Why are T cells tolerant to hepatitis B virus?

October 14, 2008

The level of PD-1 expression has been proved by recent studies to be positively correlated with the extent of HBV-specific T cell impairments. However, the degree of T cell exhaustion which affects the disease statuses of hepatitis B patients has so far been only evaluated in restricted and small groups of patients between those with established chronicity and subjects with acute HBV infection. Besides, whether levels of PD-1 expression on T cells differ between acute exacerbation of hepatitis B and chronic HBV infected patients is still unknown.

A research article to be published on July 28, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Shu-Ling Zhang from Tongji Medical College of Huazhong University of Science and Technology in China examined the expression of PD-1 on antigen specific CD8+ T cells in peripheral blood of chronic hepatitis B (CHB) and acute exacerbation of hepatitis B (AEHB) patients.

They found that the levels of PD-1 on total CD8+ T cells in CHB patients were significantly higher than those in AEHB patients and healthy individuals. Conversely, lower frequencies of HBV-specific CD8+ T cells were detected in samples from chronic patients compared to AEHB patients. Our results confirmed reports that HBV specific CD8+ T-cell responses in peripheral blood were intensified in samples from AEHB patients than in those from patients with chronic hepatitis who remains viral persistence.

Besides, there was a significant positive correlation between HBV viral load and percentage of PD-1 expression on CD8+ T cells in CHB and AEHB group of subjects. However, PD-1 expression was not in association with disease flare-ups indicator alanine aminotransferase (ALT). This study clarified the correlation between PD-1 expression and two different HBV infection statuses.

Source: World Journal of Gastroenterology

Explore further: Immune analysis of on-treatment longitudinal biopsies predicts response to melanoma immunotherapy

Related Stories

New liquid biopsy techniques at the bleeding edge of cancer

June 10, 2016

(Medical Xpress)—There's many buzzwords being thrown around in medicine these days. In cancer treatment, blanket terms like "precision medicine" and "immunotherapy" hint at the promise of a rapidly changing technology base, ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Cow embryos reveal new type of chromosome chimera

May 27, 2016

I've often wondered what happens between the time an egg is fertilized and the time the ball of cells that it becomes nestles into the uterine lining. It's a period that we know very little about, a black box of developmental ...

Shaving time to test antidotes for nerve agents

February 29, 2016

Imagine you wanted to know how much energy it took to bike up a mountain, but couldn't finish the ride to the peak yourself. So, to get the total energy required, you and a team of friends strap energy meters to your bikes ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.