Innate Immunity Modulating Impurities and the Immunotoxicity of Nanobiotechnology-Based Drug Products

Innate immunity can be triggered by the presence of microbial antigens and other contaminants inadvertently introduced during the manufacture and purification of bionanopharmaceutical products. Activation of these innate immune responses, including cytokine secretion, complement, and immune cell activation, can result in unexpected and undesirable host immune responses. These innate modulators can also potentially stimulate the activation of adaptive immune responses, including the formation of anti-drug antibodies which can impact drug effectiveness. To prevent induction of these adverse responses, it is important to detect and quantify levels of these innate immunity modulating impurities (IIMIs) that may be present in drug products. However, while it is universally agreed that removal of IIMIs from drug products is crucial for patient safety and to prevent long-term immunogenicity, there is no single assay capable of directly detecting all potential IIMIs or indirectly quantifying downstream biomarkers. Additionally, there is a lack of agreement as to which of the many analytical assays currently employed should be standardized for general IIMI screening. Herein, we review the available literature to highlight cellular and molecular mechanisms underlying IIMI-mediated inflammation and its relevance to the safety and efficacy of pharmaceutical products. We further discuss methodologies used for direct and indirect IIMI identification and quantification.

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EssE Promotes Staphylococcus aureus ESS-Dependent Protein Secretion To Modify Host Immune Responses during Infection

Journal of Bacteriology ◽

10.1128/jb.00527-16 ◽

2016 ◽

Vol 199 (1) ◽

Cited By ~ 11

Author(s):

Mark Anderson ◽

Ryan Jay Ohr ◽

Khaled A. Aly ◽

Salvatore Nocadello ◽

Hwan K. Kim ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Immune Responses ◽

Bloodstream Infection ◽

Molecular Mechanisms ◽

Immune Cell ◽

Interleukin 12 ◽

Content Type ◽

Host Immune Responses ◽

Dependent Protein ◽

Host Infection

ABSTRACT Staphylococcus aureus, an invasive pathogen of humans and animals, requires a specialized ESS pathway to secrete proteins (EsxA, EsxB, EsxC, and EsxD) during infection. Expression of ess genes is required for S. aureus establishment of persistent abscess lesions following bloodstream infection; however, the mechanisms whereby effectors of the ESS pathway implement their virulence strategies were heretofore not known. Here, we show that EssE forms a complex with other members of the ESS secretion pathway and its substrates, promoting the secretion of EsxA, EsxB, EsxC, EsxD, and EssD. During bloodstream infection of mice, the S. aureus essE mutant displays defects in host cytokine responses, specifically in the production of interleukin-12 (IL-12) (p40/p70) and the suppression of RANTES (CCL5), activators of TH1 T cell responses and immune cell chemotaxis, respectively. Thus, essE-mediated secretion of protein effectors via the ESS pathway may enable S. aureus to manipulate host immune responses by modifying the production of cytokines. IMPORTANCE Staphylococcus aureus and other firmicutes evolved a specialized ESS (EsxA/ESAT-6-like secretion system) pathway for the secretion of small subsets of proteins lacking canonical signal peptides. The molecular mechanisms for ESS-dependent secretion and their functional purpose are still unknown. We demonstrate here that S. aureus EssE functions as a membrane assembly platform for elements of the secretion machinery and their substrates. Furthermore, S. aureus EssE-mediated secretion contributes to the production or the suppression of specific cytokines during host infection, thereby modifying immune responses toward this pathogen.

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Role of Alternative Splicing in Regulating Host Response to Viral Infection

Cells ◽

10.3390/cells10071720 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1720

Author(s):

Kuo-Chieh Liao ◽

Mariano A. Garcia-Blanco

Keyword(s):

Innate Immunity ◽

Alternative Splicing ◽

Immune Responses ◽

Viral Infection ◽

Rna Splicing ◽

Type I ◽

Host Immune Responses ◽

Transcriptional Regulatory Mechanisms ◽

Host Virus Interactions

The importance of transcriptional regulation of host genes in innate immunity against viral infection has been widely recognized. More recently, post-transcriptional regulatory mechanisms have gained appreciation as an additional and important layer of regulation to fine-tune host immune responses. Here, we review the functional significance of alternative splicing in innate immune responses to viral infection. We describe how several central components of the Type I and III interferon pathways encode spliced isoforms to regulate IFN activation and function. Additionally, the functional roles of splicing factors and modulators in antiviral immunity are discussed. Lastly, we discuss how cell death pathways are regulated by alternative splicing as well as the potential role of this regulation on host immunity and viral infection. Altogether, these studies highlight the importance of RNA splicing in regulating host–virus interactions and suggest a role in downregulating antiviral innate immunity; this may be critical to prevent pathological inflammation.

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β-Catenin Is Required for the cGAS/STING Signaling Pathway but Antagonized by the Herpes Simplex Virus 1 US3 Protein

Journal of Virology ◽

10.1128/jvi.01847-19 ◽

2019 ◽

Vol 94 (5) ◽

Cited By ~ 4

Author(s):

Hongjuan You ◽

Yingying Lin ◽

Feng Lin ◽

Mingyue Yang ◽

Jiahui Li ◽

...

Keyword(s):

Innate Immunity ◽

Herpes Simplex ◽

Immune Responses ◽

Signaling Pathway ◽

Kinase Activity ◽

Dna Virus ◽

Host Immune Responses ◽

Simplex Virus ◽

Antiviral Innate Immunity ◽

Hsv 1

ABSTRACT The cGAS/STING-mediated DNA-sensing signaling pathway is crucial for interferon (IFN) production and host antiviral responses. Herpes simplex virus I (HSV-1) is a DNA virus that has evolved multiple strategies to evade host immune responses. Here, we demonstrate that the highly conserved β-catenin protein in the Wnt signaling pathway is an important factor to enhance the transcription of type I interferon (IFN-I) in the cGAS/STING signaling pathway, and the production of IFN-I mediated by β-catenin was antagonized by HSV-1 US3 protein via its kinase activity. Infection by US3-deficienct HSV-1 and its kinase-dead variants failed to downregulate IFN-I and IFN-stimulated gene (ISG) production induced by β-catenin. Consistent with this, absence of β-catenin enhanced the replication of US3-deficienct HSV-1, but not wild-type HSV-1. The underlying mechanism was the interaction of US3 with β-catenin and its hyperphosphorylation of β-catenin at Thr556 to block its nuclear translocation. For the first time, HSV-1 US3 has been shown to inhibit IFN-I production through hyperphosphorylation of β-catenin and to subvert host antiviral innate immunity. IMPORTANCE Although increasing evidence has demonstrated that HSV-1 subverts host immune responses and establishes lifelong latent infection, the molecular mechanisms by which HSV-1 interrupts antiviral innate immunity, especially the cGAS/STING-mediated cellular DNA-sensing signaling pathway, have not been fully explored. Here, we show that β-catenin promotes cGAS/STING-mediated activation of the IFN pathway, which is important for cellular innate immune responses and intrinsic resistance to DNA virus infection. The protein kinase US3 antagonizes the production of IFN by targeting β-catenin via its kinase activity. The findings in this study reveal a novel mechanism for HSV-1 to evade host antiviral immunity and add new knowledge to help in understanding the interaction between the host and HSV-1 infection.

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A bi-directional dialog between vascular cells and monocytes/macrophages regulates tumor progression

Cancer and Metastasis Reviews ◽

10.1007/s10555-021-09958-2 ◽

2021 ◽

Author(s):

Victor Delprat ◽

Carine Michiels

Keyword(s):

Tumor Progression ◽

Cancer Progression ◽

Cell Activation ◽

Molecular Mechanisms ◽

Immune Cell ◽

The Body ◽

Vascular Cells ◽

Tumor Associated Macrophage ◽

Immune Cell Activation ◽

The Impact

AbstractCancer progression largely depends on tumor blood vessels as well on immune cell infiltration. In various tumors, vascular cells, namely endothelial cells (ECs) and pericytes, strongly regulate leukocyte infiltration into tumors and immune cell activation, hence the immune response to cancers. Recently, a lot of compelling studies unraveled the molecular mechanisms by which tumor vascular cells regulate monocyte and tumor-associated macrophage (TAM) recruitment and phenotype, and consequently tumor progression. Reciprocally, TAMs and monocytes strongly modulate tumor blood vessel and tumor lymphatic vessel formation by exerting pro-angiogenic and lymphangiogenic effects, respectively. Finally, the interaction between monocytes/TAMs and vascular cells is also impacting several steps of the spread of cancer cells throughout the body, a process called metastasis. In this review, the impact of the bi-directional dialog between blood vascular cells and monocytes/TAMs in the regulation of tumor progression is discussed. All together, these data led to the design of combinations of anti-angiogenic and immunotherapy targeting TAMs/monocyte whose effects are briefly discussed in the last part of this review.

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641 Spatially organized multicellular immune hubs in MMRd and MMRp colorectal cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.641 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A670-A670

Author(s):

Jonathan Chen ◽

Karin Pelka ◽

Matan Hofree ◽

Marios Giannakis ◽

Genevieve Boland ◽

...

Keyword(s):

Colorectal Cancer ◽

T Cells ◽

T Cell ◽

Immune Responses ◽

Mismatch Repair ◽

Molecular Mechanisms ◽

Immune Cell ◽

Single Cells ◽

Large Set ◽

Colon Tissue

BackgroundImmune responses to cancer are highly variable, with DNA mismatch repair-deficient (MMRd) tumors exhibiting more anti-tumor immunity than mismatch repair-proficient (MMRp) tumors. Almost all tumors are infiltrated with immune cells, but the types of immune responses and their effects on tumor growth, metastasis and death, vary greatly between different cancers and individual tumors. Which of the numerous cell subsets in a tumor contribute to the response, how their interactions are regulated, and how they are spatially organized within tumors remains poorly understood.MethodsTo understand the rules governing these varied responses, we transcriptionally profiled 371,223 single cells from colorectal tumors and adjacent normal tissues of 28 MMRp and 34 MMRd treatment-naive patients. We developed a systematic approach to discover cell types, their underlying gene programs, and cellular communities based on single cell RNA-seq (scRNAseq) profiles and applied it to study the distinguishing features of human MMRd and MMRp colorectal cancer. Cellular communities discovered from this analysis were spatially mapped in tissue sections using multiplex RNA in situ hybridization microscopy.ResultsTo understand the basis for differential immune responses in CRC, we first determined and compared the immune cell composition of MMRd and MMRp CRC and normal colon tissue, finding dramatic remodeling between tumor and normal tissue and between MMRd and MMRp tumors, particularly within the myeloid, T cell, and stromal compartments. Among the clusters enriched in MMRd tumors were activated CXCL13+ CD8 T cells. Importantly, gene program co-variation analysis revealed multicellular networks. We discovered a myeloid cell-attracting hub at the tumor-luminal interface associated with tissue damage, and an MMRd-enriched immune hub within the tumor, with activated IFNG+ and CXCL13+ T cells together with malignant and myeloid cells expressing T-cell-attracting chemokines (figure 1).ConclusionsOur study provides a rich dataset of cellular states, gene programs and their transformations in tumors across a relatively large cohort of patients with colorectal cancer. Our predictions of several multicellular hubs based on co-variation of gene expression programs, and subsequent spatial localization of two major immune-malignant hubs, organizes a large set of cell states and programs into a smaller number of coordinated networks of cells and processes. Understanding the molecular mechanisms underlying these hubs, and studying their temporal and spatial regulation upon treatment will be critical for advancing cancer therapy.Ethics ApprovalThis study was approved by the DF-HCC institutional review board (protocols 03-189 and 02-240).Abstract 641 Figure 1A coordinated network of CXCL13+ T cells with myeloid and malignant cells expressing ISGs. Image shows a portion of formalin-fixed paraffin-embedded tissue from an MMRd CRC specimen stained with multiplex RNA ISH / IF for PanCK-IF, CD3E-ISH, CXCL10/CXCL11-ISH, CXCL13-ISH, and IFNG-ISH. Note IFNG+ and CXCL13+ cells in proximity to cells expressing the chemokines CXCL10/CXCL11

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The DBL-1/TGF-β signaling pathway regulates pathogen-specific innate immune responses in C. elegans

10.1101/2021.03.30.437693 ◽

2021 ◽

Author(s):

Bhoomi Madhu ◽

Tina L. Gumienny

Keyword(s):

Innate Immunity ◽

Immune Responses ◽

Signaling Pathway ◽

Defense Responses ◽

C Elegans ◽

Host Immune Responses ◽

Wide Range ◽

Independent Functions ◽

Multiple Cell

Innate immunity in animals is orchestrated by multiple cell signaling pathways, including the TGF-β; superfamily pathway. While the role of TGF-β signaling in innate immunity has been clearly identified, the requirement for this pathway in generating specific, robust responses to different bacterial challenges has not been characterized. Here, we address the role of DBL-1/TGF-β in regulating signature host defense responses to a wide range of bacteria in C. elegans. This work reveals a role of DBL-1/TGF-β in animal survival, organismal behaviors, and molecular responses in different environments. Additionally, we identify a novel role for SMA-4/Smad that suggests both DBL-1/TGF-β-dependent and -independent functions in host avoidance responses. RNA-seq analyses and immunity reporter studies indicate DBL-1/TGF-β differentially regulates target gene expression upon exposure to different bacteria. Furthermore, the DBL-1/TGF-β pathway is itself differentially affected by the bacteria exposure. Collectively, these findings demonstrate bacteria-specific host immune responses regulated by the DBL-1/TGF-β signaling pathway.

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Molecular Mechanisms of Host Immune Responses to Entamoeba

Molecular Food Microbiology ◽

10.1201/9781351120388-37 ◽

2021 ◽

pp. 461-477

Author(s):

Moisés Martínez-Castillo ◽

Jesús Serrano-Luna ◽

Daniel Coronado-Velázquez ◽

Judith Pacheco-Yépez ◽

Mireya de la Garza ◽

...

Keyword(s):

Immune Responses ◽

Molecular Mechanisms ◽

Host Immune Responses

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Administration of cardiac mesenchymal cells modulates innate immunity in the acute phase of myocardial infarction in mice

Scientific Reports ◽

10.1038/s41598-020-71580-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Yi Kang ◽

Marjan Nasr ◽

Yiru Guo ◽

Shizuka Uchida ◽

Tyler Weirick ◽

...

Keyword(s):

Myocardial Infarction ◽

Innate Immunity ◽

Mechanism Of Action ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Mesenchymal Cell ◽

Cell Types

Abstract Although cardiac mesenchymal cell (CMC) therapy mitigates post-infarct cardiac dysfunction, the underlying mechanisms remain unidentified. It is acknowledged that donor cells are neither appreciably retained nor meaningfully contribute to tissue regeneration—suggesting a paracrine-mediated mechanism of action. As the immune system is inextricably linked to wound healing/remodeling in the ischemically injured heart, the reparative actions of CMCs may be attributed to their immunoregulatory properties. The current study evaluated the consequences of CMC administration on post myocardial infarction (MI) immune responses in vivo and paracrine-mediated immune cell function in vitro. CMC administration preferentially elicited the recruitment of cell types associated with innate immunity (e.g., monocytes/macrophages and neutrophils). CMC paracrine signaling assays revealed enhancement in innate immune cell chemoattraction, survival, and phagocytosis, and diminished pro-inflammatory immune cell activation; data that identifies and catalogues fundamental immunomodulatory properties of CMCs, which have broad implications regarding the mechanism of action of CMCs in cardiac repair.

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Molecular Mechanisms of Immune Escape for Foot-and-Mouth Disease Virus

Pathogens ◽

10.3390/pathogens9090729 ◽

2020 ◽

Vol 9 (9) ◽

pp. 729

Author(s):

Bo Yang ◽

Xiaohui Zhang ◽

Dajun Zhang ◽

Jing Hou ◽

GuoWei Xu ◽

...

Keyword(s):

Immune Responses ◽

Disease Virus ◽

Molecular Mechanisms ◽

Immune Escape ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Host Immune Responses ◽

Mouth Disease Virus ◽

Foot And Mouth ◽

Vesicular Disease

Foot-and-mouth disease virus (FMDV) causes a highly contagious vesicular disease in cloven-hoofed livestock that results in severe consequences for international trade, posing a great economic threat to agriculture. The FMDV infection antagonizes the host immune responses via different signaling pathways to achieve immune escape. Strategies to escape the cell immune system are key to effective infection and pathogenesis. This review is focused on summarizing the recent advances to understand how the proteins encoded by FMDV antagonize the host innate and adaptive immune responses.

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Persistent Activation of Innate Immunity in Patients with Primary Antibody Deficiencies

Journal of Immunology Research ◽

10.1155/2020/8317671 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Gerasimina Tsinti ◽

Demosthenes Makris ◽

Anastasios E. Germenis ◽

Matthaios Speletas

Keyword(s):

Innate Immunity ◽

Cell Activation ◽

Immune Cell ◽

Primary Antibody ◽

Favorable Effect ◽

Polymorphonuclear Cells ◽

Replacement Treatment ◽

Primary Antibody Deficiencies ◽

Immunoglobulin Replacement ◽

Clinical Conditions

Primary antibody deficiencies (PAD) represent a heterogeneous group of disorders, with common variable immunodeficiency being the most common with clinical significance. The main phenotypic defect resides in the inability of B cells to produce antibodies, and the cornerstone of therapy is immunoglobulin replacement treatment in order to fight infections. However, the management of the other inflammatory manifestations is inadequate, reinforcing the hypothesis that a complex genetic background affecting additional cell populations, such as polymorphonuclear cells (PMN) and monocytes, influences the expression of the clinical phenotype of the disease. In this study, we investigated by flow cytometry in different conditions (resting state, and after isolation and incubation, with and without stimuli) the expression pattern of several markers on PMN and monocytes, indicative of their maturation, capacity for chemotaxis, adhesion, opsonization, migration, and phagocytosis in 25 PAD patients, 12 healthy blood donors, and 4 septic patients. In this context, we also analyzed patients before and after the initiation of replacement treatment, as well as an untreated patient in different clinical conditions. Interestingly, we observed that PAD patients exhibit a chronic activation status of the innate immunity compartment, along with several differences in the expression of activation, maturation, and adhesion markers, with respect to different clinical conditions. Moreover, immunoglobulin replacement treatment had a favorable effect on PMN, as it was expressed by a more mature and less activated phenotype on basal state cells, and an enhanced activation capacity after LPS exposure. Thus, we conclude that PAD patients display a persistent innate immune cell activation, which is probably associated with the chronic inflammatory stress, usually observed in these disorders.

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