PubMed · 13882972
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
N D'ANTONA, D FUMAROLA. [Problems connected with immunity tolerance].. https://pubmed.ncbi.nlm.nih.gov/13882972/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The key role of gp120 in the cellular entry of HIV makes this glycoprotein an attractive target for new drugs. Various polyanions bind to the positively charged V3 loop of gp120. Here, we consider a series of anionic porphyrins bearing two sulfonate groups and two carboxylic chains with various degree of esterification. These molecules carry an overall negative charge between 4 and 2. Upon activation by light, these compounds, known as photosensitizers, produce highly reactive oxygen species able to damage amino acid chains. The interactions of these molecules with the V3 loop and a positively charged area in the C5 region were investigated in the dark by using specific antibodies and ELISA protocols. Competitive inhibition of the anti-V3 antibody was observed with an increased efficiency for the esterified compounds. No evidence for binding to the C5 region was found. In contrast, when gp120 was irradiated with light in presence of the porphyrin prior to the addition of the antibody, strong inhibition of the anti-C5 antibody was observed revealing irreversible photo-damages in this region. No effect on the V3 loop was observed. Irradiations at two wavelengths made it possible to identify porphyrin monomers as the photoactive forms despite the presence of large excess of dimers in the incubation solution. It is suggested that porphyrins bound to the V3 loop could produce photo-damages at some distance, in particular within the C5 region that contains several photosensitive amino acids.
Magnetic cell separation has become a popular technique to enrich or deplete cells of interest from a heterogeneous cell population. One important aspect of magnetic cell separation is the degree to which a cell binds paramagnetic material. It is this paramagnetic material that imparts a positive magnetophoretic mobility to the target cell, thus allowing effective cell separation. A mathematical relationship has been developed to correlate magnetic labeling to the magnetophoretic mobility of an immunomagnetically labeled cell. Four parameters have been identified that significantly affect magnetophoretic mobility of an immunomagnetically labeled cell: the antibody binding capacity (ABC) of a cell population, the secondary antibody amplification (psi), the particle-magnetic field interaction parameter (DeltachiV(m)), and the cell diameter (D(c)). The ranges of these parameters are calculated and presented along with how the parameters affect the minimum and maximum range of magnetophoretic mobility. A detailed understanding of these parameters allows predictions of cellular magnetophoretic mobilities and provides control of cell mobility through selection of antibodies and magnetic particle conjugates.
Capillary electrophoresis-based immunoassay (CEIA) is a developing analytical technique with a number of advantages over conventional immunoassay, such as reduced sample consumption, simpler procedure, easy simultaneous determination of multiple analytes, and short analysis time. However, there are still a number of technical issues that researchers on CEIA have to solve before the assay can be more widely used. These issues include method to improve the concentration sensitivity of the assay, requirement for robust separation strategy for different analytes, and method to increase the throughput of the assay. The approaches to solve these issues are reviewed. Several studies have been devoted to develop general separation strategies for CEIA, and to enhance the sensitivity of detection. The recent development of microchip-based CEIA is encouraging and is likely to address more drawbacks of CEIA, particularly on the throughput issue.