Decoding the patterns of self and nonself by the innate immune system

Lectin Receptor-like Kinase Signaling during Engineered Ectomycorrhiza Colonization

Mutualistic association can improve a plant’s health and productivity. G-type lectin receptor-like kinase (PtLecRLK1) is a susceptibility factor in Populus trichocarpa that permits root colonization by a beneficial fungus, Laccaria bicolor. Engineering PtLecRLK1 also permits L. bicolor root colonization in non-host plants similar to Populus trichocarpa. The intracellular signaling reprogramed by PtLecRLK1 upon recognition of L. bicolor to allow for the development and maintenance of symbiosis is yet to be determined. In this study, phosphoproteomics was utilized to identify phosphorylation-based relevant signaling pathways associated with PtLecRLK1 recognition of L. bicolor in transgenic switchgrass roots. Our finding shows that PtLecRLK1 in transgenic plants modifies the chitin-triggered plant defense and MAPK signaling along with a significant adjustment in phytohormone signaling, ROS balance, endocytosis, cytoskeleton movement, and proteasomal degradation in order to facilitate the establishment and maintenance of L. bicolor colonization. Moreover, protein–protein interaction data implicate a cGMP-dependent protein kinase as a potential substrate of PtLecRLK1.

Broccoli seed extract rich in polysaccharides and glucoraphanin ameliorates DSS-induced colitis via intestinal barrier protection and gut microbiota modulation in mice

BACKGROUND

Broccoli has received widespread attention because of its anti-inflammatory and antioxidant effects. The present study aimed to explore the composition of broccoli seed extract (BSE) and its effect on colitis induced by dextran sulfate sodium (DSS).

RESULTS

BSE mainly comprises glucoraphanin and polysaccharides composed of arabinose, galactose, glucose and mannose. Animal experiments suggested that BSE intervention effectively reversed body weight loss, suppressed the levels of proinflammatory interleukin-6, tumor necrosis factor-α and interleukin-1β, and elevated the levels of anti-inflammatory interleukin-10 and the activities of superoxide dismutase and glutathione in DSS-induced colitis mice. According to histopathologic and immunohistochemical analysis of colon tissue, BSE intervention may repair the intestinal barrier by upregulating mRNA levels and the expression of tight junction proteins (claudin-1, occludin and zonula occludens-1). Gas chromatography-mass spectrometry (MS) analysis demonstrated that cecal short-chain fatty acids in mice with BSE administration were significantly increased compared with the model group. Sulforaphane and sulforaphane-N-acetylcysteine were only detected in BSE group mice by ultra-performance liquid chromatography-MS analysis. In addition, BSE intervention evidently increased the abundance of Alistipeds, Coriobacteriaceae UCG-002 and Bifidobacterium and decreased the abundance of Escheichia-Shinella, Lachnospiraceae others, Parabacteroides, Ruminococcaceae others and Turicibacter, which possibly promoted carbohydrate metabolism and short-chain fatty acid production.

CONCLUSION

The present study aimed to elucidate the effect of BSE on colitis and found that BSE, as a novel food ingredient, has great potential for the improvement of colitis. © 2022 Society of Chemical Industry.

"Just right" combinations of adjuvants with nanoscale carriers activate aged dendritic cells without overt inflammation

BACKGROUND

The loss in age-related immunological markers, known as immunosenescence, is caused by a combination of factors, one of which is inflammaging. Inflammaging is associated with the continuous basal generation of proinflammatory cytokines. Studies have demonstrated that inflammaging reduces the effectiveness of vaccines. Strategies aimed at modifying baseline inflammation are being developed to improve vaccination responses in older adults. Dendritic cells have attracted attention as an age-specific target because of their significance in immunization as antigen presenting cells that stimulate T lymphocytes.

RESULTS

In this study, bone marrow derived dendritic cells (BMDCs) were generated from aged mice and used to investigate the effects of combinations of adjuvants, including Toll-like receptor, NOD2, and STING agonists with polyanhydride nanoparticles and pentablock copolymer micelles under in vitro conditions. Cellular stimulation was characterized via expression of costimulatory molecules, T cell-activating cytokines, proinflammatory cytokines, and chemokines. Our results indicate that multiple TLR agonists substantially increase costimulatory molecule expression and cytokines associated with T cell activation and inflammation in culture. In contrast, NOD2 and STING agonists had only a moderate effect on BMDC activation, while nanoparticles and micelles had no effect by themselves. However, when nanoparticles and micelles were combined with a TLR9 agonist, a reduction in the production of proinflammatory cytokines was observed while maintaining increased production of T cell activating cytokines and enhancing cell surface marker expression. Additionally, combining nanoparticles and micelles with a STING agonist resulted in a synergistic impact on the upregulation of costimulatory molecules and an increase in cytokine secretion from BMDCs linked with T cell activation without excessive secretion of proinflammatory cytokines.

CONCLUSIONS

These studies provide new insights into rational adjuvant selection for vaccines for older adults. Combining appropriate adjuvants with nanoparticles and micelles may lead to balanced immune activation characterized by low inflammation, setting the stage for designing next generation vaccines that can induce mucosal immunity in older adults.

Cancer-specific tissue-resident memory T-cells express ZNF683 in colorectal cancer

BACKGROUND

Tissue-resident memory T (Trm) cells are associated with cytotoxicity not only in viral infection and autoimmune disease pathologies but also in many cancers. Tumour-infiltrating CD103⁺ Trm cells predominantly comprise CD8 T cells that express cytotoxic activation and immune checkpoint molecules called exhausted markers. This study aimed to investigate the role of Trm in colorectal cancer (CRC) and characterise the cancer-specific Trm.

METHODS

Immunochemical staining with anti-CD8 and anti-CD103 antibodies for resected CRC tissues was used to identify the tumour-infiltrating Trm cells. The Kaplan-Meier estimator was used to evaluate the prognostic significance. Cells immune to CRC were targeted for single-cell RNA-seq analysis to characterise cancer-specific Trm cells in CRC.

RESULTS

The number of CD103⁺/CD8⁺ tumour-infiltrating lymphocytes (TILs) was a favourable prognostic and predictive factor of the overall survival and recurrence-free survival in patients with CRC. Single-cell RNA-seq analysis of 17,257 CRC-infiltrating immune cells revealed a more increased zinc finger protein 683 (ZNF683) expression in cancer Trm cells than in noncancer Trm cells and in high-infiltrating Trm cells than low-infiltrating Trm in cancer, with an upregulated T-cell receptor (TCR)- and interferon-γ (IFN-γ) signalling-related gene expression in ZNF683⁺ Trm cells.

CONCLUSIONS

The number of CD103⁺/CD8⁺ TILs is a prognostic predictive factor in CRC. In addition, we identified the ZNF683 expression as one of the candidate markers of cancer-specific Trm cells. IFN-γ and TCR signalling and ZNF683 expression are involved in Trm cell activation in tumours and are promising targets for cancer immunity regulation.

Mating-Induced Common and Sex-Specific Behavioral, Transcriptional Changes in the Moth Fall Armyworm (Spodoptera frugiperda, Noctuidae, Lepidoptera) in Laboratory

The intermediate process between mating and postmating behavioral changes in insects is still poorly known. Here, we studied mating-induced common and sex-specific behavioral and transcriptional changes in both sexes of Spodoptera frugiperda and tested whether the transcriptional changes are linked to postmating behavioral changes in each sex. A behavioral study showed that mating caused a temporary suppression of female calling and male courting behavior, and females did not lay eggs until the next day after the first mating. The significant differences on daily fecundity under the presence of males or not, and the same or novel males, suggest that females may intentionally retain eggs to be fertilized by novel males or to be fertilized competitively by different males. RNA sequencing in females revealed that there are more reproduction related GO (gene ontology) terms and KEGG (Kyoto encyclopedia of genes and genomes) pathways (mainly related to egg and zygote development) enriched to upregulated DEGs (differentially expressed genes) than to downregulated DEGs at 0 and 24 h postmating. In males, however, mating induced DEGs did not enrich any reproduction related terms/pathways, which may be because male reproductive bioinformatics is relatively limited in moths. Mating also induced upregulation on soma maintenance (such as immune activity and stress reaction) related processes in females at 0, 6 and 24 h postmating. In males, mating also induced upregulation on soma maintenance related processes at 0 h postmating, but induced downregulation on these processes at 6 and 24 h postmating. In conclusion, this study demonstrated that mating induced sex-specific postmating behavioral and transcriptional changes in both sexes of S. frugiperda and suggested that the transcriptional changes are correlated with postmating physiological and behavioral changes in each sex.

Ex vivo LPS-stimulated cytokine production is associated with hydration status in community-dwelling middle-to-older-aged adults

PURPOSE

Suboptimal hydration has been linked to a variety of adverse health outcomes. Few studies have examined the impact of hydration status on immune function, a plausible physiological mechanism underlying these associations. Therefore, we tested how variation in hydration status was associated with circulating pro-inflammatory cytokine levels and ex vivo lipopolysaccharide (LPS)-stimulated pro-inflammatory cytokine production.

METHODS

Blood samples were obtained from a community sample of healthy middle-to-older-aged adults (N = 72). These samples were used to assess serum osmolality, a biomarker of hydration status, and markers of immune function including circulating pro-inflammatory cytokines and stimulated pro-inflammatory cytokine production after 4 and 24 h of incubation with LPS. Multiple linear regressions were used to test the association between serum osmolality (as a continuous variable) and markers of immune function at baseline and after 4 and 24 h adjusting for age, sex, and BMI. These models were re-estimated with serum osmolality dichotomized at the cut-off for dehydration (> 300 mOsm/kg).

RESULTS

While not significantly associated with circulating cytokines (B = - 0.03, p = 0.09), serum osmolality was negatively associated with both 4 h (B = - 0.05, p = 0.048) and 24 h (B = - 0.05, p = 0.03) stimulated cytokine production when controlling for age, sex, and BMI. Similarly, dehydration was associated with significantly lower cytokine production at both 4 h (B = - 0.54, p = 0.02) and 24 h (B = - 0.51, p = 0.02) compared to adequate hydration.

CONCLUSION

These findings suggest that dehydration may be associated with suppressed immune function in generally healthy middle-to-older aged community-dwelling adults. Further longitudinal research is needed to more clearly define the role of hydration in immune function.

SHP2 deneddylation mediates tumor immunosuppression in colon cancer via the CD47/SIRPα axis

SIPRα on macrophages binds with CD47 to resist proengulfment signals, but how the downstream signal of SIPRα controls tumor-infiltrating macrophages (TIMs) is still poorly clarified. Here, we report that the CD47/signal regulatory protein α (SIRPα) axis requires the deneddylation of tyrosine phosphatase SHP2. Mechanistically, Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) was constitutively neddylated on K358 and K364 sites; thus, its autoinhibited conformation was maintained. In response to CD47-liganded SIRPα, SHP2 was deneddylated by sentrin-specific protease 8 (SENP8), which led to the dephosphorylation of relevant substrates at the phagocytic cup and subsequent inhibition of macrophage phagocytosis. Furthermore, neddylation inactivated myeloid-SHP2 and greatly boosted the efficacy of colorectal cancer (CRC) immunotherapy. Importantly, we observed that supplementation with SHP2 allosteric inhibitors sensitized immune treatment-resistant CRC to immunotherapy. Our results emphasize that the CRC subtype that is unresponsive to immunotherapy relies on SIRPαhiSHP2hiNEDD8lo TIMs and highlight the need to further explore the strategy of SHP2 targeting in CRC therapy.

Regulation of immunological tolerance by the p53-inhibitor iASPP

Maintenance of immunological homeostasis between tolerance and autoimmunity is essential for the prevention of human diseases ranging from autoimmune disease to cancer. Accumulating evidence suggests that p53 can mitigate phagocytosis-induced adjuvanticity thereby promoting immunological tolerance following programmed cell death. Here we identify Inhibitor of Apoptosis Stimulating p53 Protein (iASPP), a negative regulator of p53 transcriptional activity, as a regulator of immunological tolerance. iASPP-deficiency promoted lung adenocarcinoma and pancreatic cancer tumorigenesis, while iASPP-deficient mice were less susceptible to autoimmune disease. Immune responses to iASPP-deficient tumors exhibited hallmarks of immunosuppression, including activated regulatory T cells and exhausted CD8+ T cells. Interestingly, iASPP-deficient tumor cells and tumor-infiltrating myeloid cells, CD4+, and γδ T cells expressed elevated levels of PD-1H, a recently identified transcriptional target of p53 that promotes tolerogenic phagocytosis. Identification of an iASPP/p53 axis of immune homeostasis provides a therapeutic opportunity for both autoimmune disease and cancer.

Role of natural killer and B cell interaction in inducing pathogen specific immune responses

The innate lymphoid cell (ILC) system comprising of the circulating and tissue-resident cells is known to clear infectious pathogens, establish immune homeostasis as well as confer antitumor immunity. Human natural killer cells (hNKs) and other ILCs carry out mopping of the infectious pathogens and perform cytolytic activity regulated by the non-adaptive immune system. The NK cells generate immunological memory and rapid recall response tightly regulated by the adaptive immunity. The interaction of NK and B cell, and its role to induce the pathogen specific immunity is not fully understood. Hence, present article sheds light on the interaction between NK and B cells and resulting immune responses in the infectious diseases. The immune responses elicited by the NK-B cell interaction is of particular importance for developing therapeutic vaccines against the infectious pathogens. Further, experimental evidences suggest the immune-response driven by NK cell population elicits the host-specific antibodies and memory B cells. Also, recently developed humanized immune system (HIS) mice and their importance in to understanding the NK-B cell interaction and resulting pathogen specific immunity has been discussed.

Placental pathology is necessary to understand common pregnancy complications and achieve an improved taxonomy of obstetrical disease

The importance of a fully functioning placenta for a good pregnancy outcome is unquestioned. Loss of function can lead to pregnancy complications and is often detected by a thorough placental pathologic examination. Placental pathology has advanced the science and practice of obstetrics and neonatal-perinatal medicine by classifying diseases according to underlying biology and specific patterns of injury. Many past obstacles have limited the incorporation of placental findings into both clinical studies and day-to-day practice. Limitations have included variability in the nomenclature used to describe placental lesions, a shortage of perinatal pathologists fully competent to analyze placental specimens, and a troubling lack of understanding of placental diagnoses by clinicians. However, the potential use of placental pathology for phenotypic classification, improved understanding of the biology of adverse pregnancy outcomes, the development of treatment and prevention, and patient counseling has never been greater. This review, written partly in response to a recent critique published in a major obstetrics-gynecology journal, reexamines the role of placental pathology by reviewing current concepts of biology; explaining the most recent terminology; emphasizing the usefulness of specific diagnoses for obstetrician-gynecologists, neonatologists, and patients; previewing upcoming changes in recommendations for placental submission; and suggesting future improvements. These improvements should include further consideration of overall healthcare costs, cost-effectiveness, the clinical value added of placental assessment, improvements in placental pathology education and practice, and leveraging of placental pathology to identify new biomarkers of disease and evaluate novel therapies tailored to specific clinicopathologic phenotypes of both women and infants.

Anti-Inflammatory Effect of Garcinol Extracted from Garcinia dulcis via Modulating NF-κB Signaling Pathway

Garcinia is a significant medicinal plant with many beneficial phytoconstituents, including garcinol. This study investigated the anti-inflammatory effect of garcinol isolated from Garcinia dulcis fruit in LPS-activated THP-1 and Raw 264.7 macrophages. The results demonstrated that the low concentration of garcinol did not alter cell viability. Furthermore, co-incubation of garcinol with LPS inhibited the production of pro-inflammatory cytokines, including TNF-α, IL-8, IL-6, IL-1β, and pro-inflammatory mediators, including iNOS and COX-2 at the mRNA and protein expression levels. Garcinol also decreased the secretion of TNF-α, IL-6, IL-1β, PGE2, and NO. Moreover, the anti-inflammatory effects involved an alteration in the NF-κB signaling pathway. Downregulation of pIKKα/β, pIκBα, and pNF-κB was observed, hence reducing the translocation of pNF-κB from the cytosol into the nucleus, which subsequently decreased the production of pro-inflammatory molecules. Therefore, garcinol isolated from Garcinia dulcis is a potential candidate as an anti-inflammatory agent for inflammation-related disease treatment.

A Review on Immune-Inspired Node Fault Detection in Wireless Sensor Networks with a Focus on the Danger Theory

The use of fault detection and tolerance measures in wireless sensor networks is inevitable to ensure the reliability of the data sources. In this context, immune-inspired concepts offer suitable characteristics for developing lightweight fault detection systems, and previous works have shown promising results. In this article, we provide a literature review of immune-inspired fault detection approaches in sensor networks proposed in the last two decades. We discuss the unique properties of the human immune system and how the found approaches exploit them. With the information from the literature review extended with the findings of our previous works, we discuss the limitations of current approaches and consequent future research directions. We have found that immune-inspired techniques are well suited for lightweight fault detection, but there are still open questions concerning the effective and efficient use of those in sensor networks.

Caspase-8 contributes to an immuno-hot microenvironment by promoting phagocytosis via an ecto-calreticulin-dependent mechanism

BACKGROUND

Caspase-8 (Casp8) acts as an initiator in cell apoptosis signaling. However, the role of Casp8 in tuning the tumor immune microenvironment remains controversial due to the complicated crosstalk between immune-tolerogenic apoptotic cell death and immunogenic cell death cascades.

METHODS

The Cancer Genome Atlas (TCGA) and publicly accessible immune checkpoint blockade (ICB)-treated cohorts were used to investigate the clinical relevance of Casp8. A tumor-bearing mouse model was used to characterize changes in the tumor microenvironment and to explore the efficacy of ICB treatment under Casp8 knockout conditions.

RESULTS

By exploring TCGA datasets, we showed that the expression level of Casp8 was associated with an immuno-hot microenvironment across various solid tumor types. Casp8 deficiency leads to decreased CD8⁺ T cell infiltration and resistance to anti-PD-L1 therapy in a mouse model. Mechanistically, Casp8 deficiency or pharmacological disruption results in impaired ecto-calreticulin transition in tumor cells, which in turn hampers antigen presentation in draining lymph nodes. Furthermore, radiotherapy restored sensitivity to anti-PD-L1 treatment via elevated calreticulin surface expression.

CONCLUSIONS

Our data revealed a causative role of Casp8 in modulating the immunogenicity of tumor cells and responsiveness to ICB immunotherapies and proposed radiotherapy as a salvage approach to overcome Casp8 deficiency-mediated ICB resistance.

Multi Epitopic Peptide Based Vaccine Development Targeting Immobilization Antigen of Ichthyophthirius multifiliis: A Computational Approach

The white spot disease causes significant damage to global aquaculture production. A prominent vaccine, eliciting the immunogenicity of freshwater fishes against Ichthyophthirius multifiliis yet to be developed. Thus, an Immunoinformatic drive was implemented to find out the potential epitopes from the surface immobilization antigens. B-cell derived T-cell epitopes are promiscuous elements for new generation peptide-based vaccine designing. A total of eight common B and T-cell epitopes had filtered out with no overlapping manner. Subsequently, the common epitopes are linked up with EAAAKEAAAKEAAAK linker peptides, we also added L7/L12 ribosomal protein adjuvant at the N- terminal side of peptide sequence for eliciting the immune response in a better way. The secondary and tertiary structural properties of the modeled 3D protein revealed that the protein had all the properties required for a protective immunogen. Afterward, three globally used validation server: PROCKECK, ProSA and ERRAT were used to justify the proper coordinate. NMR, Crystallographic range and error plot calculation for vaccine model also been done respectively. This was followed by molecular docking, MD simulation, NMA analysis, in silico cloning and vaccine dose-based immune response simulation to evaluate the immunogenic potency of the vaccine construct. The in silico immune simulation in response to multi-epitopes show antibody generation and elevated levels of cell-mediated immunity during repeated exposure of the vaccine. The favourable results of the in silico analysis significantly specify that the vaccine construct is really a powerful vaccine candidate and ready to proceed to the next steps of experimental validation and efficacy studies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10989-022-10475-1.

Calcium decoders and their targets: The holy alliance that regulate cellular responses in stress signaling

Calcium (Ca²⁺) signaling is versatile communication network in the cell. Stimuli perceived by cells are transposed through Ca²⁺-signature, and are decoded by plethora of Ca²⁺ sensors present in the cell. Calmodulin, calmodulin-like proteins, Ca²⁺-dependent protein kinases and calcineurin B-like proteins are major classes of proteins that decode the Ca²⁺ signature and serve in the propagation of signals to different parts of cells by targeting downstream proteins. These decoders and their targets work together to elicit responses against diverse stress stimuli. Over a period of time, significant attempts have been made to characterize as well as summarize elements of this signaling machinery. We begin with a structural overview and amalgamate the newly identified Ca²⁺ sensor protein in plants. Their ability to bind Ca²⁺, undergo conformational changes, and how it facilitates binding to a wide variety of targets is further embedded. Subsequently, we summarize the recent progress made on the functional characterization of Ca²⁺ sensing machinery and in particular their target proteins in stress signaling. We have focused on the physiological role of Ca²⁺, the Ca²⁺ sensing machinery, and the mode of regulation on their target proteins during plant stress adaptation. Additionally, we also discuss the role of these decoders and their mode of regulation on the target proteins during abiotic, hormone signaling and biotic stress responses in plants. Finally, here, we have enumerated the limitations and challenges in the Ca²⁺ signaling. This article will greatly enable in understanding the current picture of plant response and adaptation during diverse stimuli through the lens of Ca²⁺ signaling.

Association of NOD1 and NOD2 Polymorphisms With Susceptibility to Subacute Sclerosing Panencephalitis

Background: Subacute sclerosing panencephalitis is a progressive neurodegenerative disease that is a late complication of measles infection. However, to date, the pathogenesis of subacute sclerosing panencephalitis is still not explained; both viral and host factors seem to be associated. The present study aimed to investigate the relationship between NOD1 and NOD2 gene variants and subacute sclerosing panencephalitis. Methods: The gene variants of NOD1 (rs2075820 and rs2075818) and NOD2 (R334Q and R334W) were explored in 64 subacute sclerosing panencephalitis patients and 70 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The frequencies of the AA genotype and A allele of rs2075820 (NOD1; c.796G>A) polymorphism were lower in patients compared with controls (P = .022 and .014, respectively). The presence of the A allele of rs2075820 may be considered as a protective factor for subacute sclerosing panencephalitis. There was a significant difference between the groups in rs2075818 (NOD1 G/C) polymorphism, and the CC genotype increased the risk of subacute sclerosing panencephalitis by 3.471-fold. The carriers of the C allele of rs2075818 (G/C) had a 1.855-fold susceptibility to subacute sclerosing panencephalitis (P = .018). The GC genotype might be associated with subacute sclerosing panencephalitis susceptibility in the patients compared with patients without having that haplotype (P = .03). Conclusions: Thus, we identified an association between subacute sclerosing panencephalitis and the rs2075820 (NOD1 G/A) and rs2075818 (NOD1 G/C) polymorphisms. These findings implicate a possible effect of this genetic polymorphism in susceptibility to subacute sclerosing panencephalitis, which needs to be confirmed in bigger populations.

Pasteurella multocida toxin - lessons learned from a mitogenic toxin

The gram-negative, zoonotic bacterium Pasteurella multocida was discovered in 1880 and found to be the causative pathogen of fowl cholera. Pasteurella-related diseases can be found in domestic and wild life animals such as buffalo, sheep, goat, deer and antelope, cats, dogs and tigers and cause hemorrhagic septicemia in cattle, rhinitis or pneumonia in rabbits or fowl cholera in poultry and birds. Pasteurella multocida does not play a major role in the immune-competent human host, but can be found after animal bites or in people with close contact to animals. Toxigenic strains are most commonly found in pigs and express a phage-encoded 146 kDa protein, the Pasteurella multocida toxin (PMT). Toxin-expressing strains cause atrophic rhinitis where nasal turbinate bones are destroyed through the inhibition of bone building osteoblasts and the activation of bone resorbing osteoclasts. After its uptake through receptor-mediated endocytosis, PMT specifically targets the alpha subunit of several heterotrimeric G proteins and constitutively activates them through deamidation of a glutamine residue to glutamate in the alpha subunit. This results in cytoskeletal rearrangement, proliferation, differentiation and survival of cells. Because of the toxin's mitogenic effects, it was suggested that it might have carcinogenic properties, however, no link between Pasteurella infections and cell transformation could be established, neither in tissue culture models nor through epidemiological data. In the recent years it was shown that the toxin not only affects bone, but also the heart as well as basically all cells of innate and adaptive immunity. During the last decade the focus of research shifted from signal transduction processes to understanding how the bacteria might benefit from a bone-destroying toxin. The primary function of PMT seems to be the modulation of immune cell activation which at the same time creates an environment permissive for osteoclast formation. While the disease is restricted to pigs, the implications of the findings from PMT research can be used to explore human diseases and have a high translational potential. In this review our current knowledge will be summarized and it will be discussed what can be learned from using PMT as a tool to understand human pathologies.

Measuring embodiment: A review of methods for prosthetic devices

The development of neural interfaces to provide improved control and somatosensory feedback from prosthetic limbs has initiated a new ability to probe the various dimensions of embodiment. Scientists in the field of neuroprosthetics require dependable measures of ownership, body representation, and agency to quantify the sense of embodiment felt by patients for their prosthetic limbs. These measures are critical to perform generalizable experiments and compare the utility of the new technologies being developed. Here, we review outcome measures used in the literature to evaluate the senses of ownership, body-representation, and agency. We categorize these existing measures based on the fundamental psychometric property measured and whether it is a behavioral or physiological measure. We present arguments for the efficacy and pitfalls of each measure to guide better experimental designs and future outcome measure development. The purpose of this review is to aid prosthesis researchers and technology developers in understanding the concept of embodiment and selecting metrics to assess embodiment in their research. Advances in the ability to measure the embodiment of prosthetic devices have far-reaching implications in the improvement of prosthetic limbs as well as promoting a broader understanding of ourselves as embodied agents.

Gaps and opportunities in sepsis translational research

Infection initiates sepsis, but the clinical disease arises through the innate immune response of the host. A rapidly evolving understanding of the biology of that response has not been paralleled by the development of successful new treatment. The COVID-19 pandemic has begun to change this revealing the promise of distinct therapeutic approaches and the feasibility of new approaches to evaluate them. We review the history of mediator-targeted therapy for sepsis and explore the conceptual, biological, technological, and organizational challenges that must be addressed to enable the development of effective treatments for a leading cause of global morbidity and mortality.

Global patterns in symbiont selection and transmission strategies in sponges

Sponges host dense and diverse communities of microbes (known as the microbiome) beneficial for the host nutrition and defense. Symbionts in turn receive shelter and metabolites from the sponge host, making their relationship beneficial for both partners. Given that sponge-microbes associations are fundamental for the survival of both, especially the sponge, such relationship is maintained through their life and even passed on to the future generations. In many organisms, the microbiome has profound effects on the development of the host, but the influence of the microbiome on the reproductive and developmental pathways of the sponges are less understood. In sponges, microbes are passed on to oocytes, sperm, embryos, and larvae (known as vertical transmission), using a variety of methods that include direct uptake from the mesohyl through phagocytosis by oocytes to indirect transmission to the oocyte by nurse cells. Such microbes can remain in the reproductive elements untouched, for transfer to offspring, or can be digested to make the yolky nutrient reserves of oocytes and larvae. When and how those decisions are made are fundamentally unanswered questions in sponge reproduction. Here we review the diversity of vertical transmission modes existent in the entire phylum Porifera through detailed imaging using electron microscopy, available metabarcoding data from reproductive elements, and macroevolutionary patterns associated to phylogenetic constraints. Additionally, we examine the fidelity of this vertical transmission and possible reasons for the observed variability in some developmental stages. Our current understanding in marine sponges, however, is that the adult microbial community is established by a combination of both vertical and horizontal (acquisition from the surrounding environment in each new generation) transmission processes, although the extent in which each mode shapes the adult microbiome still remains to be determined. We also assessed the fundamental role of filtration, the cellular structures for acquiring external microbes, and the role of the host immune system, that ultimately shapes the stable communities of prokaryotes observed in adult sponges.

TLR4-Pathway-Associated Biomarkers in Subarachnoid Hemorrhage (SAH): Potential Targets for Future Anti-Inflammatory Therapies

Subarachnoid hemorrhage is associated with severe neurological deficits for survivors. Among survivors of the initial bleeding, secondary brain injury leads to additional brain damage. Apart from cerebral vasospasm, secondary brain injury mainly results from cerebral inflammation taking place in the brain parenchyma after bleeding. The brain’s innate immune system is activated, which leads to disturbances in brain homeostasis, cleavage of inflammatory cytokines and, subsequently, neuronal cell death. The toll-like receptor (TLR)4 signaling pathway has been found to play an essential role in the pathophysiology of acute brain injuries such as subarachnoid hemorrhage (SAH). TLR4 is expressed on the cell surface of microglia, which are key players in the cellular immune responses of the brain. The participants in the signaling pathway, such as TLR4-pathway-like ligands, the receptor itself, and inflammatory cytokines, can act as biomarkers, serving as clues regarding the inflammatory status after SAH. Moreover, protein complexes such as the NLRP3 inflammasome or receptors such as TREM1 frame the TLR4 pathway and are indicative of inflammation. In this review, we focus on the activity of the TLR4 pathway and its contributors, which can act as biomarkers of neuroinflammation or even offer potential new treatment targets for secondary neuronal cell death after SAH.

Enhanced Immunotherapy Based on Combining the Pro-phagocytosis and Anti-phagocytosis Checkpoint Blockade for Tumor Eradication

Compared to the activation of acquired immunity by the immune checkpoint blockade, the activation of innate immunity via anti-phagocytosis checkpoint blockade could significantly increase the beneficiary population of immunotherapy. However, the activation of innate immunity and the occurrence of phagocytosis are only accomplished when the interaction between pro-phagocytosis signals and anti-phagocytosis signals is realized. Herein, a versatile nanoplatform (DHMR) based on mesoporous silicon nanoparticles (MSNPs) has been constructed. Two drugs, doxorubicin, a chemotherapeutic drug which could initiate tumor cells to release pro-phagocytosis signals, and RRx-001, an immunoadjuvant that could effectively implement the anti-phagocytosis checkpoint blockade, were loaded in MSNPs. Further decoration of hyaluronic acid encapsulation endows DHMR with the function of tumor targeting and long circulation. Ultimately, the DHMR system could efficiently and accurately target tumor tissue, release the drugs in the tumor microenvironment, achieve the activation of innate immunity, and finally dramatically inhibit the growth and metastasis of tumor cells.

Altered-Self MHC Class I Sensing via Functionally Disparate Paired NK Cell Receptors Counters Murine Cytomegalovirus gp34-Mediated Immune Evasion

The murine CMV (MCMV) immunoevasin m04/gp34 escorts MHC class I (MHC I) molecules to the surface of infected cells where these complexes bind Ly49 inhibitory receptors (IRs) and prevent NK cell attack. Nonetheless, certain self-MHC I-binding Ly49 activating and inhibitory receptors are able to promote robust NK cell expansion and antiviral immunity during MCMV infection. A basis for MHC I-dependent NK cell sensing of MCMV-infected targets and control of MCMV infection however remains unclear. In this study, we discovered that the Ly49R activation receptor is selectively triggered during MCMV infection on antiviral NK cells licensed by the Ly49G2 IR. Ly49R activating receptor recognition of MCMV-infected targets is dependent on MHC I Dk and MCMV gp34 expression. Remarkably, although Ly49R is critical for Ly49G2-dependent antiviral immunity, blockade of the activation receptor in Ly49G2-deficient mice has no impact on virus control, suggesting that paired Ly49G2 MCMV sensing might enable Ly49R+ NK cells to better engage viral targets. Indeed, MCMV gp34 facilitates Ly49G2 binding to infected cells, and the IR is required to counter gp34-mediated immune evasion. A specific requirement for Ly49G2 in antiviral immunity is further explained by its capacity to license cytokine receptor signaling pathways and enhance Ly49R+ NK cell proliferation during infection. These findings advance our understanding of the molecular basis for functionally disparate self-receptor enhancement of antiviral NK cell immunity.

Combinatorial regimens of chemotherapeutic agents: A new perspective on raising the heat of the tumor immune microenvironment

Harnessing the broad immunostimulatory capabilities of chemotherapy in combination with immune checkpoint inhibitors has improved immunotherapy outcomes in patients with cancer. Certain chemotherapeutic agents can extensively modify the tumor microenvironment (TME), resulting in the reprogramming of local immune responses. Although chemotherapeutic agents with an enhanced generation of potent anti-tumor immune responses have been tested in preclinical animal models and clinical trials, this strategy has not yet shown substantial therapeutic efficacy in selected difficult-to-treat cancer types. In addition, the efficacy of chemotherapeutic agent-based monotherapy in eliciting a long-term anti-tumor immune response is restricted by the immunosuppressive TME. To enhance the immunomodulatory effect of chemotherapy, researchers have made many attempts, mainly focusing on improving the targeted distribution of chemotherapeutic agents and designing combination therapies. Here, we focused on the mechanisms of the anti-tumor immune response to chemotherapeutic agents and enumerated the attempts to advance the use of chemo-immunotherapy. Furthermore, we have listed the important considerations in designing combinations of these drugs to maximize efficacy and improve treatment response rates in patients with cancer.

An allergenic plant calmodulin from Artemisia pollen primes human DCs leads to Th2 polarization

Artemisia pollen is the major cause of seasonal allergic respiratory diseases in the northern hemisphere. About 28.57% of Artemisia allergic patients’ IgE can recognize ArtCaM, a novel allergenic calmodulin from Artemisia identified in this study. These patients exhibited stronger allergic reactions and a longer duration of allergic symptoms. However, the signaling mechanism that triggers these allergic reactions is not fully understood. In this study, we found that extracellular ArtCaM directly induces the maturation of human dendritic cells (DCs), which is attributed to a series of Ca²⁺ relevant cascades, including Ca²⁺/NFAT/CaMKs. ArtCaM alone induces inflammatory response toward Th1, Th17, and Treg. Interestingly, a combination of ArtCaM and anti-ArtCaM IgE led to Th2 polarization. The putative mechanism is that anti-ArtCaM IgE partially blocks the ArtCaM-induced ERK signal, but does not affect Ca²⁺-dependent cascades. The crosstalk between ERK and Ca²⁺ signal primes DCs maturation and Th2 polarization. In summary, ArtCaM related to clinical symptoms when combined with anti-ArtCaM IgE, could be a novel allergen to activate DCs and promote Th2 polarization. Such findings provide mechanistic insights into Th2 polarization in allergic sensitization and pave the way for novel preventive and therapeutic strategies for efficient management of such pollen allergic disease.

The right microbe-associated molecular patterns for effective recognition by plants

Plants are constantly exposed to diverse microbes and thus develop a sophisticated perceive system to distinguish non-self from self and identify non-self as friends or foes. Plants can detect microbes in apoplast via recognition of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) on the cell surface to activate appropriate signaling in response to microbes. MAMPs are highly conserved but essential molecules of microbes and often buried in microbes’ complex structure. Mature MAMPs are released from microbes by invasion-induced hydrolytic enzymes in apoplast and accumulate in proximity of plasma membrane-localized PRRs to be perceived as ligands to activate downstream signaling. In response, microbes developed strategies to counteract these processing. Here, we review how the form, the concentration, and the size of mature MAMPs affect the PRR-mediated immune signaling. In particular, we describe some potential applications and explore potential open questions in the fields.

Gut microbiota-derived metabolites contribute negatively to hindgut barrier function development at the early weaning goat model

Early weaning induces intestinal injury, leading to a series of long-term symptoms such as inflammation, malabsorption and diarrhea. In this study, we hypothesized that microbes and their metabolites modulate the host's inflammatory response to early weaning stress in a goat model. A total of 18 female Tibetan goat kids (n = 9) were weaned from their mothers at 28 d (D28) and 60 d (D60) postpartum. D60 and D28 groups were fed the same solid diet ad libitum from weaning to 75 d of age. The colonic epithelium was subject to RNA-sequencing, the caecal digesta metabolomics were assessed by liquid chromatography–tandem mass spectrometry (LC-MS/MS), and the caecal microbiota composition was analysed by 16S ribosomal RNA gene sequencing. We found that early weaning substantially increased the colonic pro-apoptotic gene expression of B-cell lymphoma associated X (Bax), caspase-9, and caspase-3, and decreased the expression of zonula occludens-1 (ZO-1) and claudin-1 (P < 0.01). In addition, a significant Bacteroides acidifaciens enrichment was observed in the hindgut of early-weaned goats (P < 0.01), which negatively correlated with lysophosphatidylcholine products. Similarly, the chemokine signaling, IL-17 signaling, and peroxisome proliferators-activated receptor (PPAR) signaling pathways were upregulated in the colonic mucosa of the early-weaned goats. By applying caecal microbiota transplantation from goats to defaunated C57/6J mice, we confirmed that caecal microbiota of D28 goat kids increased the relative abundance of B. acidifaciens and significantly up-regulated the genes of Bax, G protein–coupled receptor (GPR) 109A, GPR 43, fatty acid binding protein 6, nuclear receptor subfamily 1 group H member 3, angiotensin converting enzyme 2, and IL-6 expression (P < 0.05), and decreased ZO-1, and claudin-1 protein expression in the mice jejunum and colon (P < 0.001). These results proposed that the hindgut microbiota and metabolites mediate the barrier function weakening during early weaning, and the relative abundance of B. acidifaciens was negatively correlated with the hindgut barrier gene expression. This study demonstrates how weaning stress can affect key host–microbe interaction regulators in the hindgut, in a lysophosphatidylcholine dependent and independent manner. Furthermore, based on our mice data, these results are transferable to other mammal species.

Aberrant liquid-liquid phase separation and amyloid aggregation of proteins related to neurodegenerative diseases

Recent evidence has shown that the processes of liquid-liquid phase separation (LLPS) or liquid-liquid phase transitions (LLPTs) are a crucial and prevalent phenomenon that underlies the biogenesis of numerous membrane-less organelles (MLOs) and biomolecular condensates within the cells. Findings show that processes associated with LLPS play an essential role in physiology and disease. In this review, we discuss the physical and biomolecular factors that contribute to the development of LLPS, the associated functions, as well as their consequences for cell physiology and neurological disorders. Additionally, the finding of mis-regulated proteins, which have long been linked to aggregates in neuropathology, are also known to induce LLPS/LLPTs, prompting a lot of interest in understanding the connection between aberrant phase separation and disorder conditions. Moreover, the methods used in recent and ongoing studies in this field are also explored, as is the possibility that these findings will encourage new lines of inquiry into the molecular causes of neurodegenerative diseases.

Exosome-based strategies for diagnosis and therapy of glioma cancer

Glioblastoma belongs to the most aggressive type of cancer with a low survival rate that is characterized by the ability in forming a highly immunosuppressive tumor microenvironment. Intercellular communication are created via exosomes in the tumor microenvironment through the transport of various biomolecules. They are primarily involved in tumor growth, differentiation, metastasis, and chemotherapy or radiation resistance. Recently several studies have highlighted the critical role of tumor-derived exosomes against immune cells. According to the structural and functional properties, exosomes could be essential instruments to gain a better molecular mechanism for tumor understanding. Additionally, they are qualified as diagnostic/prognostic markers and therapeutic tools for specific targeting of invasive tumor cells such as glioblastomas. Due to the strong dependency of exosome features on the original cells and their developmental status, it is essential to review their critical modulating molecules, clinical relevance to glioma, and associated signaling pathways. This review is a non-clinical study, as the possible role of exosomes and exosomal microRNAs in glioma cancer are reported. In addition, their content to overcome cancer resistance and their potential as diagnostic biomarkers are analyzed.

Noncoding RNAs in pyroptosis and cancer progression: Effect, mechanism, and clinical application

Cell death is generally classified into two categories: regulated cell death (RCD) and accidental cell death (ACD). In particular, RCD is a kind of genetically controlled process, including programmed apoptotic death and programmed necrotic death. Pyroptosis, an inflammatory form of programmed necrotic death, causes inflammation in cells. The influence of pyroptosis on tumor is complicated. On the one hand, pyroptosis triggers antitumor response. On the other hand, pyroptosis may induce carcinogenesis. Pyroptosis is initiated by various factors, especially non-coding RNAs. In this review, we discuss the effects of ncRNAs on pyroptosis and the mechanisms by which ncRNAs initiate pyroptosis. Moreover, we introduce the influence of ncRNA on tumor resistance via pyroptosis. Additionally, we summarize how ncRNA-associated pyroptosis modulates the tumor microenvironment (TME) and thereafter triggers antitumor immune response. Finally, pyroptosis-related ncRNAs are promising diagnostic and immunotherapeutic biomarkers and therapeutic targets

Identification of PGRP2 and its three splice variants in grass carp Ctenopharyngodon idella

In this study, peptidoglycan recognition protein 2 (PGRP2) gene was cloned in grass carp Ctenopharyngodon idella, with the open reading frame (ORF) of PGRP2 being 1452 bp, encoding a protein of 483 amino acids. Three splice variants, PGRP2a, PGRP2b, and PGRP2c, were found also in grass carp with the absence of entire exon two and partial exon two of the PGRP2, and were predicted to have 124, 371 and 311 amino acids. But, they all have PGRP domain and signal peptide, except PGRP2a. The PGRP2 and its variants were expressed in all organs/tissues examined, and stimulated following PGN injection. It is further detected that the expression of gcPGRP2 and its variants was up-regulated after the single transfection of each of gcPGRP2 and its variant expression plasmids in CO cells. It is considered that the cloning of PGRP2 in grass carp provides a compositional completeness of PGRP members in this fish with the inclusion of previously reported PGRP5 and PGRP6.

A RAC-alpha serine/threonine-protein kinase (CgAKT1) involved in the synthesis of CgIFNLP in oyster Crassostrea gigas

The RAC-alpha serine/threonine-protein kinase (AKT) is one of the most important protein kinases involved in many biological processes in eukaryotes. In the present study, a novel AKT homologue named CgAKT1 was identified from the Pacific oyster Crassostrea gigas. The open reading frame (ORF) of CgAKT1 cDNA was of 1482 bp encoding a peptide with 493 amino acid residues. There were classical domains in the predicted CgAKT1 protein, including an N-terminal pleckstrin homology domain, a central catalytic domain and a C-terminal hydrophobic domain. The mRNA transcripts of CgAKT1 were detected in all the examined tissues of C. gigas with higher level in gills (8.24-fold of that in mantle, p < 0.05) and haemocytes (3.62-fold of that in mantle, p < 0.05). After poly (I:C) stimulation, the mRNA expression of CgAKT1 decreased significantly in haemocytes from 3 h (0.44-fold of that in the control group, p < 0.001) to 24 h (0.20-fold of that in the control group, p < 0.001), and then increased significantly at 48 h (3.65-fold of that in the control group, p < 0.05). The expression level of CgAKT1 mRNA increased significantly at 6 h after rCgIFNLP stimulation, which was 3.60-fold of that in the control group (p < 0.001). The Alexa Fluor 488 positive signals of CgAKT1 protein were found to be distributed in the cytoplasm and cell membrane of haemocytes, while those in the cytoplasm became weaker after poly (I:C) stimulation. In CgAKT1-RNAi oysters, the mRNA expression of cyclic GMP-AMP synthase (CgcGAS) and TANK-binding kinase 1 (CgTBK1) did not change significantly, but the mRNA expression level of stimulator of interferon gene (CgSTING), interferon regulatory factor-1 (CgIRF-1), interferon regulatory factor-8 (CgIRF-8) and IFN-like protein (CgIFNLP) increased significantly, which was 1.40-fold, 1.53-fold, 1.72-fold and 1.99-fold of that in EGFP-RNAi oysters (p < 0.05), respectively. In CgIFNLP-RNAi oysters, the transcripts of CgAKT1 decreased significantly compared to those in EGFP-RNAi oysters (0.16-fold, p < 0.01). Moreover, the expression of p-CgTBK1, CgSTING and CgIFNLP at the protein level in the oysters treated with p-AKT1 activator (SC-79) was significantly suppressed after poly (I:C) stimulation. After the transfection of CgAKT1, the expression of p-cGAS protein in HEK293T cells increased significantly, while the cyclic GMP-AMP in the cells and the interferon (IFN-β) in the cell culture fluid decreased significantly compared with that in the control group. These results indicated that CgAKT1 might play a negative role in antiviral immunity of oyster by regulating the synthesis of CgIFNLP.

Mapping linear B-cell epitopes of the Tryparedoxin Peroxidase and its implications in the serological diagnosis of tegumentary leishmaniasis

Diagnosis of tegumentary leishmaniasis (TL) is essential to avoid permanent damage and severe functional sequelae and there is an urgent need to discover new antigens. The present study aimed to comprehensively evaluate the potential use of the Tryparedoxin Peroxidase (TryP) as an antigen for serological tests. The proposal integrates data from immunoproteomics with immunoinformatics, in addition to a precise analysis of protein levels in the evolutionary stages of the parasite by flow cytometry. To evaluate the performance in the diagnosis of TL, Enzyme-Linked Immunosorbent Assay (ELISA) assays were performed using the recombinant protein and the respective B-cell epitope, followed by an analysis of the contribution of this peptide in the recognition of the protein by patients, evaluated by serum depletion assays. We showed that the TryP has a linear B-cell epitope with high divergence compared to orthologs from Trypanosoma cruzi and Homo sapiens. The results also show high expression and positive cells for TryP (TryP⁺) in the infective metacyclic promastigotes (MET) and intracellular (24 and 48 hours) stages. From the depletion assays, it was possible to confirm the contribution of the peptide in the specific recognition of the TryP protein by patients with TL (13.7-15.9%). ELISA using the peptide showed high performance in the diagnosis compared to the recombinant TryP (rTryP), Soluble Leishmania braziliensis Antigen (sLba) and Immunofluorescence Assay (IFA) with accuracy of 94.29, 89.29, 65.00 and 37.14%, respectively). We can conclude that the MNEPAPP peptide is a potential antigen for the diagnosis of TL.

A plausible contributor to multiple sclerosis; presentation of antigenic myelin protein epitopes by major histocompatibility complexes

BACKGROUND

Multiple sclerosis (MS) can be induced upon successful presentation of myelin antigens by MHC I/II. Antigenic similarity between the myelin and viral proteins may worsen the immunological responses.

METHODOLOGY

Antigenic regions within myelin proteins; PLP1, MBP, MOG, and MAG were analyzed using SVMTrip and EMBOSS. Homology search identified sequence similarity between the predicted host epitopes and viral proteins. NetMHCpan predicted MHC I/II binding followed by peptide-protein docking through the HPEPDOCK server. Thereafter we analyzed conformational flexibility and stability of 15 protein-peptide complexes based on high docking scores. The binding free energy was calculated using conventional (MD) and Gaussian accelerated molecular dynamics simulation.

RESULTS

PLP1, MBP, MAG and MOG contained numerous antigenic epitopes. MBP and MOG epitopes had sequence similarity to HHV-6 BALF5; EBNA1 and CMV glycoprotein M (gM), and EBV LMP2B, gp350/220; HHV-8 ORFs respectively. Many herpes virus proteins like tegument, envelope glycoproteins, and ORFs of EBV, CMV, HHV-6, and HHV-8 demonstrated sequence similarity with MAG and PLP1. Some antigenic peptides were also linear B-cell epitopes and influenced cytokine production by T-cell. MHC I allele HLA-B*57:01 bound to PLP1 peptide and HLA-A*68:02 bound to a MAG peptide strongly. MHC II alleles HLA-DRB1*04:05 and HLA-DR1*01:01 associated with MAG- and MOG-derived peptides, respectively, demonstrating high HPEPDOCK scores. MD simulations established stable binding of certain peptides with the MHC namely HLA-B*51:01-MBP(DYKSAHKGFKGVDAQGTLSKIFKL), HLA-B*57:01-PLP1(PDKFVGITYALTVVWLLVFACSAVPVYIYF), HLA-DR1*01:01-MOG(VEDPFYWVSPGVLVLLAVLPVLLLQITVGLVFLCLQYR) and HLA-DRB1*04:05-MAG(TWVQVSLLHFVPTREA).

CONCLUSIONS

Cross-reactivity between self-antigens and pathogen derived immunodominant epitopes may induce MS. Our study supported the role of specific MHC alleles as a contributing MS risk factor.

To protect or to kill: A persisting Darwinian immune dilemma

The immune system, which evolved as a protective system, can paradoxically mediate lethal effects when it is over-activated. These effects can be traced back to infected insects and are mainly mediated by phylogenetically old cytokines that have been found already in starfishes and sponges. We hypothesize that these anti-homeostatic effects are important for restricting the cumulative risk of transmission of highly mutating environmental pathogens that may endanger species, particularly when they start to originate and expand. Considering the Darwinian view that evolution is a permanent process, this anti-homeostatic program is preserved and expressed even when there is no risk for the species. Here, we review these aspects and discuss how evolutionary-imposed anti-homeostatic immune programs are expressed during acute and chronic human diseases, which can be further aggravated in the absence of medical interventions. The relevance of early identification of ancestral biomarkers that predict a shift from protective to deleterious immune outcomes is emphasized.

Revisiting the Tenascins: Exploitable as Cancer Targets?

For their full manifestation, tumors require support from the surrounding tumor microenvironment (TME), which includes a specific extracellular matrix (ECM), vasculature, and a variety of non-malignant host cells. Together, these components form a tumor-permissive niche that significantly differs from physiological conditions. While the TME helps to promote tumor progression, its special composition also provides potential targets for anti-cancer therapy. Targeting tumor-specific ECM molecules and stromal cells or disrupting aberrant mesenchyme-cancer communications might normalize the TME and improve cancer treatment outcome. The tenascins are a family of large, multifunctional extracellular glycoproteins consisting of four members. Although each have been described to be expressed in the ECM surrounding cancer cells, tenascin-C and tenascin-W are currently the most promising candidates for exploitability and clinical use as they are highly expressed in various tumor stroma with relatively low abundance in healthy tissues. Here, we review what is known about expression of all four tenascin family members in tumors, followed by a more thorough discussion on tenascin-C and tenascin-W focusing on their oncogenic functions and their potential as diagnostic and/or targetable molecules for anti-cancer treatment purposes.

Harnessing anti-tumor and tumor-tropism functions of macrophages via nanotechnology for tumor immunotherapy

Reprogramming the immunosuppressive tumor microenvironment by modulating macrophages holds great promise in tumor immunotherapy. As a class of professional phagocytes and antigen-presenting cells in the innate immune system, macrophages can not only directly engulf and clear tumor cells, but also play roles in presenting tumor-specific antigen to initiate adaptive immunity. However, the tumor-associated macrophages (TAMs) usually display tumor-supportive M2 phenotype rather than anti-tumor M1 phenotype. They can support tumor cells to escape immunological surveillance, aggravate tumor progression, and impede tumor-specific T cell immunity. Although many TAMs-modulating agents have shown great success in therapy of multiple tumors, they face enormous challenges including poor tumor accumulation and off-target side effects. An alternative solution is the use of advanced nanostructures, which not only can deliver TAMs-modulating agents to augment therapeutic efficacy, but also can directly serve as modulators of TAMs. Another important strategy is the exploitation of macrophages and macrophage-derived components as tumor-targeting delivery vehicles. Herein, we summarize the recent advances in targeting and engineering macrophages for tumor immunotherapy, including (1) direct and indirect effects of macrophages on the augmentation of immunotherapy and (2) strategies for engineering macrophage-based drug carriers. The existing perspectives and challenges of macrophage-based tumor immunotherapies are also highlighted.

A single-CRD C-type lectin from Haliotis discus hannai acts as pattern recognition receptor enhancing hemocytes opsonization

C-type lectins (CTLs), as a member of the Ca²⁺-dependent carbohydrate recognition protein superfamily, play multiple roles in non-self recognition and the elimination of invading pathogens. In this study, a C-type lectin was identified and characterized from the Pacific abalone Haliotis discus hannai (designed as HdClec), and its open reading frame (ORF) encoded a polypeptide of 163 amino acids containing a typical signal peptide and only one carbohydrate-recognition domain (CRD). The deduced amino acid sequence of CRD in HdClec shared identities ranging from 22.4% to 39.8% with that of other identified CRDs of CTLs. A novel NPN motif was found in Ca²⁺-binding site 2 of HdClec. The mRNA transcripts of HdClec were detectable in all the examined tissues of non-stimulated abalones, with the highest expression in hepatopancreas (224.13-fold of that in gills). The expression of HdClec mRNA in hemocytes was significantly up-regulated after Vibrio harveyi challenge. Recombinant HdClec protein (rHdClec) could bind lipopolysaccharide (LPS) and peptidoglycan (PGN) in vitro in the presence of Ca²⁺. Coinciding with the PAMPs binding assay, rHdClec displayed broad agglutination activities towards Gram-negative bacteria V. splendidus, V. anguillarum, V. parahaemolyticus, V. harveyi, Escherichia coli, and Gram-positive bacteria Micrococcus luteus. Moreover, rHdClec could significantly elicit the chemotactic response of hemocytes in vitro. And the phagocytosis and encapsulation ability of hemocytes could be significantly enhanced by rHdClec. All these results showed that HdClec could function as pattern recognition receptors (PRRs) and further enhance the opsonization of hemocytes, which might play a crucial role in the innate immune responses of Pacific abalone.

The Evasion Mechanisms of Cancer Immunity and Drug Intervention in the Tumor Microenvironment

Recently, in the field of cancer treatment, the paradigm has changed to immunotherapy that activates the immune system to induce cancer attacks. Among them, immune checkpoint inhibitors (ICI) are attracting attention as excellent and continuous clinical results. However, it shows not only limitations such as efficacy only in some patients or some indications, but also side-effects and resistance occur. Therefore, it is necessary to understand the factors of the tumor microenvironment (TME) that affect the efficacy of immunotherapy, that is, the mechanism by which cancer grows while evading or suppressing attacks from the immune system within the TME. Tumors can evade attacks from the immune system through various mechanisms such as restricting antigen recognition, inhibiting the immune system, and inducing T cell exhaustion. In addition, tumors inhibit or evade the immune system by accumulating specific metabolites and signal factors within the TME or limiting the nutrients available to immune cells. In order to overcome the limitations of immunotherapy and develop effective cancer treatments and therapeutic strategies, an approach is needed to understand the functions of cancer and immune cells in an integrated manner based on the TME. In this review, we will examine the effects of the TME on cancer cells and immune cells, especially how cancer cells evade the immune system, and examine anti-cancer strategies based on TME.

Immunological defense of CNS barriers against infections

Neuroanatomical barriers with physical, chemical, and immunological properties play an essential role in preventing the spread of peripheral infections into the CNS. A failure to contain pathogens within these barriers can result in very serious CNS diseases. CNS barriers are inhabited by an elaborate conglomerate of innate and adaptive immune cells that are highly responsive to environmental challenges. The CNS and its barriers can also be protected by memory T and B cells elicited by prior infection or vaccination. Here, we discuss the different CNS barriers from a developmental, anatomical, and immunological standpoint and summarize our current understanding of how memory cells protect the CNS compartment. We then discuss a contemporary challenge to CNS-barrier system (SARS-CoV-2 infection) and highlight approaches to promote immunological protection of the CNS via vaccination.

Bacteria in cancer therapy: A new generation of weapons

Tumors are presently a major threat to human life and health. Malignant tumors are conventionally treated through radiotherapy and chemotherapy. However, traditional therapies yield unsatisfactory results due to high toxicity to the normal cells, inability to treat deep tumor tissues, and the possibility of inducing drug resistance in the tumor cells. This has caused immunotherapy to emerge as an effective and alternate treatment strategy. To overcome the limitations of the conventional treatments as well as to avert the risk of various drug resistance and cytotoxicity, bacterial anti-tumor immunotherapy has raised the interest of researchers. This therapeutic strategy employs bacteria to specifically target and colonize the tumor tissues with preferential accumulation and proliferation. Such bacterial accumulation initiates a series of anti-tumor immune responses, effectively eliminating the tumor cells. This immunotherapy can use the bacteria alone or concomitantly with the other methods. For example, the bacteria can deliver the anti-cancer effect mediators by regulating the expression of the bacterial genes or by synthesizing the bioengineered bacterial complexes. This review will discuss the mechanism of utilizing bacteria in treating tumors, especially in terms of immune mechanisms. This could help in better integrating the bacterial method with other treatment options, thereby, providing a more effective, reliable, and unique treatment therapy for tumors.

Toxicity response to benzo[α]pyrene exposure: Modulation of immune parameters of the bay scallop, Argopectenirradians

Bay scallops were exposed to four BaP concentrations (0.5, 1.0, 10 and 50 μg/L) for 72 h to elucidate their immune response. Immune parameters were evaluated by measuring nitric oxide (NO) levels in hemolymph. Additionally, we measured peptidoglycan recognition proteins (PGRP), fibrinogen-domain-containing protein (FReDC1), metallothionein (MT), and heat shock protein (HSP) 70 mRNA expression in digestive diverticula. NO as well as FReDC1 and MT expression in each BaP group increased significantly over time except for the BaP 0.5 group. The PGRP and HSP70 mRNA expression in the BaP 50 group increased in the range 6-24 h and then decreased. In situ hybridization also confirmed that there was higher MT mRNA expression in the BaP 50 group than in the control group at 72 h. Our results suggest that higher levels of BaP dampened scallop immune responses, while simultaneously reducing their ability to cope with oxidative stress and DNA damage. BaP exposure can be considered a potential immune inducer in bay scallop.

Molecular tug-of-war: Plant immune recognition of herbivory

Plant defense responses against insect herbivores are induced through wound-induced signaling and the specific perception of herbivore-associated molecular patterns (HAMPs). In addition, herbivores can deliver effectors that suppress plant immunity. Here we review plant immune recognition of HAMPs and effectors, and argue that these initial molecular interactions upon a plant-herbivore encounter mediate and structure effective resistance. While the number of distinct HAMPs and effectors from both chewing and piercing-sucking herbivores has expanded rapidly with omics-enabled approaches, paired receptors and targets in the host are still not well characterized. Herbivore-derived effectors may also be recognized as HAMPs depending on the host plant species, potentially through the evolution of novel immune receptor functions. We compile examples of HAMPs and effectors where natural variation between species may inform evolutionary patterns and mechanisms of plant-herbivore interactions. Finally, we discuss the combined effects of wounding and HAMP recognition, and review potential signaling hubs, which may integrate both sensing functions. Understanding the precise mechanisms for plant sensing of herbivores will be critical for engineering resistance in agriculture.

Functional analysis of a peptidoglycan recognition protein involved in the immune response in the common cutworm, Spodoptera litura

Peptidoglycan recognition proteins (GRPs) are family of pattern recognition receptors (PRRs), which can recognize the peptidoglycan and trigger the innate immune system against the microorganisms in insects. In this study, we identified a GRP-LB from Spodoptera litura genome database and named SlGRP-LB, which contained a complete open reading frame (ORF) of 639 bp, encoding a protein of 212 amino acids with a signal peptide and GRP domain. Phylogenetic tree analysis suggested that the SlGRP-LB has a close relationship with Helicoverpa armigera GRP-LB (HaGRP-LB). Tissue expression analysis revealed that SlGRP-LB had a high expression level in the fat body. The expression levels of SlGRP-LB were significantly upregulated in the hemolymph, fat body, and midgut from 3 to 12 h after injection of Escherichia coli and Staphylococcus aureus, while the expression levels were not downregulated at 24 h postinfection. Knockdown of SlGRP-LB expression by RNA interference reduced the expression of antibacterial peptide-related genes in the fat body and midgut, while their expression levels were upregulated in the hemolymph. In addition, the recombinant SlGRP-LB was expressed by using E. coli expression system, and it exhibited binding activity to E. coli. Taken together, the data suggest that S. litura GRP-LB might play a crucial role in regulating immune response in S. litura.

Inflammasome Contribution to the Activation of Th1, Th2, and Th17 Immune Responses

Inflammasomes are cytosolic polyprotein complexes formed in response to various external and internal stimuli, including viral and bacterial antigens. The main product of the inflammasome is active caspase 1 which proteolytically cleaves, releasing functional interleukin-1 beta (IL-1β) and interleukin-18 (IL-18). These cytokines play a central role in shaping immune response to pathogens. In this review, we will focus on the mechanisms of inflammasome activation, as well as their role in development of Th1, Th2, and Th17 lymphocytes. The contribution of cytokines IL-1β, IL-18, and IL-33, products of activated inflammasomes, are summarized. Additionally, the role of cytokines released from tissue cells in promoting differentiation of lymphocyte populations is discussed.

Effect of Early Pathogenic Escherichia coli Infection on the Intestinal Barrier and Immune Function in Newborn Calves

We studied the effect of early pathogenic Escherichia coli infection on newborn calves’ intestinal barrier and immune function. A total of 64 newborn Holstein male calves (40–43 kg) were divided into two groups: normal (NG) and test (TG), each with 32 heads. At the beginning of the experiment, the TG calves were orally administered pathogenic E. coli O1 (2.5 × 10¹¹ CFU/mL, 100 mL) to establish a calf diarrhea model. In contrast, the NG calves were given the same amount of normal saline. During the 30 d trial period, the feeding and management of the two groups remained constant. Enzyme-linked immunosorbent assay, quantification PCR, and high-throughput 16S rRNA sequencing technology were used to detect indicators related to the intestinal barrier and immune function in the calf serum and tissues. Pathogenic E. coli O1 had a significant effect on calf diarrhea in the TG; it increased the bovine diamine oxidase (P < 0.05) and endotoxin levels in the serum and decreased (P < 0.05) the intestinal trefoil factor (P < 0.05), Occludin, Claudin-1, and Zonula Occludens 1 (ZO-1) levels in the colon tissue, as well as downregulated the mRNA expression of Occludin, Claudin-1,and ZO-1 in the colon mucosa, leading to increased intestinal permeability and impaired intestinal barrier function. Additionally, pathogenic E. coli had a significant impact on the diversity of colonic microbial flora, increasing the relative abundance of Proteobacteria at the phylum level and decreasing the levels of Firmicutes and Bacteroides. At the genus level, the relative abundance of Escherichia and Shigella in the TG increased significantly (P < 0.05), whereas that of Bacteroides, Butyricicoccus, Rikenellaceae_RC9_gut_group, Blautia, and Lactobacillus was significantly decreased (P < 0.05). In addition, the level of IL-6 in the serum of the TG calves was significantly increased (P < 0.05), whereas the IL-4 and IL-10 levels were significantly decreased (P < 0.05), compared to those in the NG calves. Thus, pathogenic E. coli induced diarrhea early in life disrupts intestinal barrier and impairs immune function in calves.

Critical Roles of Spätzle5 in Antimicrobial Peptide Production Against Escherichia coli in Tenebrio molitor Malpighian Tubules

The dimeric cytokine ligand Spätzle (Spz) is responsible for Toll pathway activation and antimicrobial peptide (AMP) production upon pathogen challenge in Tenebrio molitor. Here, we indicated that TmSpz5 has a functional role in response to bacterial infections. We showed that the highest expression of TmSpz5 is induced by Candida albicans. However, TmSpz5 knockdown reduced larval survival against Escherichia coli and Staphylococcus aureus. To evaluate the molecular mechanism underlying the observed survival differences, the role of TmSpz5 in AMP production was examined by RNA interference and microbial injection. T. molitor AMPs that are active against Gram-negative and -positive bacteria, including Tmtenecins, Tmattacins, Tmcoleoptericins, Tmtaumatin-like-proteins, and Tmcecropin-2, were significantly downregulated by TmSpz-5 RNAi in the Malpighian tubules (MTs) following a challenge with E. coli and S. aureus. However, upon infection with C. albicans the mRNA levels of most AMPs in the dsTmSpz5-injected group were similar to those in the control groups. Likewise, the expression of the transcription factors NF-κB, TmDorX2, and TmRelish were noticeably suppressed in the MTs of TmSpz5-silenced larvae. Moreover, E. coli-infected TmSpz5 knockdown larvae showed decreased antimicrobial activity in the MTs and hindgut compared with the control group. These results demonstrate that TmSpz5 has a defined role in T. molitor innate immunity by regulating AMP expression in MTs in response to E. coli.

The Emerging Roles of Pellino Family in Pattern Recognition Receptor Signaling

The Pellino family is a novel and well-conserved E3 ubiquitin ligase family and consists of Pellino1, Pellino2, and Pellino3. Each family member exhibits a highly conserved structure providing ubiquitin ligase activity without abrogating cell and structure-specific function. In this review, we mainly summarized the crucial roles of the Pellino family in pattern recognition receptor-related signaling pathways: IL-1R signaling, Toll-like signaling, NOD-like signaling, T-cell and B-cell signaling, and cell death-related TNFR signaling. We also summarized the current information of the Pellino family in tumorigenesis, microRNAs, and other phenotypes. Finally, we discussed the outstanding questions of the Pellino family in immunity.