Immunotherapy Toxicity Management in Clinical Practice: Building the Clinical Infrastructure for Immune-related Adverse Event Evaluation and Care.

Cancer immunotherapy is revolutionary for survival but has complications due to immunogenicity with unpredictable and potentially long-lasting autoimmune side effects known as immune-related adverse events (irAEs). Currently, treatment beyond corticosteroids can be complicated by the diversity of providers who are needed across a variety of clinical settings to manage irAEs. We outline the role of critical players in the management of irAEs, discuss the current limitations that exist, and propose various methodologies that can be adapted across clinical settings to tackle these needs. We aim to better understand who can be affected by irAEs and tailor diagnostics and therapeutics appropriately.

Thyroid Disease in Lupus: An Updated Review.

In the following review, we seek to provide an overview of the current understanding of various thyroid manifestations affecting patients with systemic lupus erythematosus (SLE), including topics ranging from thyroid-related complications to SLE in pregnancy. Autoimmune diseases tend to coincide, and an association between thyroid disease and SLE has been reported for more than 50 years. There is no evidence that the coexistence of thyroid disease and lupus alters the disease course or manifestations of either. Both hypothyroidism and thyroid nodules are seen more frequently in patients with SLE than in the general population. The rate of thyroid cancer is twice as prevalent in patients with SLE compared with those without SLE. Several forms of thyroid disease are more common among patients with SLE, with adverse consequences in pregnancy. Future work will require delineating the mechanism behind these associations and understanding the role of antirheumatic agents with concomitant thyroid disease.

Pembrolizumab-Induced Immune-Mediated Colitis in a Patient with Concurrent Clostridium Difficile Infection.

Pembrolizumab is a programmed death receptor-1 (PD-1) inhibitor that has been approved for treatment of a wide variety of malignancies. Immune-mediated colitis is a known but uncommon adverse effect of pembrolizumab. Symptoms of immune-mediated colitis can be similar to those of many other gastrointestinal illnesses, including Clostridium difficile infection (CDI). If not recognized and treated in a timely fashion, immune-mediated colitis can lead to significant morbidity in cancer patients. We report the case of a 56-year-old woman on pembrolizumab for metastatic non-small cell lung cancer (NSCLC) who presented with severe colitis symptoms and initially tested positive for CDI. Her colitis symptoms worsened despite appropriate treatment for CDI but later improved rapidly after systemic corticosteroid was started for suspected immune-mediated colitis. To our knowledge, this is the first reported case of concurrent pembrolizumab-induced colitis and CDI. Immune-mediated colitis should be considered in the differential diagnoses in patients on pembrolizumab or other immune checkpoint inhibitors who present with colitis symptoms, even when a concurrent infectious etiology is suspected.

Immune tolerance induction by nonmyeloablative haploidentical HSCT combining T-cell depletion and posttransplant cyclophosphamide.

The establishment of safe approaches to attain durable donor-type chimerism and immune tolerance toward donor antigens represents a major challenge in transplantation biology. Haploidentical hematopoietic stem cell transplantation (HSCT) is currently used for cancer therapy either as a T-cell-depleted megadose HSCT following myeloablative conditioning or with T-cell-replete HSCT following nonmyeloablative conditioning (NMAC) and high-dose posttransplant cyclophosphamide (PTCY). The latter approach suffers from a significant rate of chronic graft-versus-host disease (GVHD), despite prolonged immunosuppression. The use of T-depleted grafts, although free of GVHD risk, is not effective after NMAC because of graft rejection. We now demonstrate in mice conditioned with NMAC that combining the power of high-dose PTCY with T-cell-depleted megadose HSCT can overcome this barrier. This approach was evaluated in 2 patients with multiple myeloma and 1 patient with Hodgkin lymphoma. The first myeloma patient now followed for 25 months, exhibited full donor-type chimerism in the myeloid and B-cell lineages and mixed chimerism in the T-cell compartment. The second myeloma patient failed to attain chimerism. Notably, the low toxicity of this protocol enabled a subsequent successful fully myeloablative haploidentical HSCT in this patient. The third patients was conditioned with slightly higher total body irradiation and engrafted promptly. All patients remain in remission without GVHD. Both engrafted patients were able to control cytomegalovirus reactivation. Enzyme-linked immunospot analysis revealed immune tolerance toward donor cells. Our results demonstrate a novel and safer nonmyeloablative haplo-HSCT offering a platform for immune tolerance induction as a prelude to cell therapy and organ transplantation.

Novel immunoregulatory role of perforin-positive dendritic cells.

The recently described generation of a highly defined population of dendritic cells which express perforin and granzyme A (termed "perf-DCs") and their ability to selectively delete cognate CD8+ T cell has raised the possibility that these cells play a role in the maintenance of peripheral tolerance. Using bone marrow transplantation, we generated mice selectively lacking perforin expressing dendritic cells. These mice progressively gain weight and exhibit features resembling metabolic syndrome as well as an enhanced susceptibility to autoimmunity induction. Interestingly, these pathological phenotypes were reversed upon treatment with CD4/CD8 neutralizing antibodies. Thus, it appears that this rare subpopulation of dendritic cells (perf-DCs) displays a major regulatory role in adipose tissue inflammatory processes and in autoimmunity.

Perforin-Positive Dendritic Cells Exhibit an Immuno-regulatory Role in Metabolic Syndrome and Autoimmunity.

Emerging evidence suggests that immunological mechanisms underlie metabolic control of adipose tissue. Here, we have shown the regulatory impact of a rare subpopulation of dendritic cells, rich in perforin-containing granules (perf-DCs). Using bone marrow transplantation to generate animals selectively lacking perf-DCs, we found that these chimeras progressively gained weight and exhibited features of metabolic syndrome. This phenotype was associated with an altered repertoire of T cells residing in adipose tissue and could be completely prevented by T cell depletion in vivo. A similar impact of perf-DCs on inflammatory T cells was also found in a well-defined model of multiple sclerosis, experimental autoimmune encephlalomyelitis (EAE). Thus, perf-DCs probably represent a regulatory cell subpopulation critical for protection from metabolic syndrome and autoimmunity.

Preconditioning allows engraftment of mouse and human embryonic lung cells, enabling lung repair in mice.

Repair of injured lungs represents a longstanding therapeutic challenge. We show that human and mouse embryonic lung tissue from the canalicular stage of development (20-22 weeks of gestation for humans, and embryonic day 15-16 (E15-E16) for mouse) are enriched with progenitors residing in distinct niches. On the basis of the marked analogy to progenitor niches in bone marrow (BM), we attempted strategies similar to BM transplantation, employing sublethal radiation to vacate lung progenitor niches and to reduce stem cell competition. Intravenous infusion of a single cell suspension of canalicular lung tissue from GFP-marked mice or human fetal donors into naphthalene-injured and irradiated syngeneic or SCID mice, respectively, induced marked long-term lung chimerism. Donor type structures or 'patches' contained epithelial, mesenchymal and endothelial cells. Transplantation of differentially labeled E16 mouse lung cells indicated that these patches were probably of clonal origin from the donor. Recipients of the single cell suspension transplant exhibited marked improvement in lung compliance and tissue damping reflecting the energy dissipation in the lung tissues. Our study provides proof of concept for lung reconstitution by canalicular-stage human lung cells after preconditioning of the pulmonary niche.

Breastfeeding and Methadone Therapy: The Maternal Experience.

BACKGROUND: Despite evidence of low transfer of methadone into breast milk and the potential physical and psychological benefits that breastfeeding offers for methadone-exposed mothers and infants, the rate of breastfeeding initiation in this population is about half that reported nationally. This study describes the perceptions surrounding breastfeeding decisions and management among pregnant and postpartum women taking methadone. METHODS: Seven pregnant women and 4 postpartum women enrolled in methadone maintenance programs participated in semistructured, audiotaped interviews and focus groups, respectively, about their breastfeeding experiences. Transcripts were analyzed and coded using qualitative content analysis. RESULTS: Three major content categories were identified: (1) fears, barriers, and misconceptions about breastfeeding while taking methadone; (2) motivation and perceived benefits of breastfeeding; and (3) sources of information, support, and anxiety about general breastfeeding management and breastfeeding while taking methadone. Lack of support from the health care community and misinformation about the dangers of combining breastfeeding and methadone therapy represented significant, yet modifiable, barriers to breastfeeding success in methadone-exposed women. CONCLUSIONS: Interventions to increase the prevalence of breastfeeding among women taking methadone should address identified logistical, educational, and psychological barriers and consider inclusion of women themselves, partners, peers, and clinicians. In particular, clinicians who care for methadone-exposed mothers and infants should be educated on therapeutic communication, up-to-date breastfeeding contraindications, and the health benefits of breastfeeding in this population.

A novel role for factor VIII and thrombin/PAR1 in regulating hematopoiesis and its interplay with the bone structure.

Analysis of hematopoietic stem cells (HSCs) in factor VIII knockout (FVIIIKO) mice revealed a novel regulatory role for the coagulation cascade in hematopoiesis. Thus, HSCs in FVIIIKO mice had reduced proportions of CD34(low) cells within Lin(-)Sca(+)Kit(+) progenitors, and exhibited reduced long-term repopulating capacity as well as hyper granulocyte-colony-stimulating factor (G-CSF)-induced mobilization. This disregulation of HSCs is likely caused by reduced levels of thrombin, and is associated with altered protease-activated receptor 1 (PAR1) signaling, as PAR1 KO mice also exhibited enhanced G-CSF-induced mobilization. Analysis of reciprocal bone marrow (BM) chimera (FVIIIKO BM into wild-type recipients and vice versa) and the detection of PAR1 expression on stromal elements indicates that this phenotype is likely controlled by stromal elements. Micro-computed tomography analysis of distal tibia metaphyses also revealed for the first time a major impact of the FVIII/thrombin/PAR1 axis on the dynamic bone structure, showing reduced bone:tissue volume ratio and trabecular number in FVIIIKO and PAR1KO mice. Taken together, these results show a critical and novel role for the coagulation cascade, mediated in part by thrombin-PAR1 interaction, and regulates HSC maintenance and a reciprocal interplay between HSCs and the dynamic bone structure.

Deletion of cognate CD8 T cells by immature dendritic cells: a novel role for perforin, granzyme A, TREM-1, and TLR7.

Immature dendritic cells (imDCs) can have a tolerizing effect under normal conditions or after transplantation. However, because of the significant heterogeneity of this cell population, it is extremely difficult to study the mechanisms that mediate the tolerance induced or to harness the application of imDCs for clinical use. In the present study, we describe the generation of a highly defined population of imDCs from hematopoietic progenitors and the direct visualization of the fate of TCR-transgenic alloreactive CD4(+) and CD8(+) T cells after encountering cognate or noncognate imDCs. Whereas CD4(+) T cells were deleted via an MHC-independent mechanism through the NO system, CD8(+) T-cell deletion was found to occur through a unique MHC-dependent, perforin-based killing mechanism involving activation of TLR7 and signaling through Triggering Receptor-1 Expressed on Myeloid cells (TREM-1). This novel subpopulation of perforin-expressing imDCs was also detected in various lymphoid tissues in normal animals and its frequency was markedly enhanced after GM-CSF administration.

Embryonic pig pancreatic tissue for the treatment of diabetes: potential role of immune suppression with "off-the-shelf" third-party regulatory T cells.

BACKGROUND: Xenogeneic embryonic pancreatic tissue can provide an attractive alternative for organ replacement therapy. However, immunological rejection represents a major obstacle. This study examines the potential of regulatory T cells (Tregs) in the prevention of E42 pancreas rejection. METHODS: To develop new approaches to combat rejection, we evaluated engraftment, growth, and development of E42 pig pancreatic tissue in mice treated with ex vivo expanded Tregs in combination with T-cell debulking and the conventional immunosuppressive drugs, rapamycin and FTY720. RESULTS: Transplantation of E42 pig pancreas into C57BL/6 mice immunosuppressed by this protocol resulted in complete rejection within less than 6 weeks. In contrast, additional treatment with a single infusion of ex vivo expanded third-party Tregs markedly delayed the onset of graft rejection to 10 weeks. The infusion of Tregs was associated with a significant reduction in CD4 and CD8 expansion in the lymph nodes and other peripheral organs at the priming stages after implantation. Freezing and thawing of the Tregs did not affect their efficacy, indicating the potential of Tregs banking. CONCLUSION: Considering the technical difficulties encountered in the generation of Tregs from patients or from specific donors, our results demonstrate the feasibility of using "off-the-shelf" fresh or frozen third-party Tregs to control rejection in organ transplantation.

Growth enhancement by embryonic fibroblasts upon cotransplantation of noncommitted pig embryonic tissues with fully committed organs.

BACKGROUND: We recently defined the optimal gestational time windows for the transplantation of several embryonic tissues. We showed that the liver and kidney obtained from E28 pig embryos can grow and differentiate normally after transplantation, whereas 1 week earlier in gestation, these tissues develop into teratoma-like structures or fibrotic mass. In this study, we investigated whether cotransplantation of E28 with E21 tissue could control its tumorogenic potential, or alternatively whether the stem cells derived from the earlier tissue contribute to the growth of the more committed one. METHODS: Pig embryonic precursors from E21 and E28 gestational age were transplanted alone or together, into nonobese diabetic/severe combined immunodeficiency mice, and their growth and differentiation was evaluated by immunohistology. In situ analysis, based on sex disparity between the E21 and E28 tissues, was used to identify the tissue source. In some experiments, mouse embryonic fibroblasts (MEF) were cotransplanted with E28 liver, and their effect was evaluated. RESULTS: E28 tissues could not abrogate the propensity of the cells within the undifferentiated tissue to form teratoma-like structures. However, E21 kidney or liver tissue markedly enhanced the growth and function of E28 kidney, liver, and heart grafts. Moreover, similar growth enhancement was observed on coimplantation of E28 liver tissue with MEF or on infusion of MEF culture medium, indicating that this enhancement is likely mediated through soluble factors secreted by the fibroblasts. CONCLUSION: Our results suggest a novel approach for the enhancement of growth and differentiation of transplanted embryonic tissues by the use of soluble factors secreted by embryonic fibroblasts.

Enhancement of pig embryonic implants in factor VIII KO mice: a novel role for the coagulation cascade in organ size control.

Very little is known about the mechanisms that contribute to organ size differences between species. In the present study, we used a mouse model of embryonic pig tissue implantation to define the role of host Factor VIII in controlling the final size attained by the implant. We show here that pig embryonic spleen, pancreas, and liver all grow to an increased size in mice that are deficient in the Factor VIII clotting cascade. Similar results were obtained using the transplantation model after treatment with the low molecular weight heparin derivative Clexane which markedly enhanced transplant size. Likewise, enhanced size was found upon treatment with the direct thrombin inhibitor Dabigatran, suggesting that organ size regulation might be mediated by thrombin, downstream of Factor VIII. Considering that thrombin was shown to mediate various functions unrelated to blood clotting, either directly by cleavage of protease-activated receptors (PARs) or indirectly by cleaving osteopontin (OPN) on stroma cells, the role of PAR1 and PAR4 antagonists as well as treatment with cleaved form of OPN (tcOPN) were tested. While the former was not found to have an impact on overgrowth of embryonic pig spleen implants, marked reduction of size was noted upon treatment with the (tcOPN). Collectively, our surprising set of observations suggests that factors of the coagulation cascade have a novel role in organ size control.

Pig embryonic pancreatic tissue as a source for transplantation in diabetes: transient treatment with anti-LFA1, anti-CD48, and FTY720 enables long-term graft maintenance in mice with only mild ongoing immunosuppression.

OBJECTIVE: Defining an optimal costimulatory blockade-based immune suppression protocol enabling engraftment and functional development of E42 pig embryonic pancreatic tissue in mice. RESEARCH DESIGN AND METHODS: Considering that anti-CD40L was found to be thrombotic in humans, we sought to test alternative costimulatory blockade agents already in clinical use, including CTLA4-Ig, anti-LFA1, and anti-CD48. These agents were tested in conjunction with T-cell debulking by anti-CD4 and anti-CD8 antibodies or with conventional immunosuppressive drugs. Engraftment and functional development of E42 pig pancreatic tissue was monitored by immunohistology and by measuring pig insulin blood levels. RESULTS: Fetal pig pancreatic tissue harvested at E42, or even as early as at E28, was fiercely rejected in C57BL/6 mice and in Lewis rats. A novel immune suppression comprising anti-LFA1, anti-CD48, and FTY720 afforded optimal growth and functional development. Cessation of treatment with anti-LFA1 and anti-CD48 at 3 months posttransplant did not lead to graft rejection, and graft maintenance could be achieved for >8 months with twice-weekly low-dose FTY720 treatment. These grafts exhibited normal morphology and were functional, as revealed by the high pig insulin blood levels in the transplanted mice and by the ability of the recipients to resist alloxan induced diabetes. CONCLUSIONS: This novel protocol, comprising agents that simulate those approved for clinical use, offer an attractive approach for embryonic xenogeneic transplantation. Further studies in nonhuman primates are warranted.