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An illustration that shows how antigens induce the immune system response by interacting with an antibody that matches the molecular structure of an antigen. In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. [1]
A Langerhans cell (LC) is a tissue-resident macrophage of the skin [2] once thought to be a resident dendritic cell. [3] These cells contain organelles called Birbeck granules . They are present in all layers of the epidermis and are most prominent in the stratum spinosum . [ 4 ]
A patch test relies on the principle of a type IV hypersensitivity reaction.. The first step in becoming allergic is sensitization. When skin is exposed to an allergen, the antigen-presenting cells (APCs) – also known as Langerhans cell or Dermal Dendritic Cell – phagocytize the substance, break it down to smaller components and present them on their surface bound major histocompatibility ...
The tine test is a multiple-puncture tuberculin skin test used to aid in the medical diagnosis of tuberculosis (TB). The tine test is similar to the Heaf test, although the Mantoux test is usually used instead. There are various forms of the tine tests which usually fall into two categories: the old tine test (OT) and the purified protein ...
S. pyogenes is the cause of many human diseases, ranging from mild superficial skin infections to life-threatening systemic diseases. [2] The most frequent manifestations of disease are commonly known as scarlet fever. Infections typically begin in the throat or skin. The most striking sign is a strawberry-like rash.
Skin immunity is a property of skin that allows it to resist infections from pathogens. In addition to providing a passive physical barrier against infection, the skin also contains elements of the innate and adaptive immune systems which allows it to actively fight infections. Hence the skin provides defense in depth against infection.
Langerhans cells are antigen-presenting cells but have undergone further differentiation. Skin Langerhans cells express CD1a, as do cortical thymocytes (cells of the cortex of the thymus gland). They also express S-100, and their cytoplasm contains tennis-racket like ultra-structural inclusions called Birbeck granules.
In humans, CD27 is a good marker for plasma cells; naïve B cells are CD27−, memory B-cells are CD27+ and plasma cells are CD27++. [5] The surface antigen CD138 (syndecan-1) is expressed at high levels. [6] Another important surface antigen is CD319 (SLAMF7). This antigen is expressed at high levels on normal human plasma cells.