. However, whether alloreactive CD8+ T cells require traditional cytolytic pathways such as perforin and Fas ligand (FasL) to mediate graft rejection has been a controversial issue. In the present studies, we examined the role of varied effector pathways in CD8+ T cell-mediated rejection of pancreatic islet allografts. Our goal was to systematically determine the relative requirements, if any, of perforin and FasL as well as the proinflammatory cytokine IFN-gamma in triggering graft destruction. To study CD8+ T cell effector pathways independently of other lymphocyte populations, purified alloreactive CD8+ T cells were adoptively transferred into severe combined immune-deficient (SCID) recipients bearing established islet allografts. Results indicate that to reject established islet allografts, primed CD8+ T cells do not require the individual action of the conventional cytotoxic effectors perforin and Fas ligand. In contrast, the ability to produce IFN-gamma is critical for efficient CD8+ T cell-mediated rejection of established islet allografts. Furthermore, alloreactive CD8+ TCR transgenic T cells (2C) also show IFN-gamma dependence for mediating islet allograft rejection in vivo. We speculate from these results that the production of IFN-gamma by alloreactive CD8+ T cells is a rate-limiting step in the process of islet allograft rejection.
Collapse
Affiliation(s)
- A S Diamond
- Department of Immunology and Medicine, Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | |
Collapse
|
25
|
Nicolls MR, Coulombe M, Yang H, Bolwerk A, Gill RG. Anti-LFA-1 therapy induces long-term islet allograft acceptance in the absence of IFN-gamma or IL-4. J Immunol 2000; 164:3627-34. [PMID: 10725719 DOI: 10.4049/jimmunol.164.7.3627] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
mAb therapy directed against a variety of cell surface accessory molecules has been effectively utilized to prolong allograft acceptance in various models of tissue and organ transplantation. The purpose of this study was to determine whether transient therapy directed against the adhesion molecule LFA-1 (CD11a) was sufficient to induce donor-specific tolerance to pancreatic islet allografts. Anti-LFA-1 monotherapy was found to be efficacious in inducing long-term islet allograft acceptance in multiple donor-recipient strain combinations. Graft acceptance following anti-LFA-1 therapy was not simply due to clonal ignorance of donor Ags in that the majority of recipients bearing established islet allografts resisted rejection induced by immunization with donor-type APCs. Furthermore, donor-specific tolerance from anti-LFA-1-treated animals could be transferred to secondary immune-deficient animals. Taken together, these results indicated that transient anti-LFA-1 monotherapy resulted in donor-specific tolerance. In vitro, functionally tolerant animals retained normal anti-donor reactivity as assessed by proliferative, cytotoxic, and cytokine release assays that demonstrated that tolerance was not secondary to general clonal deletion or anergy of donor-reactive T cells. Finally, anti-LFA-1 treatment was effective in both IL-4-deficient and IFN-gamma-deficient recipients, indicating that neither of these cytokines are universally required for allograft acceptance. These results suggest that anti-adhesion-based therapy can induce a nondeletional form of tolerance that is not overtly dependent on the prototypic Th1 and Th2 cytokines, IFN-gamma and IL-4, respectively, in contrast to results in other transplantation models.
Collapse
Affiliation(s)
- M R Nicolls
- Division of Pulmonary Sciences, Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences University, Denver, CO 80262, USA
| | | | | | | | | |
Collapse
|
26
|
Affiliation(s)
- D Hunkeler
- Laboratory of polymers and biomaterials, Swiss Federal Institute of Technology, Lausanne, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
The ability of nonobese diabetic (NOD) mice to mount a cellular immune response to the secretory granule protein tyrosine phosphatase (PTP), phogrin was evaluated by immunization of 8- to 12-week-old animals with recombinant phogrin in complete Freund's adjuvant. Draining lymph nodes displayed a robust proliferative response to the protein, as did derived T-cell lines and clones. Ten clones obtained by limiting dilution were all CD4+ and of a T-helper-1-like phenotype, but showed variation in their Vbeta usage. Of the 10 clones, 3 responded to endogenous antigens in rat islets. Two of these caused the destruction of rat islets that had been transplanted under the kidney capsule of streptozotocin-treated NOD scid mice without affecting adjacent thyroid implants. The results demonstrate the feasibility of generating antigen-specific diabetes-inducing CD4+ cells by direct immunization of NOD mice and their potential use for further studies of the antigenic epitopes in the PTP family members. The conclusion, based on serological studies, that PTP members do not play a role in the pathogenesis of type 1 diabetes in rodent models needs reevaluation in light of these findings.
Collapse
MESH Headings
- Animals
- Cell Division/physiology
- Clone Cells
- Diabetes Mellitus, Experimental/surgery
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/pathology
- Diabetes Mellitus, Type 1/physiopathology
- Female
- Immunity, Cellular/physiology
- Immunization
- Islets of Langerhans Transplantation/immunology
- Lymph Nodes/pathology
- Male
- Membrane Glycoproteins/immunology
- Membrane Proteins
- Mice
- Mice, Inbred NOD/immunology
- Mice, SCID
- Phenotype
- Protein Tyrosine Phosphatase, Non-Receptor Type 1
- Protein Tyrosine Phosphatases/immunology
- Rats
- Rats, Inbred Strains
- Receptor-Like Protein Tyrosine Phosphatases, Class 8
- Recombinant Proteins
- T-Lymphocytes/immunology
- T-Lymphocytes/pathology
- T-Lymphocytes/physiology
- Transplantation, Heterologous
Collapse
Affiliation(s)
- K Kelemen
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | |
Collapse
|
28
|
Abstract
Tremendous advances have been made over the past several years in the development of diverse biocompatible materials and structural designs for the implantation of immunoisolated cells and tissues. This area of bioengineering has clear application to insulin-dependent diabetes for which the implantation of micro- or macroencapsulated pancreatic islets or surrogate beta cells has great potential therapeutic benefit. This discussion concentrates on three antigen-specific immunologic processes that impede the application of islet transplantation as a therapy for insulin-dependent diabetes: (1) Allograft immunity, (2) Xenograft immunity, and (3) Autoimmune pathogenesis of Type I diabetes. Special emphasis is placed on the potential impact of these immune pathways on immunoisolated tissues.
Collapse
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA.
| |
Collapse
|
29
|
Coulombe M, Yang H, Wolf LA, Gill RG. Tolerance to antigen-presenting cell-depleted islet allografts is CD4 T cell dependent. J Immunol 1999; 162:2503-10. [PMID: 10072489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Pretreatment of pancreatic islets in 95% oxygen culture depletes graft-associated APCs and leads to indefinite allograft acceptance in immunocompetent recipients. As such, the APC-depleted allograft represents a model of peripheral alloantigen presentation in the absence of donor-derived costimulation. Over time, a state of donor-specific tolerance develops in which recipients are resistant to donor APC-induced graft rejection. Thus, persistence of the graft is sufficient to induce tolerance independent of other immune interventions. Donor-specific tolerance could be adoptively transferred to immune-deficient SCID recipient mice transplanted with fresh immunogenic islet allografts, indicating that the original recipient was not simply "ignorant" of donor antigens. Interestingly, despite the fact that the original islet allograft presented only MHC class I alloantigens, CD8+ T cells obtained from tolerant animals readily collaborated with naive CD4+ T cells to reject donor-type islet grafts. Conversely, tolerant CD4+ T cells failed to collaborate effectively with naive CD8+ T cells for the rejection of donor-type grafts. In conclusion, the MHC class I+, II- islet allograft paradoxically leads to a change in the donor-reactive CD4 T cell subset and not in the CD8 subset. We hypothesize that the tolerant state is not due to direct class I alloantigen presentation to CD8 T cells but, rather, occurs via the indirect pathway of donor Ag presentation to CD4 T cells in the context of host MHC class II molecules.
Collapse
Affiliation(s)
- M Coulombe
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver, CO 80262, USA
| | | | | | | |
Collapse
|
30
|
Stegall MD, Elices M, Pietra W, Shepard G, Gup C, Gill RG. Different roles for alpha 4-integrin/VCAM-1 and alpha 4/fibronectin interactions in allograft rejection. Transplant Proc 1999; 31:786. [PMID: 10083336 DOI: 10.1016/s0041-1345(98)01767-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- M D Stegall
- Mayo Clinic, Rochester, Minnesota 55905, USA
| | | | | | | | | | | |
Collapse
|
31
|
Affiliation(s)
- B Pietra
- Children's Hospital, Denver, Colorado, USA
| | | | | | | |
Collapse
|
32
|
Stegall MD, Elices M, Shepard G, Gup C, Ninova D, Ferguson D, Gill RG. The 2C T-cell transgenic mouse: an in vivo model of allospecific cytotoxic T-cell activation and homing. Transplant Proc 1999; 31:779. [PMID: 10083330 DOI: 10.1016/s0041-1345(98)01761-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
33
|
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, U.S.A
| |
Collapse
|
34
|
Affiliation(s)
- M Coulombe
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | |
Collapse
|
35
|
Affiliation(s)
- M Crawford
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Science Center, Denver 80262, USA
| | | | | | | | | |
Collapse
|
36
|
Coulombe M, Yang H, Guerder S, Flavell RA, Lafferty KJ, Gill RG. Tissue immunogenicity: the role of MHC antigen and the lymphocyte costimulator B7-1. J Immunol 1996; 157:4790-5. [PMID: 8943380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pancreatic islet transplantation represents a potential treatment for insulin-dependent diabetes mellitus. One approach to circumvent the requirement for recipient immune suppression is to reduce or eliminate the immunogenicity of the donor graft prior to transplantation. In this study, we have examined the relative contributions of graft MHC Ag expression and donor-derived costimulatory (CoS) activity to the rejection of islet allografts. Depletion of donor hemopoietic APCs from islet tissue facilitated long-term allograft survival even when donor class I MHC Ag expression was greatly increased by IFN-gamma treatment prior to grafting. Conversely, islet allografts from transgenic mice expressing the CoS molecule B7-1 (CD80) on islet beta cells were acutely rejected even when hemopoietic APCs were eliminated. Thus, B7-1 is sufficient to confer the capacity of islet parenchymal cells to stimulate allorejection. Taken together, these results point towards donor-derived CoS activity as a primary target of intervention therapy to modulate tissue immunogenicity.
Collapse
Affiliation(s)
- M Coulombe
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | | | | | |
Collapse
|
37
|
Coulombe M, Yang H, Guerder S, Flavell RA, Lafferty KJ, Gill RG. Tissue immunogenicity: the role of MHC antigen and the lymphocyte costimulator B7-1. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.157.11.4790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Pancreatic islet transplantation represents a potential treatment for insulin-dependent diabetes mellitus. One approach to circumvent the requirement for recipient immune suppression is to reduce or eliminate the immunogenicity of the donor graft prior to transplantation. In this study, we have examined the relative contributions of graft MHC Ag expression and donor-derived costimulatory (CoS) activity to the rejection of islet allografts. Depletion of donor hemopoietic APCs from islet tissue facilitated long-term allograft survival even when donor class I MHC Ag expression was greatly increased by IFN-gamma treatment prior to grafting. Conversely, islet allografts from transgenic mice expressing the CoS molecule B7-1 (CD80) on islet beta cells were acutely rejected even when hemopoietic APCs were eliminated. Thus, B7-1 is sufficient to confer the capacity of islet parenchymal cells to stimulate allorejection. Taken together, these results point towards donor-derived CoS activity as a primary target of intervention therapy to modulate tissue immunogenicity.
Collapse
Affiliation(s)
- M Coulombe
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | - H Yang
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | - S Guerder
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | - R A Flavell
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | - K J Lafferty
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | - R G Gill
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| |
Collapse
|
38
|
Stegall MD, Loberman Z, Ostrowska A, Coulombe M, Gill RG. Autoimmune destruction of islet grafts in the NOD mouse is resistant to 15-deoxyspergualin but sensitive to anti-CD4 antibody. J Surg Res 1996; 64:156-60. [PMID: 8812627 DOI: 10.1006/jsre.1996.0322] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Islet allografts transplanted into Type I diabetic recipients may be destroyed by allorejection or recurrent autoimmune diabetes. We studied islet transplantation in three murine models in order to determine the relative sensitivity of autoimmunity and alloimmunity to two immunosuppressive agents that may be useful in clinical islet transplantation: 15-deoxyspergualin (DSG) and anti-CD4 antibody (GK 1.5). In the model in which only allorejection occurs (BALB/c islets transplanted into streptozotocin-induced diabetic CBA or streptozotocin-induced diabetic NOD recipients), both DSG and anti-CD4 antibody treatment led to indefinite survival of allogeneic islets (>100 days in both treatments). In the second model in which only recurrent autoimmunity can destroy islet grafts (islets from NOD donors transplanted into spontaneously diabetic NOD recipients), only anti-CD4 treatment caused prolonged graft survival [MST 36.7 +/- 6.8 days vs 9.8 +/- 1.8 days (controls), P < 0.0002]. Treatment with DSG did not cause any increase in graft survival (MST 12.6 +/- 5.4 days, NS). Finally, using a model in which both autoimmunity and allorejection may occur (BALB/c to spontaneously diabetic NOD mice), treatment with anti-CD4 caused marked graft prolongation [42.0 +/- 14.5 days vs 7.2 +/- 0.8 days (control), P < 0.002] while DSG again did not prolong graft survival with respect to untreated recipients (9.8 +/- 3.0, NS). We conclude that recurrent autoimmunity in the NOD mouse involves a CD4+ T cell that is not sensitive to DSG. Anti-CD4 antibody may be useful in human clinical islet transplantation trials because it seems to prevent both allorejection and recurrent autoimmunity.
Collapse
Affiliation(s)
- M D Stegall
- Department of Surgery, University of Colorado School of Medicine, Denver, 80262, USA
| | | | | | | | | |
Collapse
|
39
|
Abstract
We transplanted 10,000 isolated, handpicked human pancreatic islets into the subfascial compartment of the forearm muscle of a type I diabetic recipient who had received a successful renal transplant one year prior. The recipient was maintained on his usual immunosuppressive therapy of cyclosporine, azathioprine, and prednisone. A biopsy performed 7 days after transplantation showed normal islets with both insulin- and glucagon-staining cells present and no lymphocytic infiltration. A second biopsy performed 14 days after transplantation showed a dense mononuclear cell infiltrate with a preferential loss of insulin-staining cells relative to glucagon-staining cells in the islets. These data are consistent with recurrent autoimmune diabetes in an isolated islet allograft in an immunosuppressed type I diabetic recipient. In addition, this forearm subfascial site may be a useful means to monitor islet rejection and autoimmune recurrence in therapeutic intraportal islet allografts.
Collapse
Affiliation(s)
- M D Stegall
- Department of Surgery, University of Colorado School of Medicine, Denver, CO 80262, USA
| | | | | | | |
Collapse
|
40
|
Coulombe M, Gill RG. T lymphocyte indifference to extrathymic islet allografts. J Immunol 1996; 156:1998-2003. [PMID: 8596055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Although the deletion of self-reactive T cells maturing in the thymus is well documented, the nature of tolerance to Ags expressed exclusively on peripheral (extrathymic) tissues is less clear. Numerous studies have examined T cell reactivity to transgene-encoded Ags expressed in the periphery through tissue-specific promoters. These studies have yielded varied results concerning the degree and nature of tolerance induced to these Ags, ranging from T cell clonal deletion or inactivation to clonal "ignorance" of the peripheral transgene-encoded Ag. Furthermore, the relationship of these findings to the generation and maintenance of transplantation tolerance to extrathymic tissue allografts remains unclear. Whereas transgenic studies represent a developmental form of tolerance, grafted tissues are introduced into adult, nontolerant recipients. To relate these two model systems, we determined whether extrathymic tissue allografts could induce a developmental form of tolerance. As a model of extrathymic alloantigen expression, pancreatic islet allografts, depleted of donor APCs, were established in the periphery of severe combined immune-deficient (SCID) mice. We then examined the potential donor reactivity of adoptively transferred bone marrow-derived T cell precursors maturing in the presence of the established peripheral allograft. Such T cells were neither activated nor tolerized either in vitro or in vivo, suggesting that T cells are indifferent to Ags expressed by extrathymic islet allografts when presented in the absence of a second costimulatory signal.
Collapse
Affiliation(s)
- M Coulombe
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | |
Collapse
|
41
|
Abstract
Abstract
Although the deletion of self-reactive T cells maturing in the thymus is well documented, the nature of tolerance to Ags expressed exclusively on peripheral (extrathymic) tissues is less clear. Numerous studies have examined T cell reactivity to transgene-encoded Ags expressed in the periphery through tissue-specific promoters. These studies have yielded varied results concerning the degree and nature of tolerance induced to these Ags, ranging from T cell clonal deletion or inactivation to clonal "ignorance" of the peripheral transgene-encoded Ag. Furthermore, the relationship of these findings to the generation and maintenance of transplantation tolerance to extrathymic tissue allografts remains unclear. Whereas transgenic studies represent a developmental form of tolerance, grafted tissues are introduced into adult, nontolerant recipients. To relate these two model systems, we determined whether extrathymic tissue allografts could induce a developmental form of tolerance. As a model of extrathymic alloantigen expression, pancreatic islet allografts, depleted of donor APCs, were established in the periphery of severe combined immune-deficient (SCID) mice. We then examined the potential donor reactivity of adoptively transferred bone marrow-derived T cell precursors maturing in the presence of the established peripheral allograft. Such T cells were neither activated nor tolerized either in vitro or in vivo, suggesting that T cells are indifferent to Ags expressed by extrathymic islet allografts when presented in the absence of a second costimulatory signal.
Collapse
Affiliation(s)
- M Coulombe
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | - R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| |
Collapse
|
42
|
Abstract
The principle assumption of this discussion is that costimulation (CoS) forms the primary stimulus that compels T cells to mount a response to their specific antigen. However, this response can be either positive or negative, depending on the developmental stage of the T cell and the microenvironment in which the antigen and CoS are received. Thus, both immunity and tolerance may represent different outcomes of a two-signal process. We would emphasize that CoS is a functional term and not a strict molecular definition. While many molecular interactions have been described as providing CoS activity, notably those involving the B-7 family of cell surface molecules, it is not yet clear what combination(s) of non-antigen-specific signals may fulfil this function. This point is important because many studies have achieved tolerance through strategies designed to inhibit specific CoS molecules. However, it may be that differential signaling through distinct CoS molecules, rather than a global inhibition of CoS per se, plays a role in the generation of active tolerance in such studies (Bluestone 1995). A corollary of this notion is that antigen (signal 1) delivery to T cells is a null event and so is not an inherently paralysing signal. Of course, if signal 1 is not itself a tolerogenic signal, then other mechanisms are necessary to explain many empirical observations of tolerance to allogeneic or self antigens. This is best illustrated by those forms of functional tolerance to either alloantigens or self antigens that do not appear to be the result of clonal deletion/inactivation. It would be relatively simple to invoke a model of tolerance whereby the relevant tissue-destructive cell is eliminated or inactivated; such a model would preclude the necessity to suggest active regulatory mechanisms of tolerance. However, in several model systems, including our own observations concerning tolerance induction to APC-depleted islet allografts, tissue-destructive T cells can persist in recipients tolerant to allogeneic or self antigens. Furthermore, there are key examples in which tolerance demonstrates a dominant phenotype; that is, tolerant cells can regulate the activity of naive, non-tolerant cells. This latter observation points to the function of an active, regulatory form of tolerance. As such, we would emphasize that tolerance should not be defined as unresponsiveness since the tolerant state is the consequence of very active immune reactions.
Collapse
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | |
Collapse
|
43
|
Abstract
Donor-derived antigen-presenting cells (APC) are thought to serve as major stimulators for triggering the rejection of tissue allografts. However, the capacity of APC to stimulate xenogeneic T cells is generally deficient relative to the corresponding response from allogeneic T cells. For this reason, the contribution of donor-type APC to xenogeneic graft rejection remains unclear. Using a concordant species combination (rat to mouse), we examined the requirement for donor-type APC in triggering islet xenograft rejection. While the depletion of donor-type APC resulted in indefinite allograft survival, similar depletion of APC from xenogeneic rat islets resulted in only modest graft prolongation. Furthermore, APC-depleted rat xenografts were rejected by a CD8+ T cell-independent mechanism, as determined by appropriate depletion of T cell subsets through monoclonal antibody therapy. This contrasts with the dependence of islet allograft rejection on both CD4+ and CD8+ T cells. Although in vitro experiments show that rat APC can directly stimulate mouse T cells, rat APC do not appear to be required for xenograft immunity in vivo. We conclude that the mechanisms of islet allograft and xenograft rejection differ both in the dependence on donor-type APC and in the role of T cell subsets in the response.
Collapse
Affiliation(s)
- L A Wolf
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | |
Collapse
|
44
|
Stegall MD, Ostrowska A, Haynes J, Karrer F, Kam I, Gill RG. Prolongation of islet allograft survival with an antibody to vascular cell adhesion molecule 1. Surgery 1995; 118:366-9; discussion 369-70. [PMID: 7543705 DOI: 10.1016/s0039-6060(05)80346-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND The purpose of this study was to determine whether an antibody to vascular cell adhesion molecule 1 (VCAM1) prolongs the survival of neovascularized pancreatic islet allografts. METHODS We treated CBA (H-2k) recipients of BALB/c (H-2d) islet allografts with anti-VCAM1 antibody (400 micrograms/day for 20 days). Sensitized recipients of islet grafts also were treated with anti-VCAM1. To study mechanism we performed mixed lymphocyte reactions (MLRs) with anti-VCAM1 and studied the graft infiltrate in treated recipients. RESULTS Anti-VCAM1-treated CBA recipients showed prolonged graft survival with indefinite survival in five of nine cases. Anti-VCAM1 prevented proliferation in an MLR but not when added 36 hours after the beginning of the MLR. Anti-VCAM1 did not prolong allograft survival in sensitized recipients and did not prevent lymphocytic infiltration of the graft at 7 days. CONCLUSIONS Anti-VCAM1 prolongs allograft survival in neovascularized islets in which the donor vascular endothelium plays little or no role in immunogenicity. VCAM1 appears to be important in the afferent phase (lymphocyte activation) of the allograft response. Once activated, either late in an MLR or in sensitized recipients, lymphocytes are not dependent on VCAM1 for function. Finally, anti-VCAM1 does not appear to affect the homing of lymphocytes to the allograft.
Collapse
Affiliation(s)
- M D Stegall
- Department of Surgery, University of Colorado School of Medicine, Denver, USA
| | | | | | | | | | | |
Collapse
|
45
|
Abstract
The goal of cellular transplantation is to allow long-term function of the grafted cells using minimal host immunosuppression. To this end, the major strategies to implant cells and tissues are through: (i) the pretreatment of the graft to reduce tissue immunogenicity; (ii) the application of immunoisolation technologies to prevent host sensitization to implanted cells; and (iii) the induction of immunological tolerance to the donor tissues. Further, a major dilemma facing clinical tissue grafting is the shortage of donor tissue for transplantation. This problem requires the consideration of tissues from other species (xenografts) as a potential source of donor material. In light of these issues, the focus of this discussion is on the T cell-dependent response to allogeneic and xenogeneic transplants and the implications of this reactivity on the field of cellular replacement therapy.
Collapse
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | |
Collapse
|
46
|
Daniel D, Gill RG, Schloot N, Wegmann D. Epitope specificity, cytokine production profile and diabetogenic activity of insulin-specific T cell clones isolated from NOD mice. Eur J Immunol 1995; 25:1056-62. [PMID: 7537670 DOI: 10.1002/eji.1830250430] [Citation(s) in RCA: 285] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
T cells are known to play an important role in beta cell destruction in the nonobese diabetic (NOD) mouse model of Type I diabetes and islet-specific T cell clones have been demonstrated to be capable of adoptive transfer of diabetes. One important issue involves the identity of beta cell antigens that are recognized by nominally islet cell-specific T cell clones. We have previously reported that insulin-specific T cells are a predominant component of islet-specific T cells isolated from islet infiltrates of pre-diabetic NOD mice. In this report we examine six independently derived insulin-specific T cell clones established from islet infiltrates of pre-diabetic NOD mice in detail. All six clones were found to be specific to a region of the insulin molecule defined by a synthetic peptide encompassing residues 9-23 of the B chain. Despite this restricted specificity, each member of this panel exhibited a distinct receptor specificity defined either by V beta usage or antigen fine specificity. Five clones produced interferon (IFN)-gamma but not interleukin (IL)-4, placing them in the T helper type 1 (TH1)-like category whereas one clone produced both IL-4 and IFN-gamma, a characteristic of TH0 cells. All six clones were capable of either acceleration of diabetes in young NOD mice or adoptive transfer to NODscid mice. Taken together, these results suggest that spontaneously arising insulin-specific T cells participate in beta cell destruction during development of diabetes in NOD mice.
Collapse
Affiliation(s)
- D Daniel
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
| | | | | | | |
Collapse
|
47
|
Abstract
Insulin-specific T cells have been found to be present in high frequency among nominally islet-cell-specific T cells in the islet infiltrates that accumulate in NOD mice. In a previous report in which clones obtained from 7- and 12-week-old mice were examined, we identified a 15-residue peptide of the B chain as the dominent epitope for this response. Despite the fact that the response to insulin appears to be directed toward this single peptide, diverse TCR V beta usage was observed. That insulin-specific T cells contribute to beta cell damage is suggested by the fact that all clones tested could mediate beta cell destruction upon adoptive transfer. In the present report we extend this examination of insulin-specific T cells to lines and clones established from mice ranging in age from 4-12 weeks. These clones were found to be very similar to those from 7- and 12-week-old mice. The response was directed to the same peptide and most were found to produce IFN gamma, but none produced IL-4.
Collapse
Affiliation(s)
- D R Wegmann
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262
| | | | | | | | | |
Collapse
|
48
|
Affiliation(s)
- E H Leiter
- Jackson Laboratory, Bar Harbor, Maine 04609
| | | |
Collapse
|
49
|
Gill RG, Wolf L, Daniel D, Coulombe M. CD4+ T cells are both necessary and sufficient for islet xenograft rejection. Transplant Proc 1994; 26:1203. [PMID: 7913259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver 80262
| | | | | | | |
Collapse
|
50
|
Gill RG, Coulombe M. Islet xenografting in autoimmune diabetes. Transplant Proc 1994; 26:1140. [PMID: 7913256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences, Denver 80262
| | | |
Collapse
|