where are dendritic cells located in the epidermis
Langerhans cell Langerhans cells are dendritic cells (antigen-presenting immune cells) of the skin, and contain organelles called Birbeck granules. They are present in all layers of the epidermis and are most prominent in the stratum spinosum.[2] They also occur in the papillary dermis, particularly around blood vessels,[2] as well as in the mucosa of the mouth, foreskin, and vaginal epithelium.[3] They can be found in other tissues, such as lymph nodes, particularly in association with the condition Langerhans cell histiocytosis (LCH).
Epithelium Epithelium lines both the outside (skin) and the inside cavities and lumina of bodies. The outermost layer of human skin is composed of dead stratified squamous, keratinized epithelial cells.[14]
Skin flora Many of them are bacteria of which there are around 1000 species upon human skin from 19 phyla.[1][2] Most are found in the superficial layers of the epidermis and the upper parts of hair follicles.
Antigen Antigen presenting cells present antigens in the form of peptides on histocompatibility molecules. The T cell/T lymphocyte (a subtype of white blood cell), of the adaptive immune system, selectively recognize the antigens. Depending on the antigen and the type of the histocompatibility molecule, different types of T cells will be activated. For T-Cell Receptor (TCR) recognition, the peptide must be processed into small fragments inside the cell and presented by a major histocompatibility complex (MHC).[5] The antigen cannot elicit the immune response without the help of an immunologic adjuvant.[3] Similarly, the adjuvant component of vaccines plays an essential role in the activation of the innate immune system.[6][7]