Programmed Death-1 Restrains the Germinal Center in Type 1 Diabetes.

Programmed death-1 (PD-1) inhibits T and B cell function upon ligand binding. PD-1 blockade revolutionized cancer treatment, and although numerous patients respond, some develop autoimmune-like symptoms or overt autoimmunity characterized by autoantibody production. PD-1 inhibition accelerates autoimmunity in mice, but its role in regulating germinal centers (GC) is controversial. To address the role of PD-1 in the GC reaction in type 1 diabetes, we used tetramers to phenotype insulin-specific CD4+ T and B cells in NOD mice. PD-1 or PD-L1 deficiency, and PD-1 but not PD-L2 blockade, unleashed insulin-specific T follicular helper CD4+ T cells and enhanced their survival. This was concomitant with an increase in GC B cells and augmented insulin autoantibody production. The effect of PD-1 blockade on the GC was reduced when mice were treated with a mAb targeting the insulin peptide:MHC class II complex. This work provides an explanation for autoimmune side effects following PD-1 pathway inhibition and suggests that targeting the self-peptide:MHC class II complex might limit autoimmunity arising from checkpoint blockade.

Cutting Edge: Allograft Rejection Is Associated with Weak T Cell Responses to Many Different Graft Leukocyte-Derived Peptides.

Organ transplants are rapidly rejected because T cells in the recipient attack the foreign MHC molecules on the graft. The robustness of the T cell response to histoincompatible tissue is not understood. We found that mice have many small T cell populations with Ag receptors specific for a foreign MHC class II molecule type loaded with peptides from leukocytes from the graft. These T cells proliferated modestly after skin transplantation and underwent relatively weak functional differentiation compared with T cells stimulated by a vaccine. Thus, the potency of the T cell response to histoincompatible tissue is likely due to many small T cell populations responding weakly to hundreds of MHC-bound peptides from graft-derived leukocytes.

Self-Efficacy and the Impact of Inflammatory Bowel Disease on Patients' Daily Lives.

INTRODUCTION: Self-efficacy, i.e., the confidence in one's capacity to perform a behavior, is crucial to the development of inflammatory bowel disease (IBD) self-management skills. We aimed to measure IBD self-efficacy and the relationship between self-efficacy and the patient-reported impact of IBD on daily life. METHODS: We surveyed patients with IBD from a single academic center using the IBD Self-Efficacy Scale (IBD-SES) and patient-reported outcome (PRO) measures. The IBD-SES assesses 4 IBD domains: patients' confidence in managing stress and emotions, symptoms and disease, medical care, and remission. IBD PROs evaluate daily life impact, coping strategies, emotional impact, and systemic symptoms. We examined the association between IBD-SES domains with the lowest scores and IBD daily life impact. RESULTS: A total of 160 patients completed the survey. Domain scores on the IBD-SES were lowest for managing stress and emotions (mean 6.76, SD 1.86) and symptoms and disease (mean 6.71, SD 2.12) on a 1-10 scale. Controlling for age, sex, IBD type, disease activity, moderate-to-severe disease, depression and anxiety, a higher confidence in managing stress and emotions (ß -0.12, 95% confidence interval -0.20 to -0.05, P = 0.001), and managing symptoms and disease (ß -0.28, 95% confidence interval -0.35 to -0.20, P < 0.001) were each associated with lower IBD daily life impact. DISCUSSION: Patients with IBD report low confidence in managing stress and emotion and managing symptoms and disease. Higher self-efficacy in these domains was associated with lower IBD daily life impact. Self-management tools that promote self-efficacy in managing these domains have the potential to reduce IBD's daily life impact.

Insulin B peptide-MHC class II-specific chimeric antigen receptor-Tregs prevent autoimmune diabetes.

Adoptive immunotherapy with Tregs is a promising approach for prevention or treatment of type 1 diabetes. Islet antigen-specific Tregs have more potent therapeutic effects than polyclonal cells, but their low frequency is a barrier for clinical application. To generate Tregs that recognize islet antigens, we engineered a chimeric antigen receptor (CAR) derived from a monoclonal antibody with specificity for the insulin B-chain 10-23 peptide presented in the context of the IA g7 MHC class II allele present in NOD mice. Peptide specificity of the resulting InsB-g7 CAR was confirmed by tetramer staining and T cell proliferation in response to recombinant or islet-derived peptide. The InsB-g7 CAR re-directed NOD Treg specificity such that insulin B 10-23-peptide stimulation enhanced suppressive function, measured via reduction of proliferation and IL-2 production by BDC2.5 T cells and CD80 and CD86 expression on dendritic cells. Co-transfer of InsB-g7 CAR Tregs prevented adoptive transfer diabetes by BDC2.5 T cells in immunodeficient NOD mice. In wild type NOD mice, InsB-g7 CAR Tregs stably expressed Foxp3 and prevented spontaneous diabetes. These results show that engineering Treg specificity for islet antigens using a T cell receptor-like CAR is a promising new therapeutic approach for the prevention of autoimmune diabetes. Brief Summary: Chimeric antigen receptor Tregs specific for an insulin B-chain peptide presented by MHC class II prevent autoimmune diabetes.

Tregs with an MHC class II peptide-specific chimeric antigen receptor prevent autoimmune diabetes in mice.

Adoptive immunotherapy with Tregs is a promising approach for preventing or treating type 1 diabetes. Islet antigen-specific Tregs have more potent therapeutic effects than polyclonal cells, but their low frequency is a barrier for clinical application. To generate Tregs that recognize islet antigens, we engineered a chimeric antigen receptor (CAR) derived from a monoclonal antibody with specificity for the insulin B chain 10-23 peptide presented in the context of the IAg7 MHC class II allele present in NOD mice. Peptide specificity of the resulting InsB-g7 CAR was confirmed by tetramer staining and T cell proliferation in response to recombinant or islet-derived peptide. The InsB-g7 CAR redirected NOD Treg specificity such that insulin B 10-23-peptide stimulation enhanced suppressive function, measured via reduction of proliferation and IL-2 production by BDC2.5 T cells and CD80 and CD86 expression on dendritic cells. Cotransfer of InsB-g7 CAR Tregs prevented adoptive transfer diabetes by BDC2.5 T cells in immunodeficient NOD mice. In WT NOD mice, InsB-g7 CAR Tregs prevented spontaneous diabetes. These results show that engineering Treg specificity for islet antigens using a T cell receptor-like CAR is a promising therapeutic approach for the prevention of autoimmune diabetes.

Liver injury during durvalumab-based immunotherapy is associated with poorer patient survival: A retrospective analysis.

Background: Durvalumab is approved for the treatment of lung cancer, advanced biliary tract cancers, and is also being evaluated in many other solid organ tumors. The aim of our study is to define the incidence, etiology, and outcomes of liver injury in consecutive patients receiving durvalumab-based immunotherapy. Patients and methods: Durvalumab treated patients between 1/2016 - 7/2020 were identified from the electronic medical record. Liver injury was defined as serum AST or ALT ≥ 5x upper limit of normal (ULN), ALP ≥ 2x ULN, bilirubin ≥ 2.5 mg/dl, or INR ≥ 1.5. Potential drug induced liver injury (DILI) cases were adjudicated using expert opinion scoring and confirmed with Roussel Uclaf Causality Assessment Method (RUCAM). Results: Amongst 112 patients, 58 (52%) had non-small cell lung cancer, the median age was 65 years, and 60% were male. The 21 (19%) liver injury patients were significantly more likely to harbor hepatic metastases (52% vs 17%, p=<0.001), experience tumor progression (67% vs 32%, p=0.01) or die (48% vs 11%, p<0.001) during follow-up compared to the 91 without liver injury. Using multivariate regression analysis, the development of liver injury during treatment as well as baseline hepatic metastases were independently associated with mortality during follow-up. Six of the 21 (29%) liver injury cases were adjudicated as probable DILI with four attributed to durvalumab and two due to other drugs (paclitaxel, pembrolizumab). Durvalumab was permanently discontinued in two DILI patients, three received corticosteroids, and one was successfully rechallenged. Only one patient with DILI developed jaundice, and none required hospitalization. Liver biochemistries normalized in all 6 DILI cases, while they only normalized in 27% of the 15 non-DILI cases (p=0.002). The 6 DILI patients also had a trend towards improved survival compared to those with other causes of liver injury. Conclusion: Liver injury was observed in 19% of durvalumab-treated patients and is associated with a greater likelihood of tumor progression and death during follow-up. The four durvalumab DILI cases were mild and self-limited, highlighting the importance of causality assessment to determine the cause of liver injury in oncology patients receiving immunotherapy.

Infrequent liver injury from cemiplimab in patients with advanced cutaneous squamous cell carcinoma.

Aim: To describe the incidence and outcomes of liver injury in patients with advanced cutaneous squamous cell carcinoma (cSCC) receiving cemiplimab. Methods: Charts of cSCC patients receiving cemiplimab between 28 September 2018 and 14 July 2020 were reviewed. Liver injury was determined using laboratory criteria, and causality assessment was completed. Results: Of 39 cemiplimab-treated patients, four (10.3%) developed liver injury. Two cases of hepatotoxicity were attributed to immune-mediated liver injury caused by cemiplimab and the two other cases were attributed to other causes. The four patients with liver injury had tumor responses and survival similar to those of the patients without liver injury. Conclusion: Liver injury arising during cemiplimab therapy is mild and infrequent in cSCC patients. Due to its favorable safety profile, cemiplimab should be considered in patients with cSCC and pre-existing liver disease.

A new type of cancer treatment termed 'immunotherapy' alters a patient's own immune system to attack the cancer cells. However, cemiplimab and similar medications can sometimes inadvertently injure the liver or other organs due to off-target activation of the immune system. This study describes the frequency and outcomes of liver injury observed in 39 patients with advanced skin cancer who were treated with cemiplimab at a single center. The authors found that 10% of patients developed liver injury, but only half of the cases were due to immune-mediated liver injury. The liver injury in these four patients was generally mild and self-limited. This study suggests that cemiplimab may be a preferred immunotherapy agent for patients with underlying liver disease due to its generally favorable side-effect profile, but further studies are needed.

Repeated hapten exposure induces persistent tactile sensitivity in mice modeling localized provoked vulvodynia.

BACKGROUND: Vulvodynia is a remarkably prevalent chronic pain condition of unknown etiology. Epidemiologic studies associate the risk of vulvodynia with a history of atopic disease. We used an established model of hapten-driven contact hypersensitivity to investigate the underlying mechanisms of allergy-provoked prolonged sensitivity to pressure. METHODS: We sensitized female ND4 Swiss mice to the hapten oxazolone on their flanks, and subsequently challenged them four days later with oxazolone or vehicle for ten consecutive days on the labia. We evaluated labiar sensitivity to touch, local mast cell accumulation, and hyperinnervation after ten challenges. RESULTS: Oxazolone-challenged mice developed significant tactile sensitivity that persisted for over three weeks after labiar allergen exposures ceased. Allergic sites were characterized by mast cell accumulation, sensory hyper-innervation and infiltration of regulatory CD4+CD25+FoxP3+ T cells as well as localized early increases in transcripts encoding Nerve Growth Factor and nerve-mast cell synapse marker Cell Adhesion Molecule 1. Local depletion of mast cells by intra-labiar administration of secretagogue compound 48/80 led to a reduction in both nerve density and tactile sensitivity. CONCLUSIONS: Mast cells regulate allergy-provoked persistent sensitivity to touch. Mast cell-targeted therapeutic strategies may provide novel means to manage and limit chronic pain conditions associated with atopic disease.

Clonal differences in IgE antibodies affect cutaneous anaphylaxis-associated thermal sensitivity in mice.

Cellular and molecular mediators of immune responses are increasingly implicated in acute and chronic pain pathophysiologies. Here we demonstrate that passive cutaneous IgE/Ag anaphylaxis provokes increased thermal sensitivity in the hind paw tissue of mice. The murine anti-DNP IgE antibodies SPE-7 and ɛ26 are known to induce differential cytokine production in bone marrow cultured mast cells in vitro without antigen challenge. We found a novel, antigen-dependent heterogeneity in the thermal pain responses elicited in the hind paws between SPE-7 and ɛ26 sensitized DNP-challenged mice. Mice experienced pronounced hind paw thermal sensitivity lasting 6h after DNP challenge when sensitized with SPE-7 but not ɛ26 IgE. The two IgE clones induced equivalent hind paw edema, neutrophil influx, cytokine production, and reduction in tissue histamine content in vivo, and bound to the same or overlapping epitopes on the DNP antigen in vitro. Therefore IgE antibodies against the same antigen can induce comparable inflammation, yet contribute to markedly different anaphylaxis-associated pain within an allergic response, suggesting that non-canonical IgE binding partners such as sensory neurons may play a role in allergy-related pain responses.

Contact hypersensitivity to oxazolone provokes vulvar mechanical hyperalgesia in mice.

The interplay among pain, allergy and dysregulated inflammation promises to yield significant conceptual advances in immunology and chronic pain. Hapten-mediated contact hypersensitivity reactions are used to model skin allergies in rodents but have not been utilized to study associated changes in pain perception in the affected skin. Here we characterized changes in mechanical hyperalgesia in oxazolone-sensitized female mice challenged with single and repeated labiar skin exposure to oxazolone. Female mice were sensitized with topical oxazolone on their flanks and challenged 1-3 times on the labia. We then measured mechanical sensitivity of the vulvar region with an electronic pressure meter and evaluated expression of inflammatory genes, leukocyte influx and levels of innervation in the labiar tissue. Oxazolone-sensitized mice developed vulvar mechanical hyperalgesia after a single labiar oxazolone challenge. Hyperalgesia lasted up to 24 hours along with local influx of neutrophils, upregulation of inflammatory cytokine gene expression, and increased density of cutaneous labiar nerve fibers. Three daily oxazolone challenges produced vulvar mechanical hyperalgesic responses and increases in nerve density that were detectable up to 5 days post-challenge even after overt inflammation resolved. This persistent vulvar hyperalgesia is resonant with vulvodynia, an understudied chronic pain condition that is remarkably prevalent in 18-60 year-old women. An elevated risk for vulvodynia has been associated with a history of environmental allergies. Our pre-clinical model can be readily adapted to regimens of chronic exposures and long-term assessment of vulvar pain with and without concurrent inflammation to improve our understanding of mechanisms underlying subsets of vulvodynia and to develop new therapeutics for this condition.