Interleukin-3 administration enhances human monocyte function in vivo.
In addition to its haemopoietic effects, interleukin-3 (IL-3) enhances leucocyte function in vitro. In this study we examined the effects on haematological variables and monocyte function of a single IL-3 infusion in five haematologically normal individuals. There was a rapid fall in circulating monocyte (to 24 +/- 6% of pre-infusion value) and eosinophil numbers (to 3 +/- 2%) with a nadir at 30 min and gradual return to baseline over 6 h. No significant changes in monocyte expression of the adhesion molecules CD11b or L-selectin or of monocyte respiratory burst activity were detected. There was a significant increase in monocyte phagocytosis and killing of Candida after IL-3 infusion: the percentage of monocytes which had ingested Candida increased from 39 +/- 10% to 62 +/- 12% and the total number of Candida killed per 100 monocytes increased from 63 +/- 34 to 210 +/- 59 (P < 0.05 and P < 0.01 respectively). There was no inhibition of neutrophil migration into a 'skin window' site and monocyte migration was moderately enhanced (peak increase of 260 +/- 47%). These results show that IL-3 has significant effects on monocyte function in vivo and could be of use in augmenting host defence mechanisms in immunocompromised patients.
Khwaja
A
A
Department of Haematology, University College London Medical School.
Addison
I E
IE
Johnson
B
B
Yong
K
K
Linch
D C
DC
D018845:CD11 Antigens / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002465:Cell Movement; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007377:Interleukin-3 / Q000493:pharmacokinetics / Q000494:pharmacology*; D019041:L-Selectin; D007958:Leukocyte Count; D009000:Monocytes / Q000378:metabolism / Q000502:physiology*; D009504:Neutrophils / Q000378:metabolism; D010587:Phagocytosis; D016897:Respiratory Burst
D018845:CD11 Antigens; D015815:Cell Adhesion Molecules; D007377:Interleukin-3; D019041:L-Selectin