Inclusion Membrane Proteins of Protochlamydia amoebophila UWE25 Reveal a Conserved Mechanism for Host Cell Interaction among the Chlamydiae

ABSTRACT Chlamydiae are a group of obligate intracellular bacteria comprising several important human pathogens. Inside the eukaryotic cell, chlamydiae remain within a host-derived vesicular compartment, termed the inclusion. They modify the inclusion membrane through insertion of unique proteins, which are involved in interaction with and manipulation of the host cell. Among chlamydiae, inclusion membrane proteins have been exclusively found in members of the family Chlamydiaceae, which predominantly infect mammalian and avian hosts. Here, the presence of inclusion membrane proteins in Protochlamydia amoebophila UWE25, a chlamydial endosymbiont of free-living amoebae, is reported. A genome-wide screening for secondary structure motifs resulted in the identification of 23 putative inclusion membrane proteins for this organism. Immunofluorescence analysis demonstrated that five of these proteins were expressed, and four of them could be localized to a halo surrounding the intracellular bacteria. Colocalization studies showed an almost complete overlap of the signals obtained for the four putative inclusion membrane proteins, and immuno-transmission electron microscopy unambiguously demonstrated their location in the inclusion membrane. The presence of inclusion membrane proteins (designated IncA, IncQ, IncR, and IncS) in P. amoebophila shows that this strategy for host cell interaction is conserved among the chlamydiae and is used by chlamydial symbionts and pathogens alike.

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Advances in Zika Virus–Host Cell Interaction: Current Knowledge and Future Perspectives

International Journal of Molecular Sciences ◽

10.3390/ijms20051101 ◽

2019 ◽

Vol 20 (5) ◽

pp. 1101 ◽

Cited By ~ 14

Author(s):

Jae Lee ◽

Ok Shin

Keyword(s):

Host Cell ◽

Zika Virus ◽

Current Knowledge ◽

Cell Interaction ◽

Human Pathogens ◽

Zikv Infection ◽

In Vivo Models ◽

Host Cell Interaction

Emerging mosquito-transmitted RNA viruses, such as Zika virus (ZIKV) and Chikungunya represent human pathogens of an immense global health problem. In particular, ZIKV has emerged explosively since 2007 to cause a series of epidemics in the South Pacific and most recently in the Americas. Although typical ZIKV infections are asymptomatic, ZIKV infection during pregnancy is increasingly associated with microcephaly and other fetal developmental abnormalities. In the last few years, genomic and molecular investigations have established a remarkable progress on the pathogenic mechanisms of ZIKV infection using in vitro and in vivo models. Here, we highlight recent advances in ZIKV-host cell interaction studies, including cellular targets of ZIKV, ZIKV-mediated cell death mechanisms, host cell restriction factors that limit ZIKV replication, and immune evasion mechanisms utilized by ZIKV. Understanding of the mechanisms of ZIKV–host interaction at the cellular level will contribute crucial insights into the development of ZIKV therapeutics and vaccines.

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Absence of Specific Chlamydia trachomatis Inclusion Membrane Proteins Triggers Premature Inclusion Membrane Lysis and Host Cell Death

Cell Reports ◽

10.1016/j.celrep.2017.04.058 ◽

2017 ◽

Vol 19 (7) ◽

pp. 1406-1417 ◽

Cited By ~ 41

Author(s):

Mary M. Weber ◽

Jennifer L. Lam ◽

Cheryl A. Dooley ◽

Nicholas F. Noriea ◽

Bryan T. Hansen ◽

...

Keyword(s):

Cell Death ◽

Chlamydia Trachomatis ◽

Membrane Proteins ◽

Host Cell ◽

Inclusion Membrane ◽

Host Cell Death ◽

Membrane Lysis ◽

Inclusion Membrane Proteins

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Bacteriophages Associated with Turkey Coecums in Bluecomb-Infected and Healthy Birds

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063044 ◽

1969 ◽

Vol 27 ◽

pp. 226-227

Author(s):

A. E. Ritchie

Keyword(s):

Host Cell ◽

Causal Relationship ◽

Cell Cultures ◽

Cell Interaction ◽

Etiologic Agent ◽

Viral Origin ◽

Intestinal Contents ◽

Host Cell Interaction

The cause of bluecomb disease in turkeys is unknown. Filtration of infective intestinal contents suggests a viral origin. To date, it has not been possible to isolate the etiologic agent in various cell cultures. The purpose of this work was to characterize as many virus-like entities as were recognizable in intestines of both healthy and bluecomb-infected turkeys. By a comparison of the viral populations it was hoped that some insight might be gained into the cause of this disease. Studies of turkey hemorraghic enteritis by Gross and Moore (Avian Dis. 11: 296-307, 1967) have suggested that a bacteriophage-host cell interaction may bear some causal relationship to that disease.

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Why Does SARS-CoV-2 Infection Induce Autoantibody Production?

Pathogens ◽

10.3390/pathogens10030380 ◽

2021 ◽

Vol 10 (3) ◽

pp. 380

Author(s):

Ales Macela ◽

Klara Kubelkova

Keyword(s):

Immune Response ◽

Immune System ◽

Host Cell ◽

Critical Role ◽

Cell Interaction ◽

Immune Recognition ◽

Autoantibody Production ◽

Host Cell Interaction ◽

Primary Virus

SARS-CoV-2 infection induces the production of autoantibodies, which is significantly associated with complications during hospitalization and a more severe prognosis in COVID-19 patients. Such a response of the patient’s immune system may reflect (1) the dysregulation of the immune response or (2) it may be an attempt to regulate itself in situations where the non-infectious self poses a greater threat than the infectious non-self. Of significance may be the primary virus-host cell interaction where the surface-bound ACE2 ectoenzyme plays a critical role. Here, we present a brief analysis of recent findings concerning the immune recognition of SARS-CoV-2, which, we believe, favors the second possibility as the underlying reason for the production of autoantibodies during COVID-19.

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