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The mucosal immune response

Mucosal tissues are major barriers to the entry of pathogens into the body. The IgA (and sometimes IgM) antibodies in mucus and other secretions can bind to the pathogen, and in the cases of many viruses and bacteria, neutralize them. Neutralization is the process of coating a pathogen with antibodies, making it physically impossible for the pathogen to bind to receptors. Neutralization, which occurs in the blood, lymph, and other body fluids and secretions, protects the body constantly. Neutralizing antibodies are the basis for the disease protection offered by vaccines. Vaccinations for diseases that commonly enter the body via mucous membranes, such as influenza, are usually formulated to enhance IgA production.

Immune responses in some mucosal tissues such as the Peyer’s patches (see [link] ) in the small intestine take up particulate antigens by specialized cells known as microfold or M cells ( [link] ). These cells allow the body to sample potential pathogens from the intestinal lumen. Dendritic cells then take the antigen to the regional lymph nodes, where an immune response is mounted.

Iga immunity

This diagram shows the process in which cells of the small intestine generate IgA immunity.
The nasal-associated lymphoid tissue and Peyer’s patches of the small intestine generate IgA immunity. Both use M cells to transport antigen inside the body so that immune responses can be mounted.

Defenses against bacteria and fungi

The body fights bacterial pathogens with a wide variety of immunological mechanisms, essentially trying to find one that is effective. Bacteria such as Mycobacterium leprae , the cause of leprosy, are resistant to lysosomal enzymes and can persist in macrophage organelles or escape into the cytosol. In such situations, infected macrophages receiving cytokine signals from Th1 cells turn on special metabolic pathways. Macrophage oxidative metabolism is hostile to intracellular bacteria, often relying on the production of nitric oxide to kill the bacteria inside the macrophage.

Fungal infections, such as those from Aspergillus , Candida , and Pneumocystis , are largely opportunistic infections that take advantage of suppressed immune responses. Most of the same immune mechanisms effective against bacteria have similar effects on fungi, both of which have characteristic cell wall structures that protect their cells.

Defenses against parasites

Worm parasites such as helminths are seen as the primary reason why the mucosal immune response, IgE-mediated allergy and asthma, and eosinophils evolved. These parasites were at one time very common in human society. When infecting a human, often via contaminated food, some worms take up residence in the gastrointestinal tract. Eosinophils are attracted to the site by T cell cytokines, which release their granule contents upon their arrival. Mast cell degranulation also occurs, and the fluid leakage caused by the increase in local vascular permeability is thought to have a flushing action on the parasite, expelling its larvae from the body. Furthermore, if IgE labels the parasite, the eosinophils can bind to it by its Fc receptor.

Questions & Answers

what are the classification of cartilage
isaac Reply
Bone cartilage, smooth cartilage
Magret
fibrous,elastic and hyaline cartilage
Chidiebere
Nop these are the types of cartilage hyaline cartilage fibro cartilage and elastic cartilage
Magret
ok
Chidiebere
Mention effect of endocline system
Magret
Mention types of hormone according to its function
Magret
what's ths full meaning of the NADH enzyme
ovie Reply
Nicotinamide adenine dinucleotide
Chidiebere
Thank you
ovie
no problem dear
Chidiebere
sorry,are you in Nigeria too?
Chidiebere
yes
ovie
What is down syndrome
jeniffer
is a genetic disorder caused by all or part of a third copy of chromosome
Felistus
it is also called trisomy 21
Chidiebere
it causes several malfunctioning of the body systems eg the heart, musculoskeletal system,etc due to absence of some important hormones and enzymes needed in the genetic makeup
Chidiebere
Cognitive impairment?
jeniffer
is an inclusive term to describe any characteristic that act as a barrier to cognition process
Benjamin
Nicotinamide adenine dinucleotide is a coenzyme found in all living cells. The compound is a dinucleotide, because it consists of two nucleotides joined through their phosphate groups. Wikipedia
Maria
what are the different types of respiratory system
Tejal Reply
conducting zone and respiratory zone
Benjamin
the two type of respiratory system is upper airway and lower airway
Tejal
What is cognitive impairment
jeniffer
how can I do practice question
takesha Reply
through quetion answer format
mutesi
what type of gland is the liver?
deng
A solid gland? Is that what you meant? Or u could say it's a digestive gland but also filtrates blood, among other things. So it kinda fits many roles. Unless I'm wrong, but feel free to correct me if I am.
Ryan
what is the consequence of performing CPR on a functioning heart.
Pyefa Reply
The central part of the body
Alex Reply
i thought a cell is the fuctional unit of an orgarnism.
mutesi Reply
what is the name for inflammation of middle ear?
Madu
otitis media
Chidiebere
Describe an experiment to verify the law of constant composition
Ssekamatte Reply
amazing the exprement is hard to set up can you please help us describe it for us?
Momoh
Explain the major features and properties of the cell membrane
Robina Reply
contants ofa lipid bilayers w the enbedded proteins it is faction of the cell membaren
bariise
it is made up of protein,fat and a small portion of carbohydrates. it is semipermeable but impermeable to uncharged water molecules.
Chidiebere
thx
Robina
What are blood vessels of will's circle
Madu Reply
vertebral arteries and cerebral arteries
Chidiebere
What are sutures of cranial cavity ?
Madu Reply
there are four. the coronal, sagittal, squamous and lambhoidal sutured
Chidiebere
structure of a cell
Robina
pelvic cavity contents?
unimarwat Reply
ilium ,ischium ,pubis
Madu
but that is the three parts of the hip bone
Chidiebere
Describe the muscular skeletal system in terms of definition.. Skeleton Apendicular skeleton Axial skeleton Joints
Sherrine Reply
the basic framework of body made and cartilage is called skeleton skeleton which form limbs is called appendicular skeleton skeleton which form main axis of body is called axial skeleton the points at two or more bones meets is called joints
unimarwat
write short notes on ligaments,curves and moverment of vertebral column.
mutesi Reply
cranial nerves notes
unimarwat
what is the Analysis
ROHIT Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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