Increased tumour necrosis factor-alpha production, higher mannose receptor activity and ability to kill Candida by concanavalin-A-activated macrophages.
In a previous study, our group verified that mice pretreated with concanavalin-A (Con-A) produced more tumour necrosis factor (TNF)-alpha and presented greater Candida clearance from the peritoneal cavity, liver and spleen, which yielded a higher survival rate than control animals. In this work, the hypothesis that macrophages were of crucial importance in overcoming the infection was tested. Thus, peritoneal macrophages from mice pretreated for 3 days with Con-A or phosphate-buffered saline (PBS) were coincubated with CR1, CR15 and 577 isolates of Candida albicans for 0.5, 1 and 2 h. The ability of Con-activated macrophages to produce TNF-alpha, ingest via mannose receptors and kill all the isolates was significantly greater compared with PBS-treated macrophages, and activated macrophages exhibited a lower incidence of apoptosis, verified by binding to annexin V-fluorescein isothiocyanate. The transition of yeast cells to filamentous forms during coincubation for 2 h with control macrophages was about 73-80%, whereas in the presence of Con-A-activated macrophages, it was 35-40%. Our results suggest that a greater clearance of C. albicans infection through treatment with Con-A is probably due to the activation of macrophages, which produce more TNF-alpha, express more mannose receptors and are better endowed to kill ingested C. albicans.
Department of Pathological Sciences, Londrina State University, Londrina, Brazil.
Thais Herrero
TH
Geraldino
Eliana
E
de Vito
Luiz Antonio
LA
Custódio
Ivete
I
Conchon-Costa
Luis Carlos Jabur
LC
Gaziri
Ionice
I
Felipe
Wagner
W
Loyola
Kamila Landucci
KL
Bonifácio
D000818:Animals; D017209:Apoptosis; D002176:Candida albicans / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D018920:Coculture Techniques; D003208:Concanavalin A / Q000494:pharmacology*; D007155:Immunologic Factors / Q000494:pharmacology*; D037181:Lectins, C-Type / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology*; D008297:Male; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism*; D051379:Mice; D050296:Microbial Viability; D010587:Phagocytosis; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D007155:Immunologic Factors; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; D003208:Concanavalin A