bioRxiv Science⌕ Search

Biology subjects

Ciciarello, M.

Publications and source records attributed to Ciciarello, M..

3 recordsLinked to original sources

ZEB1 shapes AML immunological niches suppressing CD8 T-cell activity while fostering Th17 cell expansion.

Acute myeloid leukemia (AML) development and progression is favored by immune suppression directly triggered by leukemia cells. ZEB1 is a key transcription factor in epithelial-to-mesenchymal transition which, we show here, is capable immune regulation in AML. Leukemic cells which had ZEB1 knocked down have reduced engraftment and extramedullary disease when transplanted into immune competent mice due to concomitant activation of CD8 T lymphocytes and reduced expansion of Th17 cells. Differently, in ZEB1 competent AML, IL-17 sustains the development of a pro-invasive and self-maintaining loop inducing MMPs and SOCS2. In humans, AML patients show, in situ on bone marrow biopsies, a direct correlation between ZEB1 and Th17 and, in gene expression profile when divided according to the median value of ZEB1 expression, a different overall survival and relapse along with the expression of MMPs, SOCS2 and Th17 cells enrichment. Overall, our data shed new light into the role of ZEB1 in AML that entwines both pro-tumoral and immune regulatory capacity in AML blasts.

immunology↗

CD40 provides immune privilege to the bone marrow hematopoietic niche

Allogeneic bone marrow transplantation remains the only therapeutic option for a wide range of hematological malignancies despite the risk of possible adverse, immune-related events, such as infection and acute graft-versus-host disease (aGVHD). aGVHD is characterized by T-cell activation, defective B-cell development and osteoblastic niche destruction in bone marrow (BM) among other issues. Transplant conditioning regimens cause excessive inflammatory cytokines production and impaired regulatory T-cell control of aberrant T-cell activation. Here, we show that mesenchymal cells (MSCs) upregulated CD40 upon irradiation at the expense of mesenchymal markers, and that CD40 endows MSC of regulatory function on Treg homeostasis and fitness. Transplantation of wild type hematopoietic cells into a CD40-null recipient reduces Treg numbers allowing persistent T-cell activation and pro-inflammatory cytokines production causing, impaired B-lymphopoiesis. These evidences find correlation in aGVHD patients showing the loss of CD40+ BM-MSCs along with reduction in cells of the B-lineage. Modeling aGVHD in mice we show that the elimination of CD40+ BM-MSCs relies on their higher expression of MHC-I molecules. Indeed, aGVHD mice compared to MHC-matched controls showed the loss of MHC-I + radio-resistant host BM-MSCs. Our data point to CD40+ MHC-I+BM-MSCs as a key regulator of BM tolerogenic niches. Key pointsO_LICD40 regulates BM immunological tolerance following total body irradiation (TBI) and transplantation (BMT). C_LIO_LILoss of CD40+MHC-IhighBM-MSCs is associated to BM manifestation of aGVHD in human and murine model. C_LI

immunology↗

TP53 abnormalities correlate with immune infiltration and are associated with response to flotetuzumab, an investigational immunotherapy, in acute myeloid leukemia

PurposeSomatic TP53 mutations and 17p deletions with genomic loss of TP53 occur in 37-46% of acute myeloid leukemia (AML) cases with adverse risk cytogenetics and are associated with primary induction failure (PIF), high risk of relapse and dismal prognosis. Herein, we aimed to characterize the immune landscape of TP53 mutated AML and to determine whether TP53 abnormalities identify a patient subgroup that may benefit from T-cell targeting immunotherapy approaches. Experimental DesignThe NanoString Pan-Cancer IO 360 assay was used for the immune transcriptomic analysis of 64 diagnostic bone marrow (BM) samples from adults with TP53 mutated AML (n=42) or TP53 wild type AML (n=22), and 35 BM samples from heavily pretreated patients with relapsed/refractory (R/R) AML (11 cases with TP53 mutations and/or 17p deletion with genomic loss of TP53) who received immunotherapy with flotetuzumab, an investigational CD123xCD3 bispecific DART(R) molecule (NCT02152956). In silico data series included The Cancer Genome Atlas (TCGA) cohort and a Dutch-Belgian Cooperative Trial Group for Hematology-Oncology (HOVON) cohort. ResultsAll TCGA cases with TP53 mutations (n=13) expressed higher levels of negative immune checkpoints, inflammatory chemokines, interferon (IFN)-{gamma}-inducible molecules, and had a higher tumor inflammation signature (TIS) score, compared with TCGA cases with other risk-defining molecular lesions. The comparison between TP53 mutated and TP53 wild type primary BM samples showed higher expression of IFNG, FoxP3, immune checkpoints and markers of exhaustion and senescence in the former cohort and allowed the computation of a 34-gene immune classifier prognostic for overall survival. In vitro modeling experiments with AML cell lines showed heightened expression of IFN-{gamma} and inflammation pathway genes in KG-1 cells (loss-of-function mutation of TP53) compared with Kasumi-1 cells (gain-of-function mutation of TP53). Finally, 5 out of 11 (45.5%) patients with R/R AML and TP53 abnormalities showed evidence of anti-leukemic activity of flotetuzumab immunotherapy and had higher TIS, FoxP3, CD8 T-cell abundance, inflammatory chemokine and PD1 gene expression scores at baseline compared with non-responders. ConclusionsThis study provides evidence for a correlation between IFN-{gamma}-dominant immune subtypes and TP53 abnormalities. The anti-leukemic activity with flotetuzumab encourages further study of this immunotherapeutic approach in this patient subgroup.

immunology↗