T Cell Zones of Lymphoid Organs Constitutively Express Th1 Cytokine mRNA: Specific Changes during the Early Phase of an Immune Response

• Published in: Journal of Immunology Vol. 176; no. 2; pp. 741 - 749
• Main Authors: Kalies, Kathrin, Blessenohl, Maike, Nietsch, Julia, Westermann, Jurgen
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 15.01.2006
• Subjects: Animals; Base Sequence; Cell Proliferation; Cytokines - genetics; DNA, Complementary - genetics; Gene Expression; Lymphocyte Activation; Lymphoid Tissue - cytology; Lymphoid Tissue - immunology; Male; Rats; Rats, Inbred Lew; RNA, Messenger - genetics; RNA, Messenger - metabolism; Th1 Cells - cytology; Th1 Cells - immunology; Th2 Cells - cytology; Th2 Cells - immunology
• ISSN: 0022-1767; 1550-6606; 1365-2567
• DOI: 10.4049/jimmunol.176.2.741

The cytokine milieu of the T cell zones in lymphoid organs is involved in the activation of naive T cells. Quantitative data regarding the local expression of cytokines are lacking. Therefore, the expression of Th1 (IL-2, IL-12p40, IFN-gamma), Th2 (IL-4, IL-10), as well as TGFbeta1 and IL-15 mRNA was studied after laser microdissection in the steady state and during an immune response in rats. Our results show that Th1 cytokines are preferentially found in lymphoid tissues and in the T cell zones, whereas Th2 cytokines are expressed throughout the organs and especially in the B cell zones. After injection of sheep RBC, IL-2 and IFN-gamma mRNA are significantly increased in the T cell zone only, a change not seen by analyzing the whole spleen. Studying the spatial and temporal expression of genes will reveal new insights into the regulation of immune responses.