Hot answers tagged immunology
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It is possible for viruses to live in mutualistic relationships with their hosts, these associations are often overlooked due to the devastating effect that many viruses can have.
To give an example in humans, when HIV-1-infected patients are also infected with hepatitis G virus, progression to AIDS is slowed significantly (Heringlake et al., 1998; Tillmann ...
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Unlike erythrocytes that have a very rigid shape and almost cannot change their size (hence the size distribution is indicative and can be used for diagnostic purposes in medicine), lymphocytes can change their size in a wider range, this is why you see the numbers 6-9 and 10-15 μm.
And they indeed cluster into several different groups: so-called "large ...
11
Vaccines work by introducing an attenuated strain of the pathogen (or alternatively the antigens that are normally present on the pathogens surface) into the body, whereupon the body mounts an immune response. As this will (hopefully) be the first time that the body has encountered the antigens on the pseudo-pathogen's surface, the response is called the ...
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According to the Wikipedia entry for the ABO blood group system:
Anti-A antibodies are hypothesized to originate from immune response towards influenza virus, whose epitopes are similar enough to the α-D-N-galactosamine on the A glycoprotein to be able to elicit a cross-reaction. Anti-B antibodies are hypothesized to originate from antibodies produced ...
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It is not only the immune system that prevents us from getting ill. Worrying much in my opinion won't make you catch a cold; rather, you can get problems with your cardiovascular system (arrhythmias, hypertension, angina pectoris) or limbic system (panic attacks, sweating attacks etc.).
The connections are many; here are some possible ones:
There are many ...
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Duration of efficacy is typically determined by tracking the antibody titers of a cohort of subjects who have gotten the vaccine, and estimating based on the trajectory of those titers where they will eventually cross the threshold to the point where the vaccine no longer confers immune resistance.
These estimates do get revised and estimated as time goes ...
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Personal comfort is the primary answer. Quite a bit of research has gone into fevers, and the current consensus is that Fevers less than 105F (40.5C) shouldn't necessarily be treated.
The primary reason the body raises its temperature (via the Hypothalamus in this case) is that bacteria and viruses tend to optimally thrive at 98.6F, which is also your ...
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MBQ and Rory M have already given decent answers on the "hows" of how the vaccine memory is formed. Now, for some twists:
There are three (general) types of vaccine, all of which are meant to make your body "think" its being infected and provoke an immune response, while at the same time not causing active infection. They are:
Live attenuated. These ...
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Infectious agents like bacteria, viruses, fungi, etc., don't know when to "attack" or produce pathogenic substances, they just do it under their preferred conditions, and your body's immune system either succeeds in fighting them off immediately, or it doesn't and you get sick. Your body is constantly confronting and clearing potentially dangerous ...
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I think the current answer to this for bacterial infections is quorum sensing. Quorum sensing is a signalling pathway in bacteria which senses a molecule that the bacteria themselves secrete. When the concentration of the quorum signal reaches a certain level, the bacteria interpret this as their population density reaching some threshhold.
Bacteria are ...
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They appear sick because they are sick, but with other, opportunistic infections. The "immune deficiency" part of AIDS means that the immune system is not functioning normally and, thus, is unable to protect them. Typical illnesses that are more found more frequently in AIDS patients are pneumocystis pneumonia and Kaposi's sarcoma.
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As I'm lucky enough to have access to that article, I'm going to extract whatever I can find to answer your question.
To begin with, innate immunity must have evolved first - we can see it at almost all stages of evolution. According to Cooper & Herrin, ever since aerobic respiration gave rise to multicellular organisms which in turn needed protection ...
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First of all we should distinguish between the physiological clotting factors that are parts of the normal clotting pathways, and those that might affect clotting pathways but are not observed under healthy conditions.
TPA (tissue plasminogen activation), PAI-1 (plasminogen activator inhibitor) and prothrombin are normal clotting factors that are essential ...
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The delay in immune attack is common for many viral infectious deceases where auto-immune response plays substantial to significant role in pathogenesis of the decease. The classical example here are the viral hepatitis B, C and D where it is auto-immune attack that causes the massive death of liver cells (hepatocytes).
The delay in immune attack is ...
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Small molecules do not have antigenic properties but they can elicit immune response by binding to a "carrier" protein. The small molecule is called a Hapten. An epitope forms at the protein-hapten binding interface.
Nickel acts like a hapten and elicits immune response by binding to proteins like transferrin, albumin etc.
Other metals also cause ...
5
There is no direct connection between CD (cluster of differentiation) receptors and T-cell receptor (TCR).
CD-receptors are used to label and distinguish different cells belonging to immune system: macrophages, T- and B-cells etc. Dendtritic cells play a significant role as antigen presenting cells and belong to vertebrate (and human) immune system and thus ...
5
I worked for a long time at a leading high-quality antibody company, so I'll try and share some of my experiences with you. The process of making a highly specific antibody (I'll focus on monoclonals) has three important parts - antigen design and immunization, cloning and subcloning, and screening/validation. Each part is crucial on its own, and the better ...
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A quick search on ISI Web of Knowledge yielded this paper:
R J North, P A Berche and M F Newborg (1981) Immunologic consequences of antibiotic-induced abridgement of bacterial infection: effect on generation and loss of protective T cells and level of immunologic memory. Journal of Immunology 127: 342-346
The authors investigated the effects of ...
5
It is common knowledge that when you're cold you could get a cold.
This may be a nice illustration why we need to be wary of “common knowledge”.
What is the mechanism linking temperature and viral infection?
This isn’t clear. There are a few proposed mechanisms but a likely explanation is: “there is no mechanism” – and the assumed correlation ...
5
As mentioned in this question , Adeno-associated virus is often used for gene therapy. This is due largely to its predictability when injecting genes (1), however it is also used as it is not implicated in any human pathology. As it is a replication deficient/helper dependent virus, natural infection is much less likely.
The human immune system does ...
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Alright, having read the citation linked, and doing a little poking of my own, here's my approach at an answer:
Some human herpes virus infections may compete with HIV infection. Essentially, some strains (not the ones you normally think of) infect CD4 cells - the same cells targeted by HIV. These strains down regulate transcription in CD4 cells, which in ...
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That's a good question - because its certainly possible to get antisera against antibodies.
Sometimes antisera is actually human antisera, so there would be no rejection at all. But that is for extreme cases, e.g. serum transfusions from convalescent Ebola survivors to current Ebola patients.
One would expect that you could only give an antiserum once ...
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Western Blot tests on young children are practically useless, since they test for antibodies. The child will likely have antibodies passed down by the HIV+ mother, regardless of whether the child has HIV. The test will show the antibodies, which may be mistaken for an active immune response from the child. As such, there will be a high false-positive rate ...
4
They don't have to -- there are times in life of a bacteria (cell division, hunger, mutations, attacks of lysozyme and other enzymes, cell lysis) when any possible antigen gets less or more exposed.
About escaping phagocitosis, there are numerous strategies to achieve it -- from forming a large slime-covered colony, through killing or disabling phagocytes ...
4
The goal of the vaccine is to provoke an immune answer, therefore some degree of inflammation is expected in order for the vaccine to work.
Since you get the shot intramuscularily, intradermally or subcutaneously, it is local, and the inflammation does not spread. The reason why your whole arm seems to hurt (rather than the place where the vaccine was ...
4
Making an antibody-enzyme conjugate isn't trivial. By using a primary/secondary set-up you can use the same well-characterised conjugate in combination with many different primary antibodies (as long as these primaries are all raised in the same species). There is also the possibility of some amplification: for example, if the secondary is an anti-Fab then ...
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We each inherit either A, B, AB or no antigens from our parents.
The current thought is that when you're between 0-6 months old you are exposed to bacteria/viruses that contain very similar antigens (A or B). These antigens are similar enough to the A and B antigens found on red blood cells that any antibody created against these bacterial antigens would ...
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In the above graph the darker blue line refers to the antibodies the baby receives from the mother in utero, as you mentioned in your question.
As you can see, the red line indicates that babies begin to produce low levels of their own antibodies between 3 and 6 months before birth. However, these are IgM antibodies, immature 'rough draft' versions. ...
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Depends on the kind of allergic reactions you want to create. If your target tissue is skin epithelium sure you can.
That's actually the way the skin allergy test is all about: The physician tries a wide variety - last time I did it were 28 well known kinds - of substances in liquid form (drops). If an allergic reaction is caused, the physician takes note. ...
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At one of my previous companies that raised antibodies to proteins and post-translational modifications, we found that 6-8 amino acids was generally the smallest peptide length required for an epitope. Anything much smaller than that won't induce the cross-linking or conformational changes required for signal transduction and an allergic response. As WYSIWYG ...
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