Biology subjects

Mendoza-Morales, L. F.

Publications and source records attributed to Mendoza-Morales, L. F..

3 recordsLinked to original sources

bioRxiv2025

Kazal-type serine protease inhibitors from Arabidopsis thaliana and Toxoplasma gondii exhibit antimicrobial activity against plant pathogens

Kazal-type serine protease inhibitors (KPIs) interfere with microbial proteases and have been associated with antimicrobial activity, yet their specific role in plant protection remains poorly understood. In this work, we evaluated the antimicrobial potential of recombinant Arabidopsis thaliana KPI (rAtKPI-1T), recombinant Toxoplasma gondii KPI (rTgPI-1), and two truncated versions of rTgPI-1 (rTgPI-1NT and rTgPI-1CT). Both rAtKPI-1T and rTgPI-1 exhibited inhibitory effects against Pseudomonas syringae DC3000, P. syringae (AvRpm1), and P. viridiflava in a concentration-dependent manner, with significant inhibition at 3.5 M. The lower MIC50 values obtained for rTgPI-1 and its truncated forms compared to rAtKPI-1T suggest a higher antibacterial potency. Binding and immunofluorescence assays further revealed that rAtKPI-1T, rTgPI-1, and rTgPI-1NT associated with bacterial surfaces, while rTgPI-1CT displayed weaker or transient interactions. In addition to their antibacterial activity, rTgPI-1NT and rTgPI-1CT also inhibited the germination of Botrytis cinerea conidia. Both truncated proteins significantly reduced germination after 6 and 9 hours of incubation, with rTgPI-1CT exerting a markedly stronger antifungal effect than rTgPI-1NT. These findings suggest that specific Kazal-type domains, particularly those in the C-terminal region, could play a critical role in suppressing early infection processes of necrotrophic fungi. Overall, this study demonstrates that rKPIs display distinct and complementary antimicrobial profiles mediated by microbial binding and protease inhibition. The contrasting activities of rTgPI-1NT and rTgPI-1CT highlight the value of domain-level analysis to discern functional contributions within multidomain KPIs. These results expand current knowledge on plant-derived protease inhibitors and underscore their potential as biotechnological tools for sustainable crop protection.

microbiology↗

bioRxiv2024

Immunization with Plant-based Vaccine Expressing Toxoplasma gondii SAG1 Fused to Plant HSP90 Elicits Protective Immune Response in Lambs

Toxoplasma gondii is a protozoan parasite causing toxoplasmosis, a principal concern for public health and livestock industries. Effective vaccination strategies are crucial for controlling toxoplasmosis, particularly in the lamb, which are significant reservoirs of T. gondii. In addition, ovine toxoplasmosis also causes economic losses due to abortions and reproductive complications. In this study, we evaluated two immunization strategies to elucidate the immune protective potential of SAG1 fused to the plant Hsp90 adjuvant against experimental toxoplasmosis in lambs. We performed an oral administration of AtHsp81.2-SAG1HC-infiltrated fresh leaves homogenate (Plant Vaccine) and a subcutaneous administration of recombinant NbHsp90.3-SAG1HC produced in Escherichia coli (Recombinant Vaccine). Our results showed that only the Recombinant Vaccine significantly increased anti-rSAG1 total IgG values. In addition, only lambs immunized with the Plant Vaccine showed a significant increase in IFN-{gamma} serum levels after the experimental infection (evaluated 8 days post-challenge). On the other hand, we also observed a statistically significant decrease in histopathological lesions (injury score) in challenged vaccinated lambs compared to challenged but not vaccinated animals (vehicle and control groups). Finally, to evaluate T. gondii infection, we choose the chimera rGra4-Gra7 as an acute phase protein marker. All lambs from the control and vehicle groups showed higher rates of serological reactivity than lambs from the vaccinated groups, concurrently with increased severity of lesions. These results suggest that both the plant-based and recombinant vaccines are promising candidates for controlling T. gondii infection in lambs, with potential benefits for enhancing public health and animal welfare.

molecular biology↗

bioRxiv2023

Safe plant Hsp90 adjuvants elicit an effective immune response against SARS-CoV2 derived RBD antigen

To better understand the role of pHsp90 adjuvant in immune response modulation, we proposed the use of the Receptor Binding Domain (RBD) of the Spike protein of SARS-CoV2, the principal candidate in the design of subunit vaccines. We evaluated the humoral and cellular immune responses against RBD through the strategy "protein mixture" (Adjuvant + Antigen). The rRBD adjuvanted with rAtHsp81.2 group showed a higher increase of the anti-rRBD IgG1, while the rRBD adjuvanted with rNbHsp90.3 group showed a significant increase of anti-rRBD IgG2b/2a. These results were consistent with the cellular immune response analysis. Spleen cell cultures from rRBD+rNbHsp90.3-immunized mice showed significantly increased IFN-{gamma} production. In contrast, spleen cell cultures from rRBD+rAtHsp81.2-immunized mice showed significant increased IL-4 levels. Finally, vaccines adjuvanted with rNbHsp90.3 induced higher neutralizing antibody responses compared to those adjuvanted with rAtHsp81.2. To know whether both chaperones must form complexes to generate an effective immune response, we performed co-immunoprecipitation (co-IP) assays. The results indicated that the greater neutralizing capacity observed in the rRBD adjuvanted with rNbHsp90.3 group would be given by the rRBD-rNbHsp90.3 interaction rather than by the quality of the immune response triggered by the adjuvants. These results, together with our previous results, provide a comparative benchmark of these two novel and safe vaccine adjuvants for their capacity to stimulate immunity to a subunit vaccine, demonstrating the capacity of adjuvanted SARS-CoV2 subunit vaccines. Furthermore, these results revealed differences in the ability to modulate the immune response between these two pHsp90s, highlighting the importance of adjuvant selection for future rational vaccine and adjuvant design.

molecular biology↗