Measurements made while a compound is present can differ from measurements after the compound is removed. Martínez and colleagues tested that distinction when studying cannabidiol and HLA-G, an immune-regulatory protein, in a choriocarcinoma cell line.
The team exposed JEG-3 cells to CBD or a high-CBD extract. They measured HLA-G messenger RNA using quantitative PCR and assessed the protein using immunocytochemistry. Both forms of exposure reduced expression. The investigators reported that the suppression depended on dose and time and reversed after withdrawal under their assay conditions.
Recovery after removing a compound helps distinguish a reversible response from a lasting change under the tested conditions. The paper evaluated cells in a laboratory. Its expression assays did not measure a human immune response, tumor outcomes, or the duration of any effect after use of a cannabis product.