Vaccines, from Neapolitan researcher discovery on the role of platelets in the longevity of the antibody response

A pioneering study led by Neapolitan researcher Mario Cortese and Professor Bali Pulendran, published in the prestigious British journal Nature Immunology, has uncovered a new mechanism underlying the duration of the immune response to vaccines. Using advanced systems vaccinology techniques, researchers from the Stanford University team in California discovered that platelets, previously known primarily for their role in clotting, play a crucial role in immune memory.

The team analyzed immune responses to several vaccines, including the one against avian influenza H5N1, and identified a “molecular signature” associated with platelets and cell adhesion processes. This signature, detectable within a week of vaccination, was found to predict the duration of immune responses not only for H5N1, but also for other vaccines, such as those against COVID-19, malaria, and meningococcal and pneumococcal infections.

At the heart of the discovery is the role of megakaryocytes, platelet progenitor cells in the bone marrow. When activated by thrombopoietin (TPO), megakaryocytes promote the survival of long-lived plasma cells, cells that are essential for maintaining antibody production over time. This support occurs through direct integrin-mediated contacts and through the secretion of key factors such as APRIL and MIF, which act in the bone marrow microenvironment to promote plasma cell stability.

The real innovation of the study lies in the ability to measure the effects of these interactions in peripheral blood. Although the primary mechanism occurs in the bone marrow, changes in genes expressed by platelets are reflected in blood samples, making it possible to detect the molecular signature through relatively simple analyses.

This represents a breakthrough: monitoring this genetic molecular signature could allow us to predict, months in advance, the success of vaccination in an individual. In other words, we could know already in the first days after vaccination how long the immune protection will last.

A discovery that not only sheds new light on a long-standing mystery in vaccinology – how some immunizations last a lifetime, while others only a few months – but also offers a potential practical innovation. The ability to monitor the early immune response paves the way for “tailor made” vaccination strategies, where the duration of immunity could be optimized for each individual.

So, a new approach that could transform the way we develop and administer vaccines, significantly increasing their effectiveness and global impact, especially in the event (and avoid) of future pandemics.

Luciano Carotenuto