RESUMEN
Effector CD8+ T cells are important mediators of adaptive immunity, and receptor-ligand interactions that regulate their survival may have therapeutic potential. Here, we identified a subset of effector CD8+ T cells that expressed the inhibitory fragment crystallizable (Fc) receptor FcγRIIB following activation and multiple rounds of division. CD8+ T cell-intrinsic genetic deletion of Fcgr2b increased CD8+ effector T cell accumulation, resulting in accelerated graft rejection and decreased tumor volume in mouse models. Immunoglobulin G (IgG) antibody was not required for FcγRIIB-mediated control of CD8+ T cell immunity, and instead, the immunosuppressive cytokine fibrinogen-like 2 (Fgl2) was a functional ligand for FcγRIIB on CD8+ T cells. Fgl2 induced caspase-3/7-mediated apoptosis in Fcgr2b+, but not Fcgr2b-/-, CD8+ T cells. Increased expression of FcγRIIB correlated with freedom from rejection following withdrawal from immunosuppression in a clinical trial of kidney transplant recipients. Together, these findings demonstrate a cell-intrinsic coinhibitory function of FcγRIIB in regulating CD8+ T cell immunity.
Asunto(s)
Apoptosis/inmunología , Linfocitos T CD8-positivos/inmunología , Fibrinógeno/inmunología , Receptores de IgG/inmunología , Adulto , Anciano , Animales , Caspasa 3/inmunología , Caspasa 7/inmunología , Línea Celular Tumoral , Femenino , Fibrinógeno/genética , Rechazo de Injerto/inmunología , Humanos , Inmunoglobulina G/inmunología , Terapia de Inmunosupresión , Masculino , Melanoma Experimental , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Receptores de IgG/genética , Adulto JovenRESUMEN
Recent human decedent model studies1,2 and compassionate xenograft use3 have explored the promise of porcine organs for human transplantation. To proceed to human studies, a clinically ready porcine donor must be engineered and its xenograft successfully tested in nonhuman primates. Here we describe the design, creation and long-term life-supporting function of kidney grafts from a genetically engineered porcine donor transplanted into a cynomolgus monkey model. The porcine donor was engineered to carry 69 genomic edits, eliminating glycan antigens, overexpressing human transgenes and inactivating porcine endogenous retroviruses. In vitro functional analyses showed that the edited kidney endothelial cells modulated inflammation to an extent that was indistinguishable from that of human endothelial cells, suggesting that these edited cells acquired a high level of human immune compatibility. When transplanted into cynomolgus monkeys, the kidneys with three glycan antigen knockouts alone experienced poor graft survival, whereas those with glycan antigen knockouts and human transgene expression demonstrated significantly longer survival time, suggesting the benefit of human transgene expression in vivo. These results show that preclinical studies of renal xenotransplantation could be successfully conducted in nonhuman primates and bring us closer to clinical trials of genetically engineered porcine renal grafts.
Asunto(s)
Rechazo de Injerto , Trasplante de Riñón , Macaca fascicularis , Porcinos , Trasplante Heterólogo , Animales , Humanos , Animales Modificados Genéticamente , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Trasplante de Riñón/métodos , Polisacáridos/deficiencia , Porcinos/genética , Trasplante Heterólogo/métodos , Transgenes/genéticaRESUMEN
The ability of the immune system to discriminate self from non-self is essential for eradicating microbial pathogens but is also responsible for allograft rejection. Whether it is possible to selectively suppress alloresponses while maintaining anti-pathogen immunity remains unknown. We found that mice deficient in coronin 1, a regulator of naive T cell homeostasis, fully retained allografts while maintaining T cell-specific responses against microbial pathogens. Mechanistically, coronin 1-deficiency increased cyclic adenosine monophosphate (cAMP) concentrations to suppress allo-specific T cell responses. Costimulation induced on microbe-infected antigen presenting cells was able to overcome cAMP-mediated immunosuppression to maintain anti-pathogen immunity. In vivo pharmacological modulation of this pathway or a prior transfer of coronin 1-deficient T cells actively suppressed allograft rejection. These results define a coronin 1-dependent regulatory axis in T cells important for allograft rejection and suggest that modulation of this pathway may be a promising approach to achieve long-term acceptance of mismatched allografts.
Asunto(s)
Rechazo de Injerto/inmunología , Trasplante de Corazón , Infecciones/inmunología , Proteínas de Microfilamentos/metabolismo , Trasplante de Piel , Linfocitos T/inmunología , Aloinjertos/inmunología , Animales , Antígenos Bacterianos/inmunología , Antígenos Fúngicos/inmunología , Antígenos Virales/inmunología , Células Cultivadas , AMP Cíclico/inmunología , Supervivencia de Injerto , Homeostasis/genética , Humanos , Inmunidad , Terapia de Inmunosupresión , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal , Tolerancia al TrasplanteRESUMEN
BACKGROUND: Antibody-mediated rejection is a leading cause of kidney-transplant failure. The targeting of CD38 to inhibit graft injury caused by alloantibodies and natural killer (NK) cells may be a therapeutic option. METHODS: In this phase 2, double-blind, randomized, placebo-controlled trial, we assigned patients with antibody-mediated rejection that had occurred at least 180 days after transplantation to receive nine infusions of the CD38 monoclonal antibody felzartamab (at a dose of 16 mg per kilogram of body weight) or placebo for 6 months, followed by a 6-month observation period. The primary outcome was the safety and side-effect profile of felzartamab. Key secondary outcomes were renal-biopsy results at 24 and 52 weeks, donor-specific antibody levels, peripheral NK-cell counts, and donor-derived cell-free DNA levels. RESULTS: A total of 22 patients underwent randomization (11 to receive felzartamab and 11 to receive placebo). The median time from transplantation until trial inclusion was 9 years. Mild or moderate infusion reactions occurred in 8 patients in the felzartamab group. Serious adverse events occurred in 1 patient in the felzartamab group and in 4 patients in the placebo group; graft loss occurred in 1 patient in the placebo group. At week 24, resolution of morphologic antibody-mediated rejection was more frequent with felzartamab (in 9 of 11 patients [82%]) than with placebo (in 2 of 10 patients [20%]), for a difference of 62 percentage points (95% confidence interval [CI], 19 to 100) and a risk ratio of 0.23 (95% confidence interval [CI], 0.06 to 0.83). The median microvascular inflammation score was lower in the felzartamab group than in the placebo group (0 vs. 2.5), for a mean difference of -1.95 (95% CI, -2.97 to -0.92). Also lower was a molecular score reflecting the probability of antibody-mediated rejection (0.17 vs. 0.77) and the level of donor-derived cell-free DNA (0.31% vs. 0.82%). At week 52, the recurrence of antibody-mediated rejection was reported in 3 of 9 patients who had a response to felzartamab, with an increase in molecular activity and biomarker levels toward baseline levels. CONCLUSIONS: Felzartamab had acceptable safety and side-effect profiles in patients with antibody-mediated rejection. (Funded by MorphoSys and Human Immunology Biosciences; ClinicalTrials.gov number, NCT05021484; and EUDRACT number, 2021-000545-40.).
Asunto(s)
Rechazo de Injerto , Isoanticuerpos , Trasplante de Riñón , Células Asesinas Naturales , Humanos , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Método Doble Ciego , Femenino , Masculino , Persona de Mediana Edad , Trasplante de Riñón/efectos adversos , Células Asesinas Naturales/inmunología , Adulto , Isoanticuerpos/sangre , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/efectos adversos , Riñón/patología , Riñón/inmunología , Anciano , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales/efectos adversosRESUMEN
Alloreactive memory T cells have been implicated as central drivers of transplant rejection. Perplexingly, innate cytokines, such as IL-6, IL-1ß, and IL-12, are also associated with rejection of organ transplants. However, the pathways of innate immune activation in allogeneic transplantation are unclear. While the role of microbial and cell death products has been previously described, we identified alloreactive memory CD4 T cells as the primary triggers of innate inflammation. Memory CD4 T cells engaged MHC II-mismatched dendritic cells (DCs), leading to the production of innate inflammatory cytokines. This innate inflammation was independent of several pattern recognition receptors and was primarily driven by TNF superfamily ligands expressed by alloreactive memory CD4 T cells. Blocking of CD40L and TNFα resulted in dampened inflammation, and mice genetically deficient in these molecules exhibited prolonged survival of cardiac allografts. Furthermore, myeloid cell and CD8 T cell infiltration into cardiac transplants was compromised in both CD40L- and TNFα-deficient recipients. Strikingly, we found that priming of naive alloreactive CD8 T cells was dependent on licensing of DCs by memory CD4 T cells. This study unravels the key mechanisms by which alloreactive memory CD4 T cells contribute to destructive pathology and transplant rejection.
Asunto(s)
Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Células Dendríticas , Rechazo de Injerto , Trasplante de Corazón , Inmunidad Innata , Inflamación , Animales , Rechazo de Injerto/inmunología , Ratones , Células Dendríticas/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD4-Positivos/inmunología , Inflamación/inmunología , Inmunidad Innata/inmunología , Ratones Endogámicos C57BL , Ligando de CD40/inmunología , Ligando de CD40/metabolismo , Células T de Memoria/inmunología , Ratones Noqueados , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/inmunología , Citocinas/metabolismo , Citocinas/inmunologíaRESUMEN
Solid organ transplantation mobilizes myeloid cells, including monocytes and macrophages, which are central protagonists of allograft rejection. However, myeloid cells can also be functionally reprogrammed by perioperative costimulatory blockade to promote a state of transplantation tolerance. Transplantation tolerance holds promise to reduce complications from chronic immunosuppression and promote long-term survival in transplant recipients. We sought to identify different mediators of transplantation tolerance by performing single-cell RNA sequencing of acute rejecting or tolerized cardiac allografts. This led to the unbiased identification of the transcription factor, hypoxia inducible factor (HIF)-2α, in a subset of tolerogenic monocytes. Using flow cytometric analyses and mice with conditional loss or gain of function, we uncovered that myeloid cell expression of HIF-2α was required for costimulatory blockade-induced transplantation tolerance. While HIF-2α was dispensable for mobilization of tolerogenic monocytes, which were sourced in part from the spleen, it promoted the expression of colony stimulating factor 1 receptor (CSF1R). CSF1R mediates monocyte differentiation into tolerogenic macrophages and was found to be a direct transcriptional target of HIF-2α in splenic monocytes. Administration of the HIF stabilizer, roxadustat, within micelles to target myeloid cells, increased HIF-2α in splenic monocytes, which was associated with increased CSF1R expression and enhanced cardiac allograft survival. These data support further exploration of HIF-2α activation in myeloid cells as a therapeutic strategy for transplantation tolerance.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Trasplante de Corazón , Macrófagos , Monocitos , Tolerancia al Trasplante , Animales , Ratones , Macrófagos/metabolismo , Macrófagos/inmunología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Tolerancia al Trasplante/inmunología , Monocitos/inmunología , Monocitos/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Rechazo de Injerto/genética , Ratones Endogámicos C57BL , Regulación de la Expresión Génica/efectos de los fármacos , Supervivencia de Injerto/inmunología , Supervivencia de Injerto/efectos de los fármacos , MasculinoRESUMEN
CD4+ T cells orchestrate immune responses and destruction of allogeneic organ transplants, but how this process is regulated on a transcriptional level remains unclear. Here, we demonstrated that interferon regulatory factor 4 (IRF4) was a key transcriptional determinant controlling T cell responses during transplantation. IRF4 deletion in mice resulted in progressive establishment of CD4+ T cell dysfunction and long-term allograft survival. Mechanistically, IRF4 repressed PD-1, Helios, and other molecules associated with T cell dysfunction. In the absence of IRF4, chromatin accessibility and binding of Helios at PD-1 cis-regulatory elements were increased, resulting in enhanced PD-1 expression and CD4+ T cell dysfunction. The dysfunctional state of Irf4-deficient T cells was initially reversible by PD-1 ligand blockade, but it progressively developed into an irreversible state. Hence, IRF4 controls a core regulatory circuit of CD4+ T cell dysfunction, and targeting IRF4 represents a potential therapeutic strategy for achieving transplant acceptance.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Rechazo de Injerto/inmunología , Supervivencia de Injerto , Trasplante de Corazón , Factores Reguladores del Interferón/inmunología , Animales , Linfocitos T CD4-Positivos/patología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Diferenciación Celular , Movimiento Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Rechazo de Injerto/genética , Rechazo de Injerto/mortalidad , Rechazo de Injerto/patología , Granzimas/genética , Granzimas/inmunología , Factores Reguladores del Interferón/deficiencia , Factores Reguladores del Interferón/genética , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-17/genética , Interleucina-17/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/inmunología , Receptor de Muerte Celular Programada 1/genética , Receptor de Muerte Celular Programada 1/inmunología , Transducción de Señal , Análisis de Supervivencia , Factores de Transcripción/genética , Factores de Transcripción/inmunología , Trasplante HomólogoRESUMEN
In transplantation, anti-HLA Abs, especially targeting the DQ locus, are well-known to lead to rejection. These Abs identified by Luminex single Ag assays recognize polymorphic amino acids on HLA, named eplets. The HLA Eplet Registry included 83 DQ eplets, mainly deduced from amino acid sequence alignments, among which 66 have not been experimentally verified. Because eplet mismatch load may improve organ allocation and transplant outcomes, it is imperative to confirm the genuine reactivity of eplets to validate this approach. Our study aimed to confirm 29 nonverified eplets, using adsorption of eplet-positive patients' sera on human spleen mononuclear cells and on transfected murine cell clones expressing a unique DQα- and DQß-chain combination. In addition, we compared the positive beads patterns obtained in the two commercially available Luminex single Ag assays. Among the 29 nonverified DQ eplets studied, 24 were confirmed by this strategy, including the 7 DQα eplets 40E, 40ERV, 75I, 76 V, 129H, 129QS, and 130A and the 17 DQß eplets 3P, 23L, 45G, 56L, 57 V, 66DR, 66ER, 67VG, 70GT, 74EL, 86A, 87F, 125G, 130R, 135D, 167R, and 185I. However, adsorption results did not allow us to conclude for the five eplets 66IT, 75S, 160D, 175E, and 185T.
Asunto(s)
Antígenos HLA-DQ , Humanos , Animales , Ratones , Antígenos HLA-DQ/inmunología , Prueba de Histocompatibilidad/métodos , Rechazo de Injerto/inmunología , Leucocitos Mononucleares/inmunología , Secuencia de AminoácidosRESUMEN
Adoptive cell therapy (ACT), especially with CD4+ regulatory T cells (CD4+ Tregs), is an emerging therapeutic strategy to minimize immunosuppression and promote long-term allograft acceptance, although much research remains to realize its potential. In this study, we investigated the potency of novel Ab-suppressor CXCR5+CD8+ T cells (CD8+ TAb-supp) in comparison with conventional CD25highFoxp3+CD4+ Tregs for suppression of humoral alloimmunity in a murine kidney transplant (KTx) model of Ab-mediated rejection (AMR). We examined quantity of peripheral blood, splenic and graft-infiltrating CD8+ TAb-supp, and CD4+ Tregs in KTx recipients and found that high alloantibody-producing CCR5 knockout KTx recipients have significantly fewer post-transplant peripheral blood and splenic CD8+ TAb-supp, as well as fewer splenic and graft-infiltrating CD4+ Tregs compared with wild-type KTx recipients. ACT with alloprimed CXCR5+CD8+ T cells reduced alloantibody titer, splenic alloprimed germinal center (GC) B cell quantity, and improved AMR histology in CCR5 knockout KTx recipients. ACT with alloprimed CD4+ Treg cells improved AMR histology without significantly inhibiting alloantibody production or the quantity of splenic alloprimed GC B cells. Studies with TCR transgenic mice confirmed Ag specificity of CD8+ TAb-supp-mediated effector function. In wild-type recipients, CD8 depletion significantly increased alloantibody titer, GC B cells, and severity of AMR pathology compared with isotype-treated controls. Anti-CD25 mAb treatment also resulted in increased but less pronounced effect on alloantibody titer, quantity of GC B cells, and AMR pathology than CD8 depletion. To our knowledge, this is the first report that CD8+ TAb-supp cells are more potent regulators of humoral alloimmunity than CD4+ Treg cells.
Asunto(s)
Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Trasplante de Riñón , Linfocitos T Reguladores , Animales , Ratones , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Rechazo de Injerto/inmunología , Isoanticuerpos , Trasplante de Riñón/efectos adversos , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Receptores CXCR5/inmunología , Inmunidad Humoral/inmunologíaRESUMEN
BACKGROUND: Much of our knowledge of organ rejection after transplantation is derived from rodent models. METHODS: We used single-nucleus RNA sequencing to investigate the inflammatory myocardial microenvironment in human pediatric cardiac allografts at different stages after transplantation. We distinguished donor- from recipient-derived cells using naturally occurring genetic variants embedded in single-nucleus RNA sequencing data. RESULTS: Donor-derived tissue resident macrophages, which accompany the allograft into the recipient, are lost over time after transplantation. In contrast, monocyte-derived macrophages from the recipient populate the heart within days after transplantation and form 2 macrophage populations: recipient MP1 and recipient MP2. Recipient MP2s have cell signatures similar to donor-derived resident macrophages; however, they lack signatures of pro-reparative phagocytic activity typical of donor-derived resident macrophages and instead express profibrotic genes. In contrast, recipient MP1s express genes consistent with hallmarks of cellular rejection. Our data suggest that recipient MP1s activate a subset of natural killer cells, turning them into a cytotoxic cell population through feed-forward signaling between recipient MP1s and natural killer cells. CONCLUSIONS: Our findings reveal an imbalance of donor-derived and recipient-derived macrophages in the pediatric cardiac allograft that contributes to allograft failure.
Asunto(s)
Aloinjertos , Rechazo de Injerto , Trasplante de Corazón , Macrófagos , Humanos , Trasplante de Corazón/efectos adversos , Macrófagos/metabolismo , Rechazo de Injerto/inmunología , Rechazo de Injerto/genética , Masculino , Femenino , Niño , Preescolar , Miocardio/patología , Supervivencia de Injerto , Lactante , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , AdolescenteRESUMEN
Autoimmunity, allergy, and transplant rejection are a collection of chronic diseases that are currently incurable, drastically decrease patient quality of life, and consume considerable health care resources. Underlying each of these diseases is a dysregulated immune system that results in the mounting of an inflammatory response against self or an innocuous antigen. As a consequence, afflicted patients are required to adhere to lifelong regimens of multiple immunomodulatory drugs to control disease and reclaim agency. Unfortunately, current immunomodulatory drugs are associated with a myriad of side effects and adverse events, such as increased risk of cancer and increased risk of serious infection, which negatively impacts patient adherence rates and quality of life. The field of immunoengineering is a new discipline that aims to harness endogenous biological pathways to thwart disease and minimize side effects using novel biomaterial-based strategies. We highlight and discuss polymeric micro/nanoparticles with inherent immunomodulatory properties that are currently under investigation in biomaterial-based therapies for treatment of autoimmunity, allergy, and transplant rejection.
Asunto(s)
Autoinmunidad , Rechazo de Injerto , Hipersensibilidad , Polímeros , Humanos , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Polímeros/química , Autoinmunidad/efectos de los fármacos , Hipersensibilidad/inmunología , Hipersensibilidad/terapia , Animales , Materiales Biocompatibles/química , Nanopartículas/química , Enfermedades Autoinmunes/terapia , Enfermedades Autoinmunes/inmunología , Agentes Inmunomoduladores/uso terapéutico , Factores Inmunológicos/uso terapéuticoRESUMEN
The ultimate outcome of alloreactivity versus tolerance following transplantation is potently influenced by the constellation of cosignaling molecules expressed by immune cells during priming with alloantigen, and the net sum of costimulatory and coinhibitory signals transmitted via ligation of these molecules. Intense investigation over the last two decades has yielded a detailed understanding of the kinetics, cellular distribution, and intracellular signaling networks of cosignaling molecules such as the CD28, TNF, and TIM families of receptors in alloimmunity. More recent work has better defined the cellular and molecular mechanisms by which engagement of cosignaling networks serve to either dampen or augment alloimmunity. These findings will likely aid in the rational development of novel immunomodulatory strategies to prolong graft survival and improve outcomes following transplantation.
Asunto(s)
Rechazo de Injerto/inmunología , Inmunoterapia/métodos , Trasplante de Órganos , Receptor Cross-Talk , Linfocitos T/inmunología , Animales , Antígenos CD28/metabolismo , Proteínas de Ciclo Celular/metabolismo , Rechazo de Injerto/prevención & control , Humanos , Inmunoterapia/tendencias , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Activación de Linfocitos , Transducción de Señal , Inmunología del Trasplante , Tolerancia al Trasplante , Trasplante Homólogo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
NK cell education, a term describing a process for NK cell acquisition of functional competence, is primarily achieved by self-MHC-I-specific inhibitory receptors. In this study, we have demonstrated that SLAM family receptors (SFRs) redundantly expressed on hematopoietic cells function as self-specific activation receptors critical for NK cell education. To overcome gene redundancy, we generated mice simultaneously lacking seven SFRs, revealing that NK-cell-mediated rejection of semi-allogeneic hematopoietic cells largely depended on the presence of SFRs on target cells. This stimulatory effect was determined by the presence of SFR-coupled adaptors; however, SFR-deficient mice displayed enhanced reactivity to hematopoietic cells. These findings demonstrate that SFRs endow NK cells with an ability to kill hematopoietic cells during the effector phase; however, the sustained engagement of SFRs can desensitize NK cell responses during an education process. Therefore, self-specific activating ligands may be "tolerogens" for NK cells, akin to self-antigens that induce T cell tolerance.
Asunto(s)
Rechazo de Injerto/inmunología , Trasplante de Células Madre Hematopoyéticas , Células Asesinas Naturales/inmunología , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/metabolismo , Tolerancia al Trasplante , Animales , Autoantígenos/inmunología , Diferenciación Celular , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Citotoxicidad Inmunológica , Humanos , Isoantígenos/inmunología , Activación de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/genéticaRESUMEN
Cytomegalovirus (CMV) infection is associated with graft rejection in renal transplantation. Memory-like natural killer (NK) cells expressing NKG2C and lacking FcεRIγ are established during CMV infection. Additionally, CD8+ T cells expressing NKG2C have been observed in some CMV-seropositive patients. However, in vivo kinetics detailing the development and differentiation of these lymphocyte subsets during CMV infection remain limited. Here, we interrogated the in vivo kinetics of lymphocytes in CMV-infected renal transplant patients using longitudinal samples compared with those of nonviremic (NV) patients. Recipient CMV-seropositive (R+) patients had preexisting memory-like NK cells (NKG2C+CD57+FcεRIγ-) at baseline, which decreased in the periphery immediately after transplantation in both viremic and NV patients. We identified a subset of prememory-like NK cells (NKG2C+CD57+FcεRIγlow-dim) that increased during viremia in R+ viremic patients. These cells showed a higher cytotoxic profile than preexisting memory-like NK cells with transient up-regulation of FcεRIγ and Ki67 expression at the acute phase, with the subsequent accumulation of new memory-like NK cells at later phases of viremia. Furthermore, cytotoxic NKG2C+CD8+ T cells and γδ T cells significantly increased in viremic patients but not in NV patients. These three different cytotoxic cells combinatorially responded to viremia, showing a relatively early response in R+ viremic patients compared with recipient CMV-seronegative viremic patients. All viremic patients, except one, overcame viremia and did not experience graft rejection. These data provide insights into the in vivo dynamics and interplay of cytotoxic lymphocytes responding to CMV viremia, which are potentially linked with control of CMV viremia to prevent graft rejection.
Asunto(s)
Infecciones por Citomegalovirus/inmunología , Citometría de Flujo/métodos , Células Asesinas Naturales/metabolismo , Adulto , Linfocitos T CD8-positivos/metabolismo , Separación Celular/métodos , Citomegalovirus/metabolismo , Citomegalovirus/patogenicidad , Infecciones por Citomegalovirus/virología , Femenino , Rechazo de Injerto/inmunología , Humanos , Trasplante de Riñón/efectos adversos , Trasplante de Riñón/métodos , Células Asesinas Naturales/inmunología , Cinética , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , Subfamília C de Receptores Similares a Lectina de Células NK/metabolismo , Análisis de la Célula Individual/métodos , Viremia/inmunología , Viremia/virologíaRESUMEN
The extent to which tissue-resident memory T (TRM) cells in transplanted organs possess alloreactivity is uncertain. This study investigates the alloreactive potential of TRM cells in kidney explants from 4 patients who experienced severe acute rejection leading to graft loss. Alloreactive T cell receptor (TCR) clones were identified in pretransplant blood samples through mixed lymphocyte reactions, followed by single-cell RNA and TCR sequencing of the proliferated recipient T cells. Subsequently, these TCR clones were traced in the TRM cells of kidney explants, which were also subjected to single-cell RNA and TCR sequencing. The proportion of recipient-derived TRM cells expressing an alloreactive TCR in the 4 kidney explants varied from 0% to 9%. Notably, these alloreactive TCRs were predominantly found among CD4+ and CD8+ TRM cells with an effector phenotype. Intriguingly, these clones were present not only in recipient-derived TRM cells but also in donor-derived TRM cells, constituting up to 4% of the donor population, suggesting the presence of self-reactive TRM cells. Overall, our study demonstrates that T cells with alloreactive potential present in the peripheral blood prior to transplantation can infiltrate the kidney transplant and adopt a TRM phenotype.
Asunto(s)
Rechazo de Injerto , Trasplante de Riñón , Células T de Memoria , Humanos , Células T de Memoria/inmunología , Rechazo de Injerto/inmunología , Masculino , Femenino , Memoria Inmunológica , Persona de Mediana Edad , Supervivencia de Injerto/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Adulto , Pronóstico , Estudios de Seguimiento , Linfocitos T CD8-positivos/inmunología , Fallo Renal Crónico/cirugía , Fallo Renal Crónico/inmunología , Donantes de TejidosRESUMEN
Following solid organ transplantation, small precursor populations of polyclonal CD8+ T cells specific for any graft-expressed antigen preferentially expand their high-affinity clones. This phenomenon, termed "avidity maturation," results in a larger population of CD8+ T cells with increased sensitivity to alloantigen, posing a greater risk for graft rejection. Using a mouse model of minor-mismatched skin transplantation, coupled with the tracking of 2 skin graft-reactive CD8+ T cell receptor-transgenic tracer populations with high and low affinity for the same peptide-major histocompatibility complex, we explored the conventional paradigm that CD8+ T cell avidity maturation occurs through T cell receptor affinity-based competition for cognate antigen. Our data revealed "interclonal CD8-CD8 help," whereby lower/intermediate affinity clones help drive the preferential expansion of their higher affinity counterparts in an interleukin-2/CD25-dependent manner. Consequently, the CD8-helped high-affinity clones exhibit greater expansion and develop augmented effector functions in the presence of their low-affinity counterparts, correlating with more severe graft damage. Finally, interclonal CD8-CD8 help was suppressed by costimulation blockade treatment. Thus, high-affinity CD8+ T cells can leverage help from low-affinity CD8+ T cells of identical specificity to promote graft rejection. Suppressing provision of interclonal CD8-CD8 help may be important to improve transplant outcomes.
Asunto(s)
Linfocitos T CD8-positivos , Rechazo de Injerto , Ratones Endogámicos C57BL , Trasplante de Piel , Animales , Linfocitos T CD8-positivos/inmunología , Ratones , Rechazo de Injerto/inmunología , Isoantígenos/inmunología , Ratones Transgénicos , Ratones Endogámicos BALB C , Supervivencia de Injerto/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/genéticaRESUMEN
Cardiac allograft vasculopathy (CAV) causes late graft failure and mortality after heart transplantation. Donor-specific antibodies (DSAs) lead to chronic endothelial cell injury, inflammation, and arterial intimal thickening. In this study, GeoMx digital spatial profiling was used to analyze arterial areas of interest (AOIs) from CAV+DSA+ rejected cardiac allografts (N = 3; 22 AOIs total). AOIs were categorized based on CAV neointimal thickening and underwent whole transcriptome and protein profiling. By comparing our transcriptomic data with that of healthy control vessels of rapid autopsy myocardial tissue, we pinpointed specific pathways and transcripts indicative of heightened inflammatory profiles in CAV lesions. Moreover, we identified protein and transcriptomic signatures distinguishing CAV lesions exhibiting low and high neointimal lesions. AOIs with low neointima showed increased markers for activated inflammatory infiltrates, endothelial cell activation transcripts, and gene modules involved in metalloproteinase activation and TP53 regulation of caspases. Inflammatory and apoptotic proteins correlated with inflammatory modules in low neointima AOIs. High neointima AOIs exhibited elevated TGFß-regulated transcripts and modules enriched for platelet activation/aggregation. Proteins associated with growth factors/survival correlated with modules enriched for proliferation/repair in high neointima AOIs. Our findings reveal novel insight into immunological mechanisms mediating CAV pathogenesis.
Asunto(s)
Rechazo de Injerto , Trasplante de Corazón , Trasplante de Corazón/efectos adversos , Rechazo de Injerto/etiología , Rechazo de Injerto/patología , Rechazo de Injerto/inmunología , Humanos , Masculino , Aloinjertos , Isoanticuerpos/inmunología , Persona de Mediana Edad , Femenino , Transcriptoma , Neointima/patología , Neointima/inmunología , Neointima/etiología , Supervivencia de Injerto/inmunología , Pronóstico , Estudios de Seguimiento , Perfilación de la Expresión Génica , Biomarcadores/metabolismo , Donantes de Tejidos , Enfermedades Vasculares/etiología , Enfermedades Vasculares/inmunología , Enfermedades Vasculares/patología , MultiómicaRESUMEN
Defining HLA mismatch at the molecular compared with the antigen level has been shown to be superior in predicting alloimmune responses, although data from across different patient populations are lacking. Using HLA-Matchmaker, HLA-EMMA and PIRCHE-II, this study reports on the association between molecular mismatch (MolMM) and de novo donor-specific antibody (dnDSA) in an ethnically diverse kidney transplant population receiving a steroid-sparing immunosuppression protocol. Of the 419 patients, 51 (12.2%) patients had dnDSA. De novo DSA were seen more frequently with males, primary transplants, patients receiving tacrolimus monotherapy, and unfavorably HLA-matched transplants. There was a strong correlation between MolMM load and antigen mismatch, although significant variation of MolMM load existed at each antigen mismatch. MolMM loads differed significantly by recipient ethnicity, although ethnicity alone was not associated with dnDSA. On multivariate analysis, increasing MolMM loads associated with dnDSA, whereas antigen mismatch did not. De novo DSA against 8 specific epitopes occurred at high frequency; of the 51 patients, 47 (92.1%) patients with dnDSA underwent a pretreatment biopsy, with 21 (44.7%) having evidence of alloimmune injury. MolMM has higher specificity than antigen mismatching at identifying recipients who are at low risk of dnDSA while receiving minimalist immunosuppression. Immunogenicity consideration is important, with more work needed on identification, especially across different ethnic groups.
Asunto(s)
Etnicidad , Rechazo de Injerto , Supervivencia de Injerto , Antígenos HLA , Prueba de Histocompatibilidad , Inmunosupresores , Trasplante de Riñón , Humanos , Masculino , Femenino , Antígenos HLA/inmunología , Persona de Mediana Edad , Rechazo de Injerto/inmunología , Adulto , Supervivencia de Injerto/inmunología , Inmunosupresores/uso terapéutico , Isoanticuerpos/inmunología , Isoanticuerpos/sangre , Estudios de Seguimiento , Terapia de Inmunosupresión/métodos , Donantes de Tejidos , Pronóstico , Factores de Riesgo , Esteroides/uso terapéutico , Fallo Renal Crónico/cirugía , Fallo Renal Crónico/inmunología , Receptores de TrasplantesRESUMEN
High frequencies of donor-reactive memory T cells in the periphery of transplant candidates prior to transplantation are linked to the development of posttransplant acute rejection episodes and reduced allograft function. Rabbit antithymocyte globulin (rATG) effectively depletes naïve CD4+ and CD8+ T cells for >6 months posttransplant, but rATG's effects on human donor-reactive T cells have not been carefully determined. To address this, we performed T cell receptor ß-chain sequencing on peripheral blood mononuclear cells aliquots collected pretransplant and serially posttransplant in 7 kidney transplant recipients who received rATG as induction therapy. We tracked the evolution of the donor-reactive CD4+ and CD8+ T cell repertoires and identified stimulated pretransplant, CTV-(surface dye)-labeled, peripheral blood mononuclear cells from each patient with donor cells or third-party cells. Our analyses showed that while rATG depleted CD4+ T cells in all tested subjects, a subset of donor-reactive CD8+ T cells that were present at high frequencies pretransplant, consistent with expanded memory cells, resisted rATG depletion, underwent posttransplant expansion and were functional. Together, our data support the conclusion that a subset of human memory CD8+ T cells specifically reactive to donor antigens expand in vivo despite induction therapy with rATG and thus have the potential to mediate allograft damage.
Asunto(s)
Suero Antilinfocítico , Linfocitos T CD8-positivos , Rechazo de Injerto , Trasplante de Riñón , Donantes de Tejidos , Trasplante de Riñón/efectos adversos , Humanos , Suero Antilinfocítico/uso terapéutico , Linfocitos T CD8-positivos/inmunología , Masculino , Rechazo de Injerto/inmunología , Rechazo de Injerto/etiología , Persona de Mediana Edad , Femenino , Adulto , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/genética , Animales , Linfocitos T CD4-Positivos/inmunología , Pronóstico , Estudios de Seguimiento , Fallo Renal Crónico/cirugía , Fallo Renal Crónico/inmunología , Conejos , Supervivencia de Injerto/inmunología , Depleción LinfocíticaRESUMEN
Recently published studies in both murine models and a meta-analysis of non-human primate renal transplant studies showed that anti-CD154 reagents conferred a significant survival advantage over CD40 blockers in both animal models and across multiple organs. Here we sought to compare the induction of donor-reactive forkhead box P3+-induced regulatory T cells (Foxp3+ iTreg) in mice treated with anti-CD154 versus anti-CD40 monoclonal antibodies (mAbs). Results indicated that while treatment with anti-CD154 mAb resulted in a significant increase in the frequency of donor-reactive CD4+ Foxp3+ iTreg following transplantation, treatment with anti-CD40 or Cd40 deficiency failed to recapitulate this result. Because we recently identified CD11b as an alternate receptor for CD154 during alloimmunity, we interrogated the role of CD154:CD11b interactions in the generation of Foxp3+ iTreg and found that blockade of CD11b in Cd40-/- recipients resulted in increased donor-reactive Foxp3+ iTreg as compared with CD40 deficiency alone. Mechanistically, CD154:CD11b inhibition decreased interleukin (IL)-1ß from CD11b+ and CD11c+ dendritic cells, and blockade of IL-1ß synergized with CD40 deficiency to promote Foxp3+ iTreg induction and prolong allograft survival. Taken together, these data provide a mechanistic basis for the observed inferiority of anti-CD40 blockers as compared with anti-CD154 mAb and illuminate an IL-1ß-dependent mechanism by which CD154:CD11b interactions prevent the generation of donor-reactive Foxp3+ iTreg during transplantation.