Tissue-Resident T Cells and Other Resident Leukocytes

Annu Rev Immunol. 2019 Apr 26:37:521-546. doi: 10.1146/annurev-immunol-042617-053214. Epub 2019 Feb 6.


Resident memory T (Trm) cells stably occupy tissues and cannot be sampled in superficial venous blood. Trm cells are heterogeneous but collectively constitute the most abundant memory T cell subset. Trm cells form an integral part of the immune sensing network, monitor for local perturbations in homeostasis throughout the body, participate in protection from infection and cancer, and likely promote autoimmunity, allergy, and inflammatory diseases and impede successful transplantation. Thus Trm cells are major candidates for therapeutic manipulation. Here we review CD8+ and CD4+ Trm ontogeny, maintenance, function, and distribution within lymphoid and nonlymphoid tissues and strategies for their study. We briefly discuss other resident leukocyte populations, including innate lymphoid cells, macrophages, natural killer and natural killer T cells, nonclassical T cells, and memory B cells. Lastly, we highlight major gaps in knowledge and propose ways in which a deeper understanding could result in new methods to prevent or treat diverse human diseases.

Keywords: T lymphocytes; immunity; lymphoid cells; memory; residence.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • B-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cell Movement
  • Humans
  • Immunity, Innate
  • Immunologic Memory
  • Killer Cells, Natural / physiology*
  • Leukocytes / immunology*
  • Macrophages / immunology*
  • Organ Specificity