Homeostasis and immunological function of self-driven memory-phenotype CD4+ T lymphocytes.
Immunol Med
; 46(1): 1-8, 2023 Mar.
Article
in En
| MEDLINE
| ID: mdl-36218322
ABSTRACT
CD4+ T lymphocytes play an essential role in adaptive immune responses. In pathogen infection, naïve CD4+ T cells that strongly respond to foreign antigens robustly proliferate to differentiate into effector/memory cells, contributing to elimination of the pathogen concerned. In addition to this conventional T cell activation pathway, naïve T cells can also weakly respond to self antigens in the periphery to spontaneously acquire a memory phenotype through homeostatic proliferation in steady state. Such 'memory-phenotype' (MP) CD4+ T lymphocytes are distinguishable from foreign antigen-specific memory cells in terms of marker expression. Once generated, MP cells are maintained by rapid proliferation while differentiating into the T-bet+ 'MP1' subset, with the latter response promoted by IL-12 homeostatically produced by type 1 dendritic cells. Importantly, MP1 cells possess innate immune function; they can produce IFN-γ in response to IL-12 and IL-18 to contribute to host defense against pathogens. Similarly, the presence of RORγt+ 'MP17' and Gata3hi 'MP2' cells as well as their potential immune functions have been proposed. In this review, I will discuss our current understanding on the unique mechanisms of generation, maintenance, and differentiation of MP CD4+ T lymphocytes as well as their functional significance in various disease conditions.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
CD4-Positive T-Lymphocytes
/
Interleukin-12
Language:
En
Journal:
Immunol Med
Year:
2023
Document type:
Article
Affiliation country:
Japan