The skin is an essential organ to the human body and it serves as the first line of defense against major pathogens and physical and chemical insults. The skin provides a sophisticated network of effector cells, microbes and molecular mechanisms to constitute a unique system of immune surveillance. An inadequate immune response leads to infections or tumors while an excessive immune responses may lead to autoimmunity or inflammation.
Billions of microbes including bacteria and fungi that live in harmony on our skin. Despite their close proximity with immune cells including DCs (Langerhans cells) and lymphocytes that reside within the skin tissue, in general no activation of the immune system occurs. This is likely due to cross-talk between skin resident immune cells that actively avert recognition of these microbes in exchange for the benefits they provide (i.e. competition for space/nutrients with pathogenic microbes).
Therefore, studying the mechanisms that regulate or disrupt skin immune cell interactions, migration and infiltration requires sophisticated yet cost-effective systems to advance new therapeutics, cosmetics and diagnostic modalities.