Immune memory is essential for host defense against invaders and it is also used as a basis for vaccine development. For these reasons, it is crucial to understand its molecular basis. In this review, we describe recent findings on memory characteristics of innate-like lymphocytes and its contribution to host protection.
In addition to adaptive immune cells, innate cells are also able to mount memory responses through a process called ‘trained immunity.’ Importantly, the lymphoid lineage is not restricted to cells carrying specific T-cell or B-cell receptors, but include cells with germline-encoded receptors. Recent studies show that these innate-like lymphocytes are able to generate efficient recall responses to reinfection. In different circumstances and depending on the cell type, innate-like lymphocyte memory can be antigen-specific or unspecific. Epigenetic changes accompany the generation of memory in these cells, but are still poorly defined.
Immune memory is not restricted to antigen-specific cells, but also encompass different populations of innate immune cells. Innate-like lymphocytes embrace features of both innate and adaptive immune memory, and thus bridge adaptive and innate immune characteristics.
aDepartment for Immunology & Metabolism, Life and Medical Sciences Institute (LIMES)
bPlatform for Single Cell Genomics and Epigenomics at the German Center for Neurodegenerative Diseases
cGenomics & Immunoregulation, LIMES Institute, University of Bonn, Bonn, Germany
dDepartment of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
Correspondence to Mihai G. Netea, Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands. E-mail: email@example.com