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Background: The antigen Na-GST-1, expressed by the hookworm Necator americanus, plays crucial biochemical roles in parasite survival. This study explores the development of mRNA vaccine candidates based on Na-GST-1, building on the success of recombinant Na-GST-1 (rNa-GST-1) protein, currently assessed as a subunit vaccine candidate, which has shown promise in preclinical and clinical studies. Methodology/findings: By leveraging the flexible design of RNA vaccines and protein intracellular trafficking signal sequences, we developed three variants of Na-GST-1 as native (cytosolic), secretory, and plasma membrane-anchored (PM) antigens. After one immunization in mice, mRNA vaccines induced an earlier onset of antigen-specific antibodies compared to rNa-GST-1. Following two immunizations, mRNA vaccines induced similar or superior levels of antigen-specific antibodies compared to rNa-GST-1. Secretory Na-GST-1 was comparable to rNa-GST1 in producing neutralizing antibodies against Na-GST-1's thiol transferase activity, while native Na-GST-1 induced a more robust CD8+ T cell response due to its intracellular accumulation. Although PM Na-GST-1 elicited one of highest titers of antigen-specific antibody and a diverse set of memory T-cell populations, it resulted in a lower ratio of neutralizing antibodies after IgG purification compared to the other vaccine candidates. Conclusions/significance: These findings emphasize the importance of antigen localization in tailoring immune responses and suggest that extracellular antigens are more effective for inducing humoral responses, whereas cytosolic antigen accumulation enhances MHC-1 peptide presentation. Future studies will determine if these in vitro and immunogenicity findings translate to in vivo efficacy. Altogether, mRNA vaccines offer numerous possibilities in the development of multivalent vaccines with single or multiple antigens. Author summary: Our work on Na-GST-1 mRNA vaccines addresses a critical need in the fight against hookworm infections, which affect more than 100 million people worldwide. Na-GST-1, a protein essential for the survival of hookworms, has been explored as a target for vaccine development. By using mRNA technology, we designed vaccine candidates that express and deliver Na-GST-1 to different locations in cells and tissues of immunized mice, including forms that are secreted, anchored to the plasma membrane, or retained within cells (the native form). Our findings reveal that the location of antigens within cells significantly impacts the immune response. Secreted and membrane-anchored forms of Na-GST-1 generated strong antibody responses, which are important for neutralizing Na-GST-1 in the hookworm. Meanwhile, the intracellular and membrane anchored forms elicited a robust cytotoxic cell response, which would be more important for targeting intracellular pathogens. This research not only advances our understanding of how protein localization affects immune responses but also highlights the versatility and potential of mRNA vaccines to target various pathogens by manipulating how and where vaccine antigens are presented to the immune system. [ABSTRACT FROM AUTHOR]

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease. Globally 6 to 7 million people are infected by this parasite of which 20–30% will progress to develop Chronic Chagasic Cardiomyopathy (CCC). Despite its high disease burden, no clinically approved vaccine exists for the prevention or treatment of CCC. Developing vaccines that can stimulate T. cruzi-specific CD8+ cytotoxic T cells and eliminate infected cells requires targeting parasitic antigens presented on major histocompatibility complex-I (MHC-I) molecules. We utilized mass spectrometry-based immunopeptidomics to investigate which parasitic peptides are displayed on MHC-I of T. cruzi infected cells. Through duplicate experiments, we identified an array of unique peptides that could be traced back to 17 distinct T. cruzi proteins. Notably, six peptides were derived from Tcj2, a trypanosome chaperone protein and member of the DnaJ (heat shock protein 40) family, showcasing its potential as a viable candidate vaccine antigen with cytotoxic T cell inducing capacity. Upon testing Tcj2 as an mRNA vaccine candidate in mice, we observed a strong memory cytotoxic CD8+ T cell response along with a Th1-skewed humoral antibody response. In vitro co-cultures of T. cruzi infected cells with splenocytes of Tcj2-immunized mice restricted the replication of T. cruzi, demonstrating the protective potential of Tcj2 as a vaccine target. Moreover, antisera from Tcj2-vaccinated mice displayed no cross-reactivity with DnaJ in lysates from mouse and human indicating a decreased likelihood of triggering autoimmune reactions. Our findings highlight how immunopeptidomics can identify new vaccine targets for Chagas disease, with Tcj2 emerging as a promising new mRNA vaccine candidate. Author summary: Chagas disease, caused by the parasite Trypanosoma cruzi, affects millions of people worldwide and leaves a substantial proportion of patients at risk for developing Chronic Chagasic Cardiomyopathy (CCC). Despite the disease's impact, no approved immunotherapies or vaccines currently exist. This study employs an advanced technique called "immunopeptidomics" to identify potential vaccine targets that can induce CD8+ cytotoxic T cells, able to detect and kill infected cells in T. cruzi–infected tissues. By analyzing infected cells, we identified T. cruzi–specific peptides displayed on these cells' surfaces. Notably, multiple peptides arose from Tcj2, one of five T. cruzi- DnaJ proteins. Employing an mRNA vaccine, this novel antigen was administered to mice, prompting a robust immune response, including strongly elevated levels of T. cruzi-specific cytotoxic T cells. Overall, this study highlights the strength of immunopeptidomics in parasitology, revealing a promising vaccine target for Chagas disease. [ABSTRACT FROM AUTHOR]

Six species of Lecanora with multispored asci (multispored species) viz., L. flavothallina, L. himachalensis, L. jatoliensis, L. pruinomarginata, L. shimlaensis, and L. uttarkashiensis are described as new to science. Lecanora flavothallina is characterized by having characteristic yellow pigments at the thallus margin, L. himachalensis is characterized by having a chlarotera-type epihymenium and the presence of hypoprotocetraric acid, L. jatoliensis has pruinose apothecial discs and usnic acid, L. shimlaensis is characterized by having dark brown to black apothecial discs, and an allophana-type amphithecium. L. pruinomarginata has whitish pruinose apothecial margins and fumarprotocetraric acid, while L. uttarkashiensis is characterized by having orange-brown epruinose apothecial discs and zeorin. All six species are reported from Himalayan regions at elevations of 2000 to 3800 m. An updated world key to the known multispored species of Lecanora is provided. [ABSTRACT FROM AUTHOR]

The development of a yeast-expressed recombinant protein-based vaccine technology co-developed with LMIC vaccine producers and suitable as a COVID-19 vaccine for global access is described. The proof-of-concept for developing a SARS-CoV-2 spike protein receptor-binding domain (RBD) antigen as a yeast-derived recombinant protein vaccine technology is described. Genetic Engineering: The strategy is presented for the design and genetic modification used during cloning and expression in the yeast system. Process and Assay Development: A summary is presented of how a scalable, reproducible, and robust production process for the recombinant protein COVID-19 vaccine antigen was developed. Formulation and Pre-clinical Strategy: We report on the pre-clinical and formulation strategy used for the proof-of-concept evaluation of the SARS-CoV-2 RBD vaccine antigen. Technology Transfer and Partnerships: The process used for the technology transfer and co-development with LMIC vaccine producers is described. Clinical Development and Delivery: The approach used by LMIC developers to establish the industrial process, clinical development, and deployment is described. Highlighted is an alternative model for developing new vaccines for emerging infectious diseases of pandemic importance starting with an academic institution directly transferring their technology to LMIC vaccine producers without the involvement of multinational pharma companies. [ABSTRACT FROM AUTHOR]