TY - JOUR
T1 - Genomic Properties and Temporal Analysis of the Interaction of an Invasive Escherichia albertii With Epithelial Cells
AU - Romão, Fabiano T.
AU - Martins, Fernando H.
AU - Hernandes, Rodrigo T.
AU - Ooka, Tadasuke
AU - Santos, Fernanda F.
AU - Yamamoto, Denise
AU - Bonfim-Melo, Alexis
AU - Jones, Nina
AU - Hayashi, Tetsuya
AU - Elias, Waldir P.
AU - Sperandio, Vanessa
AU - Gomes, Tânia A.T.
N1 - Funding Information:
This work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nıv́ el Superior (CAPES) (grant 99999.009868/ 2014-03), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (grant 2011/12664-5), National Council for Scientific and Technological Development (CNPq) (grant 141586/2013-3), National Institutes of Health (NIH) (grant AI053067), JSPS KAKENHI (grant 16K08781) and Grants-in-Aid for Scientific Research from the Research Program on Emerging and Re-emerging Infectious Diseases from the Japan Agency for Medical Research and Development (AMED).
Publisher Copyright:
© Copyright © 2020 Romão, Martins, Hernandes, Ooka, Santos, Yamamoto, Bonfim-Melo, Jones, Hayashi, Elias, Sperandio and Gomes.
PY - 2020/12/16
Y1 - 2020/12/16
N2 - Diarrhea is one of the main causes of infant mortality worldwide, mainly in the developing world. Among the various etiologic agents, Escherichia albertii is emerging as an important human enteropathogen. E. albertii promote attaching and effacing (AE) lesions due to the presence of the locus of enterocyte effacement (LEE) that encodes a type three secretion system (T3SS), the afimbrial adhesin intimin and its translocated receptor, Tir, and several effector proteins. We previously showed that E. albertii strain 1551-2 invades several epithelial cell lineages by a process that is dependent on the intimin-Tir interaction. To understand the contribution of T3SS-dependent effectors present in E. albertii 1551-2 during the invasion process, we performed a genetic analysis of the LEE and non-LEE genes and evaluated the expression of the LEE operons in various stages of bacterial interaction with differentiated intestinal Caco-2 cells. The kinetics of the ability of the 1551-2 strain to colonize and form AE lesions was also investigated in epithelial HeLa cells. We showed that the LEE expression was constant during the early stages of infection but increased at least 4-fold during bacterial persistence in the intracellular compartment. An in silico analysis indicated the presence of a new tccP/espFU subtype, named tccP3. We found that the encoded protein colocalizes with Tir and polymerized F-actin during the infection process in vitro. Moreover, assays performed with Nck null cells demonstrated that the 1551-2 strain can trigger F-actin polymerization in an Nck-independent pathway, despite the fact that TccP3 is not required for this phenotype. Our study highlights the importance of the T3SS during the invasion process and for the maintenance of E. albertii 1551-2 inside the cells. In addition, this work may help to elucidate the versatility of the T3SS for AE pathogens, which are usually considered extracellular and rarely reach the intracellular environment.
AB - Diarrhea is one of the main causes of infant mortality worldwide, mainly in the developing world. Among the various etiologic agents, Escherichia albertii is emerging as an important human enteropathogen. E. albertii promote attaching and effacing (AE) lesions due to the presence of the locus of enterocyte effacement (LEE) that encodes a type three secretion system (T3SS), the afimbrial adhesin intimin and its translocated receptor, Tir, and several effector proteins. We previously showed that E. albertii strain 1551-2 invades several epithelial cell lineages by a process that is dependent on the intimin-Tir interaction. To understand the contribution of T3SS-dependent effectors present in E. albertii 1551-2 during the invasion process, we performed a genetic analysis of the LEE and non-LEE genes and evaluated the expression of the LEE operons in various stages of bacterial interaction with differentiated intestinal Caco-2 cells. The kinetics of the ability of the 1551-2 strain to colonize and form AE lesions was also investigated in epithelial HeLa cells. We showed that the LEE expression was constant during the early stages of infection but increased at least 4-fold during bacterial persistence in the intracellular compartment. An in silico analysis indicated the presence of a new tccP/espFU subtype, named tccP3. We found that the encoded protein colocalizes with Tir and polymerized F-actin during the infection process in vitro. Moreover, assays performed with Nck null cells demonstrated that the 1551-2 strain can trigger F-actin polymerization in an Nck-independent pathway, despite the fact that TccP3 is not required for this phenotype. Our study highlights the importance of the T3SS during the invasion process and for the maintenance of E. albertii 1551-2 inside the cells. In addition, this work may help to elucidate the versatility of the T3SS for AE pathogens, which are usually considered extracellular and rarely reach the intracellular environment.
KW - Escherichia albertii
KW - Tir cytoskeleton-coupling protein/EspFu
KW - attaching and effacing lesion
KW - diarrhea
KW - invasion
KW - locus of enterocyte effacement
KW - pathogenicity
KW - type three secretion system
UR - http://www.scopus.com/inward/record.url?scp=85098552731&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85098552731&partnerID=8YFLogxK
U2 - 10.3389/fcimb.2020.571088
DO - 10.3389/fcimb.2020.571088
M3 - Article
C2 - 33392102
AN - SCOPUS:85098552731
SN - 2235-2988
VL - 10
JO - Frontiers in cellular and infection microbiology
JF - Frontiers in cellular and infection microbiology
M1 - 571088
ER -