RESUMO
BACKGROUND: Giant viruses have brought new insights into different aspects of virus-cell interactions. The resulting cytopathic effects from these interactions are one of the main aspects of infection assessment in a laboratory routine, mainly reflecting on the morphological features of an infected cell. OBJECTIVES: In this work, we follow the entire kinetics of the cytopathic effect in cells infected by viruses of the Mimiviridae family, spatiotemporally quantifying typical features such as cell roundness, loss of motility, decrease in cell area and cell lysis. METHODS: Infections by Acanthamoeba polyphaga mimivirus (APMV), Tupanvirus (TPV) and M4 were carried out at multiplicity of infection (MOI) 1 and MOI 10 in Acanthamoeba castellanii. Monitoring of infections was carried out using time lapse microscopy for up to 72 hours. The images were analyzed using ImageJ software. FINDINGS: The data obtained indicate that APMV is the slowest virus in inducing the cytopathic effects of rounding, decrease in cell area, mobility and cell lysis. However, it is the only virus whose MOI increase accelerates the lysis process of infected cells. In turn, TPV and M4 rapidly induce morphological and behavioral changes. MAIN CONCLUSIONS: Our results indicate that mimiviruses induce different temporal responses within the host cell and that it is possible to use these kinetic data to facilitate the understanding of infection by these viruses.
Assuntos
Acanthamoeba castellanii , Efeito Citopatogênico Viral , Mimiviridae , Mimiviridae/fisiologia , Cinética , Acanthamoeba castellanii/virologiaRESUMO
BACKGROUND Giant viruses have brought new insights into different aspects of virus-cell interactions. The resulting cytopathic effects from these interactions are one of the main aspects of infection assessment in a laboratory routine, mainly reflecting on the morphological features of an infected cell. OBJECTIVES In this work, we follow the entire kinetics of the cytopathic effect in cells infected by viruses of the Mimiviridae family, spatiotemporally quantifying typical features such as cell roundness, loss of motility, decrease in cell area and cell lysis. METHODS Infections by Acanthamoeba polyphaga mimivirus (APMV), Tupanvirus (TPV) and M4 were carried out at multiplicity of infection (MOI) 1 and MOI 10 in Acanthamoeba castellanii. Monitoring of infections was carried out using time lapse microscopy for up to 72 hours. The images were analyzed using ImageJ software. FINDINGS The data obtained indicate that APMV is the slowest virus in inducing the cytopathic effects of rounding, decrease in cell area, mobility and cell lysis. However, it is the only virus whose MOI increase accelerates the lysis process of infected cells. In turn, TPV and M4 rapidly induce morphological and behavioral changes. MAIN CONCLUSIONS Our results indicate that mimiviruses induce different temporal responses within the host cell and that it is possible to use these kinetic data to facilitate the understanding of infection by these viruses.
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The Salmonella enterica bacteriophage P22 is one of the most promising models for the development of virus-like particle (VLP) nanocages. It possesses an icosahedral T = 7 capsid, assembled by the combination of two structural proteins: the coat protein (gp5) and the scaffold protein (gp8). The P22 capsid has the remarkable capability of undergoing structural transition into three morphologies with differing diameters and wall-pore sizes. These varied morphologies can be explored for the design of nanoplatforms, such as for the development of cargo internalization strategies. The capsid proteic nature allows for the extensive modification of its structure, enabling the addition of non-native structures to alter the VLP properties or confer them to diverse ends. Various molecules were added to the P22 VLP through genetic, chemical, and other means to both the capsid and the scaffold protein, permitting the encapsulation or the presentation of cargo. This allows the particle to be exploited for numerous purposes-for example, as a nanocarrier, nanoreactor, and vaccine model, among other applications. Therefore, the present review intends to give an overview of the literature on this amazing particle.
Assuntos
Bacteriófago P22 , Viroides , Capsídeo , Proteínas do Capsídeo/genética , Núcleo Celular , NanotecnologiaRESUMO
Although giant viruses have existed for millennia and possibly exerted great evolutionary influence in their environment. Their presence has only been noticed by virologists recently with the discovery of Acanthamoeba polyphaga mimivirus in 2003. Its virion with a diameter of 500 nm and its genome larger than 1 Mpb shattered preconceived standards of what a virus is and triggered world-wide prospection studies. Thanks to these investigations many giant virus families were discovered, each with its own morphological peculiarities and genomes ranging from 0.4 to 2.5 Mpb that possibly encode more than 400 viral proteins. This review aims to present the morphological diversity, the different aspects observed in host-virus interactions during replication, as well as the techniques utilized during their investigation.