Anti-CD155 and anti-CD112 monoclonal antibodies conjugated to a fluorescent mesoporous silica nanosensor encapsulating rhodamine 6G and fluorescein for sensitive detection of liver cancer cells.

A novel method for sensitive detection of liver cancer cells using anti-CD155 and anti-CD112 monoclonal antibodies conjugated to ultrabright fluorescent mesoporous silica nanoparticles (FMSNs) encapsulating Rhodamine 6G and fluorescein was developed. The diameter of the obtained nanoparticles was 90 nm, and the quantum yield was 69%. Because the emission of fluorescein has a high degree of overlap with the excitation of Rhodamine 6G, and these two dyes were sufficiently close to each other on the nanoparticles, fluorescence resonance energy transfer can occur between these two dyes. This transfer not only maintains the original feature of the nanochannels and the skeletal network of the silica weakening the inner filtering of the dye, but also makes the excitation peak of the nanoparticles wider and increases the useful load amount of the dye. Because the wider Stokes shifts weaken the interference of excitation, the detection sensitivity is enhanced at the same time. The NaIO4 oxidation method does not use a cross-linker but rather uses covalent immobilization of the monoclonal antibodies on the FMSNs. This method can maintain the activity of the monoclonal antibodies more easily than the glutaraldehyde method. These advantages ensure that the nanosensor has high sensitivity and specificity for detecting liver cancer SMMC-7721 and HHCC cells. The in vivo imaging experiment also ensured that the biosensor can target tumor tissue in mice.

BAP31, a promising target for the immunotherapy of malignant melanomas.

PURPOSE: Malignant melanoma's (MM) incidence is rising faster than that of any other cancer in the US and the overall survival at 5 years is less than 10%. B cell associated protein 31 (BAP31) is overexpressed in most MMs and might be a promising target for immunotherapy of this disease. EXPERIMENTAL DESIGN: Firstly, we investigated the expression profiles of human BAP31 (hBAP31) and mouse BAP31 (mBAP31) in human and mouse normal tissues, respectively. The expression level of hBAP31 in human MMs and mBAP31 in B16 melanoma cells was also analyzed. Then we constructed novel mBAP31 DNA vaccines and tested there ability to stimulate mBAP31-specific immune responses and antitumor immunity in B16 melanoma-bearing mice. RESULTS: For the first time, we found that protein expression of hBAP31 were dramatically upregulated in human MMs when compared with human normal tissues. Predominant protein expression of mBAP31 was found in mouse B16 melanoma cells but not in mouse important organs. When mice were immunized with mBAP31 DNA vaccines, strong cellular response to mBAP31 was observed in the vaccinated mice. CTLs isolated from immunized mice could effectively kill mBAP31-positive target mouse B16 melanoma tumor cells in vitro and vaccination with mBAP31 DNA vaccines had potent anti-tumor activity in therapeutic model using B16 melanoma cells. CONCLUSIONS: These are the first data supporting a vaccine targeting BAP31 that is capable of inducing effective immunity against BAP31-expressing MMs and will be applicable to human MMs and hBAP31 DNA vaccine warrants investigation in human clinical trials.

Immunocytochemical and immunohistochemical application of monoclonal antibodies against peroxisomal biogenesis factor 14.

PEX14 is an integral membrane protein essential for protein docking onto the peroxisomes and is a bi-functional protein capable of acting as a transcriptional co-repressor and a polypeptide transport modulator. Further studies showed that PEX14 is the sole peroxin that has a unique dual function in peroxisome formation and selective degradation. Its RNA transcripts are ubiquitously expressed; there is, however, no data on the expression profiles of PEX14 at the protein level due to a lack of MAbs suitable for immunohistochemical staining, thus hindering studies on its functions. In the present study, we generated one MAb that could be used in immunocytochemistry and immunohistochemistry and investigated PEX14 expression in normal and malignant human tissues. In contrast to the ubiquitous expression of its RNA transcripts, there is no PEX14 protein expression in normal human tissue, including liver, spleen, lung, rectum, brain, prostate, breast, ovary, and stomach. Protein expression of PEX14 was dramatically upregulated in some malignancies. Presented here are the first data on the expression profiles of PEX14 at the protein level, which will further our understanding of its functions.