Phenotypic and Functional Analysis of HL-60 Cells Used in Opsonophagocytic-Killing Assay for Streptococcus pneumoniae

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.

Phenotypic and Functional Analysis of HL-60 Cells Used in Opsonophagocytic-Killing Assay for Streptococcus pneumoniae

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.

B7-H3 and CD 133 expression in non-small cell lung cancer and correlation with clinicopathologic factors and prognosis

To detect the expression of B7-H3 and CD 133 in human non-small cell lung cancer [NSCLC] specimens and lung benign lesions, and to evaluate the correlation between the 2 biomarkers and clinicopathologic features. This is a case-control study of 102 tissue specimens collected from NSCLC participants undergoing thoracic surgery in the Second Affiliated Hospital of Soochow University, Suzhou, China, between January 2006 and December 2008. From the 102 patients, 25 adjacent non-cancer samples were verified pathologically as normal tissue [positive group], and 24 benign inflammatory lesion tissues were used as control [negative group]. Specimens from 126 participants were stained immunohistochemically using Image-Pro Plus software, and the cell number was measured in each section. Of the 102 specimens, 71 expressed B7-H3, and 51 expressed CD 133, higher than that in benign lesions [p<0.001] or non-cancer tissues [p<0.001]. B7-H3 expression in squamous cell carcinoma [SCC] was significantly higher than those in adenocarcinoma [p=0.048], while CD 133 expression in large cell lung carcinoma was higher than that in SCC [p=0.023]. The mean number of tumor-infiltrating lymphocytes [TILs] in the B7-H3-positive group was lower than that in the B7-H3-negative group [p=0.026]. The mean TILs in the CD133-positive group was significantly lower than that in CD133-negative group [p=0.029]. We found that CD 133 was related to tumor cell differentiation degree and CD 133 expression was negatively correlated with B7-H3 expression. The CD 133 positive or B7-H3 negative was associated with poor prognosis of NSCLC patients by Cox regression analysis. Both CD 133 and B7-H3 might induce apoptosis of TILs in NSCLC and tumor evading host immune surveillance. Either CD 133 or B7-H3 might be an independent risk factor of NSCLC participants

El receptor "pepenador" y su importancia en procesos amiloidáticos / The scavenger receptor and its importance in amyloid processes

The scavenger receptor (SRA or RPA) belongs to a wide family of receptor proteins. The classification is based on sequence homologies and structural similarities; nevertheless, it has been useful to group them on the basis of ligand specificity. The SRA was first identified as a receptor for modified low-density lipoproteins, where such modification permits to regulate the uptake of modified LDL by macrophages leading to a massive cholesterol accumulation. Moreover, SRA facilitates the clearance by phagocytic cells of microbial pathogens and senescent cells. SRA is a transmembrane glycoprotein that exists as a trimer comprised of a cystein-linker dimer and a non-covalently bound monomer. SRA has an a-helical coiled coil domain, which is essential for both trimer formation and acid-dependent ligand dissociation. It also contains a collagenous domain, essential for ligand binding. The majority of these ligands are polyanionic molecules, such as the A beta-peptide, important in the development of Alzheimer's disease. Present findings including our own consider that binding of these peptides to SRA activates an inflammatory response with the production of oxidative stress.