Ccr5 & cxcr4 - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum > USMLE Step 1 High Yield > USMLE Step 1 Bits & Pieces

USMLE Step 1 Bits & Pieces High yield short focused points, monographs, charts, illustrations, tables, and other stuff related to the USMLE Step 1 Exam.


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-19-2009
Ex-USMLE Forums Staff
 
Steps History: 1+CK+CS+3
Posts: 753
Threads: 106
Thanked 2,166 Times in 464 Posts
Reputation: 2214
Immunology Ccr5 & cxcr4

The two chemokines present on immune cells that serve as co receptors for the HIV entry into the cell.
Since these are relatively new discoveries and are the target of new novel therapies for HIV they have been frequently seen popping up in recent USMLE exams.
Here's a quick encounter that serves enough for the exam.

CCR5
Is a beta chemokine receptor present on human lymphocytes and macrophages and has been recently designated CD195 (unlikely to be seen in USMLE under this name).
It's believed that CCR5 is the cause for the HIV macrophage-tropism early in the infection.
The gene for CCR5 is located on chromosome 3 and delta 32 mutation results in absent production of this protein.
Persons who are homozygous for the mutation are believed to be almost totally resistant to HIV infections while those heterzygous for delta 32 mutation are believed to have partial resistance and HIV infection would be slow in these individuals.

CXCR4
Is the other alfa chemokine mainly present on T cells (T cell tropic) and typically used by the HIV virus late in the infection and it's unclear whether it is a cause or a consequence of HIV infection.
CXCR4 has been also named Fusin (don't confuse that with Fuzeon the trade name of Enfuvirtide which is new HIV fusion inhibitor that binds gp41 and blocks viral entry).
Some experimental drugs are targeting CXCR4 receptors as they also have a role in mobilizing hematopoeitic stem cells from the bone marrow to the peripheral circulation.

Here's a table summerizing the high yield differences
Ccr5 & cxcr4-hiv-coreceptors.jpg
Reply With Quote Quick reply to this message
The above post was thanked by:
Aviram (10-21-2009), docspike (10-22-2009), louaisalama (10-10-2012), R777 (09-16-2013), Rookie (03-20-2012), wahaha007 (01-10-2010)



  #2  
Old 10-21-2009
Aviram's Avatar
USMLE Forums Scout
 
Steps History: Not yet
Posts: 56
Threads: 3
Thanked 24 Times in 17 Posts
Reputation: 34
Default

Finally I understood the delimma
Thanks Lee for the great info

How can I print the table?
Reply With Quote Quick reply to this message
  #3  
Old 10-21-2009
Ex-USMLE Forums Staff
 
Steps History: 1+CK+CS+3
Posts: 753
Threads: 106
Thanked 2,166 Times in 464 Posts
Reputation: 2214
Default

Quote:
Originally Posted by Aviram View Post
How can I print the table?
  1. Click on thread tools above
  2. Choose view printable version
  3. the table will change into a link
  4. click on that link
  5. then in the opened page right click on the table and choose save picture as
  6. save it to your computer
  7. then print it from there
Reply With Quote Quick reply to this message
  #4  
Old 10-22-2009
docspike's Avatar
USMLE Forums Scout
 
Steps History: ---
Posts: 52
Threads: 9
Thanked 42 Times in 22 Posts
Reputation: 62
Send a message via AIM to docspike
Default

CCR5 antagonist drug available is Maraviroc..Already US-FDA approved..
__________________
Proud to be an INQUISITIVE!

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message



Reply

Tags
Immunology-, Tables-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mutation of CXCR4 drpisho USMLE Step 1 Forum 5 12-24-2013 07:12 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)