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5

It is an interesting question. The reason for why new immune responses can be launched but the memory of old ones are not deleted is based on the concept of irreversibility of certain chemical reactions. Launching an immune response involves clonal expansion of cells expressing the epitope sensors such as the immunoglobins and T-cell receptors, accompanied ...


5

This question has two answers: The difference was first described in 1936 by Harold Percival Himsworth, which described it in this article. At this time it was established that there are two forms of Diabetes, one sensitive to insuline while the other is not. The terms Diabetes type 1 and 2 where established somewhere between 1974 and 1976, for details see ...


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It looks moderately muddled, but perhaps. This paper1 is a good place to start; it's free and the intro lists a number of more recent studies. That study found a connection to lifetime reproductive success in sticklebacks (a fish) with intermediate MHC diversity. This 2007 study in mice2 is a particularly nice one, dealing with a inbred line outbred to ...


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Yes, here is an article on it: "The role of X-chromosome inactivation in female predisposition to autoimmunity" Below see the method and results summarised. Using a DNA methylation assay, we have examined the X-chromosome inactivation patterns in peripheral blood from normal females (n = 30), female patients with a variety of autoimmune diseases (n ...


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EDITS - I appreciate the comments and have incorporated them here. Thanks to @Superbest and @user22406 for raising them. I hope this makes a better answer for the community. Under normal circumstances, genomic (self) or mtDNA released into your cell or body cause absolutely no (known) problems. I'll explain why that is, how the body can detect ...


3

T-cell migration to the brain is very limited and occurs at a very low level in healthy conditions, however during diseases the number of T cells passing through the blood-brain barrier is elevate due to increased expression of traffic signals and adhesive molecules. I've found two good articles on how T-cells migrate through blood-brain barrier: J Neural ...


3

Immunosuppression is not used in cancer, in fact it is typically harmful unless of course the cancer is a immune or white blood cell cancer where suppressing their growth may be helpful. What you are perhaps alluding to is that an adverse effect of cytotoxic chemotherapy used in the medical treatment of cancer can cause immunosuppression. Immunosuppression ...


3

They do not, at least not normally or noticeably. MHC I occurs on all nucleated cells, and red blood cells do not have nuclei. If they did indeed have MHC on them, blood transfusions would be as successful and as tricky as organ donation. There are reports of MHC detection on red blood cells, but the amount is orders of magnitude smaller than elsewhere, ...


3

Too long for a comment: Because we don't know how to do this. The immune system is an extremely complex and highly regulated function of the human body and it is not easy to shut down single pieces of it without affecting the whole rest. We can completely block immune responses (more or less), which is beneficial for people who got a transplant. These ...


3

Adalimumab is an antibody that binds to tumor necrosis factor alpha. Antibodies have high-affinity binding sites for their antigen, and for a small antigen such as TNF-alpha, would bind to it and prevent it from binding to its target receptors. Antibodies, like all proteins, degrade after a certain period of time and are removed from circulation, and since ...


2

Broad question. Summary: The innate immune system processes everything. When it senses that something is dangerous it tells the adaptive immune system, that is T and B cells, that this thing I'm holding is dangerous (via coreceptors and cytokines). T and B cells that are specific for this dangerous protein (or sometimes non-protein) are activated. ...


2

Awesome question! The immune system detects the presence of non-self using MHC and T cells and the lack of self using NK cells. The placenta first of all doesn't display MHC so T cells can't detect it, and expresses NK inhibitory receptors which stop NK cells killing it. Furthermore, the immune system isn't able to get to the foetus so it isn't able to ...


2

Self-antigens are not recognized by the body. This is due to self-antigens being presented to the immune system of the body during the embryological development. Any immune cell which recognize the pattern are destroyed during the intrauterine period, preventing the emergence of Auto-immunity in the Life-time. Self-antigens become important in the ...


2

There can be many responses. They are important for alloimmunity (so by transfusion, transplantation, etc...), for recognizing pathogens, cancer, virus, etc... By T cell activation, the regulator T cells recognize these antigens as self, and prevent the autoimmune reaction. I guess they were thinking on MHC1 and MHC2. MHC1 shows the inside of the cells, so ...


2

Cancer is uncontrolled division of abnormal cells. This is caused by mutations in a cell which causes a cell to divide more frequently and the lack of control by intracellular AND extracellular mechanisms. The extracellular mechanisms include growth inhibition by hormones, local factors, contact and also the immune system. These cancerous cells could be ...


2

No. When a different blood type is introduced in the body, the host immune system recognizes the foreign blood as non-self and attacks it. The transfused blood becomes useless, and the potentially massive immune reaction can cause shock, which itself can be fatal. More details in the book Blood Groups and Red Cell Antigens, which can be found at the NCBI ...


1

The "proper" term to use in a case of growth retardation in children is "failure to thrive", abbreviated as FTT. Celiac disease is one of the most common Organic endogenous (genetically based) FTT syndromes. The main cause of FTT in pediatric celiac patients is malabsorption. In a case of insufficient vitamins and nutrients absorption the child will (have) ...


1

Since these cells are there by the development of the immune system, the immune cells recognize them as self. By blood transfusion with incompatible blood type, the immune system recognizes the blood cells with different histocompatibility antigens (A,B,Rh etc...) as non-self, that's why it attacks them.


1

The immune system recognizes patterns - incase of innate immunity and shapes - incase of active immunity. I am making a few assumptions: The Shrinking would result in a smaller version of "the person" - meaning he/she is a bacteria sized person capable of executing all actions that a human can do. The shrunk person is placed inside the blood vessel or ...


1

This is a very interesting question. As others have alluded to, the body generally recognises self and non-self. However, as with any biology it's not that simple. Even leaving aside autoimmune disorders, the body doesn't always attack non-self and doesn't always leave self alone. Think of a pregnancy - the foetus is non-self, and yet the body doesn't reject ...


1

There are other histocompatibility antigens on the surface of blood cells, e.g. A, B, Rh, etc... (There are probably a lot more which change less by person to person, so they have lower effect on the outcome of blood transfusion.) These antigens can be recognized by immune cells as self, that's why they don't destroy them. Before complete differentiation ...


1

I often have to reiterate this question in my head to clarify to myself how it works, though I tend to take an approach that asks more: What is different between a part of the body and something foreign which triggers an immune response? Here is the part that concerns B and T cells: The adaptive immune system (B and T cells) is based on random genetic ...



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