Questions tagged [immunology]

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

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1answer
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Transplant rejection through direct allogenic antigen detection: where do the T cells come from?

I just read a chapter in Janeway's Immunology on T cell development and thought about transplant rejection. But I couldn't figure out how the t cells develop which lead to the rejection. So in direct ...
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1answer
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Is there a measure in flu vaccine studies we can use to gauge immunogenicity or efficacy of the vaccine? [closed]

For example, often in flu vaccine trials antibody response to HA is measured, and in some response to Neuraminidase, or T cells. Is there an 'industry standard' quantitative measure for these ...
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Negetive selection of thymus

what happen to t cell which poorly aware of bodies antigen in negative selection of thymus? Do they enter the bloodstream or they die? I mean we have 3 kind of Tcell in medulla,some of them are ...
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1answer
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Are fully vaccinated people more likely to not get infected at all with COVID-19?

I've found some papers which describe that the viral shedding does not decrease during infection (for fully vaccinated people). But the overall shedding time does decrease. Therefore it is possible to ...
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How could all your Helper T-Cells have weapons against every possible enemy?

How could all your Helper T-Cells have weapons against every possible enemy? I tried to google it but found no good answer. Here is the source: https://www.youtube.com/watch?v=lXfEK8G8CUI&t=362s
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1answer
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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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1answer
63 views

What antibody targets are being tested for in the publicly offered UK antibody test?

In late August 2021 the NHS (UK) offered people who test positive for COVID what is referred to in this BBC report as a “new antibody test”. However, I have been unable to find out what exactly is new ...
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1answer
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Why would this viral strain-specific antiserum fail to immunoprecipitate the same (98% identical protein) from another strain?

I'm reading this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC392475/ and I can't work out why a certain immune serum didn't work on the same viral protein but from different strains. The serum ...
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2answers
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Is it possible for a plant extract to have different effects, depending on the type of cell line it was tested on?

My plant extract (ethyl acetate fraction) seems to have two different effects depending on the cell/cell line it's being tested on. On liver cancer cells (HepG2), it is moderately cytotoxic. But on ...
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1answer
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Why are basophils and eosinophils considered granulocytes?

I have read that granulocytes are a type of leukocytes that have granules (hence the name) visible by microscopy. But then there is something called a granulocyte/monocyte progenitor cell, which I ...
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1answer
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Fluctuations in disease burden of respiratory viruses (especially influenza/coronaviruses)

Compared to peaks in terms of disease burden (morbidity and mortality, or incidence of severely symptomatic cases and deaths caused by a viral strain within a population), is the relatively light ...
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Are autoantibodies against intracellular proteins "functional"?

Autoantibodies against intracellular proteins have been detected in some autoimmune diseases (For example, TRIM21 in Sjögren's syndrome and NALP5 in Autoimmune Polyendocrine Syndrome Type 1). My ...
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1answer
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How to identify plasma cells that only produce monoclonal antibodies?

I am studying the procedures of forming hybridoma cells for generating a large number of monoclonal antibodies. Before the procedure of fusion (with multiple myeloma cells) happens, I would like to ...
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1answer
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Why is the antibody light chain essential for function?

Humans and most other mammals produce antibodies consisting of two heavy chains, each linked to a light chain. Both heavy and light chain contribute to the variable region, and thus the antigen ...
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NF-κB activated, but IRF blocked - Rewiring of immune response

Rubela virus has the following PAMPs: ssRNA, which will activate the following PRRs: TLR7, TLR8, RIG-I, and possibly MDA5. Dendritic cells infected with Rubela virus are reported to produce very low ...
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why secondary/booster vaccine shots may sometimes induce worse side effects?

Background: I had my first shot about 1.5 months ago, I just had my shot yesterday. Unmistakable fever like symptom started within 4 hours. within 10 hours the whole body started aching, accompanied ...
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2answers
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Why do T cells have MHC II receptors?

I have seen the answer to this question which says that T cells do not express MHC II proteins which would make sense. However, my textbook "The immune system" by Peter Parham disagrees. It ...
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Differentiating molecules based on peptide sequence? How to annotate?

I want to differentiate between classical class I and non classical class I MHC molecules in a model organism using well conserved structural features within classical MHC I molecules (eg intradomain ...
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2answers
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Why is there not an immune response to injected immunoglobulins?

When you inject immunoglobulins as a treatment for certain diseases, the immunoglobulins are a foreign substance. I can appreciate that maybe the constant region would be similar to the hosts as it is ...
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Acute cytotoxic T lymphocyte killing capacity

how many cells can a CTL eliminate sequentially? Cytotoxic T lymphocytes (CTLs) are a subset of the adaptive immune system which can target cells for apoptotic elimination. This elimination begins ...
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2answers
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Which viruses still present today caused a deadly pandemic/epidemic in the past?

The current Covid-19 pandemic and its virus Sars-Cov-2 can be dangerous, especially for vulnerable groups like the elders. But however, I have seen studies that this virus become less dangerous in the ...
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How important is the antigen presented by cTECs during TCR beta-selection?

During beta selection, a candidate T cell tries to use its pre-TCR to bind to cTECs in the thymus. If tonic signaling occurs between the pre-TCR and the cTEC MHC, then it will progress through later ...
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How do APCs find their specific T-cells in the lymph nodes?

My understanding is that when an APC (more specifically a dendritic cell) encounters an antigen in the periphery, it ingests it and presents it on its surface. It then migrates to lymph nodes to ...
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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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1answer
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Immunological factors for the cause of headaches following SAR-CoV-2/COVID vaccination

It is generally-accepted that headaches are a common side effect from receiving the COVID vaccine. Vaccine recipients with pre-existing immunity experience systemic side effects with a significantly ...
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Why am I finding peculiar B cell population when pbmcs are cultured for 3 days with CD40L?

While performing intracellular cytokine assay on B cells, I am finding a peculiar population. I use 2*10^6 cells for studying each functional marker. The pbmcs are cultured for 72 hours, with CD40L ...
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Is there any plausible biological mechanism for "universally protective vaccines" via "MHC allotype-independent immune effector memory cells"?

Geert Vanden Bossche, who has recently gained some fame for dissing all current Covid-19 vaccines (and who is also asking the WHO to meet him so they can be infused with his wisdom), has had the same ...
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1answer
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Why are certain cells more likely to be attacked in autoimmune conditions?

For example, type 1 diabetes occurs when the immune system attacks and kills beta cells in the pancreas. This is relatively common. What makes beta cells more likely to be targeted than, say, alpha ...
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Help with histological cell identification in colon

I have scans of a histology slide of tissue of colorectal cancer and its surrounding tissue. This slide has been stained with the typical Hematoxylin & Eosin (HE) staining then unstained and ...
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What makes a bacterium move away from a neutrophil cell?

In this video we see a bacterium seemingly moving away from the neutrophil that is chasing it. What mechanism makes it "want" to avoid the neutrophil? It doesn't seem to mind being around ...
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2answers
118 views

SARS-CoV-2 : does vaccination provide a better immunity than being sick and recover?

I recently read in the news that countries are thinking to offer a "green passport" based on the vaccination against SARS-CoV-2, allowing vaccinated people to do things with less ...
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Need help designing an enzyme immunoassay (EIA)

I have a FITC-labelled DNA sequence and an anti-FITC antibody, however this antibody is not conjugated with HRP or any other enzyme. I work in a lab with limited finances, so is there a way I could ...
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Why V(D)J recombination only happens in B and T cell development?

Does V(D)J recombination only happen in B and T cell development? Can it happen in other types of cells? If V(D)J recombination only happens in B and T cell development, why other types of cells ...
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VDJ sequencing in mice, DNA or RNA?

I am wondering if anyone who is well versed with VDJ sequencing for TCR repertoire analysis (specifically CDR3) would know if DNA or RNA is a better starting material? We are looking at the effects of ...
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1answer
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Do plant viruses attack animals? examples? [duplicate]

Do plant viruses attack animals, if yes please give an example of the virus. I feel both plant and animal viruses are different, and they cannot attack each other hosts.
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How do short polypeptide chains serve as identifiable antigens?

My understanding is that MHC class I and II bind to relatively short polypeptide chains (~ 20ish amino acids). I'm surprised that a non-self protein fragment that short would be distinctive enough to ...
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1answer
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Could a vaccine injecting B cells theoretically work?

So I was in the car riding to school today when I was struck with genius. Each B cell is attuned to a different pathogen, am I correct? By that logic, would a vaccine injecting a dose of B cells ...
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1answer
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Sensitivity vs. Limit of Detection of rapid antigen tests

I'm comparing a bunch of SARS-CoV2 rapid antigen tests: Source Columns 4 and 6 list the values for sensitivity and limit of detection (LOD). How come that a test with a several times lower limit of ...
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1answer
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What does "culture" mean here? [closed]

India becomes first country to culture U.K. variant strain. Source What does "culture" mean here?
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What happens if a circulating naive B cell is met with a polysaccharide/lipid antigen?

These antigens should provoke a T-independent response, so will they differentiate then and there to form short-lived plasma cells? Or do they have to go to lymphoid tissue, enter a B follicle, and ...
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How do we regulate the production of proteins when designing plasmids?

I think it should be no surprise that I, as many others, am interested in the new COVID-19 vaccines being developed. In my region of the world there are two mayor candidates. One is mRNA based and one ...
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2answers
151 views

How can mutation of viruses lead to loss of fit to antibodies without loss of fit to antigen of cells they infect?

Viruses are known to mutate, thereby escaping immune cells and evading vaccination. Given that there is one and the same specificity of the key to both the receptor on the infected cell causing the ...
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Why don't memory cells of the adaptive immune system get activated immediately after being created?

Why don't memory B and memory T cells of the adaptive immune system get activated immediately after being created? As this video explains they are created in the heat of the battle. Aren't the ...
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1answer
220 views

To a population with no immunity, why is smallpox or measles more deadly compared to COVID-19?

Specifically, this is not a question asking how easily a virus spread in a population (airborne, asymptomatic spread, etc), but regarding the mechanism or the "havoc" it wreaks once inside a ...
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Why is peanut allergy often more dangerous then other allergies?

From reading public media I have the impression that while peanut allergy is not more common then pollen allergies, peanut allergy is often more problematic and sometimes even deadly. The most common ...
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4answers
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What does vaccine efficacy mean?

In the last few weeks, Pfizer/BionTech, Moderna and AstraZeneca have each released preliminary estimates of the efficacy of their SARS-COV-2 vaccines. But what do their respective efficacy percentages ...
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1answer
60 views

How does HIV know to attack specific immune system cells?

I'm no biologist, but curious of the answer to which I could not find online. How are Human Immunodeficiency viruses able to detect and distinguish immune system cells with a CD4 receptor on the ...
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SARS-COV-2 detectability versus viability

This week (#47 of 2020) two meta-reviews were published in the Lancet. Ct values and infectivity of SARS-CoV-2 on surfaces, a brief review published on 19 November in The Lancet Infectious Diseases, ...
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Do mRNA vaccines cause transfected cells to be killed by cytotoxic T cells?

Based on my research on how mRNA vaccines (specifically for COVID-19) work: An mRNA sequence, that contains the sequence of the coronavirus spike protein, is absorbed by some cells. These cells now ...
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How do injected purified anti-D antibodies prevent the natural production of antibodies in order to prevent Hemolytic Disease of the Newborn?

Treatments involving Anti-D antibodies are given to pregnant women carrying Rh+ fetuses when the mother has an Rh- blood type in order to prevent Hemolytic Disease of the Newborn during the 2nd ...

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