sábado, 18 de noviembre de 2017

Immunology and Medicine

Disclaimer: This information is absolutely biased and has been written by a General Surgeon

Innate Immunity: 

Provides the body’s first line of defense against infectious agents. It is responsible for reacting quickly to invading microbes and for keeping the host alive while the adaptive immune system is developing a very specific response (the surgery).

The innate cellular response includes phagocytic cells (monocytes/macrophages, neutrophils and dendritic cells). A special type of lymphocyte, the Natural Killer is also Included here.

Macrophage: ER Doctor

Located in tissues produce IL-8 that provides the initial signal for the Neutrophil to leave the bleed and go to the inflammation site. In other words, they page the neutrophil to come and help. However, they are able to eliminate many agents by themselves.

Neutrophil:  The Internal Medicine doctor

 They are the first cell to arrive to any place where there are inflammation once they receive the signal to extravasate. You find them in any inflammation place, regardless the cause. They need to be able to deal with any organ failure, at least at the beginning, and many times they get ride off the threat (the desease) the same as the internist. Furthermore, once they are there they can recruit more cells by means of LT and other cytokines. They can page more doctors.

Natural killer: The surgical PA

They are still part of the innate system (not Antibodies implied) but they share a common progenitor with the other lymphocytes in some point they decided not underwent the hard process of selection than the others lymphocytes suffer. They work in the same team, and they are very efficient at killing tumor and virus-infected cells. With the difference of the previous cells type that could address any issue the NK have a specific training (Neuro PA, Trauma PA…)

Adaptative response: The features of adaptive immunity are designed to give the individual the best possible defense against disease. 

B cell: The surgical resident

There are many stages founds here, from a B cell naive to a plasma cell (from the first year to the Chief Resident). The membrane receptors of B lymphocytes are designed to bind unprocessed antigens of almost any chemical composition, i.e., polysaccharides, proteins, lipids. They can be called to asses anything suspicious to be surgical. They undergo selection in the bone marrow with the goal of avoid auto-reactive cells that could harm. They need to know when to operate, but more important they need to know when not to operate, or they will be deleted. Once they have been trained they are able to recognize and eliminate pathogens quicker. T cell present specific protein antigens to T cells to help elicit a humoral immune response.

T cell: The surgical attending:

They undergo a hard process of selection. Only 5% of the lymphocytes that start the process at college (the bone marrow)  become Board Certified in the thymus. T cell receptor (TCR) is designed to bind only peptides complexed to MHC. They are not required for non surgical processes. 

T-Helper cell: 
Plays a central role within the immunity. Assist other white blood cells in immunologic processes, including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages. These cells can differentiate into one of several subtypes, including TH1TH2TH3TH17TH9, or TFH, which secrete different cytokines to facilitate different types of immune responses (General, Neurological, Oncology, Vascular…). They only interact when the information is presented to them by the profesional APCs by means of a MHC classII. They do not assess every patient and do not listen every cell, only those cells that are antigen presenting cells and knows how to present the information properly.

Cytotoxic T-cell or T-Killer: The Trauma Surgeon:

They have also a very specific response. These cells recognize their targets by binding to antigen associated with MHC class I molecules, which are present on the surface of all nucleated cells. In other words, you do not need a profesional APC to present the information to them you just need to have a nucleus (or a brain). They are trained to treat tumor cells and virus infected cells (Trauma patients).

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