CD2 engagement induces dendritic cell activation: implications for immune surveillance and T-cell activation

Abstract

We have shown previously that primary dendritic cells and monocytes express equal levels of CD14 but are distinguishable by the presence of CD2 on dendritic cells. CD2 is known to mediate the activation of T and natural killer (NK) cells through its interaction with CD58. CD2 epitopes recognized by anti-T111, -T112, and -T113 monoclonal antibodies (mAbs) are present on dendritic cells. Here we show that CD2 engagement significantly increases class II, costimulatory (CD40, CD80, CD86), adhesion (CD54, CD58), and CCR7 molecule expression on primary dendritic cells. Conversely, minimal or no change in the expression of the above antigens occurs on monocyte-derived dendritic cells, because these molecules are already maximally expressed. However, both kinds of dendritic cells release interleukin-1beta (IL-1beta) and IL-12 after CD2 engagement. Lastly, interference with dendritic cell CD2-T-cell CD58 engagement decreases naive CD4+CD45RA+ T-cell proliferation. Collectively, our results suggest another role of the CD2-CD58 pathway that allows nonimmune and immune cells to interact directly with dendritic cells and initiate innate and adaptive immune responses.

Human embryonic stem cell–derived hematopoietic cells are capable of engrafting primary as well as secondary fetal sheep recipients

“…The post-GM-CSF data confirmed differentiation of hematopoietic elements into both myeloid (CD15, CD36) and lymphoid-like (CD2) lineages. 13,14 We also show HLA-DR, a major histocompatibility complex (MHC) class II marker for antigen-presenting cells, to be expressed in vivo as has been noted in vitro for hematopoietic progeny derived from hESCs. 15 MHC II molecules are decreased on most erythroid and myeloid differentiated cells.…”

Dendritic Cells Induce MUC1 Expression and Polarization on Human T Cells by an IL-7-Dependent Mechanism

“…Standard unstained, isotypestained, and positively stained control T cells were used for quadrant gate settings. Where indicated, results are expressed as an expression index (EI) (percentage positive population multiplied by the mean fluorescence intensity (MFI)) (40,41). RT-PCR and immunoblot analysis for MUC1 and ␤-actin expression were performed as described (18).…”

Immunization of Stage IV Melanoma Patients with Melan-A/MART-1 and gp100 Peptides plus IFN-α Results in the Activation of Specific CD8+ T Cells and Monocyte/Dendritic Cell Precursors

“…In addition, several studies reported an increased number of circulating CD14 + CD16 + in the course of infections, inflammation, and malignant diseases (17)(18)(19)(20). Another subpopulation of circulating monocytes expresses the CD2 marker and these cells have been described as dendritic cells (21,22). In particular, we have recently reported that peripheral blood monocytes may differentiate into highly active antigen-presenting cells and CD14 + CD2 + monocytes can rapidly acquire the expression of the dendritic cell maturation marker CD83 after a short time (i.e., 4 hours) of incubation in the presence of IFN-a and granulocyte macrophage colony-stimulating factor (GM-CSF; ref.…”