Faculty Opinions recommendation of Brassinosteroids modulate the efficiency of plant immune responses to microbe-associated molecular patterns.

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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Biomarkers of Radiotherapy-Induced Immunogenic Cell Death

Cells ◽

10.3390/cells10040930 ◽

2021 ◽

Vol 10 (4) ◽

pp. 930

Author(s):

Rianne D. W. Vaes ◽

Lizza E. L. Hendriks ◽

Marc Vooijs ◽

Dirk De Ruysscher

Keyword(s):

Cell Death ◽

Immune Responses ◽

Tumor Cells ◽

Immunogenic Cell Death ◽

Type I ◽

Future Studies ◽

Regulated Cell Death ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns ◽

Potential Biomarkers

Radiation therapy (RT) can induce an immunogenic variant of regulated cell death that can initiate clinically relevant tumor-targeting immune responses. Immunogenic cell death (ICD) is accompanied by the exposure and release of damage-associated molecular patterns (DAMPs), chemokine release, and stimulation of type I interferon (IFN-I) responses. In recent years, intensive research has unraveled major mechanistic aspects of RT-induced ICD and has resulted in the identification of immunogenic factors that are released by irradiated tumor cells. However, so far, only a limited number of studies have searched for potential biomarkers that can be used to predict if irradiated tumor cells undergo ICD that can elicit an effective immunogenic anti-tumor response. In this article, we summarize the available literature on potential biomarkers of RT-induced ICD that have been evaluated in cancer patients. Additionally, we discuss the clinical relevance of these findings and important aspects that should be considered in future studies.

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TLR4 regulates rabies virus-induced humoral immunity through recruitment of cDC2 to lymph organs

Journal of Virology ◽

10.1128/jvi.00829-21 ◽

2021 ◽

Author(s):

Chen Chen ◽

Chengguang Zhang ◽

Haoqi Li ◽

Zongmei Wang ◽

Yueming Yuan ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Rabies Virus ◽

Humoral Immunity ◽

Humoral Immune Response ◽

Critical Role ◽

Wild Type ◽

Humoral Immune ◽

Specific Igg ◽

Molecular Patterns

Rabies, caused by rabies virus (RABV), is fatal to both humans and animals around the world. Effective clinical therapy for rabies has not been achieved, and vaccination is the most effective means of preventing and controlling rabies. Although different vaccines, such as live attenuated and inactivated vaccines, can induce different immune responses, different expression of pattern recognition receptors (PRRs) also causes diverse immune responses. Toll-like receptor 4 (TLR4) is a pivotal PRR that induces cytokine production and bridges innate and adaptive immunity. Importantly, TLR4 recognizes various virus-derived pathogen-associated molecular patterns (PAMPs) and virus-induced damage-associated molecular patterns (DAMPs), usually leading to the activation of immune cells. However, the role of TLR4 in the humoral immune response induced by RABV has not been revealed yet. Based on TLR4-deficient ( TLR4 -/- ) and wild-type (WT) mouse models, we report that TLR4-dependent recruitment of the conventional type-2 dendritic cells (CD8α - CD11b + cDC2) into secondary lymph organs (SLOs) is critical for antigen presentation. cDC2-initiated differentiation of Tfh cells promotes the proliferation of germinal centre (GC) B cells, the formation of GCs, and the production of plasma cells (PCs), all of which contribute to the production of RABV-specific IgG and virus-neutralizing antibodies (VNAs). Collectively, our work demonstrates that TLR4 is necessary for the recruitment of cDC2 and for the induction of RABV-induced humoral immunity, which is regulated by the cDC2-Tfh-GC B axis. IMPORTANCE Vaccination is the most efficient method to prevent rabies. TLR4, a well-known immune sensor, plays a critical role in initiating innate immune response. Here, we found that TLR4 deficiency ( TLR4 -/- ) mice suppressed the induction of humoral immune response after immunization with rabies virus (RABV), including reduced production of VNAs and RABV-specific IgG, compared with that occurred in wild-type (WT) mice. As a consequence, TLR4 -/- mice exhibited higher mortality than WT mice after challenge with virulent RABV. Importantly, further investigation found that TLR4 signaling promoted the recruitment of cDC2 (CD8α + CD11b - ), a subset of cDCs known to induce CD4 + T cell immunity through their MHC-II presentation machinery. Our results imply that TLR4 is indispensable for an efficient humoral response to rabies vaccine, which provides new insight into the development of novel rabies vaccines.

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

European Journal of Pharmacology ◽

10.1016/j.ejphar.2016.11.013 ◽

2017 ◽

Vol 808 ◽

pp. 8-13 ◽

Cited By ~ 23

Author(s):

Mehdi Taghavi ◽

Alireza Khosravi ◽

Esmaeil Mortaz ◽

Donya Nikaein ◽

Seyyed Shamsadin Athari

Keyword(s):

Immune Responses ◽

Fungal Infections ◽

Molecular Patterns

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Divergent Evolution of PcF/SCR74 Effectors in Oomycetes Is Associated with Distinct Recognition Patterns in Solanaceous Plants

mBio ◽

10.1128/mbio.00947-20 ◽

2020 ◽

Vol 11 (3) ◽

Author(s):

Xiao Lin ◽

Shumei Wang ◽

Laura de Rond ◽

Nicoletta Bertolin ◽

Roland H. M. Wouters ◽

...

Keyword(s):

Disease Resistance ◽

Cell Surface ◽

Immune Responses ◽

Arms Race ◽

Wild Potato ◽

Content Type ◽

Surface Receptors ◽

Molecular Patterns ◽

Solanaceous Plants ◽

Coevolutionary Arms Race

ABSTRACT Plants deploy cell surface receptors known as pattern-recognition receptors (PRRs) that recognize non-self molecules from pathogens and microbes to defend against invaders. PRRs typically recognize microbe-associated molecular patterns (MAMPs) that are usually widely conserved, some even across kingdoms. Here, we report an oomycete-specific family of small secreted cysteine-rich (SCR) proteins that displays divergent patterns of sequence variation in the Irish potato famine pathogen Phytophthora infestans. A subclass that includes the conserved effector PcF from Phytophthora cactorum activates immunity in a wide range of plant species. In contrast, the more diverse SCR74 subclass is specific to P. infestans and tends to trigger immune responses only in a limited number of wild potato genotypes. The SCR74 response was recently mapped to a G-type lectin receptor kinase (G-LecRK) locus in the wild potato Solanum microdontum subsp. gigantophyllum. The G-LecRK locus displays a high diversity in Solanum host species compared to other solanaceous plants. We propose that the diversification of the SCR74 proteins in P. infestans is driven by a fast coevolutionary arms race with cell surface immune receptors in wild potato, which contrasts the presumed slower dynamics between conserved apoplastic effectors and PRRs. Understanding the molecular determinants of plant immune responses to these divergent molecular patterns in oomycetes is expected to contribute to deploying multiple layers of disease resistance in crop plants. IMPORTANCE Immune receptors at the plant cell surface can recognize invading microbes. The perceived microbial molecules are typically widely conserved and therefore the matching surface receptors can detect a broad spectrum of pathogens. Here we describe a family of Phytophthora small extracellular proteins that consists of conserved subfamilies that are widely recognized by solanaceous plants. Remarkably, one subclass of SCR74 proteins is highly diverse, restricted to the late blight pathogen Phytophthora infestans and is specifically detected in wild potato plants. The diversification of this subfamily exhibits signatures of a coevolutionary arms race with surface receptors in potato. Insights into the molecular interaction between these potato-specific receptors and the recognized Phytophthora proteins are expected to contribute to disease resistance breeding in potato.

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Overexpression of OsPUB41, a Rice E3 ubiquitin ligase induced by cell wall degrading enzymes, enhances immune responses in Rice and Arabidopsis

BMC Plant Biology ◽

10.1186/s12870-019-2079-1 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 1

Author(s):

Neha Rajendra Kachewar ◽

Vishal Gupta ◽

Ashish Ranjan ◽

Hitendra Kumar Patel ◽

Ramesh V. Sonti

Keyword(s):

Cell Wall ◽

Immune Responses ◽

Ubiquitin Ligase ◽

Ectopic Expression ◽

E3 Ubiquitin Ligase ◽

Defense Responses ◽

Cell Wall Degrading Enzymes ◽

Degrading Enzymes ◽

Transient Overexpression ◽

Molecular Patterns

Abstract Background Cell wall degrading enzymes (CWDEs) induce plant immune responses and E3 ubiquitin ligases are known to play important roles in regulating plant defenses. Expression of the rice E3 ubiquitin ligase, OsPUB41, is enhanced upon treatment of leaves with Xanthomonas oryzae pv. oryzae (Xoo) secreted CWDEs such as Cellulase and Lipase/Esterase. However, it is not reported to have a role in elicitation of immune responses. Results Expression of the rice E3 ubiquitin ligase, OsPUB41, is induced when rice leaves are treated with either CWDEs, pathogen associated molecular patterns (PAMPs), damage associated molecular patterns (DAMPs) or pathogens. Overexpression of OsPUB41 leads to induction of callose deposition, enhanced tolerance to Xoo and Rhizoctonia solani infection in rice and Arabidopsis respectively. In rice, transient overexpression of OsPUB41 leads to enhanced expression of PR genes and SA as well as JA biosynthetic and response genes. However, in Arabidopsis, ectopic expression of OsPUB41 results in upregulation of only JA biosynthetic and response genes. Transient overexpression of either of the two biochemically inactive mutants (OsPUB41C40A and OsPUB41V51R) of OsPUB41 in rice and stable transgenics in Arabidopsis ectopically expressing OsPUB41C40A failed to elicit immune responses. This indicates that the E3 ligase activity of OsPUB41 protein is essential for induction of plant defense responses. Conclusion The results presented here suggest that OsPUB41 is possibly involved in elicitation of CWDE triggered immune responses in rice.

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Broad-Spectrum Disease Resistance Conferred by the Overexpression of Rice RLCK BSR1 Results from an Enhanced Immune Response to Multiple MAMPs

International Journal of Molecular Sciences ◽

10.3390/ijms20225523 ◽

2019 ◽

Vol 20 (22) ◽

pp. 5523 ◽

Cited By ~ 1

Author(s):

Yasukazu Kanda ◽

Hitoshi Nakagawa ◽

Yoko Nishizawa ◽

Takashi Kamakura ◽

Masaki Mori

Keyword(s):

Disease Resistance ◽

Immune Responses ◽

Broad Spectrum ◽

Transcriptional Activation ◽

Intracellular Signaling ◽

Cultured Cells ◽

Plant Immunity ◽

Production Of Hydrogen ◽

Defense Related Gene ◽

Molecular Patterns

Plants activate their immune system through intracellular signaling pathways after perceiving microbe-associated molecular patterns (MAMPs). Receptor-like cytoplasmic kinases mediate the intracellular signaling downstream of pattern-recognition receptors. BROAD-SPECTRUM RESISTANCE 1 (BSR1), a rice (Oryza sativa) receptor-like cytoplasmic kinase subfamily-VII protein, contributes to chitin-triggered immune responses. It is valuable for agriculture because its overexpression confers strong disease resistance to fungal and bacterial pathogens. However, it remains unclear how overexpressed BSR1 reinforces plant immunity. Here we analyzed immune responses using rice suspension-cultured cells and sliced leaf blades overexpressing BSR1. BSR1 overexpression enhances MAMP-triggered production of hydrogen peroxide (H2O2) and transcriptional activation of the defense-related gene in cultured cells and leaf strips. Furthermore, the co-cultivation of leaves with conidia of the blast fungus revealed that BSR1 overexpression allowed host plants to produce detectable oxidative bursts against compatible pathogens. BSR1 was also involved in the immune responses triggered by peptidoglycan and lipopolysaccharide. Thus, we concluded that the hyperactivation of MAMP-triggered immune responses confers BSR1-mediated robust resistance to broad-spectrum pathogens.

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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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Comparison of Two Mice Strains, A/J and C57BL/6, in Caspase-1 Activity and IL-1βSecretion of Macrophage toMycobacterium lepraeInfection

Mediators of Inflammation ◽

10.1155/2010/708713 ◽

2010 ◽

Vol 2010 ◽

pp. 1-5 ◽

Cited By ~ 6

Author(s):

Tae Jin Kang ◽

Geum Seon Lee ◽

Se Kon Kim ◽

Song Hou Jin ◽

Gue Tae Chae

Keyword(s):

Immune Response ◽

Amino Acid ◽

Immune Responses ◽

Innate Immune Response ◽

Mycobacterium Leprae ◽

Adaptor Proteins ◽

Innate Immune ◽

Intracellular Pathogens ◽

Caspase 1 ◽

Molecular Patterns

A/J mice were found to have amino acid differences in Naip5, one of the NOD-like receptors (NLRs) involved in the cytosolic recognition of pathogen-associated molecular patterns and one of the adaptor proteins for caspase-1 activation. This defect was associated with a susceptibility toLegionellainfection, suggesting an important role for Naip5 in the immune response also to other intracellular pathogens, such asMycobacterium leprae. In this study, the immune responses of macrophages from A/J mice againstM. lepraewere compared to those of macrophages from C57BL/6 mice. Infection withM. lepraeinduced high levels of TNF-αproduction and NF-κB activation in A/J and C57BL/6 macrophages. Caspase-1 activation and IL-1βsecretion were also induced in both macrophages. However, macrophages from A/J mice exhibited reduced caspase-1 activation and IL-1βsecretion compared to C57BL/6 macrophages. These results suggest that NLR family proteins may have a role in the innate immune response toM. leprae.

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