B lymphocyte-derived IL-16 attracts dendritic cells and Th cells.
Interaction of B lymphocytes with Th cells is a fundamental step in the establishment of humoral immunity, and recent evidence suggests that direct interaction between B lymphocytes and dendritic cells (DCs) is also an important prerequisite. Factors involved in the selective recruitment of Th cells and DCs by B lymphocytes are insufficiently defined. We set out to delineate the role of IL-16, the soluble ligand of CD4, which is expressed on Th cells and DCs. B lymphocytes express IL-16 mRNA and synthesize bioactive IL-16 protein, and IL-16 is expressed in lymph node follicles in situ. B lymphocyte supernatant efficiently induces migration of CD4+ Th cells, monocyte-derived DCs, and circulating blood DCs in nitrocellulose filter-based assays. Neutralization of IL-16 bioactivity strongly inhibits this migratory response, suggesting that IL-16 might be a major chemotactic factor derived from B cells. The present data further support the idea that IL-16 might have a role in the initiation of cellular as well as humoral immunity by mediating the cellular cross-talk among T lymphocytes, B cells, and DCs, leading to recruitment of these cell types at common anatomical sites.
Kaser
A
A
Division of Gastroenterology and Hepatology, Department of Medicine, University Hospital Innsbruck, Innsbruck, Austria.
Dunzendorfer
S
S
Offner
F A
FA
Ludwiczek
O
O
Enrich
B
B
Koch
R O
RO
Cruikshank
W W
WW
Wiedermann
C J
CJ
Tilg
H
H
D001402:B-Lymphocytes / Q000378:metabolism / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology; D002474:Cell-Free System / Q000276:immunology / Q000502:physiology; D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000502:physiology*; D002634:Chemotaxis, Leukocyte; D003713:Dendritic Cells / Q000502:physiology*; D006801:Humans; D019410:Interleukin-16 / Q000096:biosynthesis / Q000502:physiology*; D014066:Palatine Tonsil / Q000166:cytology / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology*
D002630:Chemotactic Factors; D019410:Interleukin-16