Mammalian Host Defenses: Innate and Adaptive Immunity

Georgiev, Vassil St.

doi:10.1007/978-1-60327-297-1_38

Cited by 2 publications

(2 citation statements)

References 646 publications

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“…Similar to Gram-negative bacteria, Gram-positive bacteria can also trigger the immune response [70]. Gram-positive bacteria associated and colonized with the grass pollen influence the allergic immune responses during skin prick test in human as well as in cell culture [71].…”

Section: Discussionmentioning

confidence: 99%

Bacterial Species Associated with Highly Allergenic Plant Pollen Yield a High Level of Endotoxins and Induce Chemokine and Cytokine Release from Human A549 Cells

et al. 2022

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Sensitization to pollen allergens has been increasing in Europe every year. Most studies in this field are related to climate change, phenology, allergens associated with different pollens, and allergic disorders. As a plant microhabitat, pollen is colonized by diverse microorganisms, including endotoxin-producing bacteria which may contribute to pollen allergy (pollinosis). Therefore, bacteria isolated from high allergenic and low allergenic plant pollen, as well as the pollen itself with all microbial inhabitants, were used to assess the effect of the pollen by measuring the endotoxins lipopolysaccharides (LPS) and lipoteichoic acid (LTA) concentrations and their effect on chemokine and cytokine release from transwell cultured epithelial A549 cells as a model of epithelial lung barrier. High allergenic pollen showed a significantly higher level of bacterial endotoxins; interestingly, the endotoxin level found in the bacterial isolates from high allergenic pollen was significantly higher compared to that of bacteria from low allergenic pollen. Moreover, bacterial LPS concentrations across different pollen species positively correlated with the LPS concentration across their corresponding bacterial isolates. Selected bacterial isolates from hazel pollen (HA5, HA13, and HA7) co-cultured with A549 cells induced a potent concentration-dependent release of the chemokine interleukin-8 and monocyte chemotactic protein-1 as well as the cytokine TNF-alpha and interleukin-2 to both apical and basal compartments of the transwell model. This study clearly shows the role of bacteria and bacterial endotoxins in the pollen allergy as well as seasonal allergic rhinitis.

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Section: Discussionmentioning

confidence: 99%

Bacterial Species Associated with Highly Allergenic Plant Pollen Yield a High Level of Endotoxins and Induce Chemokine and Cytokine Release from Human A549 Cells

et al. 2022

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“…Many flaviviruses have been known to evolve specific tactics, resulting in evasion of the innate and adaptive immune responses [17] ; which usually occur among mammalian hosts in response to infection of the viruses [18] , [19] . However, it seems like mosquitoes preferentially select innate responses due to lack of an adaptive immunity [20] .…”

Section: Discussionmentioning

confidence: 99%

Additive Protection by Antioxidant and Apoptosis-Inhibiting Effects on Mosquito Cells with Dengue 2 Virus Infection

Chen

Yang

et al. 2012

PLoS Negl Trop Dis

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Cytopathic effects (CPEs) in mosquito cells are generally trivial compared to those that occur in mammalian cells, which usually end up undergoing apoptosis during dengue virus (DENV) infection. However, oxidative stress was detected in both types of infected cells. Despite this, the survival of mosquito cells benefits from the upregulation of genes related to antioxidant defense, such as glutathione S transferase (GST). A second defense system, i.e., consisting of antiapoptotic effects, was also shown to play a role in protecting mosquito cells against DENV infection. This system is regulated by an inhibitor of apoptosis (IAP) that is an upstream regulator of caspases-9 and -3. DENV-infected C6/36 cells with double knockdown of GST and the IAP showed a synergistic effect on activation of these two caspases, causing a higher rate of apoptosis (>20%) than those with knockdown of each single gene (∼10%). It seems that the IAP acts as a second line of defense with an additional effect on the survival of mosquito cells with DENV infection. Compared to mammalian cells, residual hydrogen peroxide in DENV-infected C6/36 cells may signal for upregulation of the IAP. This novel finding sheds light on virus/cell interactions and their coevolution that may elucidate how mosquitoes can be a vector of DENV and probably most other arboviruses in nature.

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Mammalian Host Defenses: Innate and Adaptive Immunity

Cited by 2 publications

References 646 publications

Bacterial Species Associated with Highly Allergenic Plant Pollen Yield a High Level of Endotoxins and Induce Chemokine and Cytokine Release from Human A549 Cells

Bacterial Species Associated with Highly Allergenic Plant Pollen Yield a High Level of Endotoxins and Induce Chemokine and Cytokine Release from Human A549 Cells

Additive Protection by Antioxidant and Apoptosis-Inhibiting Effects on Mosquito Cells with Dengue 2 Virus Infection

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