Treatment News : Hep A Immune Response Mystery Has Implications for Hep C Research

POZ - Health, Life and HIV
Subscribe to:
POZ magazine
Join POZ: Facebook MySpace Twitter Pinterest
Tumblr Google+ Flickr MySpace
POZ Personals
Sign In / Join

Back to home » Treatment News » June 2011

Most Popular Links
Most Popular Lessons

The HIV Life Cycle


Herpes Simplex Virus

Syphilis & Neurosyphilis

Treatments for Opportunistic Infections (OIs)

What is AIDS & HIV?

Hepatitis & HIV

20 Years Ago In POZ

More Treatment News

Click here for more news

Have news about HIV? Send press releases, news tips and other announcements to


June 21, 2011

Hep A Immune Response Mystery Has Implications for Hep C Research

A surprising finding in a study comparing hepatitis C virus (HCV) with hepatitis A virus (HAV) infections in chimpanzees sheds new light on the nature of the body’s immune response to these viruses. The results are published online ahead of print by the Proceedings of the National Academy of Sciences (PNAS) and highlighted in a press release issued by the Texas Biomedical Research Institute in San Antonio, Texas.

Understanding how HCV becomes chronic for most people infected with the virus—whereas HAV is an infection that can always be cleared by the immune system—is very important because some 200 million people worldwide are chronically infected with HCV and are at risk for progression to cirrhosis and liver cancer.  

“Remarkably, we found that HAV was more adept at evading the innate immune response than HCV, the virus that ultimately causes chronic infections,” said Robert E. Lanford, PhD, a virologist at the Texas Biomedical Research Institute and a lead author of the study. In other words, the researchers point out, HAV is the stealthier virus when it comes to evading the innate immune response—the immune system’s first-line response against invading microorganisms—despite the lack of persistent infections.

HCV infection is usually characterized by a failure of the immune system to combat and eliminate the virus. “We suspect this failure of the immune system shares attributes with other persistent viruses, such as HIV and hepatitis B virus,” Lanford said.

By comparing two similar viruses that infect the liver, one that is always cleared by the immune system, HAV, and one that frequently evades the immune response, HCV, the team hoped to unravel the mystery of how HCV causes lifelong persistent infections.

The new study points out the critical need for more information about how the immune system reacts to HCV. It also reinforces the importance of chimpanzee research in this effort. The chimpanzee, the only animal model susceptible to HCV infection, was critical for probing the molecular differences in gene expression in the liver related to infection by the two viruses.

Examination of the adaptive immune response—immune system cells trained to respond to disease-causing microorganisms—found that the T-cell response to HAV was unique as well. “We expected the immune response to kill all HAV infected cells in a short time frame, and yet we could detect the genome of the virus in the liver for up to one year, long after symptoms of the disease were resolved,” Lanford explained.

“Hepatitis viruses have co-evolved with humans over a very long period of time, and they are good at evading the immune system, but nobody understands how hepatitis C becomes a chronic infection,” said Stanley Lemon, MD, of the University of North Carolina and another researcher associated with the study. The one thing that is clear, the researchers conclude, is that “HAV infections represent a distinctly different paradigm in virus–host interactions within the liver.”

Search: hepatitis A, hepatitis C, HAV, HCV, innate immunity, adaptive immunity, interferon, PNAS

Scroll down to comment on this story.


(will display; 2-50 characters)


(will NOT display)


(will display; optional)

Comment (500 characters left):

(Note: The POZ team reviews all comments before they are posted. Please do not include either ":" or "@" in your comment. The opinions expressed by people providing comments are theirs alone. They do not necessarily reflect the opinions of Smart + Strong, which is not responsible for the accuracy of any of the information supplied by people providing comments.)

Comments require captcha.
Please enter this number for verification:

| Posting Rules

Show comments (0 total)

[Go to top]

Facebook Twitter Google+ MySpace YouTube Tumblr Flickr Instagram
Quick Links
Current Issue

HIV Testing
Safer Sex
Find a Date
Newly Diagnosed
HIV 101
Disclosing Your Status
Starting Treatment
Help Paying for Meds
Search for the Cure
POZ Stories
POZ Opinion
POZ Exclusives
Read the Blogs
Visit the Forums
Job Listings
Events Calendar
POZ on Twitter

Ask POZ Pharmacist

Talk to Us
Did you participate in an event for National Black HIV/AIDS Awareness Day 2016?


more surveys
Contact Us
We welcome your comments!
[ about Smart + Strong | about POZ | POZ advisory board | partner links | advertising policy | advertise/contact us | site map]
© 2016 Smart + Strong. All Rights Reserved. Terms of use and Your privacy.
Smart + Strong® is a registered trademark of CDM Publishing, LLC.