The Formation of Non-Specific Immunological Memory Phenotype in Human Monocyte-Like THP-1 and U-937 Cell Lines

We studied the formation of the phenotype of non-specific immunological memory (trained immunity) in human monocyte-like THP-1 and U-937 cell lines. The absence of the lag phase after primary contact with the pathogen ( Mycobacterium bovis , BCG vaccine) does not contribute to the formation of the trained immunity phenotype in the cells. The presence of the lag phase promotes the development of the trained immunity phenotype, especially in THP-1 cells. The second stimulation (bacterial LPS) did not increase the production of lactate, nitric oxide, and glucose consumption by cells, which can be a consequence of the Warburg phenomenon in these monocyte-like human cell lines.