Selezione e processazione di cellule Natural Killer da donatore aploidentico "KIR-ligand" incompatibile per l'immunoterapia adottiva di pazienti con Leucemia Acuta Mieloblastica ad alto rischio

The effector function of natural killer (NK) cells is regulated by activating and inhibitory receptors, termed killer immunoglobulin-like receptors (KIRs). In haploidentical T-cell depleted transplantation the donor/recipient KIR mismatch significantly impacts on NK-mediated tumor cell killing, particularly in acute myeloid leukaemia (AML). Thirty-four high risk AML patients entered a phase I-II study of adoptive NK-cell based immunotherapy and were screened for the availability of one haploidentical KIR ligand mismatched donor. Thirteen of them resulted as having one suitable donor. NK cells were enriched from steady-state leukaphereses by using a double-step immunomagnetic separation system, consisting in depletion of CD3+ T cells followed by positive selection of CD56+ NK cells. CD56+ cells were enriched from 7,70% (1,26-11,70) to 93,50% (66,41-99,20) (median recovery 53,05% (30,97-72,85), median T-depletion 3,03 log (2,15-4,52) viability >92%) and their citotoxic activity was inalterate. All patients (4 progressions, 1 partial remission and 8 complete remissions) received NK cell infusion which was preceeded by immunosuppressive chemotherapy (fludarabine and cyclophosphamide) and followed by interleukin 2 injections. The median number of reinfused NK cells was 2,74x10(e)6/kg(1,11-5,00) and contamining CD3+ T cells were always less than 1x10(e)5/kg. The procedure was well-tolerated and no significant toxicity, including GvHD, related to NK cell infusion was observed. The donor NK cells were demonstrated in 5/10 patients. Among the 8 patients in complete remission 5 patients are stable after 18, 15, 4, 2 months of follow-up. Three other patients relapsed after 2 and 7 months. The patient in partial remission obtained a complete remission, which lasted for 6 months. The 4 patients with active/progressive disease showed the persistence of disease. This clinical observation may be correlated with in vitro studies, indicating that AML cells are capable to induce NK cell apoptosis in a dose-depend manner. In summery, a two-step enrichment of CD56+ NK cells allows the collection of a suitable number of target cells to be used as adoptive immunotherapy in AML patients. Infusion of NK cells is feasible and safe and adoptively transferred NK cells can be detected after infusion.

Pathogenesis of cell toxicity by plant toxins

Ribosome inactivating proteins (RIPs) are a family of plant proteins that depurinate the major rRNA, inhibiting the protein synthesis. RIPs are divided into type 1, single chain proteins with enzymatic activity, and type 2 RIPs (toxic and non-toxic), with the enzymatic chain linked to a binding chain. RIPs have been used alone or as toxic component of immunotoxins for experimental therapy of many diseases. The knowledge of cell death pathway(s) induced by RIPs could be useful for clarifying the mechanisms induced by RIPs and for designing specific immunotherapy. The topic of the current study was (i) the determination of the amino acid sequence of the type 2 RIP stenodactylin. The comparison with other RIPs showed that the A chain is related to other toxic type 2 RIPs. whereas the B chain is more related to the non-toxic type 2 RIPs. This latter result is surprising because stenodactylin is actually the most toxic type 2 RIP known; (ii) the study of the cell death mechanisms induced by stenodactylin in human neuroblastoma cells (NB100). High doses of stenodactylin can activate the effector caspases (perhaps through the DNA damage and/or intrinsic/extrinsic pathways) and also cause ROS generation. Low doses cause a caspase-dependent apoptosis, mainly via extrinsic pathway. Moreover, the activation of caspases precedes the inhibition of protein synthesis; (iii) the investigation of the cell death pathway induced by the non-toxic type 2 RIPs ebulin l and nigrin b. These RIPs demonstrated high enzymatic activity in a cell-free system, but they lack high cytotoxicity. These preliminary studies demonstrate that the cell death mechanism induced by the two non-toxic RIPs is partially caspase-dependent apoptosis, but other mechanisms seem to be involved

“Clinical and biological role of adjuvant dendritic cells vaccination in newly glioblastoma patients”

Background. Glioblastoma (GBM) is the most common primary tumor of central nervous system and it has a poor prognosis. Standard first line treatment, which includes surgery followed by adjuvant radio-chemotherapy,produces only modest benefits to survival. The interest for immunotherapy in this field derives from the development of new drugs and effective therapies as immune-check points inhibitors, adoptive T-cell approaches or dendritic cell (DC) based vaccines or a combinations of these. GBM is described as a typical “immune-deserted” cancer exhibiting a number of systemic and environmental immunosuppressive factors. Considering the role of microenvironment, and above all the lower tumor load and depletion of immunosuppressive cells in GBM, our hypothesis is that DC vaccine may induce an immune response. Main aims and study design. The main aim of this project is to study the role of immune system in GBM, including identification of potential prognostic and predictive markers of outcome and response to dendritic cell vaccine. Firstly, we performed a retrospective analysis on blood samples. Then, we analyzed the immuno-component in tissues samples of enrolled patients; and compared that with blood results. Then, the last part of the project is based on a prospective clinical trial on patients enrolled in DC-based vaccination produced at IRST Cell Factory and actually used for patients with melanoma and other tumors. The enrollment is still ongoing. Expected results. The project will i) develop an immune-panel of prognostic and predictive markers to help clinicians to improve the therapeutic strategy for GBM patients; ii) provide preliminary results on the effectiveness of immunotherapy on GBM patients.

Understanding molecular mechanisms of resistance to immune checkpoint inhibitors in advanced non-small cell lung cancer (NSCLC)

Immune checkpoint inhibitors (ICI) that target PD-1/PD-L1 have recently emerged as an integral component of front-line treatment in metastatic NSCLC patients. The PD-1 inhibitor pembrolizumab is approved as monotherapy for advanced NSCLC with a PD-L1 tumor proportion score (TPS) of ≥1% and in combination with platinum doublet chemotherapy regardless of PD-L1 expression level. However, responses to either regimen occur in only a minority of cases, and PD-L1 TPS is limited as a biomarker in predicting whether a cancer will respond to PD-1 inhibition alone or would be more likely to benefit from PD-1 inhibition plus chemotherapy. Additional biomarkers of immunotherapy efficacy, such as tumor mutational burden (TMB), have not been incorporated into routine clinical practice for treatment selection. The identification of patients who have the greatest likelihood of responding to immunotherapies is critical for guiding treatment decisions. IN addition, early indicators of response could theoretically prevent patients from staying on an ineffective therapy where they might experience complications due to disease progression or develop toxicities from unnecessary exposure to an inactive agent. The aim of this research project is to investigate the clinicopathologic and molecular determinant of response/resistance to the currently available immune checkpoint inhibitors, in order to identify therapeutic vulnerabilities that can be exploited to improve the clinical outcomes of patients with advanced NSCLC.

The RAS-Lung project: implementing blood and tissue genotyping in KRAS-Positive non-small cell lung cancer treatment

Background: The frontline management of non-oncogene addicted non-small cell lung cancer (NSCLC) involves immunotherapy (ICI) alone or combined with chemotherapy (CT-ICI). As therapeutic options expand, refining NSCLC genotyping gains paramount importance. The dynamic landscape of KRAS-positive NSCLC presents a spectrum of treatment options, including ICI, targeted therapy, and combination strategies currently under investigation. Methods: The two-year RASLUNG project, featuring both retrospective and prospective cohorts, aimed to analyze the predictive and prognostic impact of KRAS mutations on tumor tissue and circulating DNA (ctDNA). Secondary objectives included assessing the roles of co-mutations and longitudinal changes in KRAS mutant copies concerning treatment response and survival outcomes. An external validation study confirmed the prognostic or predictive significance of co-mutations. Results: In the prospective cohort (n=24), patients with liver metastases exhibited significantly elevated ctDNA levels(p=0.01), while those with >3 metastatic sites showed increased Allele Frequency (AF) (P=0.002). Median overall survival (OS) was 7.5 months, progression-free survival (PFS) was 4.0 months, and the objective response rate (ORR) was 33.3%. Higher AF correlated with an increased risk of death (HR 1.04, p = 0.03), though not progression. Notably, a reduction in plasma DNA levels was significantly associated with objective response(p=0.01). In the retrospective cohort, KRAS and STK11 mutations co-occurred in 14/21 patients (p=0.053). STK11 mutations were independently detrimental to OS (HR 1.97, p=0.025) after adjusting for various factors. KRAS tissue AF did not correlate with OS or PFS. Within the validation dataset, STK11 mutations were significantly associated with an increased risk of death in univariate (HR 2.01, p<0.001) and multivariate models (HR 1.66, p=0.001) after adjustments. Conclusion: The RAS-Lung Project, employing innovative genotyping techniques, underscores the significance of comprehensive NSCLC genotyping. Tailored next-generation sequencing (NGS) and ctDNA monitoring may offer potential benefits in navigating the evolving landscape of KRAS-positive NSCLC treatment.