Role of pathogen-associated molecular patterns (PAMPS) in immune responses to fungal infections

The role of immune cells associated with sporotrichosis caused by Sporothrix schenckii is not yet fully clarified. Macrophages through pattern recognition receptors (PRRs) can recognize pathogen-associated molecular patterns (PAMPs) of Sporothrix, engulf it, activate respiratory burst, and secrete pro-inflammatory or anti-inflammatory biological mediators to control infection. It is important to consider that the characteristics associated with S. schenckii and/or the host may influence macrophage polarization (M1/M2), cell recruitment, and the type of immune response (1, 2, and 17). Currently, with the use of new monocyte-macrophage cell lines, it is possible to evaluate different host–pathogen interaction processes, which allows for the proposal of new mechanisms in human sporotrichosis. Therefore, in order to contribute to the understanding of these host–pathogen interactions, the aim of this review is to summarize and discuss the immune responses induced by macrophage-S. schenckii interactions, as well as the PRRs and PAMPs involved during the recognition of S. schenckii that favor the immune evasion by the fungus.

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TmSpz4 Plays an Important Role in Regulating the Production of Antimicrobial Peptides in Response to Escherichia coli and Candida albicans Infections

International Journal of Molecular Sciences ◽

10.3390/ijms21051878 ◽

2020 ◽

Vol 21 (5) ◽

pp. 1878 ◽

Cited By ~ 2

Author(s):

Tariku Tesfaye Edosa ◽

Yong Hun Jo ◽

Maryam Keshavarz ◽

Young Min Bae ◽

Dong Hyun Kim ◽

...

Keyword(s):

Escherichia Coli ◽

Candida Albicans ◽

Immune Responses ◽

Fungal Infections ◽

Larval Survival ◽

Gram Negative Bacteria ◽

Functional Importance ◽

E Coli ◽

Microbial Infections

Spätzle family proteins activate the Toll pathway and induce antimicrobial peptide (AMP) production against microbial infections. However, the functional importance of Tmspätzle4 (TmSpz4) in the immune response of Tenebrio molitor has not been reported. Therefore, here, we have identified and functionally characterized the role of TmSpz4 against bacterial and fungal infections. We showed that TmSpz4 expression was significantly induced in hemocytes at 6 h post-injection with Escherichia coli, Staphylococcus aureus, and Candida albicans. TmSpz4 knock-down significantly reduced larval survival against E. coli and C. albicans. To understand the reason for the survivability difference, the role of TmSpz4 in AMP production was examined in TmSpz4-silenced larvae following microbe injection. The AMPs that are active against Gram-negative bacteria, including TmTenecin-2, TmTenecin-4, TmAttacin-1a, TmDefensin-2, and TmCecropin-2, were significantly downregulated in response to E. coli in TmSpz4-silenced larvae. Similarly, the expression of TmTenecin-1, TmTenecin-3, TmThaumatin-like protein-1 and -2, TmDefensin-1, TmDefensin-2, and TmCecropin-2 were downregulated in response to C. albicans in TmSpz4-silenced larvae. In addition, the transcription factor NF-κB (TmDorX1 and TmDorX2) expression was significantly suppression in TmSpz4-silenced larvae. In conclusion, these results suggest that TmSpz4 plays a key role in regulating immune responses of T. molitor against to E. coli and C. albicans.

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The Role of Peptide Signals Hidden in the Structure of Functional Proteins in Plant Immune Responses

International Journal of Molecular Sciences ◽

10.3390/ijms20184343 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4343 ◽

Cited By ~ 3

Author(s):

Irina Lyapina ◽

Anna Filippova ◽

Igor Fesenko

Keyword(s):

Immune Responses ◽

Defense Responses ◽

Innate Immune ◽

Functional Protein ◽

Diverse Range ◽

Peptide Signals ◽

Plant Pathogen Interactions ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns

Plants have evolved a sophisticated innate immune system to cope with a diverse range of phytopathogens and insect herbivores. Plasma-membrane-localized pattern recognition receptors (PRRs), such as receptor-like kinases (RLK), recognize special signals, pathogen- or damage-associated molecular patterns (PAMPs or DAMPs), and trigger immune responses. A growing body of evidence shows that many peptides hidden in both plant and pathogen functional protein sequences belong to the group of such immune signals. However, the origin, evolution, and release mechanisms of peptide sequences from functional and nonfunctional protein precursors, known as cryptic peptides, are largely unknown. Various special proteases, such as metacaspase or subtilisin-like proteases, are involved in the release of such peptides upon activation during defense responses. In this review, we discuss the roles of cryptic peptide sequences hidden in the structure of functional proteins in plant defense and plant-pathogen interactions.

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SPINK7 Recognizes Fungi and Initiates Hemocyte-Mediated Immune Defense Against Fungal Infections

Frontiers in Immunology ◽

10.3389/fimmu.2021.735497 ◽

2021 ◽

Vol 12 ◽

Author(s):

Zhaoming Dong ◽

Lingna An ◽

Mengyao Lu ◽

Muya Tang ◽

Haiqin Chen ◽

...

Keyword(s):

Fungal Infections ◽

Fungal Spores ◽

Immune Defense ◽

Proteinase K ◽

Binding Assays ◽

Activity Inhibition ◽

Agarose Beads ◽

Molecular Patterns

Serine protease inhibitors of Kazal-type (SPINKs) were widely identified in vertebrates and invertebrates, and played regulatory roles in digestion, coagulation, and fibrinolysis. In this study, we reported the important role of SPINK7 in regulating immune defense of silkworm, Bombyx mori. SPINK7 contains three Kazal domains and has 6 conserved cysteine residues in each domain. Quantitative real-time PCR analyses revealed that SPINK7 was exclusively expressed in hemocytes and was upregulated after infection with two fungi, Saccharomyces cerevisiae and Candida albicans. Enzyme activity inhibition test showed that SPINK7 significantly inhibited the activity of proteinase K from C. albicans. Additionally, SPINK7 inhibited the growth of three fungal spores, including S. cerevisiae, C. albicans, and Beauveria bassiana. The pathogen-associated molecular patterns (PAMP) binding assays suggested that SPINK7 could bind to β-D-glucan and agglutinate B. bassiana and C. albicans. In vitro assays were performed using SPINK7-coated agarose beads, and indicated that SPINK7 promoted encapsulation and melanization of agarose beads by B. mori hemocytes. Furthermore, co-localization studies using immunofluorescence revealed that SPINK7 induced hemocytes to aggregate and entrap the fungi spores of B. bassiana and C. albicans. Our study revealed that SPINK7 could recognize fungal PAMP and induce the aggregation, melanization, and encapsulation of hemocytes, and provided valuable clues for understanding the innate immunity and cellular immunity in insects.

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The Immune Response toTrypanosoma cruzi: Role of Toll-Like Receptors and Perspectives for Vaccine Development

Journal of Parasitology Research ◽

10.1155/2012/507874 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 47

Author(s):

Mauricio M. Rodrigues ◽

Ana Carolina Oliveira ◽

Maria Bellio

Keyword(s):

Immune Response ◽

Immune Responses ◽

Vaccine Development ◽

State Of The Art ◽

Toll Like Receptor ◽

Vaccine Research ◽

The Past ◽

Acquired Immune Responses ◽

Molecular Patterns

In the past ten years, studies have shown the recognition ofTrypanosoma cruzi-associated molecular patterns by members of the Toll-like receptor (TLR) family and demonstrated the crucial participation of different TLRs during the experimental infection with this parasite. In the present review, we will focus on the role of TLR-activated pathways in the modulation of both innate and acquired immune responses toT. cruziinfection, as well as discuss the state of the art of vaccine research and development against the causative agent of Chagas disease (or American trypanosomiasis).

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Role of Damage-Associated Molecular Pattern/Cell Death Pathways in Vaccine-Induced Immunity

Viruses ◽

10.3390/v13122340 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2340

Author(s):

Sun Min Lee ◽

Paul Kim ◽

Jinsuh You ◽

Eui Ho Kim

Keyword(s):

Cell Death ◽

Immune Responses ◽

Natural Infection ◽

Cell Death Pathways ◽

Molecular Pattern ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns ◽

Induced Immunity ◽

Pathogenic Infection

Immune responses induced by natural infection and vaccination are known to be initiated by the recognition of microbial patterns by cognate receptors, since microbes and most vaccine components contain pathogen-associated molecular patterns. Recent discoveries on the roles of damage-associated molecular patterns (DAMPs) and cell death in immunogenicity have improved our understanding of the mechanism underlying vaccine-induced immunity. DAMPs are usually immunologically inert, but can transform into alarming signals to activate the resting immune system in response to pathogenic infection, cellular stress and death, or tissue damage. The activation of DAMPs and cell death pathways can trigger local inflammation, occasionally mediating adaptive immunity, including antibody- and cell-mediated immune responses. Emerging evidence indicates that the components of vaccines and adjuvants induce immunogenicity via the stimulation of DAMP/cell death pathways. Furthermore, strategies for targeting this pathway to enhance immunogenicity are being investigated actively. In this review, we describe various DAMPs and focus on the roles of DAMP/cell death pathways in the context of vaccines for infectious diseases and cancer.

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The Role of B-Cells and Antibodies against Candida Vaccine Antigens in Invasive Candidiasis

Vaccines ◽

10.3390/vaccines9101159 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1159

Author(s):

Manisha Shukla ◽

Pankaj Chandley ◽

Soma Rohatgi

Keyword(s):

Monoclonal Antibodies ◽

B Cells ◽

Immune Responses ◽

Fungal Infections ◽

Systemic Candidiasis ◽

Single Chain ◽

Biofilm Inhibition ◽

Vaccine Candidates ◽

Recent Emergence

Systemic candidiasis is an invasive fungal infection caused by members of the genus Candida. The recent emergence of antifungal drug resistance and increased incidences of infections caused by non-albicans Candida species merit the need for developing immune therapies against Candida infections. Although the role of cellular immune responses in anti-Candida immunity is well established, less is known about the role of humoral immunity against systemic candidiasis. This review summarizes currently available information on humoral immune responses induced by several promising Candida vaccine candidates, which have been identified in the past few decades. The protective antibody and B-cell responses generated by polysaccharide antigens such as mannan, β-glucan, and laminarin, as well as protein antigens like agglutinin-like sequence gene (Als3), secreted aspartyl proteinase (Sap2), heat shock protein (Hsp90), hyphally-regulated protein (Hyr1), hyphal wall protein (Hwp1), enolase (Eno), phospholipase (PLB), pyruvate kinase (Pk), fructose bisphosphate aldolase (Fba1), superoxide dismutase gene (Sod5) and malate dehydrogenase (Mdh1), are outlined. As per studies reviewed, antibodies induced in response to leading Candida vaccine candidates contribute to protection against systemic candidiasis by utilizing a variety of mechanisms such as opsonization, complement fixation, neutralization, biofilm inhibition, direct candidacidal activity, etc. The contributions of B-cells in controlling fungal infections are also discussed. Promising results using anti-Candida monoclonal antibodies for passive antibody therapy reinforces the need for developing antibody-based therapeutics including anti-idiotypic antibodies, single-chain variable fragments, peptide mimotopes, and antibody-derived peptides. Future research involving combinatorial immunotherapies using humanized monoclonal antibodies along with antifungal drugs/cytokines may prove beneficial for treating invasive fungal infections.

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The Role of IL-36 in Infectious Diseases: Potential Target for COVID-19?

Frontiers in Immunology ◽

10.3389/fimmu.2021.662266 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xiaofang Wang ◽

Panpan Yi ◽

Yuejin Liang

Keyword(s):

Infectious Diseases ◽

Immune Responses ◽

Lupus Erythematosus ◽

Fungal Infections ◽

Inflammatory Diseases ◽

Interleukin 1 ◽

Functional Roles ◽

Cellular Expression ◽

Inflammatory Bowel

IL-36 is a member of the interleukin 1 cytokine family, which is currently experiencing a renaissance due to the growing understanding of its context-dependent roles and advances in our understanding of the inflammatory response. The immunological role of IL-36 has revealed its profound and indispensable functional roles in psoriasis, as well as in several inflammatory diseases, including inflammatory bowel disease (IBD), systemic lupus erythematosus, rheumatoid arthritis (RA) and cancer. More recently, an increasing body of evidence suggests that IL-36 plays a crucial role in viral, bacterial and fungal infections. There is a growing interest as to whether IL-36 contributes to host protective immune responses against infection as well as the potential implications of IL-36 for the development of new therapeutic strategies. In this review, we summarize the recent progress in understanding cellular expression, regulatory mechanisms and biological roles of IL-36 in infectious diseases, which suggest more specific strategies to maneuver IL-36 as a diagnostic or therapeutic target, especially in COVID-19.

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The Role of Toll-Like Receptor Signaling in the Progression of Heart Failure

Mediators of Inflammation ◽

10.1155/2018/9874109 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 17

Author(s):

Lili Yu ◽

Zhiwei Feng

Keyword(s):

Heart Failure ◽

Immune Responses ◽

Target Therapy ◽

Innate Immune ◽

Innate Immune Responses ◽

Medical Systems ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns ◽

Tlr Signaling Pathway

Medical systems worldwide are being faced with a growing need to understand mechanisms behind the pathogenesis of heart failure (HF) that is considered as a leading cause of morbidity and mortality around the world. Elevated levels of inflammatory mediators have been identified in patients with HF, which are primarily manifestations of innate immune responses mediated by pattern recognition receptors (PRRs). Toll-like receptors (TLRs), which belong to PRRs, are subjected to the release of pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) to generate innate immune responses. More and more emerging data indicate that TLR signaling pathway molecules are involved in the progression of HF. Herein, we present new data with regard to the activation of TLRs in the failing heart, focusing on TLR2, TLR3, TLR4, and TLR9, and suggest the potential use of TLRs in target therapy.

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A receptor-like protein mediates plant immune responses to herbivore-associated molecular patterns

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2018415117 ◽

2020 ◽

Vol 117 (49) ◽

pp. 31510-31518 ◽

Cited By ~ 1

Author(s):

Adam D. Steinbrenner ◽

Maria Muñoz-Amatriaín ◽

Antonio F. Chaparro ◽

Jessica Montserrat Aguilar-Venegas ◽

Sassoum Lo ◽

...

Keyword(s):

Immune Responses ◽

Spodoptera Exigua ◽

Plant Responses ◽

Food Crops ◽

Agricultural Crop ◽

Leucine Rich Repeat ◽

Induced Plant Responses ◽

Molecular Patterns ◽

Global Food

Herbivory is fundamental to the regulation of both global food webs and the extent of agricultural crop losses. Induced plant responses to herbivores promote resistance and often involve the perception of specific herbivore-associated molecular patterns (HAMPs); however, precisely defined receptors and elicitors associated with herbivore recognition remain elusive. Here, we show that a receptor confers signaling and defense outputs in response to a defined HAMP common in caterpillar oral secretions (OS). Staple food crops, including cowpea (Vigna unguiculata) and common bean (Phaseolus vulgaris), specifically respond to OS via recognition of proteolytic fragments of chloroplastic ATP synthase, termed inceptins. Using forward-genetic mapping of inceptin-induced plant responses, we identified a corresponding leucine-rich repeat receptor, termed INR, specific to select legume species and sufficient to confer inceptin-induced responses and enhanced defense against armyworms (Spodoptera exigua) in tobacco. Our results support the role of plant immune receptors in the perception of chewing herbivores and defense.

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