Biology subjects

Molina-Cruz, A.

Publications and source records attributed to Molina-Cruz, A..

3 recordsLinked to original sources

bioRxiv2026

Mannosylated nanoparticle immunogens enhance the circumsporozoite protein-specific B cell response and improve protection against sporozoite challenge

Underprocessed oligomannose glycans on protein nanoparticle immunogens engage the innate immune system through mannose-binding lectin and complement, enhancing immunogen trafficking and B cell responses. However, the extent to which oligomannose glycans directly improve protective immunity has remained unclear. Here we generate a series of CSP-bearing I53-50 nanoparticle malaria vaccine candidates with defined numbers and types of engineered N-linked glycans and systematically evaluate their immunogenicity and protective efficacy. Oligomannose display enhanced early plasmablast and germinal center B cell responses, leading to increased CSP-specific memory B cells, long-lived plasma cells, and durable serum antibody titers. Furthermore, nanoparticles bearing oligomannose glycans conferred the strongest protection against sporozoite challenge. By comparing immunogens with defined glycoforms, we attribute improved immune responses and protection specifically to oligomannose rather than complex or truncated glycans. These results will help guide the development of general strategies for glycan engineering aimed at enhancing the protective efficacy of nanoparticle vaccines.

immunology↗

bioRxiv2021

Malaria parasite evades mosquito immunity by glutaminyl cyclase mediated protein modification

Glutaminyl cyclase (QC) modifies N-terminal glutamine or glutamic acid residues of target proteins into cyclic pyroglutamic acid (pGlu). Here, we report the biochemical and functional analysis of Plasmodium QC. We show that Plasmodium sporozoites of QC-null mutants are recognized by the mosquito immune system and melanized when they reach the hemocoel. Sporozoite numbers in salivary glands are also reduced in mosquitoes infected with QC-null or QC catalytically-dead mutants. This phenotype can be rescued by genetic complementation or by disrupting mosquito hemocytes or melanization immune responses. Mutation of a single QC-target glutamine of the major sporozoite surface protein (CSP) also results in immune recognition of sporozoites. These findings reveal QC-mediated post-translational modification of surface proteins as a major mechanism of mosquito immune evasion by Plasmodium sporozoites.

microbiology↗

bioRxiv2020

Proliferation of DBLOX Peroxidase-Expressing Oenocytes Maintains Innate Immune Memory in Primed Mosquitoes

Immune priming in Anopheles gambiae mosquitoes following infection with Plasmodium parasites is mediated by the systemic release of a hemocyte differentiation factor (HDF), a complex of lipoxin A4 bound to Evokin, a lipid carrier. HDF increases the proportion of circulating granulocytes and enhances mosquito cellular immunity. We found that Evokin is constitutively produced by hemocytes and fat-body cells, but expression increases in response to infection. Insects synthesize lipoxins, but lack lipoxygenases. Here, we show that the Double Peroxidase (DBLOX) enzyme, present in insects but not in vertebrates, is essential for HDF synthesis. DBLOX is highly expressed in oenocytes in the fat body tissue, and these cells proliferate in response to Plasmodium challenge. We provide direct evidence that modifications mediated by the histone acetyltransferase AgTip60 (AGAP01539) are essential for sustained oenocyte proliferation, HDF synthesis and immune priming. We propose that oenocytes function as a population of "memory" cells that continuously release lipoxin to orchestrate and maintain a broad, systemic and long-lasting state of enhanced immune surveillance.

immunology↗