Effects of interleukin-2 on the expression of corticotropin-releasing hormone in nerves and lymphoid cells in secondary lymphoid organs from the Fischer 344 rat.
This study examined the influence of interleukin (IL)-2 on corticotropin releasing hormone (CRH) immunoreactivity in the Fischer 344 (F344) rat spleen. Rats were given either vehicle or 1, 10, 25, 50, 100, or 200 ng of human recombinant (hr)IL-2 by intraperitoneal (i.p.) injection, and were sacrificed 0.5, 1, 4, 12, or 24 h after treatment. Spleens and mesenteric lymph nodes were prepared for immunocytochemistry to localize CRH. In spleens from vehicle-treated animals, CRH immunoreactivity was present in several types of cells of the immune system, but CRH(+) nerves were not observed in either spleens or lymph nodes from vehicle-treated animals. Treatment with IL-2 induced CRH expression in nerves in the spleen in a dose- and time-dependent manner. CRH(+) nerves were not found in the mesenteric lymph nodes after IL-2 treatment, instead a dramatic time- and dose-dependent accumulation of CRH(+) cells (resembling small lymphocytes and large granular mononuclear cells) in the cortex and medulla. These findings indicate that IL-2 stimulates the synthesis of CRH in nerves that innervate the F344 rat spleen, and promote the appearance of CRH(+) immunocytes into draining mesenteric lymph nodes.
Bellinger
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DL
Center for Neuroimmunology, Department of Neurobiology and Anatomy, Loma Linda University School of Medicine, Box 603, 11021 Campus Street, Loma Linda, CA 92352, USA. dbellinger@som.llu.edu
Felten
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DL
Lorton
D
D
Brouxhon
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S
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007150:Immunohistochemistry; D007376:Interleukin-2 / Q000008:administration & dosage / Q000494:pharmacology*; D008198:Lymph Nodes / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*; D008297:Male; D008643:Mesentery; D009417:Nerve Tissue / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*
D007376:Interleukin-2; D011994:Recombinant Proteins; D003346:Corticotropin-Releasing Hormone