These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cytokine expression by germinal center cells.
    Author: Butch AW, Chung GH, Hoffmann JW, Nahm MH.
    Journal: J Immunol; 1993 Jan 01; 150(1):39-47. PubMed ID: 7678034.
    Abstract:
    Germinal centers (GC) primarily consist of B cells along with a small number of T cells (5 to 10%) and follicular dendritic cells (FDC) (< or = 1%). Although extensive Ag-driven B cell proliferation and maturation occurs in GC, very little is known about the role of cytokines in the development of GC B cells. Therefore, to identify cytokines present in the GC microenvironment that may influence B cell development, we systematically examined cytokine gene expression by GC cells. GC T cells (CD57+/CD4+), GC B cells (CD77+), and FDC (HJ2+) were isolated from human tonsils by cell sorting using a flow cytometer. Freshly isolated GC cells were examined for mRNA expression for IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, TNF-alpha, and IFN-gamma using reverse transcription polymerase chain reaction. Freshly isolated GC T cells consistently expressed IL-4 mRNA (11 of 12 tonsils), whereas CD57- Th cells (mostly non-GC Th cells) were often negative for IL-4 mRNA. When the other nine cytokine mRNA were studied, freshly isolated CD57+ Th cells occasionally expressed mRNA for IL-10, TNF-alpha, and IFN-gamma. CD57- Th cells were occasionally positive for IL-1 beta, IL-10, IFN-gamma, and TNF-alpha, and negative for IL-2 and IL-6. Freshly isolated GC B cells as well as FDC failed to express detectable quantities of mRNA for all 10 cytokines that were studied. Thus, IL-4 is the only cytokine out of 10 that is consistently expressed in GC and may be important for the development of B cells in GC. After stimulation of CD57+ Th cells with PWM, production of IL-4 mRNA was dramatically reduced, whereas CD57- Th cell production of IL-4 was greatly augmented. This finding indicates that GC T cells may differ from other Th cells in cytokine gene expression and that results of cytokine production obtained after in vitro stimulation do not always reflect in vivo results.
    [Abstract] [Full Text] [Related] [New Search]