Reduced virulence of melanized Cryptococcus neoformans in Galleria mellonella.
Fungal melanins are important in the virulence of many pathogenic fungi. In this study, we examined the role of melanin in the interaction between Cryptococcus neoformans and the invertebrate host, Galleria mellonella. C. neoformans was able to melanize in the presence of G. mellonella homogenate, indicating the presence of melanin substrates. Melanization was confirmed by the recovery of acid-resistant particles that were recognized by anti-melanin antibodies. In addition, we tested the effect of fungal melanization on virulence. Surprisingly, G. mellonella larvae infected with melanized fungal cells lived longer than those infected with non-melanized fungi. When the cellular immune response of G. mellonella to melanized and non-melanized cells was compared, inflammatory nodules were observed in both groups. However the response was stronger in larvae infected with melanized cells. These results suggest that fungal melanin activates the immune response of G. mellonella, thereby resulting in the decreased virulence observed with melanized cells.
Department of Natural Sciences; Baruch College and Graduate Center; The City University of New York; New York, NY USA.
Helene C
HC
Eisenman
Department of Natural Sciences; Baruch College and Graduate Center; The City University of New York; New York, NY USA.
Raymond
R
Duong
Department of Natural Sciences; Baruch College and Graduate Center; The City University of New York; New York, NY USA.
Hsi
H
Chan
Department of Natural Sciences; Baruch College and Graduate Center; The City University of New York; New York, NY USA.
Ryan
R
Tsue
Department of Biology; Middle Tennessee State University; Murfreesboro, TN USA.
Erin E
EE
McClelland
D000818:Animals; D003455:Cryptococcus neoformans / Q000276:immunology / Q000378:metabolism* / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D007814:Larva / Q000276:immunology / Q000382:microbiology / Q000502:physiology; D007915:Lepidoptera / Q000276:immunology / Q000382:microbiology* / Q000502:physiology; D008543:Melanins / Q000276:immunology / Q000378:metabolism*; D016019:Survival Analysis; D014774:Virulence
D008543:Melanins
Cryptococcus neoformans; Galleria mellonella; cellular immunity; inflammatory nodule; invertebrate; melanin