Tyrosine kinase activation in response to fungal spores is primarily dependent on endogenous reactive oxygen production in macrophages.
Studies from our laboratory (Shahan, T. A., Sorenson, W. G., and Lewis, D. M. (1994) Environ. Res. 67, 98-104) demonstrated that spores from different fungal species differentially activate rat alveolar macrophages as detected by the measurement of superoxide anion and cytokine production (Shahan, T. A., Siegel, P. D., Sorenson, W. G., Kuschner, W. G., and Lewis, D. M. (1998) Am. J. Respir. Cell Mol. Biol. 18, 435-441). Spores from Aspergillus candidus stimulated production of the highest levels of superoxide anion (5.2 nmol/1.0 x 10(6) alveolar macrophages (AMs)/30 min), followed by those from Aspergillus niger (2.4 nmol/1.0 x 10(6) AMs/30 min) and Eurotium amstelodami (0.4 nmol/1.0 x 10(6) AMs/30 min). The mechanism of this differential activation was studied. Our data demonstrate that the tyrosine kinases p56(Hck), p72(Syk), p77(Btk), p62(Yes), p56(Lck), and p59(Fyn) were specifically activated in response to spores from A. candidus, whereas spores from either A. niger or E. amstelodami activated p56(Hck), p72(Syk), and p77(Btk). Kinetic analysis of specific tyrosine kinases demonstrated that p56(Hck), p72(Syk), and p77(Btk) were activated faster and to a greater extent by spores from A. candidus as compared with spores from E. amstelodami. These data suggest a relationship between reactive oxygen species and tyrosine kinase activation. Treatment of AMs with H(2)O(2) (1 mM) caused the activation of p72(Syk) only, whereas treatment with superoxide dismutase and catalase before treatment with the spores had no effect on tyrosine kinase activation. Incubation with NADPH oxidase inhibitors inhibited both superoxide anion production and the activation of p56(Hck), p72(Syk), and p77(Btk) in response to fungal spores. These data indicate that endogenous reactive oxygen species are necessary for the activation of p56(Hck), p72(Syk), and p77(Btk) by spores; they also indicate that some species of spores are capable of activating tyrosine kinases independent of superoxide anion.
Shahan
T A
TA
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-2614, USA. shahan@mail.med.upenn.edu
Sorenson
W G
WG
Simpson
J
J
Kefalides
N A
NA
Lewis
D M
DM
D000077329:Agammaglobulinaemia Tyrosine Kinase; D000818:Animals; D001203:Ascomycota / Q000502:physiology*; D001230:Aspergillus / Q000502:physiology*; D001234:Aspergillus niger / Q000502:physiology; D002374:Catalase / Q000378:metabolism; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000201:enzymology / Q000382:microbiology* / Q000502:physiology*; D008297:Male; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D051572:Proto-Oncogene Proteins c-hck; D051575:Proto-Oncogene Proteins c-yes; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species; D013045:Species Specificity; D013172:Spores, Fungal / Q000502:physiology; D013482:Superoxide Dismutase / Q000494:pharmacology; D000072377:Syk Kinase; D019061:src-Family Kinases
D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D011518:Proto-Oncogene Proteins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C494961:Fyn protein, rat; C496633:Hck protein, rat; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn; D051572:Proto-Oncogene Proteins c-hck; D051575:Proto-Oncogene Proteins c-yes; D000072377:Syk Kinase; C000606898:Syk protein, rat; D019061:src-Family Kinases