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Biology subjects

Inderberg, E. M.

Publications and source records attributed to Inderberg, E. M..

4 recordsLinked to original sources

CD38hiCD19dim cells in lymph nodes predict favorable prognosis in patients with stage III melanoma receiving adjuvant PD-1-blockade

BackgroundAdjuvant immunotherapy has significantly improved survival for patients with stage III cutaneous melanoma, yet a fraction of patients will not benefit from immune checkpoint inhibitors (ICI). The tumor microenvironment plays a pivotal role in generating durable responses to ICI. By analyzing the cellular composition of tumor-associated subsets, key immune components essential for promoting an anti-tumor environment can be pinpointed. This will allow for both patient stratification and identification of biomarkers associated with improved patient outcome. MethodRegional lymph nodes were obtained from patients with stage III melanoma at surgery (n=29). Patients eligible for anti-PD-1 therapy (PD-1; pembrolizumab or nivolumab) received adjuvant treatment for up to one year. CyTOF was used to determine cellular composition in pre-treatment surgical specimens. Bulk gene expression data generated by NanoString from patients receiving surgery without adjuvant therapy (n=125) was implemented for evaluating trends observed in the CyTOF dataset. ResultsAlthough no significant differences were observed across major hierarchical immune cell types between patients who developed distant metastasis after surgery and those that did not, an increased proportion of CD103+PD-1+CD8+ (TRM) T cells and plasmablast-like CD38hiCD19dim cells were associated with improved prognosis in the CyTOF cohort. In the untreated cohort, a subset of patients defined as "Ultra-cold" (< 2.5 % tumor-infiltrating lymphocyte (TIL) scored by a pathologist) had significantly worse outcome than those with higher TIL infiltration. This Ultra-cold TIL group was associated with reduced B cell score, but not CD8+ T cell score, as well as reduced expression of activation genes like CD38. ConclusionIn this study, CD103+PD-1+CD8+ (TRM) T cells and plasmablast-like CD38hiCD19dim cell populations were found to be strongly associated with prolonged distant metastasis-free survival in regional lymph nodes from patients with stage III melanoma treated with PD-1. This suggests an association between progression and infiltration of these cell types at baseline and highlights the potential of using immune cell subsets as prognostic biomarkers. What is already known on this topic - Patients being diagnosed with stage III melanoma will receive immune checkpoint inhibitors but will often be cured by surgery alone. Selection of which patients might benefit from treatment is still unresolved. Accurate biomarkers would aid in treatment stratification, to avoid overtreatment, and unnecessary toxicities. What this study adds - This study highlights how baseline CD103+PD-1+CD8+ (TRM) T cells and plasmablast-like CD38hiCD19dim cell populations in the regional lymph node, is strongly associated with improved outcome in patients receiving anti-PD-1 therapy. How this study might affect research, practice or policy - The strong association between baseline plasmablast-like cell infiltration in RLN and prolonged distant metastasis free- survival, highlights this cell type as a potential treatment stratification criterion to identify patients with good prognosis.

cancer biology↗

CD20 expression regulates CD37 levels in B-cell lymphoma: implications for immunotherapies.

Rituximab (RTX) plus chemotherapy (R-CHOP) applied as a first-line therapy for lymphoma leads to a relapse in approximately 40% of patients. Therefore, novel approaches to treat aggressive lymphomas are being intensively investigated. Several RTX-resistant (RR) cell lines have been established as surrogate models to study resistance to R-CHOP. Our study reveals that RR cells are characterized with a major downregulation of CD37, a molecule currently explored as a target for immunotherapy. Using CD20 knockout (KO) cell lines, we demonstrate for the first time that CD20 and CD37 form a complex and the presence of CD20 stabilizes CD37 in the cell membrane. Consequently, we observe a diminished cytotoxicity of anti-CD37 monoclonal antibody (mAb) in complement-dependent cytotoxicity in both RR and CD20 KO cells that can be partially restored upon lysosome inhibition. On the other hand, the internalization rate of anti-CD37 mAb in CD20 KO cells is increased when compared to controls, suggesting unhampered efficacy of antibody drug conjugates. Importantly, even a major downregulation in CD37 levels does not hamper the efficacy of CD37-directed chimeric antigen receptor (CAR) T cells. In summary, we present here a novel mechanism of CD37 regulation with further implications for the use of anti-CD37 immunotherapies.

cancer biology↗

Combinatorial CAR design improves target restriction

CAR T cells targeting the B-lymphocyte antigen CD19 have led to remarkable clinical results in B-cell leukemia and lymphoma, but eliminate all B-lineage cells, leading to increased susceptibility to severe infections. As malignant B cells will express either immunoglobulin (Ig) light chain {kappa} or {lambda}, we designed a second-generation CAR targeting Ig{kappa}, IGK CAR. This construct demonstrated high target specificity, but displayed reduced efficacy in the presence of serum IgG. Since CD19 CAR is insensitive to serum IgG, we designed various combinatorial CAR constructs in order to maintain the CD19 CAR T cell efficacy, but with IGK CAR target selectivity. The Kz-19BB design, combining CD19 CAR containing a 4-1BB co-stimulatory domain with an IGK CAR containing a CD3zeta stimulatory domain, maintained the target specificity of IgK CAR and was resistant to the presence of soluble IgG. Our results demonstrate that a combinatorial CAR approach can improve target selectivity and efficacy.

immunology↗

Invariant chain with an AP3 interacting sorting signal is sorted to late endosomal compartments and may improve MHC class I loading and presentation.

Invariant chain (Ii) is traditionally known as the dedicated MHCII chaperone. Recent reports have broadened our understanding about various tasks that Ii plays including its physiological role in MHCI cross-presentation. Ii bound MHCI via the MHCII scaffolding CLIP peptide may facilitate MHCI trafficking to the endosomal pathway. The sorting function of Ii depends on two leucine-based sorting signals present in the cytoplasmic tail that acts as binding sites for the adaptor proteins AP-1/AP-2. Here we increased the Ii cross-presentation potency by replacing these with an AP3 motif resulting an efficient transport of Ii from TGN to late endosomes. We also replaced the CLIP region of li with a therapeutically relevant peptide, MART-1. We found the Ii AP3mutant-MART1 construct was capable of loading MHCI and stimulate specific T-cell response more efficiently than the wild type counterpart. The results show that Ii with an AP3 binding sorting motif carrying peptide epitope(s) can promote efficient antigen presentation to cytotoxic T cells (CTLs) independent of the ER located classical MHCI peptide loading machinery.

immunology↗