Questions tagged [immunology]
The study of the immune system in organisms, primarily responsible for fighting infection.
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Which cells are prefered by the HIV virus to establish an infection?
We always read that HIV infects CD4 cells, macrophages, and dendritic cells. However, is it a common event for HIV to infect non-immune cells within a host? If not, why?
And also if not, why are ...
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Septic Shock: I'll kill myself before you kill me
Most of the deaths caused by extracellular bacteria don't actually result directly form their action. Rather, it results from an overreaction of the immune system to antigens such as LPS and LTA (...
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If a bacterium had a protein on its surface that humans also have, would it cause an autoimmune disease?
Suppose that a bacterium happened to have a protein on its surface. This protein can also be found in the human body. If this bacterium were to then infect a human with an otherwise normal immune ...
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Why can blood group O be given to all blood groups?
The blood of persons of blood group O contains antibodies against antigens A and B. The red blood cells of persons of blood group A have A antigen on their surface. If someone with blood group A ...
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Question on compatibility of blood groups [duplicate]
How come a person with blood group O can donate to a person with blood group AB? Since there are A and B antibodies in the O blood group blood surely this would cause agglutination in the blood of the ...
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If fever is a natural immune defense, why do people take drugs to lower it?
If fever is a natural defense against pathogens, why do sick people take NSAIDs to reduce the fever?
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Do antibiotics attenuate immune response on subsequent exposure to same bacteria?
A healthy immune response to a bacterial infection includes "memory" to permit the body to thwart subsequent exposure to same bacteria. What are the dynamics of using antibiotics on initial exposure ...
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Why doesn't our immune system react to infused antibodies produced in a horse?
Calmette tried injecting horses with snake venom and then taking out the serum which has produced antibodies against the venom and injecting in the snake-bitten human.
Shouldn't our immune system ...
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Will new proteins incorporating new amino acids trigger an immune response?
This article reported that scientists have succeeded in adding two new bases to the quartet of A, C, G and T, resulting in non-canonical amino acid. Additionally, the bacteria in which this was done ...
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B -Cell activation by helper T cell
When Dendritic cell travels to nearby lymph node with antigen presented on MHC II molecule, the helper T-cell residing there gets activated. But what happens to B- cell residing there? Does it get ...
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Infant immunization
I know that polio vaccine consists of small dose of polio virus itself, which activates body's immunity against the disease. An infant is given a no of vaccines including chickenpox, tetanus, ...
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Why are haploid cancer cells not killed by immune system?
I have seen haploid cancer cells (I think it was leukemia cells) in a lab.
Sperms and eggs are haploid but are not destroyed by the body because they are protected by other cells surrounding them.
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Antigen molecular mimicry
Let us consider a situation in which the body is attacked by a microbe, and the microbe is captured by the immune system for recognition of surface antigens.
The surface antigen recognized mimics one ...
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Multi-nucleated cells: advantages and examples?
This question arises because I saw that monocytes and leukocytes are commonly called 'mononuclear cells' in the scientific literature. The implication of course being that other immune sub-types are ...
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Why is there such a large evening rise of temperature and night sweats in certain diseases like TB, lymphoma etc?
I've heard that it's got to do something with the levels of cortisol which usually dampens the effects of IL-1, but when it's night time the cortisol levels are usually low so IL-1 response is ...
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Why does the HLA show a high degree of polymorphism?
I know how the HLA undergoes high degree of polymorphism (random genetic rearrangements), but I have not understood why it undergoes rearrangements. What is the advantage offered when HLA shows a high ...
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What is the benefit of reducing inflammation when producing antibodies?
We just learned in lecture that IL-10 promotes the formation of plasma cells over memory cells. Which seemed strange to me as IL-10 also reduces inflammation, and I figure you would want inflammation ...
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Is vermiform appendix no more a vestigial organ?
The appendix has a role in the immune response.
So is it therefore recently removed from the list of vestigial organs?
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Can people with AIDS/HIV be vaccinated?
If there is no immune system,it seems like vaccines wouldn't do much since there is no adaptive immune system to develop antibodies and memory cells. But can people with AIDS/HIV still be vaccinated? ...
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How do opportunistic infections affect an immunocompromised or AIDS patient?
I mean, everyone knows that AIDS patients don't die of the HIV infection, rather the opportunistic infections. But if HIV only affects T lymphocytes, and destroys them, then that means only cell ...
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Allergy desensitization: what is the mechanism? Could it happen with other immune responses? [closed]
Allergy is a type of immune response against an otherwise harmless substance. If I understand it well, the aim of allergy immunotherapy is not to stimulate an immune response like the immunotherapy ...
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What's the difference between a lymphocyte and a plasma cell?
According to my understanding, lymphocytes is the broad terminology for both T lymphocytes as well as B lymphocytes, while plasma cells refers to mature B cells which produce antibodies. But then why ...
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What do phagocytes secrete? [closed]
What do phagocytes release after interacting with a pathogen? I know that this is a broad topic but I only need a general and concise answer.😊
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Common english name for tissues which are separated from the blood by blood-tissue barriers
Which general term is used to denote such organs/tissues as: brain, testis, thymus etc., which are separated from the blood by blood-tissue barriers?
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Why are there 2 copies of RNA in the HIV virion?
There are two copies of the RNA in the HIV virion. These are retroviruses. So, they can make cDNA from even just one copy using reverse transcriptase.
What is the use of the other? Are both ...
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White blood cells after dealing with an infection
I just have a quick question. If there was an infection of a tissue within the body, white blood cells would leave the capillaries around the tissue and enter the tissues to help cure the infection. ...
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Why aren't all infections immune-system resistant?
It's been less than a century since the widespread use of antibotics started, and already we're seeing bacteria that have evolved immunities to the antibotics we use.
On the other hand, we've been ...
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Cross-species infections
I’ve heard that HIV developed from SIV, etc.
I’ve also heard that most species (including most monkeys) can’t get a common cold like humans.
So then what causes infections to be able to travel ...
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B-cell antibody production
I've just learned about B cells in immunology lectures and some things are not clear to me.
Here's what I know:
1) Apparently, each B cell produces a specific antibody, determined randomly at the ...
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T-Cell Motility: does motility require direction specific actin polymerization?
T-cells have been shown to migrate inside concentration gradients - both in the direction of the source or away. Even under shallow gradients, t-cells move. I argue that, to be able to move in a ...
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Why do the host cells containing iC3b fragment not undergo phagocytosis?
As far as I understand, in complement system C3b gets deposited on pathogen surface but it can also be deposited on host cells. Host cells have some negative regulatory system such as membrane ...
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Is it logical for someone to be allergic to the water molecule, but be perfectly fine with drinking milk since it's only 87% water molecules? [closed]
Recently this article got into the tabloids. The comments were disabled very quickly. Strange.
The authos says she has Aquagenic Urticaria but it is a skin condition not an allergy, and hence wouldn'...
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Why human body cannot defend against HIV? [closed]
Some says that HIV destroy IRF3, and some says HIV overruns T-cells.
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Why do neutrophils need to die after pathogen phagocytosis?
From referenced article below, neutrophils need to be removed because its granule contents and oxygen metabolites (used for killing phagocytosed pathogen) are harmful to the surrounding tissue. Thus, ...
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Why does immunity from the flu vaccine appear only after two weeks?
It is said that immunity from a flu vaccine appears after about two weeks. However, from experience, the flu usually lasts only a few days.
If sufficient antibodies appear only after two weeks ...
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Are cloned spieces significantly more vulnereble to deseases than sexually reproducing species?
I would like to be able to compare the risk for species to go extinct implied by their reproduction mechanism in the very short term. Imagine we choose some species A that can reproduce both sexually ...
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Why reaginic antibodies are absent in these types of syphilis?
According to Textbook of Microbiology and Immunology
2e, Subhash Chandra Parija, pg.no; 375
These(reaginic) antibodies do not appear in early primary syphilis, latent acquired syphilis of long ...
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Why exactly does the immune system weaken with age?
Why does the immune system become weaker with age in humans and in some other mammals? Let's try to be more specific than just "everything degrades with age."
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How do memory cells(B-cells) encounter pathogens?
From what I understand, once the infection is handled, some of the B cells capable of producing the correct antigens are stored for the long-term in the lymph nodes.
They will start multiplying again ...
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Is one single antibody binding its antigen enough to elicit an immune response?
IVIG (intravenous immunoglobulin) is derived from plasma of more than 1000 donors. I wonder if in this preparation is one antibody present that recognize its antigen after infusion - if this is enough ...
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Is there a maximum amount of antibodies your body can keep?
I am wondering if you were theoretically able to get vaccinations or antibodies for any and every diseases and/or illness, would there be a limit to how many you can get and keep in your body at one ...
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Could the Immune Gene HLA-B27 be gentically altered, snipped, switched off, replaced, edited within the body
Could the Immune Gene HLA-B27 be genetically altered, snipped, switched off, replaced, edited within the body.?
Thousands upon thousands suffer immune disease as do I from this highly implicated gene....
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B cell clones and affinity maturation
As B-cells undergo affinity maturation, their BCR sequences change. Are they still considered to be part of the same clone?
I couldn't find a clear answer in response to this very similar question:
...
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Animals as organ donors and organ's life expectancy
Recent attempts to find reliable organ donors was using genetically-engineered (GE) pigs as heart donors.
The pig's DNA is altered so that its tissues will appear identical to the patient's tissue and ...
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Exactly what biochemical factors control the intensity of an allergic reaction?
I think have a functional understanding of how an allergic reaction (Type I Hyper Sensitivity) occurs: basically the allergen causes production of antibodies that attach to mast cells and basophils. ...
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Europeans succumbing to diseases they introduced to native Americans
I am reading a non-fiction account of Spanish first contact with native Americans. The Spaniards were shipwrecked, undernourished, malnourished, and dehydrated upon their arrival. Over 75% of them ...
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Why there are no RBCs in lymphatic vessels?
I know the following.
Leukocytes (white blood cells) are made in the bone marrow, and naive leukocytes go to the blood vessels. So, leukocytes mainly exist in blood vessels.
Endothelial cells ...
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Why do alpha-gal allergies only occur after a tick bite if alpha-gal is already present in red meat?
I just read an NPR article about allergies to red meat being caused by tick bites. That stood out to me because I thought allergies are triggered by an initial exposure to some allergen. In this case, ...
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Can immunity to diseases vary by populations?
A common explanation for the massive population decreases of isolated societies upon contact with Europeans during the Age of Discovery is that the natives lacked immunity to newly introduced diseases....
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How is TB harmful in HIV patients?
The mycobacterium of TB doesn't secrete any toxins. The cause of disease in the immunocompetent is the collateral damage due to the immune response against disseminated infection. But then, when HIV ...