on December 1, 2015
The group led by Federica Sallusto at the IRB, institute affiliated to the Università della Svizzera italiana (USI), published an article in the European Journal of Immunology on the mechanisms regulating the generation of antibodies, proteins produced by B lymphocytes that play a major role in host protection against infection by viruses and bacteria. To produce effective antibodies, B lymphocytes require help from a specialized subset of T lymphocytes, called T follicular helper (Tfh) cells. The study, mostly performed by a PhD student, Silvia Preite, demonstrated that there is an inverse correlation between the numbers of Tfh cells and the quality of the antibody response. Antibodies produced by B cells in the presence of high numbers of Tfh cells have low affinity and the B cells do not undergo the process of somatic mutation, which is essential to increase antibody affinity. The study also demonstrated that two other classes of T helper lymphocytes, called T regulatory and T memory, can limit the expansion of Tfh cells and therefore restore the generation of high 
affinity antibodies. These findings are relevant to improve vaccines against infectious agents; it is clear that effective vaccines have to induce appropriate and balanced responses from Tfh cells, T regulatory and T memory cells. They may also help to explain the generation of autoantibodies in autoimmune diseases, such as lupus erythematosus and rheumatoid arthritis, characterized by a high number of Tfh cells.
This study, which was given the cover in the European Journal of Immunology, was made possible by funding from the Institute for Arthritis Research (IAR) and the Swiss National Science Foundation (SNSF). Silvia Preite is currently performing her postdoctoral training at the National Human Genome Research Institute, National Institutes of Health, in Bethesda, MA, USA.
