Repeated inoculation with messenger RNA (mRNA) vaccines elicits immunoglobulin G4 (IgG4) antibody production. Such an increase in the concentration of specific and non-specific IgG4 antibodies allows the growth of some types of cancer by blocking the activation of effector immune cells. This work proposes the hypothesis that cancer growth may be indirectly promoted by increased concentrations of non-specific IgG4 antibodies by the following mechanisms: 1) IgG4 antibodies can bind to anti-tumor IgG1 antibodies and block their interaction with receptors located on effector cells, thus preventing the destruction of cancer cells, 2) IgG4 can interact with fragment crystallizable gamma receptor IIb (FcγRIIB) inhibitory receptors, thus reducing effector functions of innate immune cells, and 3) targeting of specific epitopes by IgG4 could be oncogenic by inducing the production of a microenvironment that can promote cancer development. This article reviews the supporting literature and suggests several experimental protocols to evaluate this hypothesis in the context of repeated inoculation with mRNA vaccines. Additionally, this work proposes some management options aimed at reducing the unfavorable molecular consequences that could mediate cancer development when encountering high concentrations of IgG4 antibodies.

Immunity is continuously evolving by evolutionary mechanisms shaped by pathogenic stimuli of different kinds. Man-made nanomaterials (NMs) have been developed in the last decades and represent a novel challenge for our immune system, especially when applied to medical science. Toxicological studies of such nanoparticles (NPs) revealed that size, shape, and surface chemistry are key parameters to understand their noxious effects on cellular mechanisms. Less is known on the immune reactions to NMs since prolonged exposure data are not so detailed as the results for acute administration. The importance of immunity to biocompatible NPs is underlined by their increasing use as drug or gene delivery carriers in common pharmaceutical preparations and vaccines. In the latter case, the immunomodulatory properties of NMs allow their use also as efficient adjuvants to enhance the innate immune response. In the current manuscript, the authors discuss the main concepts in this fast-growing field by restricting our view to NMs with consolidated application in biomedicine.

Atopic dermatitis (AD) is characterized by skin barrier disruption, type 2 immune dysregulation, chronic pruritus, and abnormal colonization by Staphylococcus aureus (S. aureus). Tapinarof, an aryl hydrocarbon receptor modulator, has been demonstrated to attenuate the development of AD in clinical studies. Recently, we found that tapinarof upregulated the expression of filaggrin and loricrin, which are essential proteins in skin barrier functions. Paradoxically, tapinarof induced interleukin (IL)-24 secretion by normal human keratinocytes. IL-24 is produced by T helper 2 lymphocytes and keratinocytes following stimulation by type 2 cytokines, and IL-24 is upregulated in the skin of patients with AD. Furthermore, IL-24 contributes to skin barrier disruption and hyperplasia in AD, and it may exacerbate skin inflammatory responses, itch, and S. aureus infection. In this review, we summarized the current findings regarding the detrimental role of IL-24 in AD, thereby suggesting that co-treatment of tapinarof with therapeutics that block IL-24 signaling may represent a promising strategy for managing AD.

Chemokines are homeostatic or inflammatory small proteins regulating immune cell migration and are structurally characterized by cysteine disulfide bridges. Around 50 human chemokines binding almost 20 seven-transmembrane G-protein coupled receptors have been discovered. The finding that two of them were the main human immunodeficiency virus (HIV) co-receptors intensified the research on the binding mechanism to block the viral entrance. Blockade of chemokine/chemokine receptor signaling ultimately modulates cell migration, then immune responses. Particular nanotechnologies can be designed to interfere with chemokine signaling or to exploit the ligand-receptor interaction. Surface chemical modification of nanomaterials with chemokines or specific peptides can find several applications in bio-medicine, from tissue-specific drug delivery to reduced cell migration in pathological conditions. Recent highlights on peculiar chemokine-nanoparticle design and their potential to modulate immune responses will be discussed.

Cutaneous homeostasis is maintained by dynamic cellular communications between different cell types in the skin through interactions with various mediators, including cytokines, chemokines and antimicrobial peptides/proteins (AMPs). Keratinocytes, as the major cell type of the epidermis, not only form a passive physical barrier, but also actively participate in the pathogenesis of many, if not all, inflammatory skin diseases. Keratinocytes highly interact with immune cells to shape, amplify or regulate inflammatory responses, thus triggering and/or sustaining these inflammatory skin diseases. In this review, crosstalk between keratinocytes and immune cells is summarized, and its contributions to two major inflammatory skin disorders including psoriasis and atopic dermatitis are highlighted.

Interleukin (IL)-22 is produced from immune cells such as T helper (Th)22 cells, Th17/22 cells, and group 3 innate lymphoid cells. IL-22 signals via the IL-22 receptor 1 (IL-22R1) and the IL-10 receptor 2 (IL-10R2). As the IL-22R1/IL-10R2 heterodimer is preferentially expressed on border tissue between the host and the environment, IL-22 is believed to be involved in border defense. Epidermal keratinocytes are the first-line skin barrier and express IL-22R1/IL-10R2. IL-22 increases keratinocyte proliferation but inhibits differentiation. Aryl hydrocarbon receptor (AHR) is a chemical sensor and an essential transcription factor for IL-22 production. In addition, AHR also upregulates the production of barrier-related proteins such as filaggrin in keratinocytes, suggesting a pivotal role for the AHR-IL-22 axis in regulating the physiological skin barrier. Although IL-22 signatures are elevated in atopic dermatitis and psoriasis, their pathogenic and/or protective implications are not fully understood.

There have been significant developments in the design of nanostructured scaffolds for eliciting robust immune responses named vaccine. The technique is to produce strong immune responses is to manipulate the appearance of a pathogen. Subsequently pathogens such as viruses and bacteria often demonstrate of multiple copies of ligands on their surfaces, the immune system is predominantly sensitive towards multivalent presentations of antigens. Consequently, when designing a vaccine, it is beneficial to garnish a nanostructured surface with multiple copies of an antigen so it can effectively act as an immune booster. Different methods are there for the development of the vaccine, from them most of the techniques are well developed and reported and some of in the developing state. This review focuses primarily on cellular and non-cellular vaccines, the whole cells or cellular proteins either as the source of antigens or the platform in which to deliver the antigens. Purpose of this review, understand and discussion on the various vaccine platforms which will contribute noteworthy information to vaccine research and development (R and D).

There are various types of skin immune responses including inflammatory skin diseases and skin malignancy. Macrophages and fibroblasts are skin resident cells that had been overlooked in terms of immunological research targets. In this review, cross talk among macrophages, fibroblasts, and migratory immune cells in skin diseases such as atopic dermatitis (AD), contact hypersensitivity, psoriasis, systemic sclerosis, melanoma, and cutaneous T-cell lymphoma is described. Macrophages are important in AD by antigen-presenting phagocytosis, production of inflammatory cytokines, removal of apoptotic cells, and mediating clusters between dendritic cells (DCs) and T cells. They are also increased in lesional skin of psoriasis, especially in stable plaques, and an increased ratio of M1/M2 macrophages and tumor necrosis factor-α production by macrophages are essential for development of psoriasis. The progression of skin malignancy is mediated by macrophages through promotion of tumor survival pathways via expression of cytokines and growth factors, interaction with regulatory T cells (Tregs) and myeloid-derived suppressor cells, and suppression of function of tumor-infiltrating T cells by immunosuppressive cytokines and programmed death-ligand (PD-L)1. Fibroblasts play important roles in development and maintenance of AD lesions through expression of CC chemokine ligand (CCL)17, CCL11, CCL26, C-X-C motif chemokine ligand (CXCL)12, CCL19, and periostin, interacting with T helper (Th)2 cells, natural killer T (NKT) cells, DCs, and keratinocytes. They also play important roles in psoriasis, expressing interleukin (IL)-8 and vascular endothelial growth factor, production of fibronectin, and changes in the proteomic profiles. Fibroblasts have a critical role in the progression skin malignancy via expression of cytokines, suppression natural killer (NK) functions, and establishment of Th2-dominant microenvironment. Thus, cross talk among macrophages, fibroblasts, and migratory immune cells including T cells, DCs, and NK cells in skin diseases is important and those skin-resident cells are attracting therapeutic targets in the near future.

Head and neck squamous cell carcinoma (HNSCC) is a relatively widespread cancer with high mortality rates. Many patients with locally advanced disease are treated with combinations of surgery, radiation, and chemotherapy, while others are considered incurable and develop recurrent/metastatic (R/M) disease. Despite these treatment modalities, the 5-year survival rate of HNSCC has remained at 50% due to limited treatment options in patients with recurrent disease. Immunotherapy has been shown to induce durable responses in R/M patients, but only a minority of patients currently respond. A major hurdle in tumor immunotherapy is identifying the non-responders and markers to predict resistance in patients who at first responded to the therapy. In HNSCC patients, the tumor microenvironment (TME) assumes a vital role to either diminish or augment immune responses. There is an urgent need for extensive studies to be undertaken to better understand how tumor cells escape immune surveillance and resist immune attack. In this review, the impact of TME on the efficiency of immunotherapy, addressing the factors that mediate therapy resistance are highlighted. The composition of the TME encompassing the immunosuppressive cells including myeloid-derived suppressor cell (MDSC), regulatory T cells (Treg), mesenchymal stem cell (MSC), cancer-associated fibroblast (CAF), and tumor-associated macrophages (TAMs) and intrinsic factors like hypoxia, reactive oxygen species (ROS), extracellular matrix (ECM), angiogenesis, and epithelial-mesenchymal transition (EMT), how this debilitates immunosurveillance, and also discuss existing and potential strategies aimed at targeting these cellular and molecular TME components are reviewed. Understanding the interactions between the TME and immunotherapy is not only important in dissevering the mechanisms of action of immunosuppression but also offers scope for developing newer strategies to improve the competence of current immunotherapies.

Both innate and adaptive immune cells exist in the skin, predominantly in the dermis layer. Recent studies have focused on how and which circadian rhythms contribute to maintain good health. Over recent years, we have gained a better understanding of the molecular mechanisms that control biological clocks and circadian rhythms. Circadian rhythms maintain homeostasis by providing day and night information to various physiological functions of our body. However, excessively high immune system activity can lead to a risk of developing autoimmune or allergic diseases. Recently, increasing numbers of studies with human and mouse models have been conducted to investigate the mechanisms underlying circadian regulation of the skin homeostasis. In this review, circadian regulation in the skin will be discussed from different points of view. Skin is referred as the largest organ of the body and is directly exposed to the external environment, including large changes in diurnal temperature, light, and pathogens. Immune cells as well as skin cells are the ones protecting us from these stimulants. Associations of the circadian system and these cells have been revealed in many ways, however, the specific roles of the peripheral clocks in these cells remain unknown. Circadian regulation in the skin diseases is discussed specifically in atopic dermatitis and other skin allergic symptoms as well as psoriasis.