Trichomonas vaginalis,a protist parasite of the urogenital tract in humans,is the causative agent of trichomonosis,which in recent years have been associated with the cervical cancer development.In the present study w...Trichomonas vaginalis,a protist parasite of the urogenital tract in humans,is the causative agent of trichomonosis,which in recent years have been associated with the cervical cancer development.In the present study we analyzed the modifications at the junctional complex level of Caco-2 cells after interaction with two isolates of T.vaginalis and the influence of the iron concentration present in the parasite’s culture medium on the interaction effects.Our results show that T.vaginalis adheres to the epithelial cell causing alterations in the junctional complex,such as:(a)a decrease in transepithelial electrical resistance;(b)alteration in the pattern of junctional complex proteins distribution as observed for E-cadherin,occludin and ZO-1;and(c)enlargement of the spaces between epithelial cells.These effects were dependent on(a)the degree of the parasite virulence isolate,(b)the iron concentration in the culture medium,and(c)the expression of adhesin proteins on the parasite surface.展开更多
Helium ion scanning microscopy(HIM)is a novel high-resolution scanning microscopy technique that uses helium ions instead of electrons to form images of the highest quality and resolution,providing a sub-nanometer res...Helium ion scanning microscopy(HIM)is a novel high-resolution scanning microscopy technique that uses helium ions instead of electrons to form images of the highest quality and resolution,providing a sub-nanometer resolution sputter uncoated biological cell.Here,we took advantage of HIM to explore the cell surface of Tritrichomonas foetus,a protist parasite of cattle that provokes hard infection and abortion in cows.We describe thin protrusions,like nanotubes described in other cells,with different sizes(27 nm to 81 nm in thickness)and various lengths(from 73 nm to 2μm),as well bulbous structures either budding from the cell surface or present in the extremities of some protrusions.The flagella also presented these thin protrusions and different protein decoration,similar to those previously described using freeze-fracture techniques.Nanotubes between two cells were also seen,and their role in infection is discussed.The cell surface was also examined and showed several pits indicative of endocytic activity and other types of arrays of particles.These observations were confirmed using Scanning Electron Microscopy(SEM),negative staining,and conventional thin sectioning for observation by transmission electron microscopy.Our findings provide new and relevant information that may contribute to a better understanding of protozoan biology and its interaction with mammalian cells.展开更多
基金This work was supported by Fundção Ary Frauzino para Pesquisa e Controle do Cfincer.Instituto Nacional de Cãncer.Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro(FAPERJ)Conselho Nacional de Desenvolvimento Cientfico e Tecnológico (CNPq)Associação Universitfiria Santa Ursula(AUSU).
文摘Trichomonas vaginalis,a protist parasite of the urogenital tract in humans,is the causative agent of trichomonosis,which in recent years have been associated with the cervical cancer development.In the present study we analyzed the modifications at the junctional complex level of Caco-2 cells after interaction with two isolates of T.vaginalis and the influence of the iron concentration present in the parasite’s culture medium on the interaction effects.Our results show that T.vaginalis adheres to the epithelial cell causing alterations in the junctional complex,such as:(a)a decrease in transepithelial electrical resistance;(b)alteration in the pattern of junctional complex proteins distribution as observed for E-cadherin,occludin and ZO-1;and(c)enlargement of the spaces between epithelial cells.These effects were dependent on(a)the degree of the parasite virulence isolate,(b)the iron concentration in the culture medium,and(c)the expression of adhesin proteins on the parasite surface.
基金This work was supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq),Programa de Excelência a Pesquisa/Instituto Aggeu Magalhães(CNPq/PROEP-IAM grant:400740/2019-2),Financiadora de Estudos e Projetos(FINEP),and Fundação Carlos Chagas Filho de AmparoàPesquisa no Estado do Rio de Janeiro(FAPERJ).
文摘Helium ion scanning microscopy(HIM)is a novel high-resolution scanning microscopy technique that uses helium ions instead of electrons to form images of the highest quality and resolution,providing a sub-nanometer resolution sputter uncoated biological cell.Here,we took advantage of HIM to explore the cell surface of Tritrichomonas foetus,a protist parasite of cattle that provokes hard infection and abortion in cows.We describe thin protrusions,like nanotubes described in other cells,with different sizes(27 nm to 81 nm in thickness)and various lengths(from 73 nm to 2μm),as well bulbous structures either budding from the cell surface or present in the extremities of some protrusions.The flagella also presented these thin protrusions and different protein decoration,similar to those previously described using freeze-fracture techniques.Nanotubes between two cells were also seen,and their role in infection is discussed.The cell surface was also examined and showed several pits indicative of endocytic activity and other types of arrays of particles.These observations were confirmed using Scanning Electron Microscopy(SEM),negative staining,and conventional thin sectioning for observation by transmission electron microscopy.Our findings provide new and relevant information that may contribute to a better understanding of protozoan biology and its interaction with mammalian cells.
