ULTRASTRUCTURAL OF HUMAN NEUTROPHILS STIMULATED

Abstract

The" su.ccessful use of granulocyte .,macrophage--eoiony stimulating Jaetor (GM-CSF) .and granulocycte colony stimulating factor (G-CSF) m,the enhancement of ,. , n eutrophil recovery in several hematological• disorders has ,raised the .. questiQll •of what are the structural differences under the influence of thesecytokines. Human neutrophils were isolated using density ,gradient centrifu,gation ',and .processed for electflon microscopic study. E~perimental ,des.gn was. made from• control untre,;ated "neutrophil, GM"CSF, ~ancl G .. CSFstimulated neutrophil, ousingtwo different doses: Dl=.150 IU/ml,anq D2= 250 IU/mL Hemato,poietic growth factors; Granulo.cyte colony stimulating factor (G~CSF) and granulocyte macrophage .. colony ,stimUlating factors (GM-CSF) were compared in this study using elec.tron microscopy. Untreated neutrophil demonstrated the usual mo~phological findings of aneutrophiLGJ1the otber~a .. d9 ,activated neutrophil acquired a heightened level of :jultrastltu~tuJ!lill. variations which c.orrelatewith ''.'', ' enhancedfunctioital a~ti",i~. Activatedneutrophil$uDder,:"',the effect of small d~se (D.1) o(both factors depiete4; . increased granular. vacuolar' activity ,anai beginning, .degranulatiojl'l How:~ver, granular ... f1"ee iOllt~s' of":""'the perinuclear .. "(lytop~m demonstrated e~panded Golgi'aJ,ld centriole indicating prem~tU:rity,. Higher ,d.()~age:ofth~f'acto~<»;) demonstra~ed .. ni~Dlal' stnl,~~rai activity in the formo! incr~ased granular• and vacuolar activitY,!that fill tbe, whole cytoplasmic ~~I~~s. Moreover,differeut 'forms' of degranulation were .~stabUslu"d. The demon~trated ultrastructUral changes IndicatedpronoU:nc~d:dose dependant activation" .' . ':which suppor1:stbe clinical'indicationaf tbese factors~ Structun:I'differen~es of degranulation "in' 'GM .. CSF:and G-CSF' "'stimulated' neutrophils indicated ,different modes of degranulation.