A team of researchers from the University of Lausanne (Switzerland) traced the origin of an enigmatic population of central memory MCT (MCT) cells, which possess properties that confer immunological memory in an animal model, resolving an 18-year long scientific debate.

These stem cell-like MCT cells are fundamental to the adaptive (not innate) immune system’s ability to create long-lasting immune memories. This ability is critical for controlling pathogens in episodes of infection or re-exposure, and for triggering rapid mobilization of vital host defense.

Although essential to the overall immune response, since their discovery in 2005 these MCTs have been deeply embroiled in debate and controversy over who their precursors are.

The study team, which was recently published in Science Immunology, found that MCTs emerged rapidly upon exposing laboratory animals to infection with lymphocytic choriomeningitis virus and ultimately discovered that they were derived from CD8+ T cells, known as cytotoxic or killer cells. These are essential in the defense against pathogens and cancer cells.

«In response to infection, virgin CD8+ T cells produce a large pool of short-lived terminal effector cells that kill infected host cells,» the research authors wrote.

«In parallel, a smaller population of central memory cells, similar to stem cells, is formed that have the capacity to maintain immunity after pathogen clearance,» they added.

(With information from RT en Español)