In:
The Journal of Immunology, The American Association of Immunologists, Vol. 186, No. 1_Supplement ( 2011-04-01), p. 154.21-154.21
Abstract:
B cells play a key role for adaptive immune responses by secreting antigen-specific immunoglobulins, for example in the course of infections. Recently, we found that human B cells are able to express granzyme B (GzmB) in response to IL-21. Here we demonstrate that viruses including tick-borne encephalitis, polio, hepatitis B, measles and human immunodeficiency virus (HIV) as well as Bacille Calmette-Guérin can enhance the GzmB response by B cells from healthy individuals. In contrast, B cells from patients with active HIV infection showed a lower capacity to produce GzmB in response to HIV, suggesting a novel pathogenetic mechanism in HIV patients involving B cells. Furthermore, we reveal that next to B cell receptor (BCR) stimulation ligation of toll-like receptors including TLR4 and TLR9 can be involved in B cell GzmB enhancement. After 2 days incubation, up to 77% of freshly isolated B cells directly respond with GzmB expression to stimulation with IL-21, BCR stimulation and TLR ligation. Of note, GzmB is secreted by B cells in an enzymatically active state, reaching levels comparable to those secreted by cytotoxic cells and its induction requires activation of similar signaling pathways as in CTL and NK cells. We suggest GzmB-secreting B cells may play a role in early immune responses, and may contribute to elevated serum GzmB levels found in viral diseases and sepsis. Further studies have to elucidate whether B cells exhibit cytotoxicity towards infected cells.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.186.Supp.154.21
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2011
detail.hit.zdb_id:
1475085-5
