TY - JOUR
T1 - Laccase affects the rate of cryptococcus neoformans nonlytic exocytosis from macrophages
AU - Frazão, Stefânia de Oliveira
AU - de Sousa, Herdson Renney
AU - da Silva, Lenise Gonçalves
AU - Folha, Jéssica Dos Santos
AU - Gorgonha, Kaio César de Melo
AU - de Oliveira, Getúlio Pereira
AU - Felipe, Maria Sueli Soares
AU - Silva-Pereira, Ildinete
AU - Casadevall, Arturo
AU - Nicola, André Moraes
AU - Albuquerque, Patrícia
N1 - Funding Information:
P.A., A.M.N., I.S.-P., and M.S.S.F. were supported by grants from the Brazilian funding agencies CNPq and FAP-DF. A.C. is supported by National Institutes of Health grants AI052733, AI15207, and HL059842. S.O.F., H.R.S., L.G.S., J.S.F., K.M.G., and G.P.O. were supported by scholarships from CNPq and Capes/Brazil (Capes-Brazil, finance code 001).
PY - 2020/9/1
Y1 - 2020/9/1
N2 - Nonlytic exocytosis is a process in which previously ingested microbes are expelled from host phagocytes with the concomitant survival of both cell types. This process has been observed in the interaction of Cryptococcus spp. and other fungal cells with phagocytes as distant as mammalian, bird, and fish macrophages and ameboid predators. Despite a great amount of research dedicated to unraveling this process, there are still many questions about its regulation and its final benefits for host or fungal cells. During a study to characterize the virulence attributes of Brazilian clinical isolates of C. neoformans, we observed great variability in their rates of nonlytic exocytosis and noted a correlation between this process and fungal melanin production/laccase activity. Flow cytometry experiments using melanized cells, nonmelanized cells, and lac1Δ mutants revealed that laccase has a role in the process of nonlytic exocytosis that seems to be independent of melanin production. These results identify a role for laccase in virulence, independent of its role in pigment production, that represents a new variable in the regulation of nonlytic exocytosis. IMPORTANCE Cryptococcus neoformans is a yeast that causes severe disease, primarily in immunosuppressed people. It has many attributes that allow it to survive and cause disease, such as a polysaccharide capsule and the dark pigment melanin produced by the laccase enzyme. Upon infection, the yeast is ingested by cells called macrophages, whose function is to kill them. Instead, these fungal cells can exit from macrophages in a process called nonlytic exocytosis. We know that this process is controlled by both host and fungal factors, only some of which are known. As part of an ongoing study, we observed that C. neoformans isolates that produce melanin faster are more-frequent targets of nonlytic exocytosis. Further experiments showed that this is probably due to higher production of laccase, because fungi lacking this enzyme are nonlytically exocytosed less often. This shows that laccase is an important signal/regulator of nonlytic exocytosis of C. neoformans from macrophages.
AB - Nonlytic exocytosis is a process in which previously ingested microbes are expelled from host phagocytes with the concomitant survival of both cell types. This process has been observed in the interaction of Cryptococcus spp. and other fungal cells with phagocytes as distant as mammalian, bird, and fish macrophages and ameboid predators. Despite a great amount of research dedicated to unraveling this process, there are still many questions about its regulation and its final benefits for host or fungal cells. During a study to characterize the virulence attributes of Brazilian clinical isolates of C. neoformans, we observed great variability in their rates of nonlytic exocytosis and noted a correlation between this process and fungal melanin production/laccase activity. Flow cytometry experiments using melanized cells, nonmelanized cells, and lac1Δ mutants revealed that laccase has a role in the process of nonlytic exocytosis that seems to be independent of melanin production. These results identify a role for laccase in virulence, independent of its role in pigment production, that represents a new variable in the regulation of nonlytic exocytosis. IMPORTANCE Cryptococcus neoformans is a yeast that causes severe disease, primarily in immunosuppressed people. It has many attributes that allow it to survive and cause disease, such as a polysaccharide capsule and the dark pigment melanin produced by the laccase enzyme. Upon infection, the yeast is ingested by cells called macrophages, whose function is to kill them. Instead, these fungal cells can exit from macrophages in a process called nonlytic exocytosis. We know that this process is controlled by both host and fungal factors, only some of which are known. As part of an ongoing study, we observed that C. neoformans isolates that produce melanin faster are more-frequent targets of nonlytic exocytosis. Further experiments showed that this is probably due to higher production of laccase, because fungi lacking this enzyme are nonlytically exocytosed less often. This shows that laccase is an important signal/regulator of nonlytic exocytosis of C. neoformans from macrophages.
KW - Cryptococcus neoformans
KW - Laccase
KW - Macrophages
KW - Nonlytic exocytosis
UR - http://www.scopus.com/inward/record.url?scp=85090672827&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85090672827&partnerID=8YFLogxK
U2 - 10.1128/mBio.02085-20
DO - 10.1128/mBio.02085-20
M3 - Article
C2 - 32900810
AN - SCOPUS:85090672827
VL - 11
SP - 1
EP - 6
JO - mBio
JF - mBio
SN - 2161-2129
IS - 5
M1 - e02085-20
ER -