New insights into B cells as antigen presenting cells

Increased Natural Killer (NK)-cell cytotoxicity and Trypanosoma cruzi-specific memory B cells in subjects with discordant serology for Chagas disease

The presence of memory T cell specific for Trypanosoma cruzi in subjects with discordant serology for Chagas disease supports a cleared infection in these subjects. Using high-dimensional flow cytometry, ELISPOT assays and quantitative PCR, antibody-secreting cells and memory B cells specific for T. cruzi, total B-cell phenotypes, innate immune responses and parasite DNA were evaluated in serodiscordant, seropositive and seronegative subjects for T. cruzi infection. T. cruzi-specific memory B cells but no antibody-secreting cells specific for T. cruzi, increased proportion of nonclassical monocytes and increased levels of polyfunctional NK cells were found in serodiscordant compared with seropositive subjects. None of the serodiscordant subjects evaluated showed detectable parasite DNA, most of them did not show cardiac abnormalities and a group of them had had confirmed positive serology for Chagas disease. The unique immune profiles in serodiscordant subjects support that T. cruzi infection was cleared or profoundly controlled in these subjects.

Exploring the depths of IgG4: insights into autoimmunity and novel treatments

IgG4 subclass antibodies represent the rarest subclass of IgG antibodies, comprising only 3-5% of antibodies circulating in the bloodstream. These antibodies possess unique structural features, notably their ability to undergo a process known as fragment-antigen binding (Fab)-arm exchange, wherein they exchange half-molecules with other IgG4 antibodies. Functionally, IgG4 antibodies primarily block and exert immunomodulatory effects, particularly in the context of IgE isotype-mediated hypersensitivity reactions. In the context of disease, IgG4 antibodies are prominently observed in various autoimmune diseases combined under the term IgG4 autoimmune diseases (IgG4-AID). These diseases include myasthenia gravis (MG) with autoantibodies against muscle-specific tyrosine kinase (MuSK), nodo-paranodopathies with autoantibodies against paranodal and nodal proteins, pemphigus vulgaris and foliaceus with antibodies against desmoglein and encephalitis with antibodies against LGI1/CASPR2. Additionally, IgG4 antibodies are a prominent feature in the rare entity of IgG4 related disease (IgG4-RD). Intriguingly, both IgG4-AID and IgG4-RD demonstrate a remarkable responsiveness to anti-CD20-mediated B cell depletion therapy (BCDT), suggesting shared underlying immunopathologies. This review aims to provide a comprehensive exploration of B cells, antibody subclasses, and their general properties before examining the distinctive characteristics of IgG4 subclass antibodies in the context of health, IgG4-AID and IgG4-RD. Furthermore, we will examine potential therapeutic strategies for these conditions, with a special focus on leveraging insights gained from anti-CD20-mediated BCDT. Through this analysis, we aim to enhance our understanding of the pathogenesis of IgG4-mediated diseases and identify promising possibilities for targeted therapeutic intervention.

Upregulation of IL4-induced gene 1 enzyme by B2 cells during melanoma progression impairs their antitumor properties

B cells present in human cutaneous melanoma have been associated with protective or detrimental effects on disease progression according to their phenotype. By using the RET model of spontaneous melanoma and adoptive transfer of B16 melanoma cells, we show that immature and follicular B2 (B2-FO) cells exert a protective effect on melanoma progression by promoting the generation of effector memory T cells and limiting the recruitment of polymorphonuclear myeloid-derived suppressor cells. Unfortunately, this beneficial effect progressively wanes as a consequence of enhanced expression of the IL4-induced gene 1 (IL4I1) enzyme by immature B cells and B2-FO cells. Endogenous IL4I1 selectively decreases CXCR5 expression in splenic immature B cells, subverting their trafficking to primary tumors and enhancing the production of IL-10 by B2 cells, thereby promoting an immunosuppressive microenvironment. Accordingly, B2 cells from RET IL4I1KO mice more efficiently controlled B16 melanoma growth than B2 cells from IL4I1-competent RET mice. Collectively, immature B cells and B2-FO cells are key actors in the control of melanoma growth, but their mobility and functions are differently impaired by IL4I1 overexpression during melanoma progression. Thus, our present data strongly urge us to associate an IL4I1 antagonist with current immunotherapy to improve the treatment of metastatic melanoma.

Nano-formulated delivery of active ingredients from traditional Chinese herbal medicines for cancer immunotherapy

Cancer immunotherapy has garnered promise in tumor progression, invasion, and metastasis through establishing durable and memorable immunological activity. However, low response rates, adverse side effects, and high costs compromise the additional benefits for patients treated with current chemical and biological agents. Chinese herbal medicines (CHMs) are a potential treasure trove of natural medicines and are gaining momentum in cancer immunomodulation with multi-component, multi-target, and multi-pathway characteristics. The active ingredient extracted from CHMs benefit generalized patients through modulating immune response mechanisms. Additionally, the introduction of nanotechnology has greatly improved the pharmacological qualities of active ingredients through increasing the hydrophilicity, stability, permeability, and targeting characteristics, further enhancing anti-cancer immunity. In this review, we summarize the mechanism of active ingredients for cancer immunomodulation, highlight nano-formulated deliveries of active ingredients for cancer immunotherapy, and provide insights into the future applications in the emerging field of nano-formulated active ingredients of CHMs.

Obesity, bone marrow adiposity, and leukemia: Time to act

Obesity has taken the face of a pandemic with less direct concern among the general population and scientific community. However, obesity is considered a low-grade systemic inflammation that impacts multiple organs. Chronic inflammation is also associated with different solid and blood cancers. In addition, emerging evidence demonstrates that individuals with obesity are at higher risk of developing blood cancers and have poorer clinical outcomes than individuals in a normal weight range. The bone marrow is critical for hematopoiesis, lymphopoiesis, and myelopoiesis. Therefore, it is vital to understand the mechanisms by which obesity-associated changes in BM adiposity impact leukemia development. BM adipocytes are critical to maintain homeostasis via different means, including immune regulation. However, obesity increases BM adiposity and creates a pro-inflammatory environment to upregulate clonal hematopoiesis and a leukemia-supportive environment. Obesity further alters lymphopoiesis and myelopoiesis via different mechanisms, which dysregulate myeloid and lymphoid immune cell functions mentioned in the text under different sequentially discussed sections. The altered immune cell function during obesity alters hematological malignancies and leukemia susceptibility. Therefore, obesity-induced altered BM adiposity, immune cell generation, and function impact an individual's predisposition and severity of leukemia, which should be considered a critical factor in leukemia patients.

Maternal urban particulate matter (SRM 1648a) exposure disrupted the cellular immune homeostasis during early life: The potential attribution of altered placental transcriptome profile

Ambient fine particular matter (PM2.5) exposure has been associated with numerous adverse effects including triggering functional disorders of the placenta and inducing immune imbalance in offspring. However, how maternal PM2.5 exposure impacts immune development during early life is not fully understood. In the current study, we exposed mice with low-, middle-, and high-dose PM2.5 during pregnancy to investigate the potential link between the transcriptional changes in the placenta and immune imbalance in mice offspring induced by PM2.5 exposures. Using flow cytometry, we found that the proportions of B cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and macrophage (Mφ) cells were altered in the blood of PM2.5-exposed mice pups but not dendritic cells (DCs) and natural killer cells (NKs). Using bulk RNA sequencing, we found that PM2.5 exposure altered the transcriptional profile which indicated an inhibition of the complement and coagulation cascades in the placenta. Weighted gene co-expression network analysis (WGCNA) revealed the potential crosstalk between the perturbation of placental gene expression and the changes of immune cell subsets in pups on postnatal day 10 (PND10). Specifically, WGCNA identified a cluster of genes including Defb15, Defb20, Defb25, Cst8, Cst12, and Adam7 that might regulate the core immune cell types in PND10 pups. Although the underlying mechanisms of how maternal PM2.5 exposure induces peripheral lymphocyte disturbance in offspring still remain much unknown, our findings here shed light on the potential role of placental dysfunction in these adverse effects.

Transcriptome network analysis of inflammation and fibrosis in keloids

BACKGROUND

Keloid (KL) is a common benign skin tumor. KL is typically characterized by significant fibrosis and an intensive inflammatory response. Therefore, a comprehensive understanding of the interactions between cellular inflammation and fibrotic cells is essential to elucidate the mechanisms driving the progression of KL and to develop therapeutics.

OBJECTIVE

Investigate the transcriptome landscape of inflammation and fibrosis in keloid scars.

METHODS

In this paper, we performed transcriptome sequencing and microRNA (miRNA) sequencing on unselected live cells from six human keloid tissues and normal skin tissues to elucidate a comprehensive transcriptome landscape. In addition, we used single-cell RNA sequencing (scRNA-seq) analysis to analyze intercellular communication networks and enrich fibroblast populations in two additional keloid and normal skin samples to study fibroblast diversity.

RESULTS

By RNA sequencing and a miRNA-mRNA-PPI network analysis, we identified miR-615-5p and miR-122b-3p as possible miRNAs associated with keloids, as they differed most significantly in keloids. Similarly, COL3A1, COL1A2, THBS2, TNC, IGTA, THBS4, TGFB3 as genes with significant differences in keloid may be associated with keloid development. Using single-cell RNA sequencing data from 24,086 cells collected from normal or keloid, we report reconstructed intercellular signaling network analysis and aggregation to modules associated with specific cell subpopulations at the cellular level for keloid alterations.

CONCLUSIONS

Our multitranscriptomic dataset delineates inflammatory and fibro heterogeneity of human keloids, underlining the importance of intercellular crosstalk between inflammatory cells and fibro cells and revealing potential therapeutic targets.

B cell depletion attenuates CD27 signaling of T helper cells in multiple sclerosis

Multiple sclerosis is a chronic inflammatory disease of the central nervous system. Whereas T cells are likely the main drivers of disease development, the striking efficacy of B cell-depleting therapies (BCDTs) underscore B cells' involvement in disease progression. How B cells contribute to multiple sclerosis (MS) pathogenesis-and consequently the precise mechanism of action of BCDTs-remains elusive. Here, we analyze the impact of BCDTs on the immune landscape in patients with MS using high-dimensional single-cell immunophenotyping. Algorithm-guided analysis reveals a decrease in circulating T follicular helper-like (Tfh-like) cells alongside increases in CD27 expression in memory T helper cells and Tfh-like cells. Elevated CD27 indicates disrupted CD27/CD70 signaling, as sustained CD27 activation in T cells leads to its cleavage. Immunohistological analysis shows CD70-expressing B cells at MS lesion sites. These results suggest that the efficacy of BCDTs may partly hinge upon the disruption of Th cell and B cell interactions.

Advanced subunit vaccine delivery technologies: From vaccine cascade obstacles to design strategies

Designing and manufacturing safe and effective vaccines is a crucial challenge for human health worldwide. Research on adjuvant-based subunit vaccines is increasingly being explored to meet clinical needs. Nevertheless, the adaptive immune responses of subunit vaccines are still unfavorable, which may partially be attributed to the immune cascade obstacles and unsatisfactory vaccine design. An extended understanding of the crosstalk between vaccine delivery strategies and immunological mechanisms could provide scientific insight to optimize antigen delivery and improve vaccination efficacy. In this review, we summarized the advanced subunit vaccine delivery technologies from the perspective of vaccine cascade obstacles after administration. The engineered subunit vaccines with lymph node and specific cell targeting ability, antigen cross-presentation, T cell activation properties, and tailorable antigen release patterns may achieve effective immune protection with high precision, efficiency, and stability. We hope this review can provide rational design principles and inspire the exploitation of future subunit vaccines.

Counteracting Immunosenescence-Which Therapeutic Strategies Are Promising?

Aging attenuates the overall responsiveness of the immune system to eradicate pathogens. The increased production of pro-inflammatory cytokines by innate immune cells under basal conditions, termed inflammaging, contributes to impaired innate immune responsiveness towards pathogen-mediated stimulation and limits antigen-presenting activity. Adaptive immune responses are attenuated as well due to lowered numbers of naïve lymphocytes and their impaired responsiveness towards antigen-specific stimulation. Additionally, the numbers of immunoregulatory cell types, comprising regulatory T cells and myeloid-derived suppressor cells, that inhibit the activity of innate and adaptive immune cells are elevated. This review aims to summarize our knowledge on the cellular and molecular causes of immunosenescence while also taking into account senescence effects that constitute immune evasion mechanisms in the case of chronic viral infections and cancer. For tumor therapy numerous nanoformulated drugs have been developed to overcome poor solubility of compounds and to enable cell-directed delivery in order to restore immune functions, e.g., by addressing dysregulated signaling pathways. Further, nanovaccines which efficiently address antigen-presenting cells to mount sustained anti-tumor immune responses have been clinically evaluated. Further, senolytics that selectively deplete senescent cells are being tested in a number of clinical trials. Here we discuss the potential use of such drugs to improve anti-aging therapy.

Transcriptomic analysis of B cells suggests that CD70 and LY9 may be novel features in patients with systemic lupus erythematosus

Dysfunction of B-cell subsets is critical in the development of systemic lupus erythematosus (SLE). There is a great diversity of B-lineage cells, and their features and functions in SLE need to be clarified. In this study, we analyzed single-cell RNA sequencing (scRNA-seq) data from peripheral blood mononuclear cells (PBMCs) and bulk transcriptomic data of isolated B-cell subsets from patients with SLE and healthy controls (HCs). We preformed scRNA-seq analysis focused on the diversity of B-cell subsets and identified a subset of antigen-presenting B cells in SLE patients that highly expressed ITGAX. A list of marker genes of each B-cell subset in patients with SLE was also identified. Comparison of bulk transcriptomic data of isolated B-cell subpopulations between SLE patients and HCs revealed the upregulated differentially expressed genes (DEGs) for each B-cell subpopulation in SLE. Common genes identified using these two methods were considered to be upregulated marker genes of B cells in SLE. The scRNA-seq data of SLE patients and HCs revealed that CD70 and LY9 were overexpressed in B cells vs. other cell types from SLE patients, and this pattern was validated by RT‒qPCR. Because CD70 is the cellular ligand of CD27, previous studies on CD70 have focused mainly on T cells from SLE patients. LY9 appears to have different functions in mice and humans: its expression is decreased in lupus-prone mice but is increased in T cells and some B-cell subpopulations in SLE patients. Here, we describe the overexpression of two costimulatory molecules, CD70 and LY9, which may be a novel feature of B cells in SLE patients.

TEDC2 correlated with prognosis and immune microenvironment in lung adenocarcinoma

Tubulin epsilon and delta complex 2 (TEDC2) is a protein coding gene whose functions are poorly identified yet. This study aimed to identify the role of TEDC2 in prognosis and immune microenvironment of lung adenocarcinoma (LUAD). Through The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, the mRNA expression of TEDC2 was upregulated in LUAD tissues compared to normal tissues. The protein level of TEDC2 was also higher in LUAD in the Human Protein Atlas. The receiver operating characteristic (ROC) curve showed that high TEDC2 level could distinguish LUAD patients from normal subjects. In addition, the impact of TEDC2 expression on prognosis was evaluated by Kaplan-Meier and Cox regression analyses, and the results suggested that high TEDC2 expression was significantly associated with poor prognosis and was the independent prognostic factor in LUAD. GO and KEGG pathway analyses indicated the co-expressed genes of TEDC2 were mainly related to mitotic cell cycle processes. Importantly, high expression of TEDC2 indicated low infiltration of immune cells, especially dendritic cells and B cells. TEDC2 was also positively correlated with immune checkpoints such as PDCD1, LAG3 and CD276. Taken together, this study preliminarily revealed the clinical significance of TEDC2 in LUAD and provided novel insights into the role of TEDC2 in immune microenvironment.

Active ingredients of traditional Chinese medicine for enhancing the effect of tumor immunotherapy

Immunotherapy is a type of treatment that uses our own immune system to fight cancer. Studies have shown that traditional Chinese medicine (TCM) has antitumor activity and can enhance host immunity. This article briefly describes the immunomodulatory and escape mechanisms in tumors, as well as highlights and summarizes the antitumor immunomodulatory activities of some representative active ingredients of TCM. Finally, this article puts forward some opinions on the future research and clinical application of TCM, aiming to promote the clinical applications of TCM in tumor immunotherapy and to provide new ideas for the research of tumor immunotherapy using TCM.

The Multiple Facets and Disorders of B Cell Functions in Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection continues to be a global public health burden. B cells play a pivotal role in mediating HBV clearance and can participate in the development of anti-HBV adaptive immune responses through multiple mechanisms, such as antibody production, antigen presentation, and immune regulation. However, B cell phenotypic and functional disorders are frequently observed during chronic HBV infection, suggesting the necessity of targeting the disordered anti-HBV B cell responses to design and test new immune therapeutic strategies for the treatment of chronic HBV infection. In this review, we provide a comprehensive summary of the multiple roles of B cells in mediating HBV clearance and pathogenesis as well as the latest developments in understanding the immune dysfunction of B cells in chronic HBV infection. Additionally, we discuss novel immune therapeutic strategies that aim to enhance anti-HBV B cell responses for curing chronic HBV infection.

The Tumor Microenvironment in Tumorigenesis and Therapy Resistance Revisited

Tumorigenesis is a complex and dynamic process involving cell-cell and cell-extracellular matrix (ECM) interactions that allow tumor cell growth, drug resistance and metastasis. This review provides an updated summary of the role played by the tumor microenvironment (TME) components and hypoxia in tumorigenesis, and highlight various ways through which tumor cells reprogram normal cells into phenotypes that are pro-tumorigenic, including cancer associated- fibroblasts, -macrophages and -endothelial cells. Tumor cells secrete numerous factors leading to the transformation of a previously anti-tumorigenic environment into a pro-tumorigenic environment. Once formed, solid tumors continue to interact with various stromal cells, including local and infiltrating fibroblasts, macrophages, mesenchymal stem cells, endothelial cells, pericytes, and secreted factors and the ECM within the tumor microenvironment (TME). The TME is key to tumorigenesis, drug response and treatment outcome. Importantly, stromal cells and secreted factors can initially be anti-tumorigenic, but over time promote tumorigenesis and induce therapy resistance. To counter hypoxia, increased angiogenesis leads to the formation of new vascular networks in order to actively promote and sustain tumor growth via the supply of oxygen and nutrients, whilst removing metabolic waste. Angiogenic vascular network formation aid in tumor cell metastatic dissemination. Successful tumor treatment and novel drug development require the identification and therapeutic targeting of pro-tumorigenic components of the TME including cancer-associated- fibroblasts (CAFs) and -macrophages (CAMs), hypoxia, blocking ECM-receptor interactions, in addition to the targeting of tumor cells. The reprogramming of stromal cells and the immune response to be anti-tumorigenic is key to therapeutic success. Lastly, this review highlights potential TME- and hypoxia-centered therapies under investigation.

Analysis of LC3-Associated Phagocytosis and Antigen Presentation in Macrophages and B Cells

Canonical autophagy and the non-canonical autophagy pathway LC3-associated phagocytosis (LAP) play crucial roles in the immune system by processing antigens for major histocompatibility complex (MHC) class II restricted presentation to CD4⁺ T cells. Recent studies offer insight into the relationship between LAP, autophagy, and antigen processing in macrophages and dendritic cells; however their involvement during antigen processing in B cells is less well understood.In this chapter, we describe how to monitor, manipulate, and understand the role of LAP and classical autophagy during MHC-restricted antigen presentation by human monocyte-derived macrophages as well as in B cell lymphoblastoid cell lines (LCLs). It includes an explanation on how to generate LCLs and monocyte-derived macrophages from primary human cells. Then we describe two different approaches to manipulate the autophagy pathways: silencing of the atg4b gene using CRISPR/Cas9 technology and a lentivirus delivery system for specific ATG4B overexpression. We also propose a method for triggering LAP and measuring different ATG proteins using Western blot and immunofluorescence. Finally, we show an approach to investigate MHC class II antigen presentation by an in vitro co-culture assay that uses the measurement of secreted cytokines, released by activated CD4⁺ T cells, as readout.

Immunomodulatory role of metalloproteases in cancers: Current progress and future trends

Metalloproteinases (MPs) is a large family of proteinases with metal ions in their active centers. According to the different domains metalloproteinases can be divided into a variety of subtypes mainly including Matrix Metalloproteinases (MMPs), A Disintegrin and Metalloproteases (ADAMs) and ADAMs with Thrombospondin Motifs (ADAMTS). They have various functions such as protein hydrolysis, cell adhesion and remodeling of extracellular matrix. Metalloproteinases expressed in multiple types of cancers and participate in many pathological processes involving tumor genesis and development, invasion and metastasis by regulating signal transduction and tumor microenvironment. In this review, based on the current research progress, we summarized the structure of MPs, their expression and especially immunomodulatory role and mechanisms in cancers. Additionally, a relevant and timely update of recent advances and future directions were provided for the diagnosis and immunotherapy targeting MPs in cancers.

Contribution of T- and B-cell intrinsic toll-like receptors to the adaptive immune response in viral infectious diseases

Toll-like receptors (TLRs) comprise a class of highly conserved molecules that recognize pathogen-associated molecular patterns and play a vital role in host defense against multiple viral infectious diseases. Although TLRs are highly expressed on innate immune cells and play indirect roles in regulating antiviral adaptive immune responses, intrinsic expression of TLRs in adaptive immune cells, including T cells and B cells, cannot be ignored. TLRs expressed in CD4 + and CD8 + T cells play roles in enhancing TCR signal-induced T-cell activation, proliferation, function, and survival, serving as costimulatory molecules. Gene knockout of TLR signaling molecules has been shown to diminish antiviral adaptive immune responses and affect viral clearance in multiple viral infectious animal models. These results have highlighted the critical role of TLRs in the long-term immunological control of viral infection. This review summarizes the expression and function of TLR signaling pathways in T and B cells, focusing on the in vitro and vivo mechanisms and effects of intrinsic TLR signaling in regulating T- and B-cell responses during viral infection. The potential clinical use of TLR-based immune regulatory drugs for viral infectious diseases is also explored.

Regulatory role of KCa3.1 in immune cell function and its emerging association with rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic inflammation. Immune dysfunction is an essential mechanism in the pathogenesis of RA and directly linked to synovial inflammation and cartilage/bone destruction. Intermediate conductance Ca²⁺-activated K⁺ channel (KCa3.1) is considered a significant regulator of proliferation, differentiation, and migration of immune cells by mediating Ca²⁺ signal transduction. Earlier studies have demonstrated abnormal activation of KCa3.1 in the peripheral blood and articular synovium of RA patients. Moreover, knockout of KCa3.1 reduced the severity of synovial inflammation and cartilage damage to a significant extent in a mouse collagen antibody-induced arthritis (CAIA) model. Accumulating evidence implicates KCa3.1 as a potential therapeutic target for RA. Here, we provide an overview of the KCa3.1 channel and its pharmacological properties, discuss the significance of KCa3.1 in immune cells and feasibility as a drug target for modulating the immune balance, and highlight its emerging role in pathological progression of RA.

B Cell Receptor Signaling Pathway Mutation as Prognosis Predictor of Immune Checkpoint Inhibitors in Lung Adenocarcinoma by Bioinformatic Analysis

Purpose

The advent of immune checkpoint inhibitors (ICIs) is a revolutionary breakthrough. However, without the selection of a specific target population, the response rate of ICI therapy in lung adenocarcinoma (LUAD) is low, so a clinical challenge has arisen in effectively using biomarkers to determine which patients can benefit from ICI therapy.

Methods

In this study, patients were divided according to whether or not nonsynonymous mutations were present in the BCR signaling pathway, and univariate and multivariate Cox regression models were established based on a LUAD cohort treated with ICIs (Miao-LUAD). Then the relationship between the mutation status of the BCR signaling pathway and the prognosis of immunotherapy was examined. Finally, data from The Cancer Genome Atlas (TCGA) LUAD cohort, the Rizvi-LUAD, the Samstein-LUAD, and the Zhujiang Hospital of Southern Medical University LUAD (Local-LUAD) cohort were combined, and the mutation panorama, immunogenicity, tumor microenvironment (TME) and pathway enrichment analysis between the BCR signaling pathway mutant group (BCR signaling MUT) and the BCR signaling pathway wild group (BCR signaling WT) were comprehensively compared.

Results

It was found that, compared with the BCR signaling WT, the BCR signaling MUT had a significantly improved progression-free survival (PFS) rate and overall survival (OS) rate, higher immunogenicity (tumor mutational burden, neoantigen load, and DNA damage response signaling mutations), and anti-tumor immune microenvironment.

Conclusion

These results revealed that the mutation state of the BCR signaling pathway has potential as a biomarker to predict the efficacy of ICIs in LUAD.

Belimumab or anifrolumab for systemic lupus erythematosus? A risk-benefit assessment

Treatment of systemic lupus erythematosus (SLE) currently employs agents with relatively unselective immunosuppressive properties. However, two target-specific biological drugs have been approved: belimumab (anti-B-cell-activating factor/BAFF) and anifrolumab (anti-interferon alpha receptor-1/IFNAR1). Here, we performed a comparative risk-benefit assessment for both drugs based on the role of BAFF and IFNAR1 in host defense and the pathogenesis of SLE and by considering the available data on safety and efficacy. Due to differences in target expression sites, anti-IFNAR1, but not anti-BAFF, might elicit organ-specific effects, consistent with clinical efficacy data. The IFNAR1 is specifically involved in innate and adaptive antiviral immunity in most cells of the body. Consistent with this observation, the available safety data obtained from patients negatively selected for LN and neuropsychiatric SLE, primary immunodeficiencies, splenectomy and chronic HIV, HBV, HCV infections suggest an increased risk for some viral infections such as varicella zoster and perhaps influenza. In contrast, BAFF is mainly involved in adaptive immune responses in lymphoid tissues, thus anti-BAFF therapy modulates SLE activity and prevents SLE flares without interfering with local innate host defense mechanisms and should only marginally affect immune memory to previous pathogen exposures consistent with the available safety data from SLE patients without chronic HIV, HBV or HCV infections. When using belimumab and anifrolumab, careful patient stratification and specific precautions may minimize risks and maximize beneficial treatment effects for patients with SLE.

Development of a Nanocarrier-Based Splenic B Cell-Targeting System for Loading Antigens in Vitro

B cells are types of lymphocytes that are involved in the production of antibodies against pathogens. They also deliver and present antigens for the priming of T cells. Recently, we developed an in vivo splenic marginal zone (MZ) B cell-targeting liposomes decorated with polyethylene glycol (PEG) containing a hydroxyl-terminus group (HO-PEG-Lip). In an expansion of a previous study, we used HO-PEG-Lip as an in vitro antigen delivery tool to splenic B cells to test the ability of this formulation to overcome the limitations of the poor antigen uptake ability of B cells for implantation. To achieve our purpose, various factors were optimized. These factors include cell number, liposome concentration, pre-opsonization of liposomes, fresh serum concentration, and incubation time, all of which affect the extent of interaction between liposomes and B cells. As a result, we confirmed that the HO-PEG-Lip required incubation at 37 °C for at least 20 min with 50% mouse fresh serum followed by a subsequent incubation at 37 °C for at least another 30 min with splenic B cells. By using such a loading system, fluorescein isothiocyanate (FITC)-labeled ovalbumin (OVA), a model antigen, encapsulated in HO-PEG-Lip could be efficiently loaded into splenic B cells. In addition, HO-PEG-Lip and FITC-labeled OVA encapsulated in HO-PEG-Lip were efficiently associated with MZ-B cells with high levels of complement receptors (CRs) rather than follicular B cells with low levels of CRs. These results propose a novel and useful system to efficiently load antigens into B cells in vitro by taking advantage of complement systems.

Engineering complexity in human tissue models of cancer

Major progress in the understanding and treatment of cancer have tremendously improved our knowledge of this complex disease and improved the length and quality of patients' lives. Still, major challenges remain, in particular with respect to cancer metastasis which still escapes effective treatment and remains responsible for 90% of cancer related deaths. In recent years, the advances in cancer cell biology, oncology and tissue engineering converged into the engineered human tissue models of cancer that are increasingly recapitulating many aspects of cancer progression and response to drugs, in a patient-specific context. The complexity and biological fidelity of these models, as well as the specific questions they aim to investigate, vary in a very broad range. When selecting and designing these experimental models, the fundamental question is "how simple is complex enough" to accomplish a specific goal of cancer research. Here we review the state of the art in developing and using the human tissue models in cancer research and developmental drug screening. We describe the main classes of models providing different levels of biological fidelity and complexity, discuss their advantages and limitations, and propose a framework for designing an appropriate model for a given study. We close by outlining some of the current needs, opportunities and challenges in this rapidly evolving field.

It Takes a Village: The Multifaceted Immune Response to Mycobacterium tuberculosis Infection and Vaccine-Induced Immunity

Despite co-evolving with humans for centuries and being intensely studied for decades, the immune correlates of protection against Mycobacterium tuberculosis (Mtb) have yet to be fully defined. This lapse in understanding is a major lag in the pipeline for evaluating and advancing efficacious vaccine candidates. While CD4+ T helper 1 (TH1) pro-inflammatory responses have a significant role in controlling Mtb infection, the historically narrow focus on this cell population may have eclipsed the characterization of other requisite arms of the immune system. Over the last decade, the tuberculosis (TB) research community has intentionally and intensely increased the breadth of investigation of other immune players. Here, we review mechanistic preclinical studies as well as clinical anecdotes that suggest the degree to which different cell types, such as NK cells, CD8+ T cells, γ δ T cells, and B cells, influence infection or disease prevention. Additionally, we categorically outline the observed role each major cell type plays in vaccine-induced immunity, including Mycobacterium bovis bacillus Calmette-Guérin (BCG). Novel vaccine candidates advancing through either the preclinical or clinical pipeline leverage different platforms (e.g., protein + adjuvant, vector-based, nucleic acid-based) to purposefully elicit complex immune responses, and we review those design rationales and results to date. The better we as a community understand the essential composition, magnitude, timing, and trafficking of immune responses against Mtb, the closer we are to reducing the severe disease burden and toll on human health inflicted by TB globally.

Lack of Induction of RBD-Specific Neutralizing Antibodies despite Repeated Heterologous SARS-CoV-2 Vaccination Leading to Seroconversion and Establishment of T Cell-Specific Memory in a Patient in Remission of Multiple Myeloma

Background: Prophylactic vaccination against infectious diseases may induce a state of long-term protection in the otherwise healthy host. However, the situation is less predictable in immunocompromised patients and may require adjustment of vaccination schedules and/or basic therapy. Methods: A patient in full remission of multiple myeloma since the last three years and on long-term maintenance therapy with pomalidomide, a drug inhibiting angiogenesis and myeloma cell growth, was vaccinated twice with Comirnaty followed by two vaccinations with Vaxzevria. Seroconversion and SARS-CoV-2-specific cellular responses were monitored. Results: No signs of seroconversion or T cellular memory were observed after the first “full immunization” with Comirnaty. Consequently, long-term-maintenance therapy with Pomalidomide was stopped and two additional shots of Vaxzevria were administered after which the patient seroconverted with Spike(S)-protein specific antibody levels reaching 49 BAU/mL, mild S-peptide pool-specific T cell proliferation, effector cytokine production (IL-2, IL-13), and T cellular activation with increased numbers of CD3⁺CD4⁺CD25⁺ T cells as compared to vaccinated and non-vaccinated control subjects. However, despite suspension of immunosuppression and administration of in total four consecutive heterologous SARS-CoV-2 vaccine shots, the patient did not develop neutralizing RBD-specific antibodies. Conclusions: Despite immunomonitoring-based adjustment of vaccination and/or therapy schedules vaccination success, with clear correlates of protection, the development of RBD-specific antibodies could not be achieved in the immunocompromised patient with current SARS-CoV-2 vaccines. Thus, our report emphasizes the need for improved active and passive immunization strategies for SARS-CoV-2 infections.

RIPPA: Identification of MHC-II Binding Peptides from Antigen Using a Yeast Display-Based Approach

Mapping MHC-II binding peptides derived from an antigenic protein for potential CD4+ T-cell epitopes has been challenging due to a lack of experimental approaches that are both quantitative and rapid. The rate-limiting steps in current approaches include the construction of single MHC allele expressing cell lines and/or the purification of the MHC-II allelic proteins for peptide elution (i.e., mass spectrometry) or in vitro peptide binding (i.e., ELISA) assays. These labor-intensive steps typically take up to 4 months or more. In this protocol, we describe a system that uses yeast cells to display "empty" (i.e., without covalently linked peptides) MHC-II heterodimers that are capable of binding exogenously added peptides of interest. This yeast-MHC-II system eliminates the time-consuming soluble MHC-II purification steps, allowing rapid identification of peptide ligands from protein antigens (RIPPA). The amount of peptide loading to MHC-II or the extent of competition between indicator and competitor peptides at the surface of yeast cells can be quantitatively determined using flow cytometric analysis. Importantly, the protocol only takes ∼1 month from the construction of plasmids and the yeast display of "empty" MHC-II to the quantitative determination of MHC-II binding peptides from a given antigen. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Yeast display of "empty" MHC-II Support Protocol: Construction of yeast shuttle vector expressing "empty" MHC-II Basic Protocol 2: Peptide competition on the surface of yeast cells Alternate Protocol: RIPPA in a 96-well format.

Significance of intratumoral infiltration of B cells in cancer immunotherapy: From a single cell perspective

Immunotherapy for cancer has provided new treatment approaches for malignant tumors, but there are low rates of response and high rates of resistance. The most recent sequencing method which is called single-cell RNA sequencing(scRNA-seq) determines the transcriptome at the single cell level, which allows high-resolution dynamic monitoring of the tumor microenvironment (TME) during immunotherapy. As an important part of humoral immunity, tumor-infiltrated B cells have been reported to have distinct functions in anti-tumor immunity, which are characterized by their RNA transcriptome, membrane surface receptors, and immunoglobulin secretion, suggesting great immunotherapeutic effects. On the basis of the important roles of B cells in immunotherapy reported in recent publications, we discuss the tumor-infiltrated B cells' subpopulations, differentiation trajectory, and interactions with other cells in the TME in this review, hoping to illustrate its significance in potential clinical application as biomarkers and therapeutic targets.