An interleukin 6-based genetic risk score strengthened with interleukin 10 polymorphisms associated with long-term kidney allograft outcomes

Of all kidney transplants, half are still lost in the first decade after transplantation. Here, using genetics, we probed whether interleukin 6 (IL-6) could be a target in kidney transplantation to improve graft survival. Additionally, we investigated if a genetic risk score (GRS) based on IL6 and IL10 variants could improve prognostication of graft loss. In a prospective cohort study, DNA of 1271 donor-recipient kidney transplant pairs was analyzed for the presence of IL6, IL6R, IL10, IL10RA, and IL10RB variants. These polymorphisms and their GRS were then associated with 15-year death-censored allograft survival. The C|C-genotype of the IL6 polymorphism in donor kidneys and the combined C|C-genotype in donor-recipient pairs were both associated with a reduced risk of graft loss (p =.043 and p =.042, respectively). Additionally, the GRS based on IL6, IL6R, IL10, IL10RA, and IL10RB variants was independently associated with the risk of graft loss (HR 1.53, 95%-CI [1.32–1.84]; p &lt;.001). Notably, the GRS improved risk stratification and prediction of graft loss beyond the level of contemporary clinical markers. Our findings reveal the merits of a polygenic IL-6-based risk score strengthened with IL-10- polymorphisms for the prognostication and risk stratification of late graft failure in kidney transplantation.</p

Liquid biopsy for non-invasive monitoring of patients with kidney transplants

The current tools for diagnosing and monitoring native kidney diseases as well as allograft rejection in transplant patients are suboptimal. Creatinine and proteinuria are non-specific and poorly sensitive markers of injury. Tissue biopsies are invasive and carry potential complications. In this article, we overview the different techniques of liquid biopsy and discuss their potential to improve patients’ kidney health. Several diagnostic, predictive, and prognostic biomarkers have been identified with the ability to detect and monitor the activity of native kidney diseases as well as early and chronic allograft rejection, such as donor-derived cell-free DNA, exosomes, messenger RNA/microsomal RNA, proteomics, and so on. While the results are encouraging, additional research is still needed as no biomarker appears to be perfect for a routine application in clinical practice. Despite promising advancements in biomarkers, the most important issue is the lack of standardized pre-analytical criteria. Large validation studies and uniformed standard operating procedures are required to move the findings from bench to bedside. Establishing consortia such as the Liquid Biopsy Consortium for Kidney Diseases can help expedite the research process, allow large studies to establish standardized procedures, and improve the management and outcomes of kidney diseases and of kidney transplant recipients

Regulatory CD8 T cells that recognize Qa-1 expressed by CD4 T-helper cells inhibit rejection of heart allografts

Induction of longstanding immunologic tolerance is essential for survival of transplanted organs and tissues. Despite recent advances in immunosuppression protocols, allograft damage inflicted by antibody specific for donor organs continues to represent a major obstacle to graft survival. Here we report that activation of regulatory CD8 T cells (CD8 Treg) that recognize the Qa-1 class Ib major histocompatibility complex (MHC), a mouse homolog of human leukocyte antigen-E (HLA-E), inhibits antibody-mediated immune rejection of heart allografts. We analyzed this response using a mouse model that harbors a point mutation in the class Ib MHC molecule Qa-1, which disrupts Qa-1 binding to the T cell receptor (TCR)-CD8 complex and impairs the CD8 Treg response. Despite administration of cytotoxic T lymphocyte antigen 4 (CTLA-4) immunoglobulin (Ig), Qa-1 mutant mice developed robust donor-specific antibody responses and accelerated heart graft rejection. We show that these allo-antibody responses reflect diminished Qa-1-restricted CD8 Treg-mediated suppression of host follicular helper T cell-dependent antibody production. These findings underscore the critical contribution of this Qa-1/HLA-E-dependent regulatory pathway to maintenance of transplanted organs and suggest therapeutic approaches to ameliorate allograft rejection

mTORC1 Inhibition Protects Human Regulatory T Cells From Granzyme-B-Induced Apoptosis

Regulatory T cells (T-regs) have shown great promise as a means of cellular therapy in a multitude of allo- and auto-immune diseases-due in part to their immunosuppressive potency. Nevertheless, the clinical efficacy of human T-regs in patients has been limited by their poor in vivo homeostasis. To avert apoptosis, T-regs require stable antigenic (CD3 zeta/T-cell-receptor-mediated), co-stimulatory (CD28-driven), and cytokine (IL-2-dependent) signaling. Notably, this sequence of signals supports an activated T-reg phenotype that includes a high expression of granzymes, particularly granzyme B (GrB). Previously, we have shown that aside from the functional effects of GrB in lysing target cells to modulate allo-immunity, GrB can leak out of the intracellular lysosomal granules of host T-regs, initiating pro-apoptotic pathways. Here, we assessed the role of inhibiting mechanistic target of rapamycin complex 1 (mTORC1), a recently favored drug target in the transplant field, in regulating human T-reg apoptosis via GrB. Using ex vivo models of human T-reg culture and a humanized mouse model of human skin allotransplantation, we found that by inhibiting mTORC1 using rapamycin, intracytoplasmic expression and functionality of GrB diminished in host T-regs; lowering human T-reg apoptosis by in part decreasing the phosphorylation of S6K and c-Jun. These findings support the already clinically validated effects of mTORC1 inhibition in patients, most notably their stabilization of T-reg bioactivity and in vivo homeostasis

Type I interferons augment regulatory T cell polarization in concert with ancillary cytokine signals

In the transplant community, research efforts exploring endogenous alternatives to inducing tolerogenic allo-specific immune responses are much needed. In this regard, CD4 + FoxP3+ regulatory T cells (Tregs) are appealing candidates due to their intrinsic natural immunosuppressive qualities. To date, various homeostatic factors that dictate Treg survival and fitness have been elucidated, particularly the non-redundant roles of antigenic CD3ζ/T-cell-receptor, co-stimulatory CD28, and cytokine interleukin (IL-)2 dependent signaling. Many of the additional biological signals that affect Tregs remain to be elucidated, however, especially in the transplant context. Previously, we demonstrated an unexpected link between type I interferons (IFNs) and Tregs in models of multiple myeloma (MM)—where MM plasmacytes escaped immunological surveillance by enhancing type I IFN signaling and precipitating upregulated Treg responses that could be overturned with specific knockdown of type I IFN signaling. Here, we elaborated on these findings by assessing the role of type I IFN signaling (IFN-α and -β) on Treg homeostasis within an alloimmune context. Specifically, we studied the induction of Tregs from naïve CD4 T cells. Using in vitro and in vivo models of murine skin allotransplantation, we found that type I IFN indeed spatiotemporally enhanced the polarization of naïve CD4 T cells into FoxP3+ Tregs. Notably, however, this effect was not independent of, and rather co-dependent on, ancillary cytokine signals including IL-2. These findings provide evidence for the relevance of type I IFN pathway in modulating FoxP3+ Treg responses and, by extension, stipulate an additional means of facilitating Treg fitness via type I IFNs

Chimeric antigen receptor T_reg therapy in transplantation

In the quest for more precise and effective organ transplantation therapies, chimeric antigen receptor (CAR) regulatory T cell (Treg) therapies represent a potential cutting-edge advance. This review comprehensively analyses CAR Tregs and how they may address important drawbacks of polyclonal Tregs and conventional immunosuppressants. We examine a growing body of preclinical findings of CAR Treg therapy in transplantation, discuss CAR Treg design specifics, and explore established and attractive new targets in transplantation. In addition, we explore present impediments where future studies will be necessary to determine the efficacy of CAR Tregs in reshaping alloimmune responses and transplant microenvironments to reduce reliance on chemical immunosuppressants. Overall, ongoing studies and trials are crucial for understanding the full scope of CAR Treg therapy in transplantation.</p

An interleukin 6-based genetic risk score strengthened with interleukin 10 polymorphisms associated with long-term kidney allograft outcomes

Of all kidney transplants, half are still lost in the first decade after transplantation. Here, using genetics, we probed whether interleukin 6 (IL-6) could be a target in kidney transplantation to improve graft survival. Additionally, we investigated if a genetic risk score (GRS) based on IL6 and IL10 variants could improve prognostication of graft loss. In a prospective cohort study, DNA of 1271 donor-recipient kidney transplant pairs was analyzed for the presence of IL6, IL6R, IL10, IL10RA, and IL10RB variants. These polymorphisms and their GRS were then associated with 15-year death-censored allograft survival. The C|C-genotype of the IL6 polymorphism in donor kidneys and the combined C|C-genotype in donor-recipient pairs were both associated with a reduced risk of graft loss (p =.043 and p =.042, respectively). Additionally, the GRS based on IL6, IL6R, IL10, IL10RA, and IL10RB variants was independently associated with the risk of graft loss (HR 1.53, 95%-CI [1.32–1.84]; p <.001). Notably, the GRS improved risk stratification and prediction of graft loss beyond the level of contemporary clinical markers. Our findings reveal the merits of a polygenic IL-6-based risk score strengthened with IL-10- polymorphisms for the prognostication and risk stratification of late graft failure in kidney transplantation

An interleukin 6-based genetic risk score strengthened with interleukin 10 polymorphisms associated with long-term kidney allograft outcomes

Of all kidney transplants, half are still lost in the first decade after transplantation. Here, using genetics, we probed whether interleukin 6 (IL-6) could be a target in kidney transplantation to improve graft survival. Additionally, we investigated if a genetic risk score (GRS) based on IL6 and IL10 variants could improve prognostication of graft loss. In a prospective cohort study, DNA of 1271 donor-recipient kidney transplant pairs was analyzed for the presence of IL6, IL6R, IL10, IL10RA, and IL10RB variants. These polymorphisms and their GRS were then associated with 15-year death-censored allograft survival. The C|C-genotype of the IL6 polymorphism in donor kidneys and the combined C|C-genotype in donor-recipient pairs were both associated with a reduced risk of graft loss (p =.043 and p =.042, respectively). Additionally, the GRS based on IL6, IL6R, IL10, IL10RA, and IL10RB variants was independently associated with the risk of graft loss (HR 1.53, 95%-CI [1.32–1.84]; p <.001). Notably, the GRS improved risk stratification and prediction of graft loss beyond the level of contemporary clinical markers. Our findings reveal the merits of a polygenic IL-6-based risk score strengthened with IL-10- polymorphisms for the prognostication and risk stratification of late graft failure in kidney transplantation

Targeting antigen-presenting cells by anti-PD-1 nanoparticles augments antitumor immunity.

Recent studies in cancer research have focused intensely on the antineoplastic effects of immune checkpoint inhibitors. While the development of these inhibitors has progressed successfully, strategies to further improve their efficacy and reduce their toxicity are still needed. We hypothesized that the delivery of anti-PD-1 antibody encapsulated in PLGA nanoparticles (anti-PD-1 NPs) to the spleen would improve the antitumor effect of this agent. Unexpectedly, we found that mice treated with a high dose of anti-PD-1 NPs exhibited significantly higher mortality compared with those treated with free anti-PD-1 antibody, due to the overactivation of T cells. Administration of anti-PD-1 NPs to splenectomized LT-α-/- mice, which lack both lymph nodes and spleen, resulted in a complete reversal of this increased mortality and revealed the importance of secondary lymphoid tissues in mediating anti-PD-1-associated toxicity. Attenuation of the anti-PD-1 NPs dosage prevented toxicity and significantly improved its antitumor effect in the B16-F10 murine melanoma model. Furthermore, we found that anti-PD-1 NPs undergo internalization by DCs in the spleen, leading to their maturation and the subsequent activation of T cells. Our findings provide important clues that can lead to the development of strategies to enhance the efficacy of immune checkpoint inhibitors

Targeting antigen-presenting cells by anti–PD-1 nanoparticles augments antitumor immunity

Recent studies in cancer research have focused intensely on the antineoplastic effects of immune checkpoint inhibitors. While the development of these inhibitors has progressed successfully, strategies to further improve their efficacy and reduce their toxicity are still needed. We hypothesized that the delivery of anti-PD-1 antibody encapsulated in PLGA nanoparticles (anti-PD-1 NPs) to the spleen would improve the antitumor effect of this agent. Unexpectedly, we found that mice treated with a high dose of anti-PD-1 NPs exhibited significantly higher mortality compared with those treated with free anti-PD-1 antibody, due to the overactivation of T cells. Administration of anti-PD-1 NPs to splenectomized LT-α-/- mice, which lack both lymph nodes and spleen, resulted in a complete reversal of this increased mortality and revealed the importance of secondary lymphoid tissues in mediating anti-PD-1-associated toxicity. Attenuation of the anti-PD-1 NPs dosage prevented toxicity and significantly improved its antitumor effect in the B16-F10 murine melanoma model. Furthermore, we found that anti-PD-1 NPs undergo internalization by DCs in the spleen, leading to their maturation and the subsequent activation of T cells. Our findings provide important clues that can lead to the development of strategies to enhance the efficacy of immune checkpoint inhibitors