Questions tagged [immunology]

The study of the immune system in organisms, primarily responsible for fighting infection.

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At what age are mice considered too old for their thymus to stop being functional and produce T cells?

I am studying the effects of radiation on the immune system of mice. After exposing them to radiation, we will be harvesting their spleen, lymph nodes and blood to investigate immune cells such as T ...
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Howthe body differentiate between foreign and native protein? How does it know when to create an immune response? [duplicate]

How the body differentiate between a foreign and a native protein? Suppose there is a bacteria, it has lot's protein on its membrane, with specific structures. How does our body know it's the foreign ...
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Auto-immune problems if immature B-cells released if bone marrow bone is fractured?

A fracture of a bone containing bone marrow with B-cells not yet taught to not recognize self-antigen, if the bone is fractured, can those cells get released and cause problems?
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What specific markers does a Covid-19 PCR test look for?

I've done a search and can't find anything as to what specifically makes a Covid-19 positive that identifies it as unique. I would expect to see something like this: https://madridge.org/journals-...
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Any conclusive disproof of Jerne's original model of immune system (1955)?

Before Burnet modified Jerne's original theory in 1976 (Jerne's original work was from 1955), the general idea of the immune system was very different. Jerne's model was that a general cell population ...
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Clonal selection theory, how does antigen reach lymphocytes? [closed]

Clonal selection hypothesis often defined by four basic principles of which first two are Each lymphocyte bears a single type of receptor with a unique specificity. Interaction between a foreign ...
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Help in understanding a sentence about TCR-MHC interaction and immune synapse formation

T-cell co-stimulatory and co-inhibitory molecules (collectively named co-signaling molecules) play a crucial role in regulating T-cell activation, subset differentiation, effector function and ...
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Can you still contract a disease after being vaccinated and be able to spread it?

I assume I know the answer to this already but wanted to confirm before I respond to someone that appears to be arguing that vaccines don't make you immune (they only stop your symptoms?) - but you ...
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What kind of people are more likely to catch COVID-19?

It is well known that people of old age or with respiratory problems are more vulnerable by the effects of COVID-19. However, I wasn't able to find information on any similar trends on catching the ...
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Why is it difficult for germs to jump species?

If you haven't watched CGP Grey's video Americapox: The Missing Plague, I suggest you watch it. It's an excellent video. One assertion he makes is that "germs jumping species is extraordinarily ...
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What is the mechanism responsible for long-lasting detectable antibody titers?

As I understand, when naive B cell encounters antigen matching its receptors and is activated by a T helper cell, it can either differentiate into 4 plasma cells, produce a lot of antibodies and ...
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When can we know if one develops immunity (to SARS-CoV-2)?

I've been thinking for this for a while. It seems there's no ethical experiment to perform to check if immunity is actually developed (the obvious experiment would be to expose someone that have ...
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Easy and cheap antigen/antibody couple

For an application I need to find a cheap antigen and cheap correspondent antibody. The antigen can be literally any molecule that is cheap and potentially easy to produce and with a correspondent ...
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Why is sheep erythrocyte lysis considered as classical complement activation pathway, and rabbit as alternative one?

Any suggestions are highly appreciated.
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How can I detect which antibody is produced by the B cell?

In the primary immune response, IgM is produced (in addition to IgD ). In the secondary immune response, various types of antibodies are produced. So how do I detect which antibody a B cell is ...
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Could there be a pathogen which does not activate an immune response?

In order for the immune system to be stimulated to produce antibodies, there must be a surface protein of the invading pathogen which binds to a receptor on B cell surface somewhat loosely. We need ...
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Cell-autonomous viral defense involving oxidative burst?

I'm looking for a mechanism by which a cell detects a virus (probably a retrovirus) within itself, then triggers an oxidative burst in response. This should all happen within the cell itself, ...
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How do animals contain and dispose of bacterial endotoxins (lipopolysaccharides)?

Gram negative bacteria naturally release endotoxins which are lipopolysaccharide molecules. These molecules are toxic to many eukaryote cells, including macrophages. My question is how animal ...
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Why is there no herd immunity against common cold coronaviruses?

In discussions of herd immunity against SARS-CoV-2 the underlying assumption usually appears to be that the virus basically stops spreading once a sufficient percentage of the population has overcome ...
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Do person with strong immune system have less chance of surviving SARS-COV-2 attack?

In most of the cases dealing with SARS-COV-2 disease, the major mortality cause is due to cytokine storm in response to Corona-virus that also attack healthy organs causing multiple organ failure. ...
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Examining antibody - target interactions in PyMOL

I'm a student currently looking at antibody responses against a viral target protein of interest. I have my own, annotated PyMOL session of my protein and I also have .pdbs of crystallised antibody ...
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Can intracellular protein initiate strong immune response?

Some autoantibodies escape immune tolerance and can cause autoimmune disease. In order to cause harm to the tissues by these autoantibodies, do the antigen need to be extracellular or membrane bound, ...
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Can the innate immune system defeat a pathogen by itself? Fast enough that we don't develop antibodies, etc.?

Would we have any way of knowing if our innate immune system destroyed a pathogen without involving the adaptive? Could a symptomless person who tests positive for COVID-19 with the RNA test, e.g., ...
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Why are antibodies Y-shaped?

I generally know how antibodies work by binding to antigens, but what is the specific purpose to being Y-shaped, as opposed to any other shape? Does this aid their function? Thank you.
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How is minimum infectious dose defined?

I'm a bit confused by the concept of a minimum infectious dose (MID). It seems from what my research so far has turned up, that while any dose greater than 0 could potentially cause an infection, for ...
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Why do viruses cause different symptoms?

If the sole purpose of a virus is to hijack the nucleus of a cell to replicate, why do we have different symptoms for different viruses? I can think of the following comming into play: immune ...
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What is the protein composition of complete Freund's adjuvant?

The complete form of this adjuvant uses heat inactivated and dried mycobacteria. However, to rule out cross-reactivity with an antibody, I would like to know which proteins are left in the adjuvant. ...
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How do PARPs counteract coronaviruses?

I read that [SARS-CoV-2 has] a nonstructural protein called NSP3, a component of which blocks the host’s efforts to fight off the virus. In particular, this protein shuts down host enzymes called ...
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Is it still true that C. elegans has no known natural viruses?

I read in a 2009 review that While mammals and C. elegans each have a single Dicer that makes both miRNAs and siRNAs, Drosophila has two Dicers: Dcr-1 makes miRNAs, whereas Dcr-2 is specialized for ...
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Reasons why this protein is not suitable as an immunogen?

In a paper entitled "Progress and Prospects on Vaccine Development against SARS-CoV-2", the authors write the following in section 2.5: "Compared with S, N, and M protein, E protein is not suitable ...
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Which hormones, metabolites, or other molecules build up as the day progresses, other than melatonin and adenosine?

Melatonin and adenosine reach peak levels around midnight/bedtime. I was wondering what other molecules also buildup as the day progresses. Particularly molecules that affect the CNS and/or immune ...
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How antibodies are produced in our body against intracellular proteins of infectious bacteria?

When an infectious agent invades our body, then surface antigens of the infectious agent are detected by our immune system and B-cells get activated. However, we do have antibodies in our blood ...
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How come certain antibody lateral flow assays show positive results at different dilutions?

I acquired two antibody lateral flow assays that purported to have the same sensitivity. I acquired NP antibodies and tested against them to validate they were not fake. My testing protocol involved ...
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Why do antibody tests target different antibodies?

I've noticed in various COVID-19 lateral flow assays, they seem to target different antibodies (S1, S2, NP). What are the benefits or downsides of choosing different antibodies? I know that some have ...
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Markers of lung microvascular endothelial sub-populations and lung smooth muscles?

Can someone please help me with information where I can find a publication on the distribution of various markers on lung endothelial cell sub-populations and lung smooth muscle cells? Particularly ...
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Are B-cell-Ab selected according to their true efficiency towards viruses & infected cells?

Assume that (during the first week of Covid) the lymphoid organ produced two dozens of high affinity B-cell-antibodies for the same number of epitopes on the viral proteins (after numerous rounds of ...
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T-cell “exhaustion” in patients with Covid-19

Following up on my previously asked question, which asks how COVID infects T-cells in immune system. Here's a study that shows that recovered covid patients have "exausted t-cells". To quote: T ...
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Why is untreated trypanosomiasis invariably fatal in humans?

If left untreated, African trypanosomiasis will invariably kill the patient. The human immune system is unable to clear the infection. I am aware of a few other infectious diseases with this property ...
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Is it possible for virus infected cells to continue to present a self-antigen on the MHC1?

Forgive my ignorance, as I'm new to immunology, however it seems like there would be some amount of positive selective pressure for viruses to develop the ability to continue to present the host's ...
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Why doesn't infection with Clostridium Tetani immunize you?

What Immunity to COVID-19 Really Means - Scientific American It is less clear what those antibody tests mean for real life, however, because immunity functions on a continuum. With some pathogens, ...
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What determines if a small protein / large peptide is immunogenic?

I'm wondering if there is some threshold in size or a specific structural property that determines if a small protein or large peptide would cause an immune reaction. Context: there are a number of ...
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How to prepare bacterin using formalin(formaldehyde)

I am finding how much formalin I have to use to make bacterins for vaccine experiments. I searched for it in google but I can't find about specific procedures like the concentration of formalin and ...
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Making new antibodies

Is there a model of how the B-cell-antibody pool in the lymphoid organ evolves during the first two weeks of infection by a new virus ? With a model I mean something like this At first we have $10^...
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Why hasnt been developed yet a COVID-19 vaccine? [duplicate]

I'm a complete noob when it comes to biology, but as far as I remember from my biology class, a vaccine is just a the viruses itself but in small amounts so that the immune system creates memory cells....
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What are the difficulties/challenges against developing a coronavirus vaccine?

Multiple groups of scientists are trying to develop a coronavirus vaccine but they are not yet being fruitful. What challenges or difficulties are there in the process that slowing down and/or causing ...
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How does the immune system distinguish between a TH1 and a TH2 response?

Hello and thanks for taking the time to read my post. I know that naive T-Cells (T0) can be induced to become mature T-Helper cells (TH1 or TH2) by induction with either IL2 or IL4. IL2+ TH0 -> TH1 ...
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If every person between 15-60 had an immune system equal to the healthiest people, would this affect the spread of coronavirus? [closed]

Has anyone calculated the speed or breadth of the spread of something like coronavirus (or any cold, flu, airborne pathogen) based on how well the population can master the virus with their immune ...
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How are antibodies specific for a disease detected in the blood if everybody produces a different antibody for the same antigen?

To break the title down into parts: There exist serology tests that detect the amount of an antibody (Ab) against a specific pathogen/antigen. Every human produces their own Ab for a specific ...
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How are B cells activated

I am currently an A-level biology student — what I understand is: B cells can either be independent of T cells or dependent on T cells for activation. The ones which are dependent on T cells ...
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Why do only some viruses cause a fever?

A fever is supposed to be one of the body's defense mechanisms against a virus. Raising body temperature can kill some viruses. So why isn't this response seen for all viruses, but just a few?

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