Development and Characterization of Monoclonal Antibodies Against Glycophorin A Applicable for Blood Sample Processing.

The separation of plasma from blood cells is critical for the accuracy of blood tests because cellular fractions can create discrepancies in analysis. The most common method to separate blood cells from the liquid part of the blood is centrifugation, which is not always applicable in resource-constrained areas and countries. In this study, we describe the generation of monoclonal antibodies (mAbs) against glycophorin A (GPA) of human erythrocytes. BALB/c mice were immunized with human erythrocytes followed by purified GPA. The splenocytes of the immunized mice were fused with Sp2/0 myeloma cells by hybridoma technique. Hybridoma clones were screened by hemagglutination assay and enzyme-linked immunosorbent assay (ELISA). Six hybridoma clones were obtained and subcloned. The characterization of the purified mAbs demonstrates that they are able to bind and retain erythrocytes in hemagglutination assay. Furthermore, one of the mAbs 1A9 recognizes purified GPA in ELISA, whereas the other mAb 1G7 is able to immunoprecipitate GPA from human erythrocyte lysates, and a band of 38 kDa is detected. In conclusion, the anti-GPA mAbs are useful tools in developing a quick and easy way to separate blood plasma from whole blood for clinical tests, and in developing bi-specific antibodies for other clinical applications.

Iron overloaded polarizes macrophage to proinflammation phenotype through ROS/acetyl-p53 pathway.

PURPOSE: Macrophages play critical roles in inflammation and wound healing and can be divided into two subtypes: classically activated (M1) and alternatively activated (M2) macrophages. Macrophages also play important roles in regulating iron homeostasis, and intracellular iron accumulation induces M1-type macrophage polarization which provides a potential approach to tumor immunotherapy through M2 tumor-associated macrophage repolarization. However, the mechanisms underlying iron-induced M1 polarization remain unclear. METHODS: Western blotting, qRT-PCR, and flow cytometry were used to detect the polarization indexes in RAW 264.7 murine macrophages treated with iron, and Western bloting and qRT-PCR were used to detect p21 expression. The compound 2,7-dichlorofluorescein diacetate was used to measure reactive oxygen species (ROS) levels in macrophages after iron or N-acetyl-l-cysteine (NAC) treatment. The p300/CREB-binding protein (CBP) inhibitor C646 was used to inhibit p53 acetylation, and Western bloting, qRT-PCR, and immunofluorescence were used to detect p53 expression and acetylation. BALB/c mice were subcutaneously injected with H22 hepatoma cells, and macrophage polarization status was investigated after tail intravenous injection of iron. Immunohistochemical staining was used to evaluate the protein expression of cluster of differentiation 86 (CD86) and EGF-like module-containing mucin-like hormone receptor-like 1 (F4/80) in the subcutaneous tumors. RESULTS: Iron overload induced M1 polarization by increasing ROS production and inducing p53 acetylation in RAW cells, and reduction in ROS levels by NAC repressed M1 polarization and p53 acetylation. Inhibition of acetyl-p53 by a p300/CBP inhibitor prevented M1 polarization and inhibited p21 expression. These results showed that high ROS levels induced by iron overload polarized macrophages to the M1 subtype by enhancing p300/CBP acetyltransferase activity and promoting p53 acetylation.

Development and clinical evaluation of a multi-purpose mAb and a sandwich ELISA test for hepatoma-derived growth factor in lung cancer patients.

Hepatoma-derived growth factor (HDGF) is closely related to aggressive tumor behavior and could be a broader biomarker for cancer prognosis and diagnosis. The goal of this study is to develop a sandwich ELISA system to test if HDGF can be detected in serum samples. We produced an anti-HDGF monoclonal antibody designated 2F12 using recombinant human HDGF protein. The specificity of 2F12 mAb was characterized by western blotting, immunohistochemistry (IHC), immunofluorescent staining (IF) and immunoprecipitation (IP). The results showed that 2F12 recognized HDGF in both native and denatured form, and can be used for multiple purposes. We have found that HDGF is also expressed in several cancers unreported previously by IHC staining on tumor cell array sections. In addition, we have developed a sandwich ELISA assay using mAb 2F12 and rabbit anti-HDGF polyclonal antibody, and validated the assay using normal serum and non-small cell lung cancer (NSCLC) serum samples. The sensitivity of this assay is 0.5 ng/ml and the linear range is 0.5-32 ng/ml. The HDGF average level in serum samples from lung cancer patients is significantly elevated relative to that from healthy controls, 9.43+/-6.13 ng/ml versus 4.36+/-2.50 ng/ml (p=1.12E-10).