Assignment: Haemagglutination in RBC
ORDER NOW FOR AN ORIGINAL PAPER:Assignment: Haemagglutination in RBC
Haemagglutinin • HA named because it causes haemagglutination in RBC
• Binds to sialic acid on epithelial cells to initiated viral entry
• Sialic acid is linked to galactose in different configurations
a2-3 linkage
Haemagglutinin linkages
• Isolates from different species vary in ability to bind to sialic acid/galactose – Human and swine isolates prefer Sia-Gal in an α2- 6 linkage
– Avian and equine isolates prefer α2-3 linkage
Haemagglutinin linkages • Isolates from different species vary in ability to bind to sialic acid/galactose – Human and swine isolates prefer Sia-Gal in an α2-6 linkage
– Avian and equine isolates prefer α2-3 linkage • Human epithelial cells (main target for flu) have the α2-6 configuration whereas goblet cells lower in the respiratory tract have α2-3
• Swine respiratory tract has both binding sites (and possibly more variation)
• Pigs act as mixing bowl
Neuraminidase
• HA binds to sialic acid on cell so prevents release of new virion after budding
• NA cleaves sialic acid from sugar allowing virion to be released
• Cleavage is not equivalent by all subtypes • Most strains have a preference for the α2-3 configuration
Viral replication
1. Virion is endocytosed
2. RNA released into the cytosol and then enter the nucleus 3b. Transcription occurs
6. NEP and M1 traffic newly replicated RNA to the membrane
3a-4. Transcribed RNA is transported to cytoplasm for translation or remains in nucleus
5. New viral proteins are synthesised. 5a. Other proteins returned to nucleus to form new vRNA particles 5b. NA and HA transported to membrane.
7. New virions bud off
Influenza • Occurs seasonally–generally between October and April in
the UK • Symptoms include:
– High temperature – Aches and pains in joints – Headaches – Watery eyes – Fatigue – Sore throat and watery discharge from nose – Diarrhoea
• At risk groups given flu vaccine seasonally • Nasal spray vaccine for 2, 3 and 4 year olds introduced in
September 2014
Why is flu seasonal? • People are indoors leading to increase in transmission • Less ultraviolet radiation may reduce the likelihood of the virus being
damaged or killed • Cold temperatures lead to drier air, which may dehydrate mucus
membranes • Aerosol transmission of the virus is enhanced when the air is cold and
dry – Virus degraded in moist air – Infected hosts shedding the virus for a longer period of time in cold
• The virus may linger longer on exposed surfaces (doorknobs, countertops, etc.) in colder temperatures
• Influenza virus has a “butter-like coating”. The coating melts when it enters the respiratory tract – Cold – coating becomes a hardened shell – Warm – coating melts before the virus reaches the respiratory tract
Transmission of flu • Inhaling infected droplets when people sneeze, cough or speak – Indirect – Up to 1 metre
• Inhaling droplets through direct contact – Kissing
• Indirect transmission (fomite transmission) – e.g. hand to mucous
Diagnosing flu
H1N1 09
We are a professional custom writing website. If you have searched a question and bumped into our website just know you are in the right place to get help in your coursework.
Yes. We have posted over our previous orders to display our experience. Since we have done this question before, we can also do it for you. To make sure we do it perfectly, please fill our Order Form. Filling the order form correctly will assist our team in referencing, specifications and future communication.
1. Click on the “Place order tab at the top menu or “Order Now” icon at the bottom and a new page will appear with an order form to be filled.
2. Fill in your paper’s requirements in the "PAPER INFORMATION" section and click “PRICE CALCULATION” at the bottom to calculate your order price.
3. Fill in your paper’s academic level, deadline and the required number of pages from the drop-down menus.
4. Click “FINAL STEP” to enter your registration details and get an account with us for record keeping and then, click on “PROCEED TO CHECKOUT” at the bottom of the page.
5. From there, the payment sections will show, follow the guided payment process and your order will be available for our writing team to work on it.
Need help with this assignment?
Order it here claim 25% discount
Discount Code: SAVE25