Exoenzyme Tat-C3 inhibits association of zymosan particles, phagocytosis, adhesion, and complement binding in macrophage cells.
Phagocytosis by macrophages is most important in the initial stages of an immune response. Although RhoA regulates cell adhesion, its roles in the integrin-related association of particles with macrophages and in phagocytosis are not clearly understood. We introduced C3 exoenzyme, a specific inhibitor of Rho, into J774A.1 macrophage cells fused with the 9 amino acid (49-57) transduction domain (RKKRRQRRR) of HIV-1 Tat. The presence of this Tat-C3 vector altered RhoA mobility on non-denaturing gels, indicating that Tat-C3 modified RhoA by ADP-ribosylation. Uptake of (FITC)-conjugated serum-opsonized zymosan particles and adhesion to fibrinogen-coated plates were reduced as was the association of serum-opsonized zymosan particles, and complement C3 and C3bi with the transfected cells. These results suggest that Rho regulates the activity of integrins that are involved in the association of particles with macrophages, phagocytosis, adhesion, and binding of complement C3 and C3bi.
Park
Jinseu
J
Department of Genetic Engineering, Division of Life Sciences, Hallym University, Chunchon 200-702, Korea. jbpark@hallym.ac.kr
Kim
Jun-Sub
JS
Jung
Kyeong-Cheon
KC
Lee
Hak-Ju
HJ
Kim
Jong-Il
JI
Kim
Jaebong
J
Lee
Jae-Yong
JY
Park
Jae-Bong
JB
Choi
Soo Young
SY
D036002:ADP Ribose Transferases / Q000378:metabolism*; D000818:Animals; D001905:Botulinum Toxins / Q000378:metabolism*; D002448:Cell Adhesion; D002478:Cells, Cultured; D003001:Cloning, Molecular; D005340:Fibrinogen / Q000378:metabolism; D015696:Gene Products, tat / Q000235:genetics / Q000378:metabolism; D016023:Integrins / Q000378:metabolism; D008264:Macrophages / Q000201:enzymology* / Q000502:physiology; D009895:Opsonin Proteins / Q000276:immunology / Q000502:physiology; D010587:Phagocytosis / Q000502:physiology*; D015054:Zymosan / Q000276:immunology* / Q000502:physiology; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
D015696:Gene Products, tat; D016023:Integrins; D009895:Opsonin Proteins; D005340:Fibrinogen; D015054:Zymosan; D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D001905:Botulinum Toxins; D020742:rhoA GTP-Binding Protein