Lactoferrin acts on Ia-like antigen-positive subpopulations of human monocytes to inhibit production of colony stimulatory activity in vitro.
The relationship between Ia-like antigens (Ia-antigens) on human monocytes and the ability of lactoferrin (LF) to inhibit the production of colony stimulatory activity (CSA) for granulocyte and macrophage colony formation was investigated. Complement-dependent cytotoxicity of human monocytes by antiserum to Ia-antigen-reduced CSA production by 50%. LF decreased CSA production by monocytes but had no influence on monocytes insensitive to anti-Ia and complement. Anti-Ia in the absence of complement had no effect on production of CSA but blocked the inhibitory action of LF. This suggsts that LF inhibits production of CSA from an Ia-antigen-positive subpopulation of human blood monocytes. This may be of relevance to the regulation of myelopoiesis.
D000954:Antigens, Surface; D003115:Colony-Stimulating Factors / Q000096:biosynthesis*; D003165:Complement System Proteins / Q000494:pharmacology; D006801:Humans; D007519:Isoantigens; D007781:Lactoferrin / Q000494:pharmacology*; D007782:Lactoglobulins / Q000494:pharmacology*; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D011955:Receptors, Drug / Q000378:metabolism
D000954:Antigens, Surface; D003115:Colony-Stimulating Factors; D007519:Isoantigens; D007782:Lactoglobulins; D011955:Receptors, Drug; D003165:Complement System Proteins; D007781:Lactoferrin