Biology subjects

Galluzzi, L.

Publications and source records attributed to Galluzzi, L..

3 recordsLinked to original sources

bioRxiv2025

Enhanced detection of low-expressed miRNAs in Leishmania-infected macrophages through RNA fractionation and RT-qPCR optimization

MicroRNAs (miRNAs) play critical roles in regulating host responses to Leishmania infections, yet accurate detection of low-abundance miRNAs remains challenging. This study evaluated the impact of RNA fractionation and RT-qPCR protocol optimization on miRNA quantification in Leishmania amazonensis-infected murine macrophages. Using a panel of nine infection-associated miRNAs, we compared small RNA and total RNA fractions for their ability to detect weakly expressed targets. Small RNA consistently provided greater sensitivity and specificity, particularly when combined with a modified RT-qPCR protocol. These findings underscore the importance of RNA preparation methods for studying miRNA dynamics in infectious disease contexts and support improved approaches for detecting biologically relevant, low-expressed miRNAs.

molecular biology↗

bioRxiv2025

A novel pH-sensitive probe to quantify autophagy on high throughput/content imaging platforms

Autophagy is a highly-conserved mechanism that ensures the lysosomal degradation of disposable or potential toxic cytosolic entities in support of cell survival and adaptation to stress. Autophagy is deregulated in various pathological conditions including cardiovascular, neurological, neoplastic-autoimmune and degenerative disorders. However, clinically relevant pharmacological modulators of autophagy remain elusive, calling for the development of novel screening approaches that are amenable to high throughput/content applications. Here, we describe a simple method to detect autophagy in cultured mammalian cells based on the pH-sensitive fluorescent conjugate CalRexin:pHrodo Red and high throughput/content imaging. CalRexin:pHrodo Red is promptly taken up by endosome-amphisome-autolysosome (low pH [~]4.5) pathway, which is connected to canonical autophagy, culminating with a bright red fluorescence. Importantly, this system allows for the discrimination between autophagic responses coupled with the endosome-amphisome-autolysosome pathways and the endosome-lysosome pathway as elicited by receptor-driven endocytosis and phagocytosis. In human cervical carcinoma sHeLa cells, the accumulation of CalRexin:pHrodo Red as elicited by canonical autophagy activators like the mTOR inhibitor rapamycin or serum starvation was suppressed by conventional inhibitors 3-methyladenine or chloroquine. Similarly, RB1CC1-/-(FIP200) as well as ATG5-/- sHeLa cells (which bear genetic defects in two different steps of autophagy) were unable to accumulate CalRexin:pHrodo Red upon exposure to autophagy activators. Thus, CalRexin:pHrodo Red provides a novel approach for imaging autophagy on high throughout/content platforms to screen large libraries for the identification of novel autophagy-targeting agents.

cell biology↗

bioRxiv2025

Total body irradiation primes CD19-directed CAR T cells against large B-cell lymphoma

CD19-targeting chimeric antigen receptor T cells (CART19) have demonstrated significant effectiveness in treating relapsed or refractory large B-cell lymphoma (LBCL). However, they often fail to sustain durable remissions in more than half of all treated patients. Therefore, there is an urgent need to identify approaches to enhance CART19 efficacy. Here, we studied the impact of low-dose radiation on CART19 activity in vitro and find that radiation enhances the cytotoxicity of CART19 against LBCL by upregulating death receptors. Disrupting the FAS receptor diminishes this benefit, indicating that this pathway plays an important role in enhancing the cytotoxic effects of CAR T cells. To further validate these findings, we conducted in vivo studies using a lymphoma syngeneic mouse model delivering total body irradiation (TBI). We observed that delivering TBI at a single dose of 1Gy prior to CAR T cell infusion significantly improved CART19-mediated tumor elimination and increased overall survival rates. Importantly, we characterized several important effects of TBI, including enhanced lymphodepletion, improved T cell expansion and persistence, better intra-tumoral migration, and a more favorable, anti-tumor phenotypic composition of the T cells. In summary, for the first time, we have demonstrated preclinically that administering TBI before CART19 infusion significantly accelerates tumor elimination and improves overall survival. This approach holds promise for translation into clinical practice and serves as a valuable foundation for further research to enhance outcomes for patients receiving CART19 treatment.

cancer biology↗