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Naaz A, Turnquist HR, Gorantla VS, Little SR. Drug delivery strategies for local immunomodulation in transplantation: Bridging the translational gap. Adv Drug Deliv Rev 2024:115429. [PMID: 39142608 DOI: 10.1016/j.addr.2024.115429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 08/07/2024] [Accepted: 08/11/2024] [Indexed: 08/16/2024]
Abstract
Drug delivery strategies for local immunomodulation hold tremendous promise compared to current clinical gold-standard systemic immunosuppression as they could improve the benefit to risk ratio of life-saving or life-enhancing transplants. Such strategies have facilitated prolonged graft survival in animal models at lower drug doses while minimizing off-target effects. Despite the promising outcomes in preclinical animal studies, progression of these strategies to clinical trials has faced challenges. A comprehensive understanding of the translational barriers is a critical first step towards clinical validation of effective immunomodulatory drug delivery protocols proven for safety and tolerability in pre-clinical animal models. This review overviews the current state-of-the-art in local immunomodulatory strategies for transplantation and outlines the key challenges hindering their clinical translation.
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Affiliation(s)
- Afsana Naaz
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261, United States; Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, 15213, United States.
| | - Heth R Turnquist
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, 15213, United States; Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, United States; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, 15213, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15219, United States.
| | - Vijay S Gorantla
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15219, United States; Departments of Surgery, Ophthalmology and Bioengineering, Wake Forest School of Medicine, Wake Forest Institute of Regenerative Medicine, Winston Salem, NC, 27101, United States.
| | - Steven R Little
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261, United States; Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, United States; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, 15213, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15219, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, United States; Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, United States; Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261, United States.
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Maguire C, Crivello P, Fleischhauer K, Isaacson D, Casillas A, Kramer CS, Copley HC, Heidt S, Kosmoliaptsis V, Meneghini M, Gmeiner M, Schold J, Louzoun Y, Tambur AR. Qualitative, rather than quantitative, differences between HLA-DQ alleles affect HLA-DQ immunogenicity in organ transplantation. HLA 2024; 103:e15455. [PMID: 38575370 PMCID: PMC11003724 DOI: 10.1111/tan.15455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/04/2024] [Accepted: 03/12/2024] [Indexed: 04/06/2024]
Abstract
Prolonging the lifespan of transplanted organs is critical to combat the shortage of this life-saving resource. Chronic rejection, with irreversible demise of the allograft, is often caused by the development of donor-specific HLA antibodies. Currently, enumerating molecular (amino acid) mismatches between recipient and donor is promoted to identify patients at higher risk of developing HLA antibodies, for use in organ allocation, and immunosuppression-minimization strategies. We have counseled against the incorporation of such approaches into clinical use and hypothesized that not all molecular mismatches equally contribute to generation of donor-specific immune responses. Herein, we document statistical shortcomings in previous study design: for example, use of individuals who lack the ability to generate donor-specific-antibodies (HLA identical) as part of the negative cohort. We provide experimental evidence, using CRISPR-Cas9-edited cells, to rebut the claim that the HLAMatchmaker eplets represent "functional epitopes." We further used unique sub-cohorts of patients, those receiving an allograft with two HLA-DQ mismatches yet developing antibodies only to one mismatch (2MM1DSA), to interrogate differential immunogenicity. Our results demonstrate that mismatches of DQα05-heterodimers exhibit the highest immunogenicity. Additionally, we demonstrate that the DQα chain critically contributes to the overall qualities of DQ molecules. Lastly, our data proposes that an augmented risk to develop donor-specific HLA-DQ antibodies is dependent on qualitative (evolutionary and functional) divergence between recipient and donor, rather than the mere number of molecular mismatches. Overall, we propose an immunological mechanistic rationale to explain differential HLA-DQ immunogenicity, with potential ramifications for other pathological processes such as autoimmunity and infections.
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Affiliation(s)
- Chelsea Maguire
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
| | - Pietro Crivello
- Institute for Experimental Cellular Therapy, University Hospital Essen; Essen, Germany. 45127
| | - Katharina Fleischhauer
- Institute for Experimental Cellular Therapy, University Hospital Essen; Essen, Germany. 45127
- German Cancer Consortium (DKTK), partner site Essen/Düsseldorf; Essen, Germany. 45127
| | - Dylan Isaacson
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
| | - Aurora Casillas
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
| | - Cynthia S.M. Kramer
- Department of Immunology, Leiden University Medical Center; Netherlands. 2300-2334
| | - Hannah C. Copley
- Department of Surgery, University of Cambridge; Cambridge, United Kingdom. CB2 3AX
| | - Sebastian Heidt
- Department of Immunology, Leiden University Medical Center; Netherlands. 2300-2334
| | | | - Maria Meneghini
- Vall d’Hebron Institut de Recerca, Vall d’Hebron Hospital Universitari; Barcelona, Spain. 08035
| | - Michael Gmeiner
- Department of Economics, London School of Economics; London, United Kingdom. WC2A 2AE
| | - Jesse Schold
- Department of surgery, university of Colorado Anschutz Medical campus; Aurora, CO, USA. 80045
- Department of epidemiology, university of Colorado Anschutz Medical campus; Aurora, CO, USA. 80045
| | - Yoram Louzoun
- Department of mathematics Bar Ilan University; Ramat Gan, Israel. 5290002
| | - Anat R. Tambur
- Department of Surgery, Comprehensive Transplant Center; Northwestern University, Chicago, IL, USA. 60611
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Tambur AR, Das R. Can We Use Eplets (or Molecular) Mismatch Load Analysis to Improve Organ Allocation? The Hope and the Hype. Transplantation 2023; 107:605-615. [PMID: 36163639 PMCID: PMC9944744 DOI: 10.1097/tp.0000000000004307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/14/2022] [Accepted: 07/03/2022] [Indexed: 11/25/2022]
Abstract
In recent years, there have been calls for implementation of "epitope matching" in deceased-donor organ allocation policies (later changed to "eplet matching"). Emerging data indeed support the use of molecular mismatch load analysis in specific patient groups, with the objective of posttransplant stratification into different treatment arms. For this purpose, the expectation is to statistically categorize patients as low- or high-immune-risk. Importantly, these patients will continue to be monitored' and their risk category, as well as their management, can be adjusted according to on-going findings. However, when discussing deceased donor organ allocation and matching algorithms, where the decision is not modifiable and has lasting impact on outcomes, the situation is fundamentally different. The goal of changing allocation schemes is to achieve the best possible HLA compatibility between donor and recipient. Immunologically speaking, this is a very different objective. For this purpose, the specific interplay of immunogenicity between the donor and any potential recipient must be understood. In seeking compatibility, the aim is not to redefine matching but to identify those mismatches that are "permissible" or' in other words, less immunogenic. In our eagerness to improve transplant outcome, unfortunately, we have conflated the hype with the hope. Terminology is used improperly, and new terms are created in the process with no sufficient support. Here, we call for a cautious evaluation of baseline assumptions and a critical review of the evidence to minimize unintended consequences.
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Affiliation(s)
- Anat R. Tambur
- Comprehensive Transplant Center, Department of Surgery, Northwestern University, Chicago, IL
| | - Rajdeep Das
- Comprehensive Transplant Center, Department of Surgery, Northwestern University, Chicago, IL
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Tambur AR, McDowell H, Hod-Dvorai R, Abundis MAC, Pinelli DF. The quest to decipher HLA immunogenicity: Telling friend from foe. Am J Transplant 2019; 19:2910-2925. [PMID: 31165546 DOI: 10.1111/ajt.15489] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/14/2019] [Accepted: 05/15/2019] [Indexed: 01/25/2023]
Abstract
Molecular mismatch load analysis was recently introduced as a means for performing risk stratification following organ transplantation. However, although good correlation was demonstrated between molecular mismatch load and generation of de novo donor-specific HLA antibody (DSA), quite a few exceptions exist, and the underlying factors that define HLA immunogenicity remain unclear. Herein, we present a new paradigm to interrogate differences between molecular mismatches that lead to the generation of de novo DSA and those that do not (the 2MM1DSA cohort). Specifically, patients transplanted across 2 HLA-DQ mismatches, who formed de novo DSA only to one mismatch (foe) but not the other (friend), provide a unique environment in which patient-specific factors that affect the immune response other than immunogenicity, such as infection and immunosuppression, can be controlled for. It further permits focusing on mismatches uniquely exhibited by the de novo DSA allele, rather than mismatches shared by both DSA and non-DSA alleles. This concept paper illustrates several examples, highlights the need for center-specific or population-specific cutoff values for posttransplant risk stratification, and mostly argues that if there is no direct correlation between molecular mismatch load and immunogenicity, then molecular mismatch load must not be adopted as an approach for equitable organ allocation.
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Affiliation(s)
- Anat R Tambur
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - Hannah McDowell
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - Reut Hod-Dvorai
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - Maria A C Abundis
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
| | - David F Pinelli
- Transplant Immunology Laboratory, Comprehensive Transplant Center, Northwestern University, Chicago, Illinois
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Abstract
Purpose of review Accurate and timely detection and characterization of human leukocyte antigen (HLA) antibodies are critical for pre-transplant and post-transplant immunological risk assessment. Solid phase immunoassays have provided increased sensitivity and specificity, but test interpretation is not always straightforward. This review will discuss the result interpretation considering technical limitations; assessment of relative antibody strength; and the integration of data for risk stratification from complementary testing and the patient's immunological history. Recent findings Laboratory and clinical studies have provided insight into causes of test failures – false positive reactions because of antibodies to denatured HLA antigens and false negative reactions resulting from test interference and/or loss of native epitopes. Test modifications permit detection of complement-binding antibodies and determination of the IgG subclasses. The high degree of specificity of single antigen solid phase immunoassays has revealed the complexity and clinical relevance of antibodies to HLA-C, HLA-DQ, and HLA-DP antigens. Determination of antibody specificity for HLA epitopes enables identification of incompatible antigens not included in test kits. Summary Detection and characterization of HLA antibodies with solid phase immunoassays has led to increased understanding of the role of those antibodies in graft rejection, improved treatment of antibody-mediated rejection, and increased opportunities for transplantation. However, realization of these benefits requires careful and accurate interpretation of test results.
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Abstract
Type 1 diabetes is an autoimmune disorder in which the immune system attacks and destroys insulin-producing islet cells of the pancreas. Although islet transplantation has proved to be successful for some patients with type 1 diabetes, its widespread use is limited by islet donor shortage and the requirement for lifelong immunosuppression. An encapsulation strategy that can prevent the rejection of xenogeneic islets or of stem cell-derived allogeneic islets can potentially eliminate both of these barriers. Although encapsulation technology has met several challenges, the convergence of expertise in materials, nanotechnology, stem cell biology and immunology is allowing us to get closer to the goal of encapsulated islet cell therapy for humans.
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Affiliation(s)
- Tejal Desai
- University of California, San Francisco, Department of Bioengineering and Therapeutic Sciences, Byers Hall Rm 203C, MC 2520, 1700 4th Street, San Francisco, California 94158-2330, USA
| | - Lonnie D Shea
- University of Michigan, Department of Biomedical Engineering, 1119 Carl A. Gerstacker Building, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109-2099, USA
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Abstract
The undesired destruction of healthy cells, either endogenous or transplanted, by the immune system results in the loss of tissue function or limits strategies to restore tissue function. Current therapies typically involve nonspecific immunosuppression that may prevent the appropriate response to an antigen, thereby decreasing humoral immunity and increasing the risks of patient susceptibility to opportunistic infections, viral reactivation, and neoplasia. The induction of antigen-specific immunological tolerance to block undesired immune responses to self- or allogeneic antigens, while maintaining the integrity of the remaining immune system, has the potential to transform the current treatment of autoimmune disease and serve as a key enabling technology for therapies based on cell transplantation.
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Affiliation(s)
- Xunrong Luo
- Department of Medicine, Division of Nephrology and Hypertension.,Comprehensive Cancer Center, and
| | - Stephen D Miller
- Department of Microbiology-Immunology and Interdepartmental Immunobiology Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611; ,
| | - Lonnie D Shea
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109;
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