Biology subjects

Sobhani, N.

Publications and source records attributed to Sobhani, N..

3 recordsLinked to original sources

bioRxiv2026

The CD19-4-1BBL antibody fusion protein unleashes the immune system against high-risk chronic lymphocytic leukemia

CD19-4-1BBL is a bispecific antibody fusion protein that targets CD19 and costimulates 4-1BB on T cells and other immune cells. Its antitumor activity has been reported in B-cell non-Hodgkin lymphoma with emphasis on its T-cell mediated cytotoxic activity. Its effect on other 4-1BB expressing immune cells is unexplored. Here, we investigated the molecular mechanisms and the antileukemic effect of CD19-4-1BBL in chronic lymphocytic leukemia (CLL), a B-cell malignancy profoundly marked by the immunosuppressive activity of myeloid-derived suppressor cells, tumor-associated macrophages and CD4+ regulatory T cells. We demonstrated that CD19-4-1BBL simultaneously mitigates the immunosuppressive phenotype and transcriptome machinery of these cells and promotes antitumor CD8+ T-cell immunity. Finally, in a preclinical, patient-derived xenograft model of CLL, we observed a favourable survival impact, especially in mice transplanted with immune cells from patients with high-risk/progressive leukemia. Our findings provide evidence that the CD19-4-1BBL treatment is a multifaceted, immune-based strategy that should be clinically explored in patients with chronic lymphocytic leukemia. KEY POINTSO_LICD19-4-1BBL sharpens the myeloid cell transcriptome and stimulates diverse memory CD8+ T cell clonotypic responses. C_LIO_LICD19-4-1BBL costimulation can be therapeutically exploited in high-risk chronic lymphocytic leukemia. C_LI

immunology↗

bioRxiv2025

CDK8 remodels the tumor microenvironment to resist the therapeutic efficacy of targeted KRASG12D inhibition in pancreatic ductal adenocarcinoma

Mutations in KRAS are a dominant driver of pancreatic ductal adenocarcinoma (PDAC), with over 40% of PDAC patients presenting with KRASG12D mutations. The recent development of small molecule inhibitors targeting KRASG12D has enabled targeting of mutant KRAS signaling and suppression of PDAC; however, the contribution of the tumor microenvironment (TME) to the sustained therapeutic efficacy of KRASG12D inhibition and mechanism/s of resistance to KRASG12D suppression remain to be elucidated. Here, we employed spatial transcriptomics, single cell RNA sequencing, and CODEX-based spatial proteomics to evaluate cancer cell intrinsic and extrinsic responses to KRASG12D inhibition with MRTX1133. While KRASG12D inhibition initially increases CD11c+ cells with impactful T cell infiltration within proximity to cancer cells, long-term treatment with MRTX1133 resulted in reversal of the immune responses leading to KRASG12D therapy resistance promoted by CDK8, a multiprotein mediator complex associated kinase. CDK8 imparts resistance in part through induction of downstream CXCL2 chemokine secretion, inhibition of FAS expression, and remodeling of the TME to promote immune evasion. Targeting CDK8 by itself and in combination with CTLA-4 immunotherapy overcomes resistance to KRASG12D inhibition with prolonged survival with translational implications.

cancer biology↗

bioRxiv2020

p53 plays a central role in lymphatic anomalies

Activation of the transcription factor p53 has been associated with several developmental syndromes. In normal tissues, p53 is kept at very low undetectable physiological levels. When triggered by cellular stressors, p53 prompts important anti-proliferative and apoptotic programs part of its tumor suppressor activity or as the guardian of tissue homeostasis. We generated two murine models that display cutaneous hemorrhaging, severe edema, and distended blood-filled lymphatic vessels at late-gestation due to overactive p53 uniquely affecting lymphatic endothelial cells during development. Overactive p53 operated distinctively through anti-proliferative route in this tissue resulting in a decrease in initial lymphatics that normally absorb interstitial fluid. Remarkably, genetic or pharmacologic normalization of p53 restored lymphatic homeostasis and reversed lymphatic phenotypes. In parallel, several human lymphatic disease tissues exhibited high p53 levels exclusively in the lymphatic endothelium while p53 remained undetectable in surrounding arterial or venous vessels. We report here, for the first time, an extended role that the p53 pathway plays in the genesis of lymphatic homeostasis deficiencies opening the way for new therapeutic avenues for these rare, poorly understood, and incurable lymphatic maladies.

developmental biology↗