title: Natural killer cell populations and cytotoxic activity in pigs fed mother's milk, formula, or formula supplemented with bovine lactoferrin.
abstract: BACKGROUND
  Natural killer (NK) cells are components of the innate immune defense system, and their levels differ between breast and formula-fed (FF) infants. Lactoferrin (Lf) modulates NK cell cytotoxicity ex vivo. We hypothesized that dietary bovine Lf (bLf) would increase NK cell populations and cytotoxicity.
  
  
  METHODS
  Piglets were sow-reared (SR), FF, or 1 g/l bLf-fed (LF) for 21 d. NK cells (CD3(-)CD4(-)CD8(+)) in blood (peripheral blood mononuclear cells (PBMCs)), spleen, and mesenteric lymph node (MLN) were determined by flow cytometry. PBMC NK cells were tested for cytotoxic activity against target K562 cells ex vivo in the presence of media (unstimulated), interleukin-2, or bLf. NK cell mRNA expression was determined by reverse transcription-quantitative PCR.
  
  
  RESULTS
  SR and LF piglets had more NK cells in MLN (P = 0.0097) and spleen (P = 0.0980) than FF piglets. In PBMCs, SR piglets had more NK cells than FF piglets (P = 0.0072); LF piglets were intermediate and not different from FF or SR piglets. NK cell intelectin-2 mRNA expression was 2.5-fold higher (P = 0.0095) in LF than SR or FF piglets. NK cells in SR piglets exhibited greater (P < 0.0001) cytotoxic activity than those in LF or FF piglets, which was supported by greater perforin mRNA expression.
  
  
  CONCLUSIONS
  Dietary bLf increased blood NK cell populations and NK Lf receptor expression but not NK cell cytotoxicity.
authors.affiliation: Division of Nutritional Sciences, University of Illinois, Urbana, Illinois.
authors.forename: Kilia Y
authors.initials: KY
authors.lastname: Liu
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Comstock
authors.forename: Jill M
authors.initials: JM
authors.lastname: Shunk
authors.forename: Marcia H
authors.initials: MH
authors.lastname: Monaco
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Donovan
mesh_terms: D000818:Animals; D002417:Cattle; D019587:Dietary Supplements; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D041943:Infant Formula / Q000008:administration & dosage / Q000494:pharmacology*; D007376:Interleukin-2 / Q000276:immunology; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007774:Lactation / Q000276:immunology*; D007781:Lactoferrin / Q000008:administration & dosage / Q000494:pharmacology*; D016014:Linear Models; D054353:Perforin / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D054353:Perforin; D007781:Lactoferrin