Macrophages – the big eaters

Macrophages are present in almost all tissues. They are contributing to various processes in the healthy organism, such as development, wound healing, infection and tissue homeostasis. They can rapidly change their phenotype in response to variations in their environment. Macrophages are known for their classical function as antimicrobial phagocytes but support immune function as well by the presentation of antigens. Their research applications are vast, and in vitro assays are increasingly used in a wide range of research areas, including immunology, bacteriology and parasitology, as well as in biomedical and transplantation studies. Two advantages of macrophages in cell culture are that they are relatively easy to generate and to cultivate.

Marker-free Imaging of Cryopreserved Human M1 Macrophages

In these videos – obtained with Nanolive’s 3D Cell Explorer – we present cryopreserved human M1 macrophages from PromoCell in cell culture (video 1). The 3D Cell Explorer allows to image these living macrophages in a novel, marker-free fashion. A special note goes to the visualization of membrane ruffling as waves arising at the leading edge of lamellipodia that move centripetally toward the main cell body. Macrophages were imaged for over 24h at a frequency of 1 image every 10 seconds.

Phagocytosis Assay Kits by PromoCell were used to test the viability and cellular functioning of the macrophages (video 2 & 3). E.coli particles, visible as small ellipsoid particles, are trapped by the cells, transported and lysed. This system can be used to provide a robust screening system for activators and/or inhibitors of phagocytosis and Toll-like Receptor (TLR) ligands.

Macrophages are involved in the outcome of many diseases, e.g. allergic and autoimmune disorders, cancer, diabetes, atherosclerosis and rheumatoid arthritis and they play an important role in the development of chronic diseases, such as arteriosclerosis, asthma, inflammatory bowel diseases, rheumatoid arthritis and multiple sclerosis. Thanks to major advances in the understanding of macrophages’ biology, scientists are rapidly developing new therapeutic targets.