Questions tagged [immunology]

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

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Are individual auto-reactive 'lymphocytes' or auto-reactive 'clones' generated in the central lymphoid organs?

Clonal deletion is a well-known mechanism of immune central tolerance. But individual lymphocytes or lymphocyte clones are subjected to apoptosis? If clones, then what is the reason to allow mitosis ...
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Do humans produce an immune response to their own antibodies?

As far as I know, T and B cells form a part of the adaptive immune response in humans. In their early stages, these cells undergo genetic recombination to produce a diversity of antigen receptors/...
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Do antibodies binding to the same epitope have similar electrophoretic mobility?

Serum protein electrophoresis is a commonly used blood test in medicine. It is often used for detection of paraproteins in the gamma-globulin region. If there is a narrow band with sharp borders ...
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Do both a separate B and T lymphocyte need to be activated during the immune response?

Isn't it very unlikely that there will be both: a) a B and a T with a receptor complementary to the antigen, and b) that they will come into contact with the right antigen-presenting cell? What would ...
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How do I classify cytotoxicity values, whether a sample is mildly, moderately, or highly cytotoxic?

I used LDH assay for cytotoxicity testing. I have a plant extract which I tested against HepG2 cancer cells. I did three trials, my results were 2%, 6%, and 8% cytotoxicity, respectively. How do I ...
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Other than the major histocompatibility complexes, what is the difference between professional and non-professional antigen presenting cells?

Can both professional and nonprofessional APCs activate helper T-cells? Or is that only macrophages and B-cells? Do cytotoxic T-cells only make non-professional APCs go into apoptosis?
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Why are camelid-derived nanobodies called VHH (variable heavy domain of heavy chain)?

Single-domain antibodies (or nanobodies) derived from camelid heavy-chain antibodies are called VHH antibodies, where VHH stands for "variable heavy domain of heavy chain". I assume the ...
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Why did scientists state that the Omicron COVID-19 variant was a reason to get a booster?

I was watching Vox’s video, Big questions about the Covid booster shot, answered, which references the New York Times article Omicron Prompts Swift Reconsideration of Boosters Among Scientists. In ...
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Monoclonal Antibodies

In this paper, the authors say: We demonstrate that for a considerable number of eplets, the antibody-verified status is solely based on polyclonal serum reactivity of multiparous women or on ...
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Why in organ transplantation the dendritic cells can activate the T cells but not in hematopoietic stem cell transplantation?

In the both following cases let's consider that the donor has different HLA type from the recipient. When someones let's say kidney is transplanted into someone that has different HLA alleles, the ...
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Can your T lymphocytes be activated by dendritic cells that have different MHC II alleles?

So it is clear that a T cell is activated by a dendritic cell by presenting to the T cell the MHC II and the foreign antigen. This is because T cells are taught to have high affinity for MHC II when ...
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How do T cells recognise the own bodies's infected cells?

A dendritic cell engulfs an antigen and presents it on its membrane with MHC II. This then binds to an antibody on the membrane of a T cell. It activates the T cell, let's call this X. This X then ...
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Do Tardigrades have an innate immune system, or any type of immune protection?

Do Tardigrades have any immune protection against bacteria and viruses?
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Induction of IFN-beta in HEK293T

I'm trying to increase expression of a protein we're attempting to study, UBL7, supposedly unregulated by Type I Interferon and particularly IFN-beta. I've tried treating HEK293T cells (~60% ...
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Does specific immunity affect the incubation period of viruses?

My interest was inspired by the observed variation in incubation times for different strains of Covid-19, however I ask the question in the broader sense as it seems hard to find an answer in general. ...
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qPCR from tissue to compare T-cell subpopulations

In the experiment, groups of mice have been intranasally immunised with different vaccine formulations. We have stored nasal tissue (basically, the front part of the skull without muscles, brain, etc.)...
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When the CD4+ gets activated and help B cells, does it have to be the same pathogen?

Does the peptide (presented by the class II HLA molecule) that activates a CD4+ T cell need to be from the same pathogen as the antigen recognized by a B cell when the CD4+ T cell promotes the ...
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Why don't each of T and B cells make two different TCRs/antibodies, except for the class switch?

I have not been able to find any literature that clearly states this, but if I understand correctly, T and B cells are diploid. If so, there are two sets of genomes, and if both are TCR/VDJ ...
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Do spike-protein-based vaccines undermine the DNA repair system?

I ain't no biologist, but I came across a paper recently and tried to understand it: SARS–CoV–2 Spike Impairs DNA Damage Repair and Inhibits V(D)J Recombination In Vitro My question: Is it a correct ...
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Is there a paradox in the field of immunology for the elderly patients?

Say you have an 80 year-old. You can spray anti-bacterial in their door knobs, keys, floors, walls, bathroom. So now less-bacteria. But by doing that, you weaken their immune system, so if they're ...
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Is it possible for a non-self antigen to NOT be recognized by the body?

The amazing diversity of antigens that the body can recognize (by virtue of T and B cells that express receptors complementary to them) is truly fascinating. The explanation mooted for this is the ...
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Does vaccinating people with cowpox give people immunity to smallpox?

I've just recently learned about the body's defense mechanism about how lymphocytes from memory cells that are specific to a pathogen after being infected by a pathogen for the first time, but then I ...
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What can lymphocyte-produced antibodies do that 'innate' opsonins can't?

I have a conceptual misunderstanding relating to immunology which I'd be grateful if anyone could help me clear up. My A Level textbook says that at the start of an immune response, opsonins bind to ...
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Can simultaneous double pathogen infections happen, or are they prevented?

Is there something in immunology that prevents a simultaneous infection with a 2nd pathogen? For example, I've never heard of someone getting both dengue and malaria together. Or, say, Ebola and ...
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Why does the thymus gland shrink with age?

What exactly is reason/process/mechanism for which our thymus gland starts to shrink with age? The thymus gland is the site of production of T lymphocytes which are the best defence against infection ...
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Are there autoimmune disorders caused or mediated only by T cells?

I have frequently read that 'most' or 'the vast majority' of autoimmune disorders involving the adaptive immune system are caused by autoantibodies. These comments imply that there are known disorders ...
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What's the difference between veterinary and human snake antivenom?

Recently, out of curiosity, I looked online if snake antivenom for humans were actually sold for individuals. I found out they aren't. Not only that, but bills can get really high on countries that ...
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What does genetic diversity in one species have to do with survival rate when an epidemic spreads?

I was studying about genes, and soon remembered that the more diverse the genetics of one species, the less the chance of the species to go extinct from natural disaster. One instance was an epidemic ...
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Why can human viruses that can't infect chickens be grown in embryonic chicken cells?

Embryonic chicken cells are commonly used in vaccine production. The viruses are grown in chicken eggs, or in embryonic cells taken from those eggs, and then inactivated or attenuated to produce the ...
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Can macrophages phagocytose viruses directly?

I've been reading that Macrophages, members of the innate immune system, can actively track bacteria and protozoa to devour and destroy them. In the same way, can macrophages devour free viruses, in ...
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How to correct the different (background) fluorescence for different cell types?

I am differentiating mouse bone marrow macrophages in vitro. However, I found that the differentiated macrophages have higher background fluorescence (the unstained sample) in all channels, which ...
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Does vaccination lead to short-term secondary infection suceptibility?

For clarity, here is a summary of my question, per anongoodnurse's comment: Does a lower peripheral lymphocyte count resulting from recent immunization render us more susceptible to infection by other ...
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Is COVID-19 claimed to get less deadly over time? If so, why?

From a TV news report of a press conference from (I think) the German Robert Koch Institute, I remember hearing an expert declare that he was expecting COVID-19 to get less deadly over time. ...
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Conjugate vaccines in the context of the original antigenic sin and antibody feedback inhibition

How come we can get an antibody response against a polysaccharide bound to a carrier protein, that we have antibodies towards, when antibody feedback inhibition exists? If we have antibodies against ...
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What's the exact mechanism of oral tolerance? [closed]

I have mainly two matters of confusion need to be clarified. First question: The immune system does not necessarily kill everything hat has PAMPS, the bacteria living in the gut, have PAMPS (Pathogen-...
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What's the procedure of the antigen recognition by the B cells in a clear way?

Before presenting my confusion, I really sincerely thank everyone for any advices or clarifying , every single comment is helpful. And my english writing skill is still very bad, Just ask anything ...
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how do phagocytes receptors work now and in the past?

As we know, phagocytes have receptors on their cell that are used to detect pathogens which they bind to and engulf them. That seems easy. Though, I'm trying to wrap my head around the fact how the ...
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immunotherapy - how would the inhibitor detect

It's a known fact that if PD-L1 happens to be on cancer cells, it will signall off to the T-cell's receptor(PD-1) to turn off its activation, resulting in a fact ...
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cancer cell - antigen presenting cell

We all know that if normal cell contains virus inside it, normal cell has mechanism inside it that can detect that it has abnormality inside(virus) and what it will do is present the virus's protein(...
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immune system - how does adaptive work without innate?

The way I understood immune system is that: phagocytes detect viruses and present it on their surface and become antigen presenting cells. Then, T-helper cells try to bind to these phagocytes that ...
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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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How bacteria respond to toxic viral proteins?

The lysis-lysogeny state of bacteriophage lambda is well known. Under certain conditions, the phage will enter the lysogenic state after infection of a bacterium. Then, after a while, the phage ...
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How does the body avoid making an immune response to self-antigens?

The body contains antigen-detecting and presenting cells (APCs) including leukocytes and cytokines each having their characteristic HLA genes consisting of different recognition sites that detect the ...
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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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PCR: From transgene/microgram to cell concentration

I am doing research on CAR T-cell kinetics. The measurement of CAR T-cell concentrations across time is normally carried out with qPCR (see here, Fig. 1). These concentrations are generally reported ...
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Can the psychology of a person alter their immune system and health?

Can the psychology of a middle-aged person alter their immune health? I have read about the different types of linkage between nervous system and immune system. Can someone outline the general facts ...
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Exhaustion of 'memory' CD8 T cells

I've been reading literature on the exhaustion of cytotoxic CD8 T cells. In many of the papers I read, the authors aim to delineate molecular mechanisms that differ between exhausted and memory ...
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Role of the CD3 proteins and ζ chain

Could someone please explain which of the following is correct and why? The role of the CD3 proteins and ζ chain on the surface of the cell is to: a) transduce signals to the interior of the T cell b)...
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CDRs and antigen-binding sites [duplicate]

Are complementarity determining regions (CDRs) not the same thing as antigen-binding sites? If not, what is the difference? An old exam question states: "Clarify how CDRs are related to the ...
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Heat shock proteins in T cells of tumor microenvironment

Analyzing human tumor single-cell RNA sequencing (scRNA-seq) data, I found abundant expression of Heat shock protein (HSP) family genes in T cells. My literature review on "HSPs in T cells" ...

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