Mucosal IgM and IgD responses in fish: kinetics, interactions, and secondary/memory responses

The fastest-growing food production sector, aquaculture, faces important challenges because of infectious agents. Vaccination is the most effective way to prevent and potentially eradicate such diseases, but to date, most commercial vaccines are administered by injection methods, which for fish, imply many disadvantages. On the other hand, mucosal vaccines (directly administered to mucosal tissues) offer a promising and cost-effective alternative. In my MSCA project, I aspire to bring the field of mucosal immunology to the next level by applying my expertise in immune anatomy and working in the renowned laboratory of Prof. Carolina Tafalla who specializes in characterizing teleost B cells. Through this collaboration, I will uncover the cellular mechanisms and interactions of IgM and IgD B cells at fish mucosal sites, such as gills, skin, and intestines. In these tissues, plasma-like B cells secreting IgM coexist with IgD+IgM- B cells, cells that have lost surface IgM through an unclear recombination event. These cells secrete IgD, suggesting an important but undefined role for IgD at specific mucosal surfaces. At INIA, I will be trained in flow cytometry and single-cell transcriptomics. I will complement these techniques with my knowledge of immune anatomy to comprehensively unveil the role of these mucosal plasma-like cells upon immunization in rainbow trout. This project will innovatively expedite mucosal immunology research and underline my ambitions to become an independent scientist. I will further sharpen my scientist profile through CSIC’s mentoring programs for young researchers, which will enhance my skills in formulating and managing large-scale projects. I will also supervise students, keeping me engaged in the academic sector. The proposal addresses pressing scientific questions by integrating the expertise and network of both the host and me while shaping my path to becoming a senior scientist.