Diacylglycerol kinase α inhibition cooperates with PD-1-targeted therapies to restore the T cell activation program.

BACKGROUND: Antibody-based therapies blocking the programmed cell death-1/ligand-1 (PD-1/PD-L1) axis have provided unprecedent clinical success in cancer treatment. Acquired resistance, however, frequently occurs, commonly associated with the upregulation of additional inhibitory molecules. Diacylglycerol kinase (DGK) α limits the extent of Ras activation in response to antigen recognition, and its upregulation facilitates hypofunctional, exhausted T cell states. Pharmacological DGKα targeting restores cytotoxic function of chimeric antigen receptor and CD8+ T cells isolated from solid tumors, suggesting a mechanism to reverse T cell exhausted phenotypes. Nevertheless, the contribution of DGKα downstream of the PD-1/PD-L1 inhibitory axis in human T cells and the consequences of combining DGKα and anti-PD-1/PD-L1 inhibitors are still unresolved relevant issues. MATERIALS AND METHODS: We used a human triple parameter reporter cell line to investigate DGKα contribution to the PD-1/PD-L1 inhibitory pathway. We also addressed the impact of deleting DGKα expression in the growth dynamics and systemic tumor-derived effects of a PD-1-related tumor model, the MC38 colon adenocarcinoma. RESULTS: We identify DGKα as a contributor to the PD-1/PD-L1 axis that strongly limits the Ras/ERK/AP-1 pathway. DGKα function reinforces exhausted T cell phenotypes ultimately promoting tumor growth and generalized immunosuppression. Pharmacological DGKα inhibition selectively enhances AP-1 transcription and, importantly, cooperates with antibodies blocking the PD-1/PD-L1 interrelation. CONCLUSIONS: Our results indicate that DGKα inhibition could provide an important mechanism to revert exhausted T lymphocyte phenotypes and thus favor proper anti-tumor T cell responses. The cooperative effect observed after PD-1/PD-L1 and DGKα blockade offers a promising strategy to improve the efficacy of immunotherapy in the treatment of cancer.

Association of insulin-manipulation and psychiatric disorders: A systematic epidemiological evaluation of adolescents with type 1 diabetes in Austria.

BACKGROUND/OBJECTIVE: The aim of this study was to systematically assess the association of insulin-manipulation (intentional under- and/or overdosing of insulin), psychiatric comorbidity and diabetes complications. METHODS: Two diagnostic interviews (Diabetes-Self-Management-Patient-Interview and Children's-Diagnostic-Interview for Psychiatric Disorders) were conducted with 241 patients (age 10-22) with type 1 diabetes (T1D) from 21 randomly selected Austrian diabetes care centers. Medical data was derived from medical records. RESULTS: Psychiatric comorbidity was found in nearly half of the patients with insulin-manipulation (46.3%) compared to a rate of 17.5% in patients, adherent to the prescribed insulin therapy. Depression (18.3% vs 4.9%), specific phobia (21.1% vs 2.9%), social phobia (7.0% vs 0%), and eating disorders (12.7% vs 1.9%) were elevated in patients with insulin-manipulation. Females (37.7%) were more often diagnosed (P = 0.001) with psychiatric disorders than males (18.4%). In females, the percentage of psychiatric comorbidity significantly increased with the level of non-adherence to insulin therapy. Insulin-manipulation had an effect of +0.89% in HbA1c (P = <0.001) compared to patients adherent to insulin therapy, while there was no association of psychiatric comorbidity with metabolic control (HbA1c 8.16% vs 8.12% [65.68 vs 65.25 mmol/mol]). Ketoacidosis, severe hypoglycemia, and frequency of outpatient visits in a diabetes center were highest in patients with insulin-manipulation. CONCLUSIONS: This is the first study using a systematic approach to assess the prevalence of psychiatric disorders in patients who do or do not manipulate insulin in terms of intentional under- and/or overdosing. Internalizing psychiatric disorders were associated with insulin-manipulation, especially in female patients and insulin-manipulation was associated with deteriorated metabolic control and diabetes complications.

The aged microenvironment impairs BCL6 and CD40L induction in CD4+ T follicular helper cell differentiation.

Weakened germinal center responses by the aged immune system result in diminished immunity against pathogens and reduced efficacy of vaccines. Prolonged contacts between activated B cells and CD4+ T cells are crucial to germinal center formation and T follicular helper cell (Tfh) differentiation, but it is unclear how aging impacts the quality of this interaction. Peptide immunization confirmed that aged mice have decreased expansion of antigen-specific germinal center B cells and reduced antibody titers. Furthermore, aging was associated with accumulated Tfh cells, even in naïve mice. Despite increased numbers, aged Tfh had reduced expression of master transcription factor BCL6 and increased expression of the ectonucleotidase CD39. In vitro activation revealed that proliferative capacity was maintained in aged CD4+ T cells, but not the costimulatory molecule CD40L. When activated in vitro by aged antigen-presenting cells, young CD4+ naïve T cells generated reduced numbers of activated cells with upregulated CD40L. To determine the contribution of cell-extrinsic influences on antigen-specific Tfh induction, young, antigen-specific B and CD4+ T cells were adoptively transferred into aged hosts prior to peptide immunization. Transferred cells had reduced expansion and differentiation into germinal center B cell and Tfh and reduced antigen-specific antibody titers when compared to young hosts. Young CD4+ T cells transferred aged hosts differentiated into Tfh cells with reduced PD-1 and BCL6 expression, and increased CD39 expression, though they maintained their mitochondrial capacity. These results highlight the role of the lymphoid microenvironment in modulating CD4+ T cell differentiation, which contributes to impaired establishment and maintenance of germinal centers.

Dendritic cells as orchestrators of anticancer immunity and immunotherapy.

Dendritic cells (DCs) are a heterogeneous group of antigen-presenting innate immune cells that regulate adaptive immunity, including against cancer. Therefore, understanding the precise activities of DCs in tumours and patients with cancer is important. The classification of DC subsets has historically been based on ontogeny; however, single-cell analyses are now additionally revealing a diversity of functional states of DCs in cancer. DCs can promote the activation of potent antitumour T cells and immune responses via numerous mechanisms, although they can also be hijacked by tumour-mediated factors to contribute to immune tolerance and cancer progression. Consequently, DC activities are often key determinants of the efficacy of immunotherapies, including immune-checkpoint inhibitors. Potentiating the antitumour functions of DCs or using them as tools to orchestrate short-term and long-term anticancer immunity has immense but as-yet underexploited therapeutic potential. In this Review, we outline the nature and emerging complexity of DC states as well as their functions in regulating adaptive immunity across different cancer types. We also describe how DCs are required for the success of current immunotherapies and explore the inherent potential of targeting DCs for cancer therapy. We focus on novel insights on DCs derived from patients with different cancers, single-cell studies of DCs and their relevance to therapeutic strategies.

Dendritic Cell-Mediated Cross-Priming by a Bispecific Neutralizing Antibody Boosts Cytotoxic T Cell Responses and Protects Mice against SARS-CoV-2.

Administration of neutralizing antibodies (nAbs) has proved to be effective by providing immediate protection against SARS-CoV-2. However, dual strategies combining virus neutralization and immune response stimulation to enhance specific cytotoxic T cell responses, such as dendritic cell (DC) cross-priming, represent a promising field but have not yet been explored. Here, a broadly nAb, TNT , are first generated by grafting an anti-RBD biparatopic tandem nanobody onto a trimerbody scaffold. Cryo-EM data show that the TNT structure allows simultaneous binding to all six RBD epitopes, demonstrating a high-avidity neutralizing interaction. Then, by C-terminal fusion of an anti-DNGR-1 scFv to TNT , the bispecific trimerbody TNT DNGR-1 is generated to target neutralized virions to type 1 conventional DCs (cDC1s) and promote T cell cross-priming. Therapeutic administration of TNT DNGR-1, but not TNT , protects K18-hACE2 mice from a lethal SARS-CoV-2 infection, boosting virus-specific humoral responses and CD8+ T cell responses. These results further strengthen the central role of interactions with immune cells in the virus-neutralizing antibody activity and demonstrate the therapeutic potential of the Fc-free strategy that can be used advantageously to provide both immediate and long-term protection against SARS-CoV-2 and other viral infections.

Prevalence of intentional under- and overdosing of insulin in children and adolescents with type 1 diabetes.

OBJECTIVE: The aim of this study was to evaluate the prevalence of insulin under- and overdosing in paediatric patients. RESEARCH DESIGN AND METHODS: Cross-sectional study including 241 patients (age 14.0 + 2.7 yr, 42.5% males) with type 1 diabetes from 21 diabetic outpatient clinics. Haemoglobin A1c (HbA1c), height, and weight were available from clinical records. Patients were interviewed with the Diabetes Self-Management Profile (DSMP) interview. T test, U test, and chi-squared test were used for comparison. RESULTS: On the basis of the DSMP, 103 (42.7%) patients (group A) showed adherence to the therapeutic insulin regimen, while 71 (29.5%) patients (group B) confessed intentional over and/or under-dosing of insulin. Sixty-seven (27.8%) adolescents (group C) reported management problems leading to unintended inappropriate insulin dosages. In group B, 55 (22.8%) injected higher insulin doses and 58 (24.1%) omitted insulin. Patients of group B compared to group A were older 15.0 (±2.5) vs. 14.0 (±2.5) yr (p < 0.01), older at onset 9.5 (±3.6) vs. 8.3 (±3.8) yr (p = 0.05), were more often girls (69 vs. 45.6%), had a higher actual HbA1c (8.7 ± 1.7 vs. 7.8 ± 1.2%), and a higher average HbA1c in the previous year (8.3 ± 1.6 vs. 7.9 ± 1.2%) (p < 0.01). No significant differences could be found between group A and group C. CONCLUSION: Intentional overdosing of insulin is almost as prevalent in children and adolescents as insulin omission. Females are more at risk.

El uso de un anticuerpo biespecífico neutralizante frente a SARS-CoV-2 y dirigido hacia DNGR-1 potencia la respuesta de las células T citotóxicas, mediante su acción a través de células dendríticas c1, protegiendo eficazmente frente a la infección / [The use of a bispecific neutralizing antibody against SARS-CoV-2 and directed towards DNGR-1 enhances the response of cytotoxic T cells, through its action through c1 dendritic cells, effectively protecting against infection]

En este trabajo, recientemente publicado en la prestigiosa revista Advanced Science (Adv Sci; Weinheim, Baden-Württemberg, Germany), se ha diseñado y estudiado a nivel preclínico un anticuerpo biespecífico neutralizante (nAbs) frente al virus SARS-CoV-2 y dirigido específicamente a un receptor de células dendríticas convencionales de tipo 1 (cDC1s) para estimular específicamente la respuesta de linfocitos T citotóxicos. El trabajo surge de la colaboración de un consorcio muy amplio de grupos de investigación expertos en distintas áreas de la inmunología, biología celular, virología, biología estructural, química de proteínas y partículas, que han logrado generar un anticuerpo trimérico biespecífico, TNTDNGR-1. TNT se corresponde con las siglas en inglés para anticuerpo neutralizante en tándem trimérico, mientras que DNGR-1 es la molécula inmuno-reguladora “dendritic cell natural killer group receptor-1”, también conocida como CLEC9A. TNTDNGR-1 presenta una gran avidez frente a la región RBD (“receptor binding domain”) del virus SARS-CoV-2 y también frente al receptor DNGR-1, una lectina tipo C expresada por cDC1s. Se trata, además de una colaboración público-privada, con la participación de una compañía de biotecnología española, otorgando valor añadido al trabajo de investigación, por su potencial traslación a la clínica a corto o medio plazo. Mediante el uso de técnicas de crio-microscopía electrónica se ha comprobado que la estructura TNT , backbone de TNTDNGR-1, permite la unión simultánea a sus seis epítopos en la proteína S (del inglés spike) del SARS-CoV-2, dos por cada RBD, dotándola de una interacción neutralizante de alta afinidad frente al virus. ... (AU)