Understanding virtual memory CD8+ T Cells

Virtual memory CD8+ T cells (T_VM) are a relatively recent discovery in humans. A new review discusses what is known about them from mouse models and their cellular equivalents in humans, as described in the Journal of Interferon & Cytokine Research (JICR).

Maria Cecillia Rodriguez-Galan, from Universidad Nacional de Córdoba, and coauthors review the biology and development of innate memory (T_IM) and T_VM) cells in mice and humans. They describe the effector mechanisms of T_IM/T_VM cells, the role of T_IM/T_VM in the infectious process, the role of T_IM/T_VM in cancer, T_VM cells during aging, and cytokines and T_IM/T_VM cells.

“The discovery of human CD8+ T cells with identical characteristics to murine T_VM cells has aroused enormous interest in recent years and has posed a new challenge in trying to understand not only their role in different pathological processes, but also to discriminate what roles have been erroneously assigned to specific memory cells instead of virtual memory cells,” state the investigators. “Numerous publications are currently emerging that are clarifying more and more about the origin, functional characteristics and their role in different pathological processes, especially in infections and cancer, which will provide a new edge to understand their key role in the immune system.”

“Most immunological T cell memory is trained by exposure to antigens delivered by invading pathogens. However, a population of memory T cells emerge[s] in the absence of obvious prior antigen exposure, termed ‘virtual memory’ cells. The article by Viano and colleagues is a comprehensive review of our knowledge of this mysterious population of cells—origin, phenotype, and effector function. The authors also discuss similar populations of virtual memory CD8+ T cells in humans. The manuscript will be of particular interest to vaccinologists, immunologists, and infectious disease researchers,” says Journal of Interferon & Cytokine Research Editor-in-Chief David L. (Woody) Woodland, Ph.D.