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Biology subjects

Alisson-Silva, F.

Publications and source records attributed to Alisson-Silva, F..

3 recordsLinked to original sources

HUMAN-LIKE SIALOME REMODELING LINKS HYPERGLYCEMIA TO COLORECTAL CANCER PROGRESSION

The evolutionary loss of cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) abolished endogenous N-glycolylneuraminic acid (Neu5Gc) synthesis in humans, reshaping the sialic acid at the cell surface glycans and influencing immune and metabolic processes. However, whether a human-like sialome modulates the impact of metabolic stress on colorectal cancer (CRC) progression remains unclear. Here, we investigated the diabetes-sialome-tumor axis using a spontaneous CRC model combining conditional Apc mutation with Cmah deficiency, thereby recapitulating the human sialic acid repertoire. Under euglycemic conditions, CPC-Apc Cmah-/- mice exhibited reduced polyp numbers and tumor burden compared with WT mice, accompanied by remodeling of the tumor immune microenvironment, including increased tumor-infiltrating leukocytes, enrichment of B cells, and reduced PD-1 expression in B cells and cytotoxic CD8+ T cells. Induction of chronic hyperglycemia with low-dose streptozotocin revealed a striking genotype-specific effect. Despite comparable hyperglycemia between genotypes, tumor progression was dramatically exacerbated exclusively in Cmah-/- mice, with increased tumor burden, accelerated lesion development, and progression toward high-grade dysplasia. Histopathological analyses further revealed increased mesenchymal expansion and close resemblance to colorectal tumors from diabetic patients. Together, these findings demonstrate that a human-like sialome increases susceptibility to metabolic stress and identify CPC-Apc Cmah-/- mice as a translationally relevant model for investigating diabetes-associated colorectal carcinogenesis.

cancer biology↗

Variable PD-1 glycosylation modulates the activity of immune checkpoint inhibitors

Monoclonal antibodies targeting the immune checkpoint PD-1 have provided significant clinical benefit across a number of solid tumors, with differences in efficacy and toxicity profiles possibly related to their intrinsic molecular properties. Here, we report that camrelizumab and cemiplimab engage PD-1 through interactions with its fucosylated glycan. Using a combination of protein and cell glycoengineering, we demonstrate that the two antibodies bind preferentially to PD-1 with a core fucose at the asparagine N58 residue. We then provide evidence that the concentration of fucosylated PD-1 in the blood of non-small cell lung cancer patients varies across different stages of disease. This study illustrates how glycoprofiling of surface receptors and related circulating forms can inform the development of differentiated antibodies that discriminate glycosylation variants and achieve enhanced selectivity and paves the way towards the implementation of personalized therapeutic approaches.

immunology↗

Neuraminidase inhibitors rewire neutrophil function in murine sepsis and COVID-19 patient cells

Neutrophil overstimulation plays a crucial role in tissue damage during severe infections. Neuraminidase (NEU)-mediated cleavage of surface sialic acid has been demonstrated to regulate leukocyte responses. Here, we report that antiviral NEU inhibitors constrain host NEU activity, surface sialic acid release, ROS production, and NETs released by microbial-activated human neutrophils. In vivo, treatment with Oseltamivir results in infection control and host survival in peritonitis and pneumonia models of sepsis. Single-cell RNA sequencing re-analysis of publicly data sets of respiratory tract samples from critical COVID-19 patients revealed an overexpression of NEU1 in infiltrated neutrophils. Moreover, Oseltamivir or Zanamivir treatment of whole blood cells from severe COVID-19 patients reduces host NEU-mediated shedding of cell surface sialic acid and neutrophil overactivation. These findings suggest that neuraminidase inhibitors can serve as host-directed interventions to dampen neutrophil dysfunction in severe infections. At a GlanceIn a severe systemic inflammatory response, such as sepsis and COVID-19, neutrophils play a central role in organ damage. Thus, finding new ways to inhibit the exacerbated response of these cells is greatly needed. Here, we demonstrate that in vitro treatment of whole blood with the viral neuraminidase inhibitors Oseltamivir or Zanamivir, inhibits the activity of human neuraminidases as well as the exacerbated response of neutrophils. In experimental models of severe sepsis, oseltamivir decreased neutrophil activation and increased the survival rate of mice. Moreover, Oseltamivir or Zanamivir ex vivo treatment of whole blood cells from severe COVID-19 patients rewire neutrophil function.

immunology↗