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Mangano, S.

Publications and source records attributed to Mangano, S..

6 recordsLinked to original sources

Differential serum binding patterns predicting healthy subjects and cancer patients

A viral exposure signature (VES) has been previously described predicting the development of Hepatocellular carcinoma (HCC) in at-risk patients. This has been achieved by a serological profiling of the viral infection history using a synthetic human virome including >100k epitopes (VirScan). In the present study we applied the same VirScan strategy to identify a differential serum binding pattern (DSBP) for classifying patients of different cancer types from healthy individuals. In particular, the healthy group included both age-matched (ADULTS) as well as elderly (ELDERS) individuals, the latter counting also nonagenarians and centenarians. The class comparison performed with serological data show DSBPs supporting class predictions, as confirmed by the receiver operating characteristic (ROC) curve analysis. Antibody responses supporting the class predictions are specific to peptides from persistent herpesviruses, acute-infecting viruses and, consistently in all comparisons, human respiratory syncytial virus (HRSV). Strikingly, the DSB of the ELDERS vs. CANCER comparison is characterized by higher titers in the healthy subjects; on the contrary, the DSB of the ADULTS vs. CANCER comparison is characterized by lower titers in the healthy subjects. Overall, the results show a differential serological binding pattern predicting healthy individuals (ADULTS or ELDERS) from patients with different types of cancer. Such results provide the first evidence suggesting a close link between anti-microbial immunity and cancer development. They may be of the highest relevance in terms of predictive, diagnostic and/or prognostic impact in oncology.

immunology↗

Cross-reactivity of SARS-CoV-2-specific T cells against tumor-associated antigens via molecular mimicry

BACKGROUNDWe have recently described SARS-COV-2 antigens showing sequence and conformational homology to tumor associated antigens (TAAs). Moreover, cross-reactive T cells have been identified in individuals either infected by the SARS-CoV-2 virus or vaccinated with the BNT162b2 preventive vaccine. In the present study, we analyzed the specific cross-binding TCRs by single cell RNA TCR sequencing. METHODS AND RESULTSThe paired SARS-CoV-2 epitope LLLDDFVEI (VIR) and the PRDX5 tumor associated antigen LLLDDLLVS (TAA) were selected to elicit cross-reacting T cells ex vivo. PBMCs from 5 healthy individuals were cultured for 10 days with 10 ug every 3 days of one of the two peptides and cells were selected for single cell RNA TCR sequencing. Results in CD8+ T Effector cells (TTE) showed the amplification or the de novo identification of a handful number of TRAV/TRBV genes and of CDR3{beta} motifs upon treatment ex vivo with both epitopes, which are specific for each subject in the analysis. The very same clonotypes were identified also in the CD8+ T proliferating subset, confirming that both epitopes induced a highly activated and plastic state. Conformational prediction analyses of pMHC-TCR complexes showed perfect structural overlap, supporting the functional cross-reaction of CD8+ T cells with both the viral and the tumor antigens. CONCLUSIONSOur results describe for the first time the TCR CDR3{beta} motifs amplified or de novo expanded by induction with a viral antigen showing a molecular mimicry with a tumor antigen. They are strictly individual and do not match with any motif in the publicly available TCR repository. However, considering the significant degeneracy in the TCR binding to the same epitope, the finding of identical TCR CDR3{beta} motifs elicited by two homologous epitopes is of the highest functional relevance. Such results provide a clear experimental validation proof that microbial epitopes mimicking TAAs can be used to develop off-the-shelf preventive/therapeutic vaccine formulations. Indeed, such non-self antigens are much stronger immunogens and may elicit a potent cross-reacting anti-cancer T cell response.

cancer biology↗

Proline-rich Extensin-like Receptor Kinases PERK5 and PERK12 are involved in Pollen Tube Growth

BackgroundCell wall integrity plays an essential role during polarized cell growth typical of pollen tubes and root hairs. Proline-rich Extensin-like Receptor Kinases (PERK) belong to the hydroxyproline-rich glycoprotein (HRGP) superfamily of cell surface glycoproteins. ResultsHere, we identified two PERKs from Arabidopsis thaliana, PERK5 and PERK12 highly expressed in mature pollen. Pollen tube growth was impaired in the single and double perk5-1 perk12-1 loss of function mutants, with a moderate impact on seed production. When the segregation of self- and reciprocal-crosses of the perk5-1, perk5-2 and perk12-1 single mutants, and reciprocal-crosses of the perk5-1 perk12-1 double mutant were carried out, a male gametophytic defect was found, indicating that perk5-1 and perk12-1 mutants carry defective pollen tubes, resulting in deficient pollen transmission. Furthermore, double perk5-1 perk12-1 mutants show excessive accumulation of pectins and cellulose at the cell wall pollen of the tube tip. In addition, an upregulation of cytoplasmic ROS levels were detected by using 2,7-dichlorofluorescein diacetate probe (H2DCF-DA), and in agreement, similar results were obtained with HyPer, a genetically encoded YFP-based radiometric sensor, which is used to follow the production of hydrogen peroxide (H2O2). Single and double perk5-1 perk12-1 mutants show higher levels of cytoplasmic H2O2 in their pollen tube tips. ConclusionsTaken together, our results suggest that PERK5 and PERK12 are necessary for proper pollen tube growth highlighting their role on cell wall assembly and ROS homeostasis.

plant biology↗

A cell surface O-glycosylated peptide, AGP21, acts on the brassinosteroid pathway and modulates root hair cell fate

Root hairs (RHs) develop from specialized epidermal cells called trichoblasts, whereas epidermal cells that lack RHs are known as atrichoblasts. The mechanism controlling root epidermal cell fate is only partially understood. Root epidermis cell fate is regulated by a transcription factor complex that promotes the expression of the homeodomain protein GLABRA 2 (GL2), which blocks RH development by inhibiting ROOT HAIR DEFECTIVE 6 (RHD6). Suppression of GL2 expression activates RHD6, a series of downstream TFs including ROOT HAIR DEFECTIVE 6 LIKE-4 (RSL4 [Yi et al. 2010]) and their target genes, and causes epidermal cells to develop into RHs. Brassinosteroids (BRs) influence root epidermis cell fate. In the absence of BRs, phosphorylated BIN2 (a Type-II GSK3-like kinase) inhibits a protein complex that directly downregulates GL2 [Chen et al. 2014]. Here, we show that the genetic and pharmacological perturbation of the arabinogalactan peptide (AG) AGP21 in Arabidopsis thaliana, triggers aberrant RH development, similar to that observed in plants with defective BR signaling. We reveal that an O-glycosylated AGP21 peptide, which is positively regulated by BZR1, a transcription factor activated by BR signaling, affects RH cell fate by altering GL2 expression in a BIN2-dependent manner. These results suggest that perturbation of a cell surface AGP disrupts BR responses and inhibits the downstream effect of BIN2 on the RH repressor GL2 in root epidermal cells. In addition, AGP21 also acts in a BR-independent, AGP-dependent mode that together with BIN2 signalling cascade controls RH cell fate. SignificanceIn the plant Arabidopsis thaliana, the root epidermis forms in an alternating pattern atrichoblasts with trichoblast cells that end up developing root hairs (RHs). Atrichoblast cell fate is directly promoted by the transcription factor GLABRA2 (GL2) while the lack of GL2 allows RH formation. The loss of AGP21 peptide triggers an abnormal RH cell fate in two contiguous cells in a similar manner as brassinosteroid (BRs) mutants. In the absence of BR signaling, BIN2 (a GSK3 like-kinase) in a phosphorylated state, downregulate GL2 expression to trigger RH cell fate. The absence of AGP21 is able to repress GL2 expression and activates the expression of RSL4 and EXP7 root hair proteins.

plant biology↗

The Molecular Link Between Auxin And ROS-Mediated Polar Growth

Root hair polar growth is endogenously controlled by auxin and sustained by oscillating levels of reactive oxygen species (ROS). These cells extend several hundred-fold their original size toward signals important for plant survival. Although their final cell size is of fundamental importance, the molecular mechanisms that control it remain largely unknown. Here, we show that ROS production is controlled by the transcription factors RSL4, which in turn is transcriptionally regulated by auxin through several Auxin Responsive Factors (ARFs). In this manner, auxin controls ROS-mediated polar growth by activating RSL4, which then upregulates the expression of genes encoding NADPH oxidases (also known as RBOHs, RESPIRATORY BURST OXIDASE HOMOLOG proteins) and Class-III Peroxidases (PER), which catalyse ROS production. Chemical or genetic interference with the ROS balance or peroxidase activity affect root hair final cell size. Overall, our findings establish a molecular link between auxin regulated ARFs-RSL4 and ROS-mediated polar root hair growth.\n\nSignificance StatementTip-growing root hairs are excellent model systems to decipher the molecular mechanism underlying reactive oxygen species (ROS)-mediated cell elongation. Root hairs are able to expand in response to external signals, increasing several hundred-fold their original size, which is important for survival of the plant. Although their final cell size is of fundamental importance, the molecular mechanisms that control it remain largely unknown. In this study, we propose a molecular mechanism that links the auxin-Auxin Response Factors (ARFs) module to activation of RSL4, which directly targets genes encoding ROS-producing enzymes, such as NADPH oxidases (or RBOHs) and secreted type-III peroxidases (PERs). Activation of these genes impacts apoplastic ROS homeostasis, thereby stimulating root hair cell elongation.

plant biology↗