B cell-derived circulating granzyme B is a feature of acute infectious mononucleosis.

Abstract

Granzyme B (GzmB) is a serine protease best known for inducing target cell apoptosis when released by cytotoxic T lymphocytes (CTLs) or natural killer cells with pore-forming perforin. As a result, GzmB detected in the serum of virus-infected individuals has typically been attributed to these sources. Here, we show that patients with recently diagnosed infectious mononucleosis caused by Epstein-Barr virus (EBV) have high circulating levels of GzmB that may be derived from infected B cells early in course of disease. We recently reported that human B cells from healthy donors secrete active GzmB when stimulated in vitro through B-cell receptor (BCR) ligation and interleukin (IL)-21. We found that infecting B cells with EBV greatly amplified GzmB secretion in response to the same stimuli, but the expression was terminated once the infection had become latent. Our results represent a rare instance of GzmB expression by non-CTL/natural killer cells in the context of infection with a human pathogen.

• Authors: Magdalena Hagn, Archana Panikkar, Corey Smith, Henry H Balfour Jr, Rajiv Khanna, Ilia Voskoboinik, Joseph A Trapani
• Journal: Clinical & translational immunology (Clin Transl Immunology) Vol. 4 Issue 6 Pg. e38 (Jun 2015) ISSN: 2050-0068 [Print] Australia
• PMID: 26191409 (Publication Type: Journal Article)