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Biology subjects

Gazzinelli, R.

Publications and source records attributed to Gazzinelli, R..

2 recordsLinked to original sources

Leishmania amazonensis sabotages host cell SUMOylation for intracellular survival

Leishmania parasites use elaborate virulence mechanisms to invade and thrive in macrophages. These virulence mechanisms inhibit host cell defense responses and generate a specialized replicative niche, the parasitophorous vacuole. In this work, we performed a genome-wide RNAi screen in Drosophila macrophage-like cells to identify host factors necessary for Leishmania amazonensis infection. This screen identified 52 conserved genes required specifically for parasite entry, including several components of the SUMOylation machinery. Further studies in mammalian macrophages found that L. amazonensis infection inhibited SUMOylation within infected macrophages and this inhibition enhanced parasitophorous vacuole growth and parasite proliferation through modulation of multiple genes especially ATP6V0D2, which in turn effects CD36 expression and cholesterol levels. Together, these data suggest that parasites actively sabotage host SUMOylation and alter host transcription to improve their intracellular niche and enhance their replication.

cell biology↗

Neutralizing antibody-independent immunity to SARS-CoV-2 in hamsters and hACE-2 transgenic mice immunized with a RBD/Nucleocapsid fusion protein

The nucleocapsid (N) and the receptor binding domain (RBD) of the Spike (S) proteins elicit robust antibody and T cell responses either in vaccinated or COVID-19 convalescent individuals. We generated a chimeric protein that comprises the sequences of RBD from S and N antigens (SpiN). SpiN was highly immunogenic and elicited a strong IFN{gamma} response from T cells and high levels of antibodies to the inactivated virus, but no neutralizing antibodies. Importantly, hamsters and the human Angiotensin Convertase Enzyme-2-transgenic mice immunized with SpiN were highly resistant to challenge with the wild type SARS-CoV-2, as indicated by viral load, clinical outcome, lung inflammation and lethality. Thus, the N protein should be considered to induce T-cell-based immunity to improve SARS-CoV-2 vaccines, and eventually to circumvent the immune scape by variants.

immunology↗