Monoclonal antibodies with subnanomolar affinity to tenofovir for monitoring adherence to antiretroviral therapies: from hapten synthesis to prototype development
JOURNAL OF MATERIALS CHEMISTRY B
Authors: Cavalera, Simone; Agullo, Consuelo; Mercader, Josep, V; Di Nardo, Fabio; Chiarello, Matteo; Anfossi, Laura; Baggiani, Claudio; D'Avolio, Antonio; Abad-Somovilla, Antonio; Abad-Fuentes, Antonio
Abstract
Approximately 32 million people have died of HIV infection since the beginning of the outbreak, and 38 million are currently infected. Among strategies adopted by the Joint United Nations Programme on HIV/AIDS to end the AIDS global epidemic, the treatment, diagnosis, and viral suppression of the infected subjects are considered crucial for HIV prevention and transmission. Although several antiretroviral (ARV) drugs are successfully used to manage HIV infection, their efficacy strictly relies on perfect adherence to the therapy, which is seldom achieved. Patient supervision, especially in HIV-endemic, low-resource settings, requires rapid, easy-to-use, and affordable analytical tools, such as the enzyme-linked immunosorbent assay (ELISA) and especially the lateral flow immunoassay (LFIA). In this work, high-affinity monoclonal antibodies were generated to develop ELISA and LFIA prototypes for monitoring tenofovir (TFV), an ARV drug present in several HIV treatments. TFV was functionalized by inserting a carboxylated C5-linker at the phosphonic group of the molecule, and the synthetic derivative was conjugated to proteins for mice immunization. Through a rigorous screening strategy of hybridoma supernatants, a panel of monoclonal antibodies strongly binding to TFV was obtained. Following antibody characterization for affinity and selectivity by competitive ELISA, a LFIA prototype was developed and tentatively applied to determine TFV in simulated urine. The point-of-care test showed ultra-high detectability (the visual limit of detection was 2.5 nM, 1.4 ng mL(-1)), excellent selectivity, and limited proneness to matrix interference, thus potentially making this rapid method a valuable tool for the on-site assessment of patient adherence to ARV therapy.
Rationale and design of the Baylor Infant Twin Study-A study assessing obesity-related risk factors from infancy
OBESITY SCIENCE & PRACTICE
Authors: Momin, Shabnam R.; Senn, Mackenzie K.; Buckley, Scott; Buist, Neil R. M.; Gandhi, Manisha; Hair, Amy B.; Hughes, Sheryl O.; Hodges, Kelly R.; Lange, William C.; Papaioannou, Maria A.; Phan, Mimi; Waterland, Robert A.; Wood, Alexis C.
Abstract
Background: Early childhood (0-3 years) is a critical period for obesity prevention, when tendencies in eating behaviors and physical activity are established. Yet, little is understood about how the environment shapes children's genetic predisposition for these behaviors during this time. The Baylor Infant Twin Study (BITS) is a two phase study, initiated to study obesity risk factors from infancy. Data collection has been completed for Phase 1 in which three sub-studies pilot central measures for Phase 2. A novel infant temperament assessment, based on observations made by trained researchers was piloted in Behavior Observation Pilot Protocol (BOPP) study, a new device for measuring infant feeding parameters (the "orometer") in the Baylor Infant Orometer (BIO), and methods for analyzing DNA methylation in twins of unknown chorionicity in EpiTwin. Methods: EpiTwin was a cross-sectional study of neonatal twins, while up to three study visits occurred for the other studies, at 4- (BOPP, BIO), 6- (BOPP), and 12- (BOPP, BIO) of age. Measurements for BOPP and BIO included temperament observations, feeding observations, and body composition assessments while EpiTwin focused on collecting samples of hair, urine, nails, and blood for quantifying methylation levels at 10 metastable epialleles. Additional data collected include demographic information, zygosity, chorionicity, and questionnaire-based measures of infant behaviors. Results: Recruitment for all three studies was completed in early 2020. EpiTwin recruited 80 twin pairs (50% monochorionic), 31 twin pairs completed the BOPP protocol, and 68 singleton infants participated in BIO. Conclusions: The psychometric properties of the data from all three studies are being analyzed currently. The resulting findings will inform the development of the full BITS protocol, with the goal of completing assessments at 4-, 6-, 12-, and 14-month of age for 400 twin pairs.