OBJECTIVE Both the early steps and the high recurrence of autoimmunity once the disease is established are unexplained in human type 1 diabetes. Because CD8(+) T cells are central and insulin is a key autoantigen in the disease process, our objective was to characterize HLA class I-restricted autoreactive CD8(+) T cells specific for preproinsulin (PPI) in recent-onset and long-standing type 1 d...

NKT cells express both NK cell-associated markers and TCR. Classically, these NK1.1+TCRalphabeta+ cells have been described as being either CD4+CD8- or CD4-CD8-. Most NKT cells interact with the nonclassical MHC class I molecule CD1 through a largely invariant Valpha14-Jalpha281 TCR chain in conjunction with either a Vbeta2, -7, or -8 TCR chain. In the present study, we describe the presence of...

Although CD4(+) T cells are recognized to play an important role in the inflammatory response of nasal polyps (NPs), the biological functions of CD8(+) T cells in polypogenesis remain unclear. In this study, we analyzed cell markers, cytokine expression and transcription factors in IL-21-expressing CD8(+) T cells in polyp tissues of NP patients. The results showed that the majority of IL-21-pro...

BACKGROUND For a long time, the role of CD8(+) T cells in blood-stage malaria was not considered important because erythrocytes do not express major histocompatibility complex (MHC) class I proteins. While recent evidences suggest that CD8(+) T cells may play an important role during the erythrocytic phase of infection by eliminating parasites, CD8(+) T cells might also contribute to modulate t...

The role of CD4 T cells in providing help to CD8 T cells in primary and secondary responses to infection remains controversial. Using recombinant strains of virus and bacteria expressing the same Ag, we determined the requirement for CD4 T cells in endogenous CD8 T cell responses to infection with vesicular stomatitis virus and Listeria monocytogenes (LM). Depletion of CD4 T cells had no effect...

During reinfection, high-affinity IgG Abs form complexes with both soluble Ag and Ag displayed on the surface of infected cells. These interactions regulate cellular activation of both innate cells and B cells, which express specific combinations of activating FcγRs (FcγRI, FcγRIII, FcγRIV) and/or the inhibitory FcγR (FcγRIIB). Direct proof for functional expression of FcγR by Ag-specific CD8 T...

4-1BB (CD137), a member of the tumor necrosis factor receptor superfamily (TNFRSF), is primarily expressed on activated T cells and is known to enhance proliferation of T cells, prevent activation-induced cell death, and promote memory formation of CD8+ T cells. In particular, it is well acknowledged that 4-1BB triggering preferentially enhances the expansion of CD8+ T cells rather than CD4+ T ...

CD8 T cell responses have three phases: expansion, contraction, and memory. Dynamic alterations in proliferation and apoptotic rates control CD8 T cell numbers at each phase, which in turn dictate the magnitude of CD8 T cell memory. Identification of signaling pathways that control CD8 T cell memory is incomplete. The PI3K/Akt signaling pathway controls cell growth in many cell types by modulat...

The CD8 + T-cell response comprises terminally differentiated effector cells and antigen-experienced memory T cells. The latter encompass central (TCM) and effector (TEM) memory cells. TCM cells are superior in their protection against viral and bacterial challenges and mediation of antitumor immunity due to their higher proliferative ability upon antigen re-encounter. Defining a mechanism to e...