Characterization and application of two novel monoclonal antibodies against 2IgB7‐H3: expression analysis of 2IgB7‐H3 on dendritic cells and tumor cells

Abstract

2IgB7-H3 has recently been identified as a new member of the B7 family. Its expression at the protein level remains largely unknown due to the lack of the specific monoclonal antibody (mAb). To characterize the expression of 2IgB7-H3, we newly generated two mouse antihuman 2IgB7-H3 mAbs (4H7 and 21D4). We found the constitutive expression of 2IgB7-H3 on a series of tumor cell lines. Furthermore, the expression was examined on monocyte-derived dendritic cells (Mo-DCs) and DCs from CD34(+) hematopoietic progenitor cells (HPC) by means of mAb staining. The results showed that 2IgB7-H3 was expressed on Mo-DCs at a high and stable level during differentiation in vitro. With the maturation of DCs from CD34(+) HPCs, the expression of the molecule was upregulated. However, the 2IgB7-H3 was not expressed on fresh isolated T and B lymphocytes, monocytes, or CD34(+) HPCs. These results suggested that 2IgB7-H3 may be a valuable surface antigen for the detection of DCs.

Detection and Quantitation of Soluble B7-H3 in Expressed Prostatic Secretions: A Novel Marker in Patients With Chronic Prostatitis

“…9,19 Previous studies showed that B7-H3 protein can be expressed in dendritic cells, liver, lungs and prostate, 20 and most tumor cell lines. 21,22 In addition to expression on the cell membrane, B7-H3 can be released into circulation as a soluble molecule. 11 However, the physiological and pathological role of B7-H3 is far less well known.…”

Diagnosis value of serum B7-H3 expression in non-small cell lung cancer

“…Although B7-H3 mRNA is widely detected in multiple tissues in human and other species, B7-H3 protein is not constitutively expressed in these tissues [11,12]. Previous studies showed B7-H3 protein can be expressed in dendritic cells, and most tumor cell lines derived from epithelium including lung tumor cell lines A549, H1299, H460, and SPC-A-1 [13][14][15]. B7-H3 was described in early studies to costimulate the proliferation of T cells, and selectively stimulates IFN-␥ production [11].…”

Clinical importance of B7-H3 expression in human pancreatic cancer

“…B7-H3 is thought to serve as an accessory co-regulator of T-cell responses after initial antigen priming. At present, there is no consensus with regard to the physiological and pathological roles of B7-H3, as both immunological stimulatory and inhibitory functions have been described (Chapoval et al, 2001;Sun et al, 2002;Suh et al, 2003;Castriconi et al, 2004;Prasad et al, 2004;Steinberger et al, 2004;Wang et al, 2005;Zhang et al, 2005). It was originally identified as a co-stimulatory molecule that promotes T-cell proliferation and IFN-g production (Chapoval et al, 2001).…”

“…B7-H3 is not expressed on quiescent lymphocytes and can be induced in activated dendritic cells, monocytes, T cells, and in some tumour cell lines (Chapoval et al, 2001;Sun et al, 2002;Steinberger et al, 2004;Zhang et al, 2005). B7-H3 is thought to serve as an accessory co-regulator of T-cell responses after initial antigen priming.…”