Protocol for long-term monocultures of murine macrophages derived from distinct adult tissues.

Tissue-resident macrophages (TRMs) constitute the first line of defense against infection in all organs and perform organ-specific functions during tissue homeostasis. Here, we present a protocol for long-term monocultures of murine macrophages from different adult organs, including the brain, liver, peritoneal cavity, and lung. We describe steps for tissue preparation and the use of a combination of organotypic conditions to maintain a TRM-like identity in vitro, resulting in an ideal screening platform for a wide range of assays and readouts.

Dedicated macrophages organize and maintain the enteric nervous system.

Correct development and maturation of the enteric nervous system (ENS) is critical for survival. At birth, the ENS is immature and requires considerable refinement to exert its functions in adulthood. Here we demonstrate that resident macrophages of the muscularis externa (MMϕ) refine the ENS early in life by pruning synapses and phagocytosing enteric neurons.

Microglial tissue surveillance: The never-resting gardener in the developing and adult CNS.

Immunosurveillance by microglia is a dynamic process in the central nervous system (CNS) with versatile functions to maintain tissue homeostasis and provide immune defense. A tightly controlled microglia network throughout the CNS parenchyma facilitates efficient immunosurveillance, where each cell guards a certain tissue territory. Each cell is constantly surveilling its environment and the surrounding cells, screening for pathogens but also removing cell debris and metabolites, grooming neighboring cells and facilitating cellular crosstalk.

An improved organotypic cell culture system to study tissue-resident macrophages .

Tissue-resident macrophages (TRMs) perform organ-specific functions that are dependent on factors such as hematopoietic origin, local environment, and biological influences. A diverse range of culture systems have been developed to decipher TRM functions, including bone marrow-derived macrophages (BMDMs), induced pluripotent stem cell (iPSC)-derived TRMs, or immortalized cell lines. However, despite the usefulness of such systems, there are notable limitations.

Microglia in a Dish-Which Techniques Are on the Menu for Functional Studies?

Microglia build the first line of defense in the central nervous system (CNS) and play central roles during development and homeostasis. Indeed, they serve a plethora of diverse functions in the CNS of which many are not yet fully described and more are still to be discovered. Research of the last decades unraveled an implication of microglia in nearly every neurodegenerative and neuroinflammatory disease, making it even more challenging to elucidate molecular mechanisms behind microglial functions and to modulate aberrant microglial behavior.