A novel immunosuppressive factor in human colostrum.
Human colostrum contains a factor that inhibits the induction of interleukin 2 (IL2) in T lymphocyte cell lines (colostrum inhibitory factor, CIF). In PMA-stimulated EL4.E1 cells, inhibition is the result of blocking the accumulation of IL2 mRNA. Human colostrum contains on the order of 100 U/ml of CIF activity, where 1 U/ml inhibits 50% of the IL2 response. Transient acidification to pH 3.0 increased CIF activity severalfold. Although it resembles TGF beta in some respects, antisera against TGF beta neutralized 10% or less of the CIF activity in human colostrum. Furthermore, whereas authentic TGF beta blocked the induction of IL2 by PMA-plus-calcium-stimulated cells by only about 50%, CIF inhibited it completely. A similar CIF activity was also detected in bovine colostrum, but not in normal bovine milk.
Mandalapu
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P
Department of Biochemistry, University of Alberta, Edmonton, Canada.
Pabst
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HF
Paetkau
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D000818:Animals; D002417:Cattle; D003126:Colostrum / Q000276:immunology*; D015870:Gene Expression; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007166:Immunosuppressive Agents; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000502:physiology
D007166:Immunosuppressive Agents; D007376:Interleukin-2; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta