Involvement of thymus in immune response of rabbits to somatic polysaccharides of Gram-negative bacteria

1965 ◽  
Vol 3 (6) ◽  
pp. 803
Author(s):  
&NA;
Keyword(s):  
Immune Response ◽  
Gram Negative Bacteria ◽  
Gram Negative

Lipopolysaccharide: a tool and target in enterobacterial vaccine development

2008 ◽  
Vol 389 (5) ◽  
Author(s):  
Gábor Nagy ◽  
Tibor Pál
Keyword(s):  
Immune Response ◽  
Protective Immunity ◽  
Vaccine Development ◽  
The Other ◽  
Live Vaccine Strain ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Vaccination Strategies ◽  
Optimal Balance ◽  
Alternative Approaches

AbstractLipopolysaccharide (LPS) is an essential component of Gram-negative bacteria. While mutants exhibiting truncated LPS molecules are usually over-attenuated, alternative approaches that affect the extent or timing of LPS expression, as well as its modification may establish the optimal balance for a live vaccine strain of sufficient attenuation and retained immunogenicity. On the other hand, a specific immune response to LPS molecules in itself is capable of conferring protective immunity to certain enterobacterial pathogens. Therefore, purified LPS derivatives could be used as parenteral vaccines. This review summarizes various LPS-based vaccination strategies, as well as approaches that utilize LPS mutants as whole-cell vaccines.

scholarly journals The Drosophila Inhibitor of Apoptosis Protein DIAP2 Functions in Innate Immunity and Is Essential To Resist Gram-Negative Bacterial Infection

2006 ◽  
Vol 26 (21) ◽  
pp. 7821-7831 ◽  
Author(s):  
François Leulier ◽  
Nouara Lhocine ◽  
Bruno Lemaitre ◽  
Pascal Meier
Keyword(s):  
Immune Response ◽  
Bacterial Infection ◽  
Null Alleles ◽  
Signaling Cascade ◽  
Inhibitor Of Apoptosis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Inhibitor Of Apoptosis Protein ◽  
Apoptosis Protein

ABSTRACT The founding member of the inhibitor of apoptosis protein (IAP) family was originally identified as a cell death inhibitor. However, recent evidence suggests that IAPs are multifunctional signaling devices that influence diverse biological processes. To investigate the in vivo function of Drosophila melanogaster IAP2, we have generated diap2 null alleles. diap2 mutant animals develop normally and are fully viable, suggesting that diap2 is dispensable for proper development. However, these animals were acutely sensitive to infection by gram-negative bacteria. In Drosophila, infection by gram-negative bacteria triggers the innate immune response by activating the immune deficiency (imd) signaling cascade, a NF-κB-dependent pathway that shares striking similarities with the pathway of mammalian tumor necrosis factor receptor 1 (TNFR1). diap2 mutant flies failed to activate NF-κB-mediated expression of antibacterial peptide genes and, consequently, rapidly succumbed to bacterial infection. Our genetic epistasis analysis places diap2 downstream of or in parallel to imd, Dredd, Tak1, and Relish. Therefore, DIAP2 functions in the host immune response to gram-negative bacteria. In contrast, we find that the Drosophila TNFR-associated factor (Traf) family member Traf2 is dispensable in resistance to gram-negative bacterial infection. Taken together, our genetic data identify DIAP2 as an essential component of the Imd signaling cascade, protecting the organism from infiltrating microbes.

The Drosophila immune response against Gram-negative bacteria is mediated by a peptidoglycan recognition protein

Nature ◽  
2002 ◽  
Vol 416 (6881) ◽  
pp. 640-644 ◽  
Author(s):  
Marie Gottar ◽  
Vanessa Gobert ◽  
Tatiana Michel ◽  
Marcia Belvin ◽  
Geoffrey Duyk ◽  
...  
Keyword(s):  
Immune Response ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Peptidoglycan Recognition Protein ◽  
Recognition Protein

scholarly journals Immune Responses to Gram-Negative Bacteria in Hemolymph of the Chinese Horseshoe Crab, Tachypleus tridentatus

2021 ◽  
Vol 11 ◽  
Author(s):  
Wei-Feng Wang ◽  
Xiao-Yong Xie ◽  
Kang Chen ◽  
Xiu-Li Chen ◽  
Wei-Lin Zhu ◽  
...  
Keyword(s):  
Immune Response ◽  
Horseshoe Crab ◽  
Mapk Signaling ◽  
Innate Immune ◽  
Coagulation Cascade ◽  
Gram Negative Bacteria ◽  
Fossil Species ◽  
Living Fossil ◽  
Gram Negative ◽  
Tachypleus Tridentatus

Chinese horseshoe crab, Tachypleus tridentatus, is an ancient marine arthropod with a long evolutionary history. As a kind of living fossil species, the pathogen defenses of horseshoe crabs entirely depend on the innate immune system. Although, there are abundant immune molecules found in the horseshoe crab hemolymph, the biological mechanisms underlying their abilities of distinguishing and defending against invading microbes are still unclear. In this study, we used high-throughput sequencing at mRNA and protein levels and bioinformatics analysis methods to systematically analyze the innate immune response to Gram-negative bacteria in hemolymph of Chinese horseshoe crab. These results showed that many genes in the complement and coagulation cascades, Toll, NF-κB, C-type lectin receptor, JAK-STAT, and MAPK signaling pathways, and antimicrobial substances were activated at 12 and 24 h post-infection, suggesting that Gram-negative bacteria could activate the hemolymph coagulation cascade and antibacterial substances release via the above pathways. In addition, we conjectured that Toll and NF-κB signaling pathway were most likely to participate in the immune response to Gram-negative bacteria in hemolymph of horseshoe crab through an integral signal cascade. These findings will provide a useful reference for exploring the ancient original innate immune mechanism.

scholarly journals Exposure to the Gram-Negative Bacteria Pseudomonas aeruginosa Influences the Lung Dendritic Cell Population Signature by Interfering With CD103 Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Julyanne Brassard ◽  
Joanny Roy ◽  
Anne-Marie Lemay ◽  
Marie-Josée Beaulieu ◽  
Emilie Bernatchez ◽  
...  
Keyword(s):  
Immune Response ◽  
Pseudomonas Aeruginosa ◽  
Intracellular Localization ◽  
Receptor Internalization ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gm Csf ◽  
Dendritic Cell Population ◽  
The Impact

Lung dendritic cells (DCs) are divided into two major populations, which include CD103+XCR1+ cDC1s and CD11b+Sirpα+ cDC2s. The maintenance of their relative proportions is dynamic and lung inflammation, such as caused by exposure to lipopolysaccharide (LPS), a component of the outer membrane of Gram-negative bacteria, can have a significant impact on the local cDC signature. Alterations in the lung cDC signature could modify the capacity of the immune system to respond to various pathogens. We consequently aimed to assess the impact of the Gram-negative bacteria Pseudomonas aeruginosa on lung cDC1 and cDC2 populations, and to identify the mechanisms leading to alterations in cDC populations. We observed that exposure to P. aeruginosa decreased the proportions of CD103+XCR1+ cDC1s, while increasing that of CD11b+ DCs. We identified two potential mechanisms involved in this modulation of lung cDC populations. First, we observed an increase in bone marrow pre-DC IRF4 expression suggesting a higher propensity of pre-DCs to differentiate towards the cDC2 lineage. This observation was combined with a reduced capacity of lung XCR1+ DC1s to express CD103. In vitro, we demonstrated that GM-CSF-induced CD103 expression on cDCs depends on GM-CSF receptor internalization and RUNX1 activity. Furthermore, we observed that cDCs stimulation with LPS or P. aeruginosa reduced the proportions of intracellular GM-CSF receptor and decreased RUNX1 mRNA expression. Altogether, these results suggest that alterations in GM-CSF receptor intracellular localization and RUNX1 signaling could be involved in the reduced CD103 expression on cDC1 in response to P. aeruginosa. To verify whether the capacity of cDCs to express CD103 following P. aeruginosa exposure impacts the immune response, WT and Cd103-/- mice were exposed to P. aeruginosa. Lack of CD103 expression led to an increase in the number of neutrophils in the airways, suggesting that lack of CD103 expression on cDC1s could favor the innate immune response to this bacterium.

Blood leukocyte transcriptomes in gram-positive and gram-negative community-acquired pneumonia

2021 ◽  
pp. 2101856
Author(s):  
Liza Pereverzeva ◽  
Fabrice Uhel ◽  
Hessel Peters Sengers ◽  
Joe Butler ◽  
Lonneke A. van Vught ◽  
...  
Keyword(s):  
Immune Response ◽  
Host Response ◽  
Host Immune Response ◽  
Community Acquired Pneumonia ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Icu Admission ◽  
Blood Leukocyte ◽  
Response Biomarkers

BackgroundGram-positive and Gram-negative bacteria are the most common causative pathogens in community-acquired pneumonia (CAP) on the intensive care unit (ICU). The aim of this study was to determine whether the host immune response differs between Gram-positive and Gram-negative CAP upon ICU admission.MethodsSixteen host response biomarkers providing insight in pathophysiological mechanisms implicated in sepsis and blood leukocyte transcriptomes were analysed in patients with CAP upon ICU admission in two tertiary hospitals in the Netherlands.Results309 patients with CAP with a definite or probable likelihood (determined by predefined criteria) were included. A causative pathogen was determined in 74.4% of admissions. Patients admitted with Gram-positive CAP (n=90) were not different from those admitted with Gram-negative CAP (n=75) regarding demographics, chronic comorbidities, severity of disease and mortality. Host response biomarkers reflective of systemic inflammation, coagulation activation and endothelial cell function, as well as blood leukocytes transcriptomes, were largely similar between Gram-positive and Gram-negative CAP. Blood leukocyte transcriptomes were also similar in Gram-positive and Gram-negative CAP in two independent validation cohorts. On a pathogen-specific level, Streptococcus pneumoniae and Escherichia coli induced the most distinct host immune response.ConclusionOutcome and host response are similar in critically ill patients with CAP due to Gram-positive bacteria compared to Gram-negative bacteria.

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