Immune response against adhesins of enteroaggregative Escherichia coli immunized by three different vaccination strategies (DNA/DNA, Protein/Protein, and DNA/Protein) in mice

Deeper understanding of the spread, morbidity, fatality, and development of immune response associated with coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, is necessary in order to establish an appropriate epidemiological and clinical response. Exposure control represents a key part of the combat against COVID-19, as the effectiveness of current therapeutic options remains partial. Since the preventive measures have not been sufficiently able to slow down this pandemic, in this article we explore some of the pertinent knowledge gaps, while overall looking to effective vaccination strategies as a way out. Early on, such strategies may need to rely on counting the convalescents as protected in order to speed up the immunization of the whole population.

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Autophagy—A Story of Bacteria Interfering with the Host Cell Degradation Machinery

Pathogens ◽

10.3390/pathogens10020110 ◽

2021 ◽

Vol 10 (2) ◽

pp. 110

Author(s):

Anna K. Riebisch ◽

Sabrina Mühlen ◽

Yan Yan Beer ◽

Ingo Schmitz

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Immune Response ◽

Mycobacterium Tuberculosis ◽

Listeria Monocytogenes ◽

Salmonella Typhimurium ◽

Innate Immune ◽

Intracellular Pathogens ◽

Response Mechanism ◽

Pathogenic Escherichia Coli

Autophagy is a highly conserved and fundamental cellular process to maintain cellular homeostasis through recycling of defective organelles or proteins. In a response to intracellular pathogens, autophagy further acts as an innate immune response mechanism to eliminate pathogens. This review will discuss recent findings on autophagy as a reaction to intracellular pathogens, such as Salmonella typhimurium, Listeria monocytogenes, Mycobacterium tuberculosis, Staphylococcus aureus, and pathogenic Escherichia coli. Interestingly, while some of these bacteria have developed methods to use autophagy for their own benefit within the cell, others have developed fascinating mechanisms to evade recognition, to subvert the autophagic pathway, or to escape from autophagy.

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Alteration of the phagocytosis and antimicrobial defense of Octodonta nipae (Coleoptera: Chrysomelidae) pupae to Escherichia coli following parasitism by Tetrastichus brontispae (Hymenoptera: Eulophidae)

Bulletin of Entomological Research ◽

10.1017/s0007485318000780 ◽

2018 ◽

Vol 109 (2) ◽

pp. 248-256

Author(s):

E. Meng ◽

J. Li ◽

B. Tang ◽

Y. Hu ◽

T. Qiao ◽

...

Keyword(s):

Escherichia Coli ◽

Immune Response ◽

Immune Responses ◽

Mrna Expression ◽

Bactericidal Activity ◽

Bacterial Infections ◽

Expression Level ◽

Primary Immune Response ◽

Mrna Expression Level ◽

E Coli

AbstractAlthough parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.

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