The experiment showed that part of CD14 was located in the cell and had not been transported to the cell membrane. The number of CD14 in cells was determined by specific ELISA technology. It was found that there were about 7000 CD14 molecules in each neutrophil, while the number in human monocytes was about 40-45000. Antal et al estimated that the number of CD14 molecules in each monocyte was 2.79 × 106. In neutrophils, CD14 is located in secretory vesicles and azurophilic granules, but not in some specific granules. In monocytes, CD14 is fairly dispersed in the cell, showing weak granules, most of which are distributed in the perinuclear region, equivalent to the Golgi complex, indicating that CD14 is synthesized and stored at the Golgi complex.
Other studies have also shown that more CD14 in human leukocytes form large aggregates by non-covalent binding, which are located in the plasma membrane microstructure domain of 50-100 nm, and are called caveolae structures. These microcellular organelles are combined with the cell plasma membrane, and the vesicles contain many GPI-anchored proteins, which may play an important role in the internalization and exfoliation of these molecules.