Somnogenic, pyrogenic, and anorectic activities of tumor necrosis factor-alpha and TNF-alpha fragments.
Exogenously administered tumor necrosis factor-alpha (TNF-alpha) elicits several symptoms of generalized infections such as fever, increased sleep, and anorexia. The aim of the present work was to localize these effects of TNF-alpha to specific amino acid sequences of the parent molecule by characterizing the in vivo and in vitro activities of several synthetic TNF-alpha fragments. Intracerebroventricular injection of TNF-alpha elicited dose-dependent fevers and increases in non-rapid-eye-movement sleep (NREMS) in rabbits. Four fragments also promoted NREMS and five elicited monophasic fevers. All of the somnogenic fragments share the amino acid sequence 31-36. In rats, TNF-alpha and one of the fragments [TNF-alpha-(69-100)] suppressed 12-h food intake. Furthermore, TNF-alpha increased the expression of the intercellular adhesion molecule-1 and enhanced interferon-gamma-induced HLA-DR expression in human glioblastoma cell line. In contrast, none of the fragments possessed these in vitro activities. Our in vivo results support the concept that there are biologically active regions in the TNF-alpha molecule.
Department of Physiology, University of Tennessee, Memphis 38163.
L
L
Kapás
L
L
Hong
A B
AB
Cady
M R
MR
Opp
A E
AE
Postlethwaite
J M
JM
Seyer
J M
JM
Krueger
D000818:Animals; D000855:Anorexia / Q000139:chemically induced*; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D004435:Eating / Q000187:drug effects; D005334:Fever / Q000139:chemically induced*; D006684:HLA-DR Antigens / Q000032:analysis; D018799:Intercellular Adhesion Molecule-1; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D015815:Cell Adhesion Molecules; D006684:HLA-DR Antigens; D010446:Peptide Fragments; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1