Immune Netw.  2009 Aug;9(4):127-132. 10.4110/in.2009.9.4.127.

Expression and Function of TLR2 on CD4 Versus CD8 T Cells

• Lee SM
• Joo YD
• Seo SK

• KMID: 1474584
• DOI: http://doi.org/10.4110/in.2009.9.4.127

Abstract

BACKGROUND
Toll-like receptors (TLRs) play a fundamental role in innate immunity through their capacity to recognize pathogen-associated molecular patterns. Also, TLRs that are expressed in T cells are reported to function as co-stimulatory receptors. However, the functional capacity of TLRs on CD4 T and CD8 T cells has not been directly compared. Here we compared CD4 and CD8 T cell responses to TLR2 ligand plus TCR-mediated stimulation. METHODS: TLR2 expression was analyzed on T cell subsets under naive and alloantigen-primed conditions. We analyzed the effects of TLR2 co-stimulation on proliferation and survival of T cell subsets in vitro when stimulated with soluble anti-CD3 in the presence or absence of synthetic ligand Pam3CSK4. RESULTS: TLR2 expression on CD8 T cells was induced following activation; this expression was much higher than on CD4 T cells. Thus, the molecule was constitutively expressed on Listeria-specific memory CD8 T cells. Based on these expression levels, proliferation and survival were markedly elevated in CD8 T cells in response to the TLR2 co-stimulation by Pam3CSK4 compared with those in CD4 T cells. CONCLUSION: Our data show that TLR2 co-stimulation is more responsible for proliferation and survival of CD8 T cells than for that of CD4 T cells.

Keyword

TLR2; T cell co-stimulation; CD4 T cell; CD8 T cell

MeSH Terms

Immunity, Innate
Memory
T-Lymphocyte Subsets
T-Lymphocytes
Toll-Like Receptors
Toll-Like Receptors