The activation of the adaptive immune system: Cross-talk between antigen-presenting cells, T cells and B cells

Insights into chemical components, health-promoting effects, and processing impact of golden chanterelle mushroom Cantharellus cibarius

Cantharellus cibarius (CC) is a culinary mushroom with significant commercial potential due to its diverse components and bioactive functions. CC is rich in carbohydrates, proteins, minerals, vitamins, and aroma compounds while being low in fat and calories. Moreover, CC contains an abundance of bioactive substances including phenolic compounds, vitamin precursors, and indole derivatives. Numerous studies have claimed that CC has diverse functions such as antioxidant, antimicrobial, immunoregulation, anti-inflammatory, antitumor, neuroprotective, antidiabetic, and prebiotic effects in in vivo or in vitro settings. In addition, a variety of thermal, physical, chemical, and biological treatment methods have been investigated for the processing and preservation of CC. Consequently, this study aims to present a comprehensive review of the chemical composition, health benefits, and processing techniques of CC. Furthermore, the issue of heavy metal accumulation in CC has been indicated and discussed. The study highlights the potential of CC as a functional food in the future while providing valuable insights for future research and identifying areas requiring further investigation.

The orientation of CpG conjugation on aluminum oxyhydroxide nanoparticles determines the immunostimulatory effects of combination adjuvants

In subunit vaccines, aluminum salts (Alum) are commonly used as adjuvants, but with limited cellular immune responses. To overcome this limitation, CpG oligodeoxynucleotides (ODNs) have been used in combination with Alum. However, current combined usage of Alum and CpG is limited to linear mixtures, and the underlying interaction mechanism between CpG and Alum is not well understood. Thus, we propose to chemically conjugate Alum nanoparticles and CpG (with 5' or 3' end exposed) to design combination adjuvants. Our study demonstrates that compared to the 3'-end exposure, the 5'-end exposure of CpG in combination adjuvants (Al-CpG-5') enhances the activation of bone-marrow derived dendritic cells (BMDCs) and promotes Th1 and Th2 cytokine secretion. We used the SARS-CoV-2 receptor binding domain (RBD) and hepatitis B surface antigen (HBsAg) as model antigens to demonstrate that Al-CpG-5' enhanced antigen-specific antibody production and upregulated cytotoxic T lymphocyte markers. Additionally, Al-CpG-5' allows for coordinated adaptive immune responses even at lower doses of both CpG ODNs and HBsAg antigens, and enhances lymph node transport of antigens and activation of dendritic cells, promoting Tfh cell differentiation and B cell activation. Our novel Alum-CPG strategy points the way towards broadening the use of nanoadjuvants for both prophylactic and therapeutic vaccines.

Evaluating the link between immune characteristics and attention deficit hyperactivity disorder through a bi-directional Mendelian randomization study

Context

Despite the recognition of attention deficit hyperactivity disorder (ADHD) as a multifaceted neurodevelopmental disorder, its core causes are still ambiguous. The objective of this study was to explore if the traits of circulating immune cells contribute causally to susceptibility to ADHD.

Methods

By employing a unified GWAS summary data covering 731 immune traits from the GWAS Catalog (accession numbers from GCST0001391 to GCST0002121), our analysis focused on the flow cytometry of lymphocyte clusters, encompassing 3,757 Sardinians, to identify genetically expected immune cells. Furthermore, we obtained summarized GWAS statistics from the Psychiatric Genomics Consortium to evaluate the genetic forecasting of ADHD. The studies employed ADHD2019 (20,183 cases and 35,191 controls from the 2019 GWAS ADHD dataset) and ADHD2022 (38,691 cases and 275,986 controls from the 2022 GWAS ADHD dataset). Through the examination of genome-wide association signals, we identified shared genetic variances between circulating immune cells and ADHD, employing the comprehensive ADHD2022 dataset. We primarily utilized inverse variance weighted (IVW) and weighted median methods in our Mendelian randomization research and sensitivity assessments to evaluate diversity and pleiotropy.

Results

After adjusting for false discovery rate (FDR), three distinct immunophenotypes were identified as associated with the risk of ADHD: CD33 in Im MDSC (OR=1.03, CI: 1.01~1.04, P=3.04×10-5, PFDR =0.015), CD8br NKT %T cell (OR=1.08, 95%CI: 1.04~1.12, P=9.33×10-5, PFDR =0.023), and CD8br NKT %lymphocyte (OR=1.08, 95%CI: 1.03~1.12, P=3.59×10-4, PFDR =0.066). Furthermore, ADHD showed no statistical effects on immunophenotypes. It's worth noting that 20 phenotypes exist where ADHD's appearance could diminish 85% of immune cells, including FSC-A in myeloid DC (β= -0.278, 95% CI: 0.616~0.931, P=0.008), CD3 in CD45RA- CD4+ (β= -0.233, 95% CI: 0.654~0.960, P=0.017), CD62L- monocyte AC (β=0.227, 95% CI: 0.038~1.518, P=0.019), CD33 in CD33br HLA DR+ CD14dim (β= -0.331, 95% CI: 0.543~0.950, P=0.020), and CD25 in CD39+ resting Treg (β=0.226, 95% CI: 1.522, P=0.022), and FSC-A in monocytes (β= -0.255, 95% CI: 0.621~0.967, P=0.234), among others.

Conclusion

Studies indicate that the immune system's response influences the emergence of ADHD. The findings greatly improve our understanding of the interplay between immune responses and ADHD risk, aiding in the development of treatment strategies from an immunological perspective.

Alterations in lipid metabolism accompanied by changes in protein and carotenoid content as spectroscopic markers of human T cell activation

This work aims to understand better the mechanism of cellular processes accompanying the activation of human T cells and to develop a novel, fast, label-free approach to identify molecular biomarkers for this process. The standard methodology for confirming the activation state of T cells is based on flow cytometry and using antibodies recognizing activation markers. The method provide high specificity detection but may be susceptible to background staining or non-specific secondary antibody reactions. Here, we evaluated the potential of Raman-based molecular imaging in distinguishing non-activated and activated human T cells. Confocal Raman microscopy was performed on T cells followed by chemometrics to obtain comprehensive molecular information, while Stimulated Raman Scattering imaging was used to quickly provide high-resolution images of selected cellular components of activated and non-activated cells. For the first time, carotenoids, lipids, and proteins were shown to be important biomarkers of T-cell activation. We found that T-cell activation was accompanied by lipid accumulation and loss of carotenoid content. Our findings on the biochemical, morphological, and structural changes associated with activated mature T cells provide insights into the molecular changes that occur during therapeutic manipulation of the immune response. The methodology for identifying activated T cells is based on a novel imaging method and supervised and unsupervised chemometrics. It unambiguously identifies specific and unique molecular changes without the need for staining, fixation, or any other sample preparation.

Macrophage-enriched novel functional long noncoding RNAs LRRC75A-AS1 and GAPLINC regulate polarization and innate immune responses

INTRODUCTION

Macrophages (Mφs) are functionally dynamic immune cells that bridge innate and adaptive immune responses; however, the underlying epigenetic mechanisms that control Mφ plasticity and innate immune functions are not well elucidated.

OBJECTIVE

To identify novel functions of macrophage-enriched lncRNAs in regulating polarization and innate immune responses.

METHODS

Total RNA isolated from differentiating monocyte-derived M1 and M2 Mφs was profiled for lncRNAs expression using RNAseq. Impact of LRRC75A-AS1, GAPLINC and AL139099.5 knockdown was examined on macrophage differentiation, polarization markers, phagocytosis, and antigen processing by flow cytometry and florescence microscopy. Cytokine profiles were examined by multiplex bead array and cytoskeletal signaling pathway genes were quantified by PCR-based array. Gingival biopsies were collected from periodontally healthy and diseased subjects to examine lncRNAs, M1/M2 marker expression.

RESULTS

Transcriptome profiling of M1 and M2 Mφs identified thousands of differentially expressed known and novel lncRNAs. We characterized three Mφ-enriched lncRNAs LRRC75A-AS1, GAPLINC and AL139099.5 in polarization and innate immunity. Knockdown of LRRC75A-AS1 and GAPLINC downregulated the Mφ differentiation markers and skewed Mφ polarization by decreasing M1 markers without a significant impact on M2 markers. LRRC75A-AS1 and GAPLINC knockdown also attenuated bacterial phagocytosis, antigen processing and inflammatory cytokine secretion in Mφs, supporting their functional role in potentiating innate immune functions. Mechanistically, LRRC75A-AS1 and GAPLINC knockdown impaired Mφ migration by downregulating the expression of multiple cytoskeletal signaling pathways suggesting their critical role in regulating Mφ migration. Finally, we showed that LRRC75A-AS1 and GAPLINC were upregulated in periodontitis and their expression correlates with higher M1 markers suggesting their role in macrophage polarization in vivo.

CONCLUSION

Our results show that polarized Mφs acquire a unique lncRNA repertoire and identified many previously unknown lncRNA sequences. LRRC75A-AS1 and GAPLINC, which are induced in periodontitis, regulate Mφ polarization and innate immune functions supporting their critical role in inflammation.

Exploiting the immune system in hepatic tumor targeting: Unleashing the potential of drugs, natural products, and nanoparticles

Hepatic tumors present a formidable challenge in cancer therapeutics, necessitating the exploration of novel treatment strategies. In recent years, targeting the immune system has attracted interest to augment existing therapeutic efficacy. The immune system in hepatic tumors includes numerous cells with diverse actions. CD8+ T lymphocytes, T helper 1 (Th1) CD4+ T lymphocytes, alternative M1 macrophages, and natural killer (NK) cells provide the antitumor immunity. However, Foxp3+ regulatory CD4+ T cells (Tregs), M2-like tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) are the key immune inhibitor cells. Tumor stroma can also affect these interactions. Targeting these cells and their secreted molecules is intriguing for eliminating malignant cells. The current review provides a synopsis of the immune system components involved in hepatic tumor expansion and highlights the molecular and cellular pathways that can be targeted for therapeutic intervention. It also overviews the diverse range of drugs, natural products, immunotherapy drugs, and nanoparticles that have been investigated to manipulate immune responses and bolster antitumor immunity. The review also addresses the potential advantages and challenges associated with these approaches.

A High Threshold of Biotherapeutic Aggregate Numbers is Needed to Induce an Immunogenic Response In Vitro, In Vivo, and in the Clinic

BACKGROUND AND PURPOSE

There is concern that subvisible aggregates in biotherapeutic drug products pose a risk to patient safety. We investigated the threshold of biotherapeutic aggregates needed to induce immunogenic responses.

METHODS AND RESULTS

Highly aggregated samples were tested in cell-based assays and induced cellular responses in a manner that depended on the number of particles. The threshold of immune activation varied by disease state (cancer, rheumatoid arthritis, allergy), concomitant therapies, and particle number. Compared to healthy donors, disease state patients showed an equal or lower response at the late phase (7 days), suggesting they may not have a higher risk of responding to aggregates. Xeno-het mice were used to assess the threshold of immune activation in vivo. Although highly aggregated samples (~ 1,600,000 particles/mL) induced a weak and transient immunogenic response in mice, a 100-fold dilution of this sample (~ 16,000 particles/mL) did not induce immunogenicity. To confirm this result, subvisible particles (up to ~ 18,000 particles/mL, containing aggregates and silicone oil droplets) produced under representative administration practices (created upon infusion of a drug product through an IV catheter) did not induce a response in cell-based assays or appear to increase the rate of adverse events or immunogenicity during phase 3 clinical trials.

CONCLUSION

The ability of biotherapeutic aggregates to elicit an immune response in vitro, in vivo, and in the clinic depends on high numbers of particles. This suggests that there is a high threshold for aggregates to induce an immunogenic response which is well beyond that seen in standard biotherapeutic drug products.

Amplifying Immune Responses: Microparticulate Vaccine Approach Against Breast Cancer

Introduction

The study focuses on evaluating the immune responses generated by a novel microparticulate murine breast cancer vaccine.

Methods

The methodology included the use of a co-culture model of dendritic cells (DCs), and T-cells to evaluate the immunotherapeutic responses generated by the vaccine.

Results

The study observed that the dendritic cells expressed significantly higher levels of MHC I, MHC II, CD 40, and CD 80 cell surface markers in the presence of the vaccine microparticles than the controls (p<0.05). This response was potentiated in the presence of an adjuvant, Poly (I:C). The study also demonstrated that the vaccine microparticles do not elicit inflammatory (TNF-alpha, IFN-gamma, IL-2, and IL-12) or immunosuppressive (IL-10) cytokine production when compared to the control.

Discussion

In conclusion, the study established the role of DCs in stimulating the cancer vaccine's adaptive immune responses.

Design and evaluation of a multiepitope vaccine for pancreatic cancer using immune-dominant epitopes derived from the signature proteome in expression datasets

Pancreatic cancer is a highly aggressive and often lethal malignancy with limited treatment options. Its late-stage diagnosis and resistance to conventional therapies make it a significant challenge in oncology. Immunotherapy, particularly cancer vaccines, has emerged as a promising avenue for treating pancreatic cancer. Multi-epitope vaccines, designed to target multiple epitopes derived from various antigens associated with pancreatic cancer, have gained attention as potential candidates for improving therapeutic outcomes. In this study, we have explored transcriptomics and protein expression databases to identify potential upregulated proteins in pancreatic cancer cells. After examining a total of 21,054 proteins from various databases, it was discovered that 143 proteins expressed differently in malignant and healthy cells. The CTL, HTL and BCE epitopes were predicted for the shortlisted proteins. 51,840 vaccine constructs were created by concatenating CTL, HTL, and B-cell epitopes in the respective sequences. The best 86 structures were selected from a set of 51,840 designs after they were analyzed for vaxijenicity, allergenicity, toxicity, and antigenicity scores. In further simulation of the immune response using constructs, it was found that 41417, 37961, and 40841 constructs could produce a strong immune response when injected. Further, it was found that construct 37961 showed stronger interaction and stability with TLR-9 as determined from the large-scale molecular dynamics simulations. Moreover, the 37961 construct has shown interactions with TLR-9 suggests its potential in inducing immune response. In addition, construct 37961 has shown 100% predicted solubility in the E. coli expression system. Overall, the study indicates the designed construct 37961 has the potential to induce an anti-tumor immune response and long-standing protection pending further studies.

The identification of signature genes and their relationship with immune cell infiltration in age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a prevalent source of visual impairment among the elderly population, and its incidence has risen in tandem with the increasing longevity of humans. Despite the progress made with anti-VEGF therapy, clinical outcomes have proven to be unsatisfactory.

METHOD

We obtained differentially expressed genes (DEGs) of AMD patients and healthy controls from the GEO database. GO and KEGG analyses were used to enrich the DEGs. Weighted gene coexpression network analysis (WGCNA) was used to identify modules related to AMD. SVM, random forest, and least absolute shrinkage and selection operator (LASSO) were employed to screen hub genes. Gene set enrichment analysis (GSEA) was used to explore the pathways in which these hub genes were enriched. CIBERSORT was utilized to analyze the relationship between the hub genes and immune cell infiltration. Finally, Western blotting and RT‒PCR were used to explore the expression of hub genes in AMD mice.

RESULTS

We screened 1084 DEGs in GSE29801, of which 496 genes were upregulated. These 1084 DEGs were introduced into the WGCNA, and 94 genes related to AMD were obtained. Seventy-nine overlapping genes were obtained by the Venn plot. These 79 genes were introduced into three machine-learning methods to screen the hub genes, and the genes identified by the three methods were TNC, FAP, SREBF1, and TGF-β2. We verified their diagnostic function in the GSE29801 and GSE103060 datasets. Then, the hub gene co-enrichment pathways were obtained by GO and KEGG analyses. CIBERSORT analysis showed that these hub genes were associated with immune cell infiltration. Finally, we found increased expression of TNC, FAP, SREBF1, and TGF-β2 mRNA and protein in the retinas of AMD mice.

CONCLUSION

We found that four hub genes, namely, FAP, TGF-β2, SREBF1, and TNC, have diagnostic significance in patients with AMD and are related to immune cell infiltration. Finally, we determined that the mRNA and protein expression of these hub genes was upregulated in the retinas of AMD mice.

P2X7 Receptor in Dendritic Cells and Macrophages: Implications in Antigen Presentation and T Lymphocyte Activation

The P2X7 receptor, a member of the P2X purinergic receptor family, is a non-selective ion channel. Over the years, it has been associated with various biological functions, from modulating to regulating inflammation. However, its emerging role in antigen presentation has captured the scientific community's attention. This function is essential for the immune system to identify and respond to external threats, such as pathogens and tumor cells, through T lymphocytes. New studies show that the P2X7 receptor is crucial for controlling how antigens are presented and how T cells are activated. These studies focus on antigen-presenting cells, like dendritic cells and macrophages. This review examines how the P2X7 receptor interferes with effective antigen presentation and activates T cells and discusses the fundamental mechanisms that can affect the immune response. Understanding these P2X7-mediated processes in great detail opens up exciting opportunities to create new immunological therapies.

The characteristics and alteration of peripheral immune function in patients with multiple system atrophy

Objective

Multiple system atrophy (MSA) is a degenerative disease. Immune dysfunction found to play a crucial role in the pathogenesis of this disease in the literature, while the characteristics of peripheral immune function remain unclear. This study aimed to investigate the characteristics and alterations of peripheral immune function in patients with MSA.

Methods

A case-control study was conducted between January 2021 to December 2022 at SanBo Brain Hospital, Capital Medical University, Beijing, China. A total of 74 participants were recruited, including 47 MSA patients and 27 non-MSA participants. Peripheral blood samples were collected from each participant. A total of 29 types of immune cells were measured using the flow cytometry analysis technology. Single-factor analysis and multiple-factor analysis (multiple linear regression models) were performed to determine the differences and risk factors in immune cells between the MSA and non-MSA groups.

Results

Alterations of the count or percentage of CD19+ B lymphocytes and CD3-CD56+ B lymphocytes in MSA patients were found in this study. The reductions of the count and percentage of CD19+ B lymphocytes were still robust after adjusting for variables of age, gender, body mass index, albumin, and hemoglobin. Furthermore, the reductions in the count and percentage of CD19+ B lymphocytes in the MSA patients were more significant in women and individuals aged 60 years old or above than in the non-MSA participants.

Conclusion

Our findings suggested that MSA patients may be influenced by B lymphocytes, particularly CD19+ cells. Therefore, the reductions in immune cells should be considered in the diagnosis and treatment of MSA. Further studies are warranted to confirm and expand upon these findings.

Innate and adaptive immunity to SARS-CoV-2 and predisposing factors

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), has affected all countries worldwide. Although some symptoms are relatively mild, others are still associated with severe and even fatal clinical outcomes. Innate and adaptive immunity are important for the control of SARS-CoV-2 infections, whereas a comprehensive characterization of the innate and adaptive immune response to COVID-19 is still lacking and the mechanisms underlying immune pathogenesis and host predisposing factors are still a matter of scientific debate. Here, the specific functions and kinetics of innate and adaptive immunity involved in SARS-CoV-2 recognition and resultant pathogenesis are discussed, as well as their immune memory for vaccinations, viral-mediated immune evasion, and the current and future immunotherapeutic agents. We also highlight host factors that contribute to infection, which may deepen the understanding of viral pathogenesis and help identify targeted therapies that attenuate severe disease and infection.

Self-Regulated and Bidirectional Communication in Synthetic Cell Communities

Cell-to-cell communication is not limited to a sender releasing a signaling molecule and a receiver perceiving it but is often self-regulated and bidirectional. Yet, in communities of synthetic cells, such features that render communication efficient and adaptive are missing. Here, we report the design and implementation of adaptive two-way signaling with lipid-vesicle-based synthetic cells. The first layer of self-regulation derives from coupling the temporal dynamics of the signal, H₂O₂, production in the sender to adhesions between sender and receiver cells. This way the receiver stays within the signaling range for the duration sender produces the signal and detaches once the signal fades. Specifically, H₂O₂ acts as both a forward signal and a regulator of the adhesions by activating photoswitchable proteins at the surface for the duration of the chemiluminescence. The second layer of self-regulation arises when the adhesions render the receiver permeable and trigger the release of a backward signal, resulting in bidirectional exchange. These design rules provide a concept for engineering multicellular systems with adaptive communication.

The Notch signaling pathway: a potential target for cancer immunotherapy

Dysregulation of the Notch signaling pathway, which is highly conserved across species, can drive aberrant epigenetic modification, transcription, and translation. Defective gene regulation caused by dysregulated Notch signaling often affects networks controlling oncogenesis and tumor progression. Meanwhile, Notch signaling can modulate immune cells involved in anti- or pro-tumor responses and tumor immunogenicity. A comprehensive understanding of these processes can help with designing new drugs that target Notch signaling, thereby enhancing the effects of cancer immunotherapy. Here, we provide an up-to-date and comprehensive overview of how Notch signaling intrinsically regulates immune cells and how alterations in Notch signaling in tumor cells or stromal cells extrinsically regulate immune responses in the tumor microenvironment (TME). We also discuss the potential role of Notch signaling in tumor immunity mediated by gut microbiota. Finally, we propose strategies for targeting Notch signaling in cancer immunotherapy. These include oncolytic virotherapy combined with inhibition of Notch signaling, nanoparticles (NPs) loaded with Notch signaling regulators to specifically target tumor-associated macrophages (TAMs) to repolarize their functions and remodel the TME, combining specific and efficient inhibitors or activators of Notch signaling with immune checkpoint blockers (ICBs) for synergistic anti-tumor therapy, and implementing a customized and effective synNotch circuit system to enhance safety of chimeric antigen receptor (CAR) immune cells. Collectively, this review aims to summarize how Notch signaling intrinsically and extrinsically shapes immune responses to improve immunotherapy.

Global Profiling of Differentiating Macrophages Identifies Novel Functional Long Non-coding RNAs Regulating Polarization and Innate Immune Responses

Macrophages (Mφ) are functionally dynamic immune cells that bridge innate and adaptive immune responses. However, the underlying epigenetic mechanisms that control the macrophage plasticity and innate immune functions are not well-elucidated. Here we performed transcriptome profiling of differentiating M1Mφ and M2Mφ and identified thousands of previously known and novel lncRNAs. We characterized three Mφ-enriched lncRNAs (LRRC75A-As1, GAPLINC and AL139099.5) with novel functions in Mφ differentiation, polarization and innate immunity. Knockdown of LRRC75A-As1, and GAPLINC downregulated Mφ differentiation markers CDw93 and CD68, and skewed macrophage polarization by decreasing M1 markers but had no significant impact on M2 markers. LRRC75A-As1, and GAPLINC RNAi in Mφ attenuated bacterial phagocytosis, antigen processing and inflammatory cytokine secretion supporting their functional role in potentiating innate immune functions. Mechanistically, lncRNA knockdown perturbed the expression of multiple cytoskeleton signaling thereby impairing Mφ migration suggesting their critical role in regulating macrophage polarity and motility. Together, our results show that Mφ acquire a unique repertoire of lncRNAs to shape differentiation, polarization and innate immune functions.

Recent advances in antigen targeting to antigen-presenting cells in veterinary medicine

Advances in antigen targeting in veterinary medicine have gained traction over the years as an alternative approach for diseases that remain a challenge for traditional vaccines. In addition to the nature of the immunogen, antigen-targeting success relies heavily on the chosen receptor for its direct influence on the elicited response that will ensue after antigen uptake. Different approaches using antibodies, natural or synthetic ligands, fused proteins, and DNA vaccines have been explored in various veterinary species, with pigs, cattle, sheep, and poultry as the most frequent models. Antigen-presenting cells can be targeted using a generic approach, such as broadly expressed receptors such as MHC-II, CD80/86, CD40, CD83, etc., or focused on specific cell populations such as dendritic cells or macrophages (Langerin, DC-SIGN, XCR1, DC peptides, sialoadhesin, mannose receptors, etc.) with contrasting results. Interestingly, DC peptides show high specificity to DCs, boosting activation, stimulating cellular and humoral responses, and a higher rate of clinical protection. Likewise, MHC-II targeting shows consistent results in enhancing both immune responses; an example of this strategy of targeting is the approved vaccine against the bovine viral diarrhea virus in South America. This significant milestone opens the door to continuing efforts toward antigen-targeting vaccines to benefit animal health. This review discusses the recent advances in antigen targeting to antigen-presenting cells in veterinary medicine, with a special interest in pigs, sheep, cattle, poultry, and dogs.

Nanoparticle-induced immune response: Health risk versus treatment opportunity?

Nanoparticles (NPs) are not only employed in many biomedical applications in an engineered form, but also occur in our environment, in a more hazardous form. NPs interact with the immune system through various pathways and can lead to a myriad of different scenarios, ranging from their quiet removal from circulation by macrophages without any impact for the body, to systemic inflammatory effects and immuno-toxicity. In the latter case, the function of the immune system is affected by the presence of NPs. This review describes, how both the innate and adaptive immune system are involved in interactions with NPs, together with the models used to analyse these interactions. These models vary between simple 2D in vitro models, to in vivo animal models, and also include complex all human organ on chip models which are able to recapitulate more accurately the interaction in the in vivo situation. Thereafter, commonly encountered NPs in both the environment and in biomedical applications and their possible effects on the immune system are discussed in more detail. Not all effects of NPs on the immune system are detrimental; in the final section, we review several promising strategies in which the immune response towards NPs can be exploited to suit specific applications such as vaccination and cancer immunotherapy.

Crosstalk of Transcriptional Regulators of Adaptive Immune System and microRNAs: An Insight into Differentiation and Development

MicroRNAs (miRNAs), as small regulatory RNA molecules, are involved in gene expression at the post-transcriptional level. Hence, miRNAs contribute to gene regulation of various steps of different cell subsets' differentiation, maturation, and activation. The adaptive immune system arm, which exhibits the most specific immune responses, is also modulated by miRNAs. The generation and maturation of various T-cell subsets concomitant with B-cells is under precise regulation of miRNAs which function directly on the hallmark genes of each cell subset or indirectly through regulation of signaling pathway mediators and/or transcription factors involved in this maturation journey. In this review, we first discussed the origination process of common lymphocyte progenitors from hematopoietic stem cells, which further differentiate into various T-cell subsets under strict regulation of miRNAs and transcription factors. Subsequently, the differentiation of B-cells from common lymphocyte progenitors in bone marrow and periphery were discussed in association with a network of miRNAs and transcription factors.

Repetitive Exposure to Bacteriophage Cocktails against Pseudomonas aeruginosa or Escherichia coli Provokes Marginal Humoral Immunity in Naïve Mice

Phage therapy of ventilator-associated pneumonia (VAP) is of great interest due to the rising incidence of multidrug-resistant bacterial pathogens. However, natural or therapy-induced immunity against therapeutic phages remains a potential concern. In this study, we investigated the innate and adaptive immune responses to two different phage cocktails targeting either Pseudomonas aeruginosa or Escherichia coli-two VAP-associated pathogens-in naïve mice without the confounding effects of a bacterial infection. Active or UV-inactivated phage cocktails or buffers were injected intraperitoneally daily for 7 days in C57BL/6J wild-type mice. Blood cell analysis, flow cytometry analysis, assessment of phage distribution and histopathological analysis of spleens were performed at 6 h, 10 days and 21 days after treatment start. Phages reached the lungs and although the phage cocktails were slightly immunogenic, phage injections were well tolerated without obvious adverse effects. No signs of activation of innate or adaptive immune cells were observed; however, both active phage cocktails elicited a minimal humoral response with secretion of phage-specific antibodies. Our findings show that even repetitive injections lead only to a minimal innate and adaptive immune response in naïve mice and suggest that systemic phage treatment is thus potentially suitable for treating bacterial lung infections.

Modelling of the Innate and Adaptive Immune Response to SARS Viral Infection, Cytokine Storm and Vaccination

In this work, we develop mathematical models of the immune response to respiratory viral infection, taking into account some particular properties of the SARS-CoV infections, cytokine storm and vaccination. Each model consists of a system of ordinary differential equations that describe the interactions of the virus, epithelial cells, immune cells, cytokines, and antibodies. Conventional analysis of the existence and stability of stationary points is completed by numerical simulations in order to study the dynamics of solutions. The behavior of the solutions is characterized by large peaks of virus concentration specific to acute respiratory viral infections. At the first stage, we study the innate immune response based on the protective properties of interferon secreted by virus-infected cells. Viral infection down-regulates interferon production. This competition can lead to the bistability of the system with different regimes of infection progression with high or low intensity. After that, we introduce the adaptive immune response with antigen-specific T- and B-lymphocytes. The resulting model shows how the incubation period and the maximal viral load depend on the initial viral load and the parameters of the immune response. In particular, an increase in the initial viral load leads to a shorter incubation period and higher maximal viral load. The model shows that a deficient production of antibodies leads to an increase in the incubation period and even higher maximum viral loads. In order to study the emergence and dynamics of cytokine storm, we consider proinflammatory cytokines produced by cells of the innate immune response. Depending on the parameters of the model, the system can remain in the normal inflammatory state specific for viral infections or, due to positive feedback between inflammation and immune cells, pass to cytokine storm characterized by the excessive production of proinflammatory cytokines. Finally, we study the production of antibodies due to vaccination. We determine the dose-response dependence and the optimal interval of vaccine dose. Assumptions of the model and obtained results correspond to the experimental and clinical data.

Combined supplementation with Lactobacillus sp. and Bifidobacterium thermacidophilum isolated from Tibetan pigs improves growth performance, immunity, and microbiota composition in weaned piglets

Probiotics, such as Lactobacillus and Bifidobacterium, promote growth in piglets by modulating gut microbiota composition and improving the host immune system. A strain of Lactobacillus sp. and Bifidobacterium thermacidophilum were previously isolated from fresh feces of Tibetan pigs. The effects of these isolated strains on growth performance, intestinal morphology, immunity, microbiota composition, and their metabolites were evaluated in weaned piglets. Thirty crossbred piglets were selected and fed either a basal diet (CON), a basal diet supplemented with aureomycin (ANT), or a basal diet supplemented with Lactobacillus sp. and B. thermacidophilum (LB) for 28 d. The piglets in the ANT and LB groups had significantly higher body weight gain than those in the CON group (P < 0.05). Piglets in the ANT and LB groups had regularly arranged villi and microvilli in the small intestine. Furthermore, they had improved immune function, as indicated by decreased serum concentrations of inflammatory cytokines (P < 0.05), improved components of immune cells in the blood, mesenteric lymph nodes, and spleen. Additionally, metagenomic sequencing indicated a significant shift in cecal bacterial composition and alterations in microbiota functional profiles following Lactobacillus sp. and B. thermacidophilum supplementation. Metabolomic results revealed that the metabolites were also altered, and Kyoto Encyclopedia of Genes and Genomes analysis revealed that several significantly altered metabolites were enriched in glycerophospholipid and cholesterol metabolism (P < 0.05). Furthermore, correlation analysis showed that several bacterial members were closely related to the alterations in metabolites, including Bacteroides sp., which were negatively correlated with triglyceride (16:0/18:0/20:4[5Z,8Z,11Z,14Z]), the metabolite that owned the highest variable importance of projection scores. Collectively, our findings suggest that combined supplementation with Lactobacillus sp. and B. thermacidophilum significantly improved the growth performance, immunity, and microbiota composition in weaned piglets, making them prospective alternatives to antibiotics in swine production.

B-1 cells in immunotoxicology: Mechanisms underlying their response to chemicals and particles

Since their discovery nearly 40 years ago, B-1 cells have continued to challenge the boundaries between innate and adaptive immunity, as well as myeloid and lymphoid functions. This B-cell subset ensures early immunity in neonates before the development of conventional B (B-2) cells and respond to immune injuries throughout life. B-1 cells are multifaceted and serve as natural- and induced-antibody-producing cells, phagocytic cells, antigen-presenting cells, and anti-/pro-inflammatory cytokine-releasing cells. This review retraces the origin of B-1 cells and their different roles in homeostatic and infectious conditions before focusing on pollutants comprising contact-sensitivity-inducing chemicals, endocrine disruptors, aryl hydrocarbon receptor (AHR) ligands, and reactive particles.

Rapid screening and scaled manufacture of immunogenic virus-like particles in a tobacco BY-2 cell-free protein synthesis system

Several vaccine platforms have been developed to fight pathogenic threats, with Virus-Like Particles (VLPs) representing a very promising alternative to traditional platforms. VLPs trigger strong and lasting humoral and cellular immune responses with fewer safety concerns and higher stability than other platforms. The use of extensively characterized carrier VLPs modified with heterologous antigens was proposed to circumvent the viral complexity of specific viruses that could lead to poor VLP assembly and yields. Although carrier VLPs have been successfully produced in a wide variety of cell-based systems, these are limited by low protein yields and protracted clone selection and optimization workflows that limit VLP screening approaches. In response, we have demonstrated the cell-free protein synthesis (CFPS) of several variants of the hepatitis B core (HBc) carrier VLP using a high-yielding tobacco BY-2 lysate (BYL). High VLP yields in the BYL system allowed in-depth characterization of HBc variants. Insertion of heterologous sequences at the spike region of the HBc monomer proved more structurally demanding than at the N-terminus but removal of the C-terminal domain allowed higher particle flexibility and insert acceptance, albeit at the expense of thermal and chemical stability. We also proved the possibility to scale the CFPS reaction up to 1L in batch mode to produce 0.45 grams of the native HBc VLP within a 48-hour reaction window. A maximum yield of 820 µg/ml of assembled VLP particles was observed at the 100µl scale and most remarkably the CFPS reaction was successfully scaled from 50µl to 1L without any reduction in protein yield across this 20,000-fold difference in reaction volumes. We subsequently proved the immunogenicity of BYL-derived VLPs, as flow cytometry and microscopy clearly showed prompt recognition and endocytosis of fluorescently labelled VLPs by human dendritic cells. Triggering of inflammatory cytokine production in human peripheral blood mononuclear cells was also quantitated using a multiplex assay. This research establishes BYL as a tool for rapid production and microscale screening of VLP variants with subsequent manufacturing possibilities across scales, thus accelerating discovery and implementation of new vaccine candidates using carrier VLPs.

miRNA effects on gut homeostasis: therapeutic implications for inflammatory bowel disease

Inflammatory bowel disease (IBD) spans a range of chronic conditions affecting the gastrointestinal (GI) tract, which are marked by intermittent flare-ups and remissions. IBD results from microbial dysbiosis or a defective mucosal barrier in the gut that triggers an inappropriate immune response in a genetically susceptible person, altering the immune-microbiome axis. In this review, we discuss the regulatory roles of miRNAs, small noncoding RNAs with gene regulatory functions, in the stability and maintenance of the gut immune-microbiome axis, and detail the challenges and recent advances in the use of miRNAs as putative therapeutic agents for treating IBD.

Glycoconjugates: Synthesis, Functional Studies, and Therapeutic Developments

Glycoconjugates are major constituents of mammalian cells that are formed via covalent conjugation of carbohydrates to other biomolecules like proteins and lipids and often expressed on the cell surfaces. Among the three major classes of glycoconjugates, proteoglycans and glycoproteins contain glycans linked to the protein backbone via amino acid residues such as Asn for N-linked glycans and Ser/Thr for O-linked glycans. In glycolipids, glycans are linked to a lipid component such as glycerol, polyisoprenyl pyrophosphate, fatty acid ester, or sphingolipid. Recently, glycoconjugates have become better structurally defined and biosynthetically understood, especially those associated with human diseases, and are accessible to new drug, diagnostic, and therapeutic developments. This review describes the status and new advances in the biological study and therapeutic applications of natural and synthetic glycoconjugates, including proteoglycans, glycoproteins, and glycolipids. The scope, limitations, and novel methodologies in the synthesis and clinical development of glycoconjugates including vaccines, glyco-remodeled antibodies, glycan-based adjuvants, glycan-specific receptor-mediated drug delivery platforms, etc., and their future prospectus are discussed.

Conserved Role of mTORC1 Signaling in B Cell Immunity in Teleost Fish

Mammalian studies have demonstrated that B cell immune responses are regulated by mechanistic target of rapamycin complex 1 (mTORC1) signaling. Teleost fish represent the oldest living bony vertebrates that contain bona fide B cells. So far, whether the regulatory mechanism of mTORC1 signaling in B cells occurred in teleost fish is still unknown. In this study, we developed a fish model by using rapamycin (RAPA) treatment to inhibit mTORC1 signaling and demonstrated the role of mTORC1 signaling in teleost B cells. In support, we found inhibition of mTORC1 signaling by RAPA decreased the phagocytic capacity, proliferation, and Ig production of B cells. Critically, Flavobacterium columnare induced specific IgM binding in serum, and these titers were significantly inhibited by RAPA treatment, thus decreasing Ab-mediated agglutination of F. columnare and significantly increasing the susceptibility of fish upon F. columnare reinfection. Collectively, our findings elucidated that the mTORC1 pathway is evolutionarily conserved in regulating B cell responses, thus providing a new point for understanding the B cells functions in teleost fish.

Immune Biomarkers in Blood from Sarcoma Patients: A Pilot Study

The main role of the host immune system is to identify and eliminate cancer cells, which is a complex process, but it is not a fail-safe mechanism. Many sarcoma patients succumb to this disease despite treatments rendered. The aim of this pilot study was to compare the levels of CD4+ T-cells, T-regulatory (Treg) cells, and cytokines such as tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin-17A (IL-17A), and transforming growth factor-beta-1 (TGF-β1) in peripheral blood leukocytes of sarcoma patients and healthy controls. For gene expression studies, total ribonucleic acid (RNA) was extracted from peripheral blood leukocytes and genes that were differentially regulated in peripheral blood leukocytes of sarcoma patients compared with healthy controls were determined using a commercial T-helper cell differentiation quantitative polymerase chain reaction (qPCR) array. Flow cytometer analysis was performed on blood samples from 26 sarcoma patients and 10 healthy controls to identify the levels of CD4+ T-cells and T-reg cells. The level of cytokines in plasma and culture supernatant were quantified using commercial enzyme-linked immunosorbent assay (ELISA) kits. A marked reduction in the percentage of CD4+ T-cells (p = 0.037) and levels of TNF-α (p = 0.004) and IFN-γ (0.010) was observed in sarcoma patients. Gene expression analysis showed five genes (homeobox A10 (HOXA10), GATA binding protein 3 (GATA3), prostaglandin D2 receptor 2 (PTGDR2), thymocyte selection associated high mobility group box (TOX), and C-C motif chemokine receptor 3 (CCR3)) were dysregulated (p < 0.05) in sarcoma patients. This study suggests that T-helper-1 immune responses are reduced in sarcoma patients.

Cross-Talk between the Cytokine IL-37 and Thyroid Hormones in Modulating Chronic Inflammation Associated with Target Organ Damage in Age-Related Metabolic and Vascular Conditions

Chronic inflammation is considered to be the main mechanism contributing to the development of age-related metabolic and vascular conditions. The phases of chronic inflammation that mediate the progression of target organ damage in these conditions are poorly known, however. In particular, there is a paucity of data on the link between chronic inflammation and metabolic disorders. Based on some of our own results and recent developments in our understanding of age-related inflammation as a whole-body response, we discuss the hypothesis that cross-talk between the cytokine IL-37 and thyroid hormones could be the key regulatory mechanism that justifies the metabolic effects of chronic tissue-related inflammation. The cytokine IL-37 is emerging as a strong natural suppressor of the chronic innate immune response. The effect of this cytokine has been identified in reversing metabolic costs of chronic inflammation. Thyroid hormones are known to regulate energy metabolism. There is a close link between thyroid function and inflammation in elderly individuals. Nonlinear associations between IL-37 and thyroid hormones, considered within the wider clinical context, can improve our understanding of the phases of chronic inflammation that are associated with target organ damage in age-related metabolic and vascular conditions.

Machine Learning-Assisted Screening of Herbal Medicine Extracts as Vaccine Adjuvants

Adjuvants are important vaccine components, composed of a variety of chemical and biological materials that enhance the vaccine antigen-specific immune responses by stimulating the innate immune cells in both direct and indirect manners to produce a variety cytokines, chemokines, and growth factors. It has been developed by empirical methods for decades and considered difficult to choose a single screening method for an ideal vaccine adjuvant, due to their diverse biochemical characteristics, complex mechanisms of, and species specificity for their adjuvanticity. We therefore established a robust adjuvant screening strategy by combining multiparametric analysis of adjuvanticity in vivo and immunological profiles in vitro (such as cytokines, chemokines, and growth factor secretion) of various library compounds derived from hot-water extracts of herbal medicines, together with their diverse distribution of nano-sized physical particle properties with a machine learning algorithm. By combining multiparametric analysis with a machine learning algorithm such as rCCA, sparse-PLS, and DIABLO, we identified that human G-CSF and mouse RANTES, produced upon adjuvant stimulation in vitro, are the most robust biological parameters that can predict the adjuvanticity of various library compounds. Notably, we revealed a certain nano-sized particle population that functioned as an independent negative parameter to adjuvanticity. Finally, we proved that the two-step strategy pairing the negative and positive parameters significantly improved the efficacy of screening and a screening strategy applying principal component analysis using the identified parameters. These novel parameters we identified for adjuvant screening by machine learning with multiple biological and physical parameters may provide new insights into the future development of effective and safe adjuvants for human use.

Using metabolomics to discover the immunomodulator activity of food plants

Many edible plants exhibit immunomodulator activities that have beneficial effects on human health. These activities include the ability to activate, multiply, or suppress elements of the immune response. Some of these plants promote health by strengthening host defences against different diseases. In this article, we provide a comprehensive review of the constituents of several edible plants, their immunomodulatory activity, and mechanism of actions for Carica papaya, Coffea sp, Asparagus cochinchinensis, Dioscorea alata, beans, mushrooms, herbs, spices, and several vegetables. The studies reported here are pre-clinical (in vitro and in vivo) and clinical studies (limited in number). The bioactive compounds responsible for the immunomodulator activity of these plants were yet to be identified. This is because the plant is naturally a complex mixture, whilst the immune system is also an intricate system involving many cells and cytokines/chemokines. Metabolomics is a key tool for conducting global profiling of metabolites in a complex system. Therefore, it offers the ability to identify the presence of compounds in plant extracts associated with their immunomodulation effects. Likewise, metabolomics can also be used to detect any changes to metabolites in the cell as a response to treatment. Therefore, affected metabolic pathways that lead to the activation of certain immune responses can be determined from one single experiment. However, we found in this review that the use of a metabolomics approach is not yet fully developed for an immunomodulator study of food plants. This is important for the direction of future research in this field because unlike medicinal plants, food plants are consumed on a regular basis in small amounts with more obvious effects on the immune system. Information about possible bioactive compounds, their interactions (synergism, antagonism), and how the human body responds to them should be studied in a more holistic way.

Adaptive Cellular Immunity against African Swine Fever Virus Infections

African swine fever virus (ASFV) remains a threat to global pig populations. Infections with ASFV lead to a hemorrhagic disease with up to 100% lethality in Eurasian domestic and wild pigs. Although myeloid cells are the main target cells for ASFV, T cell responses are impacted by the infection as well. The complex responses remain not well understood, and, consequently, there is no commercially available vaccine. Here, we review the current knowledge about the induction of antiviral T cell responses by cells of the myeloid lineage, as well as T cell responses in infected animals, recent efforts in vaccine research, and T cell epitopes present in ASFV.

Advances in allergen-specific immune cell measurements for improved detection of allergic sensitization and immunotherapy responses

Over the past two decades, precision medicine has advanced diagnostics and treatment of allergic diseases. Component-resolved analysis of allergen sensitization facilitates stratification of patients. Furthermore, new formulations of allergen immunotherapy (AIT) products can more effectively deliver the relevant components. Molecular insights from the identification of allergen component sensitization and clinical outcomes of treatment with new AIT formulations can now be utilized for a deeper understanding of the nature of the pathogenic immune response in allergy and how this can be corrected by AIT. Fundamental in these processes are the allergen-specific B and T cells. Within the large B- and T-cell compartments, only those that specifically recognize the allergen with their immunoglobulin (Ig) or T-cell receptor (TCR), respectively, are of clinical relevance. With peripheral blood allergen-specific B- and T-cell frequencies below 1%, bulk cell analysis is typically insufficiently sensitive. We here review the latest technologies to detect allergen-specific B and T cells, as well as new developments in utilizing these tools for diagnostics and therapy monitoring to advance precision medicine for allergic diseases.

Immunity Profiling of COVID-19 Infection, Dynamic Variations of Lymphocyte Subsets, a Comparative Analysis on Four Different Groups

Background: A novel coronavirus (SARS-CoV-2)-induced pneumonia (COVID-19) emerged in December 2019 in China, spreading worldwide. The aim of the present investigation was to evaluate the immunological response and the clinical subset of peripheral lymphocyte subset alteration in COVID-19 infection. Methods: the study was conducted on four different clinical groups (n = 4; total n = 138). Each individual was assigned to different groups based on specific criteria evaluated at the admission such as fever, dyspnea, arterial blood gas analysis (ABG), oral-nasopharyngeal swab/RT-PCR, and thoracic CT-scan. Treatment was performed only after blood samples were collected from each patient (PP and PP) at day 1. The blood samples were analyzed and tested the same day (CBC and Flowcytometry). The positive–positive group (PP n = 45; F = 18/ M = 27; median age = 62.33), comprised individuals affected by COVID-19 who showed fever, dyspnea (ABG = pO2 < 60), confirmed positive by oral-nasopharyngeal swab/RT-PCR and with CT-scan showing ground-glass opacities. The negative–positive (NP; n = 37; F = 11/M = 26; median age = 75.94) or “COVID-like” group comprised individuals with fever and dyspnea (ABG = pO2 < 60), who tested negative to nasopharyngeal swab/RT-PCR, with CT-scans showing ground-glass opacities in the lungs. The negative–affected group (NA; n = 40; F = 14/M = 26; median age = 58.5) included individuals negative to COVID-19 (RT-PCR) but affected by different chronic respiratory diseases (the CT-scans didn’t show ground-glass opacities). Finally, the negative–negative group (NN; n = 16; F = 14/M = 2) included healthy patients (NN; n = 16; median age = 42.62). Data and findings were collected and compared. Results: Lymphocytes (%) cells showed a decline in COVID-19 patients. The subsets showed a significant association with the inflammatory status in COVID-19, especially with regard to increased neutrophils, T-killer, T-active, T-suppressor, and T-CD8+CD38+ in individuals belong to the either COVID-19 and Covid-like NP group. Conclusions: Peripheral lymphocyte subset alteration was associated with the clinical characteristics and progression of COVID-19. The level of sub-set cells T-lymphocytes (either high or low) and B-lymphocytes could be used as an independent predictor for COVID-19 severity and treatment efficacy.

In vitro immunization approach to generate specific murine monoclonal IgG antibodies

Generating a monoclonal antibody to date is a time intense process that requires immunization of laboratory animals. The transfer of the humoral immune response into in vitro settings enables a shortening of this process and circumvents the necessity of in vivo immunization. However, to orchestrate the complex interplay of dendritic cells, T and B lymphocytes in vitro is very challenging. We therefore aimed for a simplified approach focusing on the protagonist of antibody production: the B lymphocyte. We activated purified murine B lymphocytes alone in vitro by using combinations of antigen and stimuli. We were able to induce a specific antibody response within ten days of culture against a viral coat protein as model antigen. Antibodies were of both IgM and IgG subclass. The stimulated B lymphocytes were transformed into permanently antibody-producing hybridomas by cell fusion technology. We furthermore used this method to induce a specific antibody response against L. pneumophilain vitro. We thus established a useful and effective in vitro protocol to generate monoclonal antibodies. By overcoming the necessity of in vivo immunization this protocol may be the first step towards a universal strategy to generate antibodies from various species.

Space Radiation Protection Countermeasures in Microgravity and Planetary Exploration

BACKGROUND

Space radiation is one of the principal environmental factors limiting the human tolerance for space travel, and therefore a primary risk in need of mitigation strategies to enable crewed exploration of the solar system.

METHODS

We summarize the current state of knowledge regarding potential means to reduce the biological effects of space radiation. New countermeasure strategies for exploration-class missions are proposed, based on recent advances in nutrition, pharmacologic, and immune science.

RESULTS

Radiation protection can be categorized into (1) exposure-limiting: shielding and mission duration; (2) countermeasures: radioprotectors, radiomodulators, radiomitigators, and immune-modulation, and; (3) treatment and supportive care for the effects of radiation. Vehicle and mission design can augment the overall exposure. Testing in terrestrial laboratories and earth-based exposure facilities, as well as on the International Space Station (ISS), has demonstrated that dietary and pharmacologic countermeasures can be safe and effective. Immune system modulators are less robustly tested but show promise. Therapies for radiation prodromal syndrome may include pharmacologic agents; and autologous marrow for acute radiation syndrome (ARS).

CONCLUSIONS

Current radiation protection technology is not yet optimized, but nevertheless offers substantial protection to crews based on Lunar or Mars design reference missions. With additional research and human testing, the space radiation risk can be further mitigated to allow for long-duration exploration of the solar system.

Immune profiles of male giant panda (Ailuropoda melanoleuca) during the breeding season

Background

The giant panda (Ailuropoda melanoleuca) is a threatened endemic Chinese species and a flagship species of national and global conservation concern. Life history theory proposes that reproduction and immunity can be mutually constraining and interrelated. Knowledge of immunity changes of male giant pandas during the breeding season is limited.

Results

Here, we researched peripheral blood gene expression profiles associated with immunity. Thirteen captive giant pandas, ranging from 9 to 11 years old, were divided into two groups based on their reproductive status. We identified 318 up-regulated DEGs and 43 down-regulated DEGs, which were enriched in 87 GO terms and 6 KEGG pathways. Additionally, we obtained 45 immune-related genes with altered expression, mostly up-regulated, and identified four hub genes HSPA4, SUGT1, SOD1, and IL1B in PPI analysis. These 45 genes were related to pattern recognition receptors, autophagy, peroxisome, proteasome, natural killer cell, antigen processing and presentation. SUGT1 and IL1B were related to pattern recognition receptors. HSP90AA1 was the most up-regulated gene and is a member of heat shock protein 90 family. HSP90 contributes to the translocation of extracellular antigen. KLRD1 encodes CD94, whose complex is an inhibitor of the cytotoxic activity of NK cells, was down-regulated. IGIP, which has the capability of inducing IgA production by B cells, was down-regulated, suggesting low concentration of IgA in male giant pandas. Our results suggest that most immune-related genes were up-regulated and more related to innate immune than adaptive immune.

Conclusions

Our results indicated that breeding male giant pandas presented an immunoenhancement in innate immunity, enhanced antigen presentation and processing in cellular immunity compared to non-breeding males. The humoral immunity of male giant pandas may show a tendency to decrease during the breeding season. This study will provide a foundation for further studies of immunity and reproduction in male giant pandas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07456-x.

Air Pollution and Polyclonal Elevation of Serum Free Light Chains: An Assessment of Adaptive Immune Responses in the Prospective Heinz Nixdorf Recall Study

BACKGROUND

Residential exposure to air pollution (AP) has been shown to activate the immune system (IS). Although innate immune responses to AP have been studied extensively, investigations on the adaptive IS are scarce.

OBJECTIVES

The aim of this study was to investigate the association between short- to long-term AP exposure and polyclonal free light chains (FLC) produced by plasma cells.

METHODS

We used repeated data from three examinations (t0: 2000-2003; t1: 2006-2008; and t2: 2011-2015) of the population-based German Heinz Nixdorf Recall cohort of initially 4,814 participants (45-75 y old). Residential exposure to total and source-specific particulate matter (PM) with an aerodynamic diameter of 10 or 2.5μm (PM10 and PM2.5 respectively), nitrogen dioxide (NO2), and particle number concentrations (accumulation mode; PNAM) was estimated using a chemistry transport model with different time windows (1- to 365-d mean ± standard deviation) before blood draw. We applied linear mixed models with a random participant intercept to estimate associations between total, traffic- and industry-related AP exposures and log-transformed FLC, controlling for examination time, sociodemographic and lifestyle variables, estimated glomerular filtration rate and season.

RESULTS

Analyzing 9,933 observations from 4,455 participants, we observed generally positive associations between AP exposures and FLC. We observed strongest associations with middle-term exposures, e.g., 3.0% increase in FLC (95% confidence interval: 1.8%, 4.3%) per interquartile range increase in 91-d mean of NO2 (14.1μg/m³). Across the different pollutants, NO2 showed strongest associations with FLC, followed by PM10 and PNAM. Effect estimates for traffic-related exposures were mostly higher compared with total exposures. Although NO2 and PNAM estimates remained stable upon adjustment for PM, PM estimates decreased considerably upon adjustment for NO2 and PNAM.

DISCUSSION

Our results suggest that middle-term AP exposures in particular might be positively associated with activation of the adaptive IS. Traffic-related PM, PNAM, and NO2 showed strongest associations. https://doi.org/10.1289/EHP7164.

Investigating the Interaction between Negative Strand RNA Viruses and Their Hosts for Enhanced Vaccine Development and Production

The current pandemic has highlighted the ever-increasing risk of human to human spread of zoonotic pathogens. A number of medically-relevant zoonotic pathogens are negative-strand RNA viruses (NSVs). NSVs are derived from different virus families. Examples like Ebola are known for causing severe symptoms and high mortality rates. Some, like influenza, are known for their ease of person-to-person transmission and lack of pre-existing immunity, enabling rapid spread across many countries around the globe. Containment of outbreaks of NSVs can be difficult owing to their unpredictability and the absence of effective control measures, such as vaccines and antiviral therapeutics. In addition, there remains a lack of essential knowledge of the host–pathogen response that are induced by NSVs, particularly of the immune responses that provide protection. Vaccines are the most effective method for preventing infectious diseases. In fact, in the event of a pandemic, appropriate vaccine design and speed of vaccine supply is the most critical factor in protecting the population, as vaccination is the only sustainable defense. Vaccines need to be safe, efficient, and cost-effective, which is influenced by our understanding of the host–pathogen interface. Additionally, some of the major challenges of vaccines are the establishment of a long-lasting immunity offering cross protection to emerging strains. Although many NSVs are controlled through immunisations, for some, vaccine design has failed or efficacy has proven unreliable. The key behind designing a successful vaccine is understanding the host–pathogen interaction and the host immune response towards NSVs. In this paper, we review the recent research in vaccine design against NSVs and explore the immune responses induced by these viruses. The generation of a robust and integrated approach to development capability and vaccine manufacture can collaboratively support the management of outbreaking NSV disease health risks.

The Role of Glycosylation in Inflammatory Diseases

The diversity of glycan presentation in a cell, tissue and organism is enormous, which reflects the huge amount of important biological information encoded by the glycome which has not been fully understood. A compelling body of evidence has been highlighting the fundamental role of glycans in immunity, such as in development, and in major inflammatory processes such as inflammatory bowel disease, systemic lupus erythematosus and other autoimmune disorders. Glycans play an instrumental role in the immune response, integrating the canonical circuits that regulate innate and adaptive immune responses. The relevance of glycosylation in immunity is demonstrated by the role of glycans as important danger-associated molecular patterns and pathogen-associated molecular patterns associated with the discrimination between self and non-self; also as important regulators of the threshold of T cell activation, modulating receptors signalling and the activity of both T and other immune cells. In addition, glycans are important determinants that regulate the dynamic crosstalk between the microbiome and immune response. In this chapter, the essential role of glycans in the immunopathogenesis of inflammatory disorders will be presented and its potential clinical applications (diagnosis, prognosis and therapeutics) will be highlighted.

Systematic Review of Multi-Omics Approaches to Investigate Toxicological Effects in Macrophages

Insights into the modes of action (MoAs) of xenobiotics are of utmost importance for the definition of adverse outcome pathways (AOPs), which are essential for a mechanism-based risk assessment. A well-established strategy to reveal MoAs of xenobiotics is the use of omics. However, often an even more comprehensive approach is needed, which can be achieved using multi-omics. Since the immune system plays a central role in the defense against foreign substances and pathogens, with the innate immune system building a first barrier, we systematically reviewed multi-omics studies investigating the effects of xenobiotics on macrophages. Surprisingly, only nine publications were identified, combining proteomics with transcriptomics or metabolomics. We summarized pathways and single proteins, transcripts, or metabolites, which were described to be affected upon treatment with xenobiotics in the reviewed studies, thus revealing a broad range of effects. In summary, we show that macrophages are a relevant model system to investigate the toxicological effects induced by xenobiotics. Furthermore, the multi-omics approaches led to a more comprehensive overview compared to only one omics layer with slight advantages for combinations that complement each other directly, e.g., proteome and metabolome.

Disease-Specific Expression of Conjunctiva Associated Lymphoid Tissue (CALT) in Mouse Models of Dry Eye Disease and Ocular Allergy

Conjunctiva-associated tissue (CALT) is assumed to play a crucial role in the immune system of the ocular surface. Its function in several ocular surface diseases (OSD) is still not fully understood. This study investigates the function of CALT in mouse models of dry-eye disease and ocular allergy. Since antigen-presentation is the central similarity in the pathologies, this study focuses on antigen-presentation in CALT Morphology and the expression of CALT, which was investigated in mice after induction of dry-eye, ocular allergy, topical antigen-stimulation, and after local depletion of phagocytic cells. Antigen uptake was investigated after the application of fluorescent ovalbumin (OVA). OSD influences the appearance and morphology of CALT in a disease-dependent manner. Ocular allergy leads to an increase and dry-eye disease to a decrease in number and size of CALT. The development of CALT is dependent on the presence of APCs. Professional APCs are present in CALT, and soluble antigen is transported into the follicle. CALT appearance is disease-specific and indicative of differing functions. Although the specific involvement of CALT in OSD needs further study, the existence of functional APCS and antigen-uptake supports the hypothesis that CALT is an immunological key player at the ocular surface.

Nucleic Acid-Based Approaches for Tumor Therapy

Within the last decade, the introduction of checkpoint inhibitors proposed to boost the patients' anti-tumor immune response has proven the efficacy of immunotherapeutic approaches for tumor therapy. Furthermore, especially in the context of the development of biocompatible, cell type targeting nano-carriers, nucleic acid-based drugs aimed to initiate and to enhance anti-tumor responses have come of age. This review intends to provide a comprehensive overview of the current state of the therapeutic use of nucleic acids for cancer treatment on various levels, comprising (i) mRNA and DNA-based vaccines to be expressed by antigen presenting cells evoking sustained anti-tumor T cell responses, (ii) molecular adjuvants, (iii) strategies to inhibit/reprogram tumor-induced regulatory immune cells e.g., by RNA interference (RNAi), (iv) genetically tailored T cells and natural killer cells to directly recognize tumor antigens, and (v) killing of tumor cells, and reprograming of constituents of the tumor microenvironment by gene transfer and RNAi. Aside from further improvements of individual nucleic acid-based drugs, the major perspective for successful cancer therapy will be combination treatments employing conventional regimens as well as immunotherapeutics like checkpoint inhibitors and nucleic acid-based drugs, each acting on several levels to adequately counter-act tumor immune evasion.

A Review of Immunomodulatory Effects of Fluoroquinolones

Past researches indicate that some types of antibiotics, apart from their antimicrobial effects, have some other important effects which indirectly are exerted by modulating and regulating the immune system's mediators. Among the compounds with antimicrobial effects, fluoroquinolones (FQs) are known as synthetic antibiotics, which exhibit the property of decomposing of DNA and prevent bacterial growth by inactivating the enzymes involved in DNA twisting, including topoisomerase II (DNA gyrase) and IV. Interestingly, immune responses are indirectly modulated by FQs through suppressing pro-inflammatory cytokines, such as interleukin 1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-α), and super-inducing IL-2, which tend to increase both the growth and activity of T and B lymphocytes. In addition, they affect the development of immune responses by influencing of expression of other cytokines and mediators. This study aims to review past research on the immunomodulatory effects of FQs on the expression of cytokines, especially IL-2 and to discuss controversial investigations.

Impaired inflammatory state of the endometrium: a multifaceted approach to endometrial inflammation. Current insights and future directions

New insights into the complex and fine-regulated inflammatory mechanisms involved in the endometrium reveal multiple facets to the problem of endometrial inflammation. However, the entity termed chronic endometritis is to date restricted to infectious etiology and managed with antibiotics. Conversely, the concept of impaired inflammatory state of the endometrium (IISE) provides a more global approach to defective endometrial inflammation, considering both infectious and non-infectious etiology. A non-systematic review was done through a search on MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database and Web of Science, research registers. Pertinent original and review articles, published in English or French until December 31, 2019, were selected. A compelling body of evidence demonstrates transient, repeated and persistent IISE to be a major factor of most problematic disorders in obstetrics/gynecology, such as endometrial polyps, unexplained infertility, miscarriage, placenta-related pathology and endometrial cancer. When scheduled accordingly, hysteroscopy can play a key role in the IISE assessment. Robust data suggests the pertinence of minimal-effective anti-inflammatory regimens for therapeutic IISE targeting. This review provides a comprehensive update on the multiple facets of inflammation in the endometrial physiology and pathology. Further research is needed to improve classification, diagnosis and treatment of IISE.

Impact of Respiratory Syncytial Virus Infection on Host Functions: Implications for Antiviral Strategies

Respiratory syncytial virus (RSV) is one of the leading causes of viral respiratory tract infection in infants, the elderly, and the immunocompromised worldwide, causing more deaths each year than influenza. Years of research into RSV since its discovery over 60 yr ago have elucidated detailed mechanisms of the host-pathogen interface. RSV infection elicits widespread transcriptomic and proteomic changes, which both mediate the host innate and adaptive immune responses to infection, and reflect RSV's ability to circumvent the host stress responses, including stress granule formation, endoplasmic reticulum stress, oxidative stress, and programmed cell death. The combination of these events can severely impact on human lungs, resulting in airway remodeling and pathophysiology. The RSV membrane envelope glycoproteins (fusion F and attachment G), matrix (M) and nonstructural (NS) 1 and 2 proteins play key roles in modulating host cell functions to promote the infectious cycle. This review presents a comprehensive overview of how RSV impacts the host response to infection and how detailed knowledge of the mechanisms thereof can inform the development of new approaches to develop RSV vaccines and therapeutics.