Addressing global health disparities in the management of RSV infection in infants and children: Strategies for preventing bronchiolitis and post-bronchiolitis recurrent wheezing.

Background: The topic of equitable access to health care and its impact on exacerbating worldwide inequities in child health not only strikes at the heart of our health-care delivery systems but also deeply resonates with our collective social consciences. Nowhere is this better seen on a global scale than in the burden of illness caused by respiratory syncytial virus (RSV) infection, which extracts the most severe morbidity and mortality in infants and children in low- and middle-income countries (LMIC). This report addresses global health disparities that exist in the management of RSV infection in infants and children, and offers strategies for preventing bronchiolitis and postbronchiolitis recurrent wheezing in LMICs. Methods: A systematic literature review was conducted across the PubMed data bases of RSV infection and the socioeconomic impact of bronchiolitis and postbronchiolitis recurrent wheezing in LMICs. Results: The results of the present study address the many issues that deal with the question if prevention of RSV bronchiolitis can mitigate recurrent wheezing episodes and links RSV risks, downstream effects, prevention, malnutrition, and socioeconomic restraints of developing countries with a call for possible global action. Conclusion: The present study stresses the importance of considering the linkage between malnutrition and disease susceptibility because of the known relationships between undernutrition and greater vulnerability to infectious diseases, including RSV infection. These complex interactions between infectious disease and undernutrition also raise issues on the longer-term sequelae of postbronchiolitis recurrent wheezing. This prompts a discussion on whether industrialized countries should prioritize the provision of newly developed monoclonal antibodies and RSV vaccines to LMICs or whether vital nutritional needs should be a first focus. The resolution of these issues will require research and greater international discourse.

The mitochondrial complex I proteins of Candida albicans moderate phagocytosis and the production of pro-inflammatory cytokines in murine macrophages and dendritic cells.

Loss of respiratory functions impairs Candida albicans colonization of host tissues and virulence in a murine model of candidiasis. Furthermore, it is known that respiratory inhibitors decrease mannan synthesis and glucan exposure and thereby promotes phagocytosis. To understand the impact of respiratory proteins of C. albicans on host innate immunity, we characterized cell wall defects in three mitochondrial complex I (CI) null mutants (nuo1Δ, nuo2Δ and ndh51Δ) and in one CI regulator mutant (goa1Δ), and we studied the corresponding effects of these mutants on phagocytosis, neutrophil killing and cytokine production by dendritic cells (DCs). We find that reductions of phosphopeptidomannan (PPM) in goa1Δ, nuo1Δ and phospholipomannan (PLM) in nuo2Δ lead to reductions of IL-2, IL-4, and IL-10 but increase of TNF-α in infected DCs. While PPM loss is a consequence of a reduced phospho-Cek1/2 MAPK that failed to promote phagocytosis and IL-22 production in goa1Δ and nuo1Δ, a 30% glucan reduction and a defective Mek1 MAPK response in ndh51Δ lead to only minor changes in phagocytosis and cytokine production. Glucan exposure and PLM abundance seem to remain sufficient to opsonize neutrophil killing perhaps via humoral immunity. The diversity of immune phenotypes in these mutants possessing divergent cell wall defects is further supported by their transcriptional profiles in each infected murine macrophage scenario. Since metabolic processes, oxidative stress-induced senescence, and apoptosis are differently affected in these scenarios, we speculate that during the early stages of infection, host immune cells coordinate their bioactivities based upon a mixture of signals generated during host-fungi interactions.

The 80th anniversary of Annals of Allergy, Asthma & Immunology (1943-2023).

The year 2023 marks the 80th year of publication of Annals of Allergy, Asthma & Immunology. To celebrate this important milestone, we look back on the history of the journal from its inception to the present day. This special article explores the rationale and people involved in creating the journal and highlights major advances in Annals history. Our celebration of Annals' 80th year of publication concludes with a glimpse into the potential future of Annals.

The PANDAS/PANS disorders. Is it time for more allergist-immunologists to get involved?

Background: The pediatric autoimmune neurologic disorders associated with streptococcal infections (PANDAS) comprise a group of patients who, after infection with group A ß-hemolytic streptococci (GAS), exhibit a spectrum of neuropsychiatric symptoms that include obsessive thoughts, compulsive behaviors, tics, hyperactivity, inattention, and mild choreiform movements. More recently, a group of patients with a symptom complex similar to PANDAS without evidence of streptococcal etiology was given the acronym pediatric acute-onset neuropsychiatric syndrome (PANS). Despite more than several decades of study and increasing numbers of patients being identified with PANDAS and PANS, there are ongoing controversies, which range from disagreements about specific pathogenetic mechanisms to whether these entities actually exist. Objective: The purpose of this report was to examine the current body of evidence that deals with the relationship(s) of immunologic host responses to infection and putative immunologic mechanisms involved in the pathogenesis of these disorders, to evaluate the effectiveness of anti-inflammatory and immunomodulatory therapies with intravenous immunoglobulin (IVIG), and to consider the extent to which allergist/immunologists might be involved in their management. Methods: An extensive literature review was conducted in medical literature data bases by applying terms such as PANDAS, PAN, autoimmune encephalitis, neuroinflammation, and autoimmune obsessive-compulsive disorders. Results: PANDAS and its later iterative form, PANS, continue to challenge clinicians, patients, and their families. Although the precise reason why these disorders develop remains unknown, both are considered to have an autoimmune basis related to the production of antibodies directed at antigens of the putative causative infectious disease agents that are cross-reactive with antigenic epitopes on selected brain nuclei, which lead to the neuroinflammatory sequelae responsible for the neuropsychiatric symptoms of these conditions, a phenomenon referred to as molecular mimicry. Conclusion: The PANDAS/PANS disorders are a continuing burden for growing numbers of patients, health-care providers, and the global health-care systems, and are a particular challenge for the allergist/immunologist who is increasingly being called upon for their management. Because of the importance of immunologic factors in the pathogenesis and treatment of these conditions with anti-inflammatory and immune-modulating treatments, the allergist/immunologist is well poised to offer consultative care.

The third pandemic: The respiratory syncytial virus landscape and specific considerations for the allergist/immunologist.

Background: Since its initial identification in 1956, respiratory syncytial virus (RSV) has been the second most common cause of mortality in infants <6 months of age and a major cause of morbidity and mortality associated with lower respiratory tract infection (LRTI) in older adults (ages >60 years) worldwide. Of particular interest to the allergist/immunologist is a growing body of evidence that suggests an association between LRTI caused by RSV in infants with later-life development of asthma, wheezing, or impaired lung function in adults. Efforts to develop a RSV vaccine have been thwarted for >70 years by the occurrence of enhanced respiratory disease (ERD), an adverse RSV vaccine reaction, in the 1960s, in which more-severe illness occurred on natural infection after vaccination of infants who were RSV naive and with a formalin-inactivated RSV vaccine. Recent advances in knowledge of the structural biology of the RSV surface fusion glycoprotein, however, have revolutionized RSV vaccine development for preventive interventions and have offered, at last, the hope of an effective and safe vaccine for the prevention of RSV disease. Objective: The purpose of this report was to examine the current evidence that supports the epidemiology, disease manifestations, molecular biology, treatments, and new vaccine development of RSV vaccines. Results: The host-immune response to RSV infection is carried out by two distinct but overlapping universes of mucosal and systemic immune systems in which a balanced set of B- and T-cell responses are involved in protective immunity that includes the mucosal immune system in which immunoglobulin A (IgA) prevails and the systemic immune system in which IgG neutralizing antibody predominates. The key to developing an effective vaccine is now thought to be linked to the availability of a stabilized prefusion F protein in the immunizing vaccine, which can perform a dual function of a balanced mucosal and/or systemic immune response as well as an effective antibody specifically directed to critical epitopes on the requisite prefusion F protein. Conclusion: The unfortunate manifestation of RSV ERD that occurred in the 1960s has led to a better understanding of the structural biology of the RSV surface fusion glycoprotein and has provided a basis for the development of more effective and safer RSV vaccines and monoclonal antibody preparations for immunoprophylaxis of the dread effects of RSV disease. There are now a large number of clinical trials in progress that are evaluating these products, which include recombinant vector, subunit, particle-based, live-attenuated, chimeric, and nucleic acid vaccines; and monoclonal antibodies. This article gives an overview of the many aspects of RSV disease and development of virus (RSV) vaccines of particular interest to the allergist/immunologist.

The long COVID syndrome: A conundrum for the allergist/immunologist.

Background: The long coronavirus disease 2019 (COVID-19) syndrome includes a group of patients who, after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibit lingering mild-to-moderate symptoms and develop medical complications that can have lasting health problems. Objective: The purpose of this report was to examine the current body of evidence that deals with the relationship of COVID-19 infection with the long COVID syndrome to define the possible immunologic mechanisms involved in the pathogenesis of long COVID and to describe potential strategies for the diagnosis and clinical management of the condition. Methods: Extensive research was conducted in medical literature data bases by applying terms such as long COVID, post-COVID-19 condition, pathogenesis of long COVID, management of the long COVID syndrome. Results: The post-COVID conditions, a more recent and less anxiety-inducing term for the patient than long COVID or "long haul," is an umbrella term for a wide range of physical and mental health symptoms similar to those seen in patients with the myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), experienced by some patients and are present ≥ 4 weeks after SARS-CoV-2 infection. Although the precise reason why long COVID develops is unknown, one of the major causes is thought to be related to chronic inflammation with overproduction of inflammatory cytokines responsible for the symptoms of the disorder. Conclusion: Long COVID is a growing burden for millions of patients, health-care providers, and global health-care systems, and is a particular challenge for the allergist/immunologist. Many survivors of COVID-19 struggle with multiple symptoms, increased disability, reduced function, and poor quality of life. The allergist/immunologist can assist the total health-care team's efforts in providing a comprehensive and coordinated approach to the management of these patients by promoting comprehensive vaccination and rehabilitation and social services that focus on improving physical, mental, and social well-being, and by establishing partnerships with specialists and other health-care professionals who can provide behavioral, lifestyle, and integrative approaches that may have much to offer in helping patients cope with their symptoms.

Monkeypox viral infection and disease: A challenge for the allergist-immunologist.

Background: Human monkeypox is a zoonosis caused by the monkeypox virus, an orthopoxvirus and close relative of variola virus, the causative agent of smallpox. The disease was first reported in central Africa in 1970, where it continues to be endemic and has historically affected some of the poorest and most marginalized communities in the world. The condition has recently attracted global attention due to >14,000 cases, including five deaths, reported by the World Health Organization, and a total of 5189 confirmed monkeypox cases in the United States reported by the Centers for Disease Control and Prevention as of July 29, 2022. On July 23, 2022, the World Health Organization declared the current monkeypox outbreak a Public Health Emergency of International Concern. Objective: The purpose of the present report was to review the epidemiology of monkeypox viral infection; its clinical manifestations; and current recommendations for diagnosis, treatment, and use of vaccines for prevention of the disease, with a focus on those aspects that have particular relevance to the allergist/immunologist. Results: Monkeypox was discovered in the early 1970s and, for years, has been well described by researchers in west and central Africa, where the disease has been present for decades. Although this outbreak thus far has mostly affected men who have sex with men, it is possible that the disease could become endemic and could begin spreading in settings where there is close physical contact, which is how the virus is transmitted. Conclusion: Monkeypox is a different viral infection from the coronavirus. Unlike the coronavirus, which is an extremely contagious respiratory pathogen, monkeypox is primarily transmitted through body fluids and/or prolonged skin-to-skin contact. Although the control of monkeypox will require renewed efforts and resources, we have learned much from the past and have the tools to stop this virus from becoming yet another serious illness with which Americans have to contend. The allergist/immunologist can play a significant role.

Essentials of allergen immunotherapy: A primer for the practitioner.

It has been more than a decade since the most recent allergen immunotherapy (AIT) practice parameter was published and 5 years since a focused practice parameter on sublingual immunotherapy (SLIT) was issued. There is an unmet need, therefore, for a more up-to-date, concise summary of AIT to be published to provide allergy/immunology practitioners, allergy/immunology fellows-in-training, medical students, residents, and other health-care practitioners with the most current information available on AIT. The Allergen Immunotherapy Primer (AITP) is not intended to define a standard of care or to be inclusive of all proper methods of care, nor is it intended to replace or supplant established AIT practice parameters; rather, the goal of this AITP is to supplement the established practice parameters and to serve primarily as an updated tool for the practicing allergist/immunologist, allergy/immunology trainees, and health-care professionals seeking practical and concise information with regard to AIT. Primer topics include the history of AIT; descriptions of the mechanisms and biomarkers of subcutaneous immunotherapy (SCIT) and SLIT; the efficacy and safety of SCIT; the efficacy and safety of SLIT, pediatric SLIT, and SCIT; the long-term efficacy of SLIT and SCIT; long-term adherence strategies for AIT; the implications of real-world data for AIT; the role of AIT for asthma; patterns of cross-allergenicity among pollens; a practical implementation guide for optimized construction of AIT vaccines; standardization of allergen extracts; updated information on federal regulations about the United States Pharmacopeia and the compounding of allergenic extracts; an update on AIT venom immunotherapy; the advantages and disadvantages of accelerated immunotherapy regimens; the important role of shared decision-making in AIT and how it can be incorporated into the informed consent process; and a forecast of future directions in allergen immunotherapy.

Long COVID: A proposed hypothesis-driven model of viral persistence for the pathophysiology of the syndrome.

Background: Long COVID (coronavirus disease 2019) syndrome includes a group of patients who, after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibit lingering mild-to-moderate symptoms and develop medical complications that can have lasting health problems. In this report, we propose a model for the pathophysiology of the long COVID presentation based on increased proinflammatory cytokine production that results from the persistence of the SARS-CoV-2 virus or one of its molecular components. Associated with this hyperproduction of inflammatory cytokines is a heightened activity of nuclear factor κ B (NF-κB) and p38 mitogen-activated protein kinase signaling pathways that regulate cytokine production. Objective: The purpose of the present report was to review the causes of long COVID syndrome and suggest ways that can provide a basis for a better understanding of the clinical symptomatology for the of improved diagnostic and therapeutic procedures for the condition. Methods: Extensive research was conducted in medical literature data bases by applying terms such as "long COVID" associated with "persistence of the SARS-CoV-2 virus" "spike protein' "COVID-19" and "biologic therapies." Results and Conclusions: In this model of the long COVID syndrome, the persistence of SARS-CoV-2 is hypothesized to trigger a dysregulated immune system with subsequent heightened release of proinflammatory cytokines that lead to chronic low-grade inflammation and multiorgan symptomatology. The condition seems to have a genetic basis, which predisposes individuals to have a diminished immunologic capacity to completely clear the virus, with residual parts of the virus persisting. This persistence of virus and resultant hyperproduction of proinflammatory cytokines are proposed to form the basis of the syndrome.

Salivary and serum IgA and IgG responses to SARS-CoV-2-spike protein following SARS-CoV-2 infection and after immunization with COVID-19 vaccines.

Background: Secretory immunoglobulin A (sIgA) plays an important role in antiviral protective immunity. Although salivary testing has been used for many viral infections, including severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS), its use has not yet been well established with the SARS coronavirus 2 (SARS-CoV-2). Quantification of salivary IgA and IgG antibodies can elucidate mucosal and systemic immune responses after natural infection or vaccination. Here, we report the development and validation of a rapid enzyme-linked immunosorbent assay (ELISA) for anti-SARS-CoV-2 salivary IgA and serum IgG antibodies, and present quantitative results for immunized subjects both prior to or following COVID-19 infections. Objective: Total and serum SARS-CoV-2 spike-specific IgG responses were compared with salivary spike-specific IgA and IgG responses in samples obtained from patients recently infected with SARS-CoV-2 and from subjects recently immunized with COVID-19 vaccines. Methods: A total of 52 paired saliva and serum samples were collected from 26 study participants: 7 subjects after COVID-19 infection and 19 subjects who were uninfected. The ELISA results from these samples were compared with five prepandemic control serum samples. Total IgG and SARS-CoV-2 spike-specific IgG in the serum samples from the subjects who were infected and vaccinated were also measured in a commercial laboratory with an enzyme immunoassay. Results: A wide variation in antibody responses was seen in salivary and serum samples measured by both methods. Three groups of serum total and IgG spike-specific SARS-CoV-2 antibody responses were observed: (1) low, (2) intermediate, and (3) high antibody responders. A correlational analysis of salivary IgA (sIgA) responses with serum IgG concentrations showed a statistical correlation in the low and intermediate antibody responder groups but not in the high group (which we believe was a result of saturation). Conclusion: These preliminary findings suggest measuring salivary and serum IgG and IgA merit further investigation as markers of current or recent SARS-CoV-2 infections.

An Exploratory Study of an Online Vaccine Education Program in Middle-School Students to Promote Vaccine Acceptance.

Background: While vaccines have reduced the incidence of vaccine-preventable diseases, vaccine hesitancy threatens the re-emergence of childhood infectious diseases. Purpose: This randomized controlled study evaluated an online vaccine education program to advance vaccine acceptance among middle-school students. Methodology: Study participants were randomly assigned to an intervention group who viewed the VEP videos or to a comparison group who viewed a science-based video unrelated to vaccines. Results: Knowledge scores improved in both groups and more favorable shifts in vaccine-related beliefs and attitudes occurred in the intervention than in the comparison group. Conclusions: This program can be feasibly delivered via an online platform to middle school students, resulting in shifts in vaccine-related knowledge, beliefs and attitudes. Implications: Delivering evidence-based content to instruct about vaccine effectiveness and safety is an area in which school nurses have demonstrated an important role as a resource for patient education to promote vaccine advocacy.

B7-H1 Promotes the Functional Effect of Human Gingiva-Derived Mesenchymal Stem Cells on Collagen-Induced Arthritis Murine Model.

Recent studies found that mesenchymal stem cells (MSCs), by virtue of their tissue recovery and immunoregulatory properties, have shown a broad prospect for applications in various autoimmune and degenerative diseases. Although the potential therapeutic use of MSCs is considerable, studies and clinical treatment efficacy are preliminary due to the heterogeneity of MSCs. Herein, based on RNA-sequencing (RNA-seq) and single cell sequence properties, we demonstrated that B7-H1 plays an important role in the immunosuppressive function of human gingiva-derived mesenchymal stem cells (GMSCs) in a collagen-induced arthritis murine model that is dependent on STAT3 signaling. Our data offer convincing evidence that B7-H1 expression by GMSCs helps to identify a new subpopulation of MSCs with a greater immunosuppressive property. The approach provides a unique and additional strategy for stem cells-based therapies of autoimmune and other inflammatory diseases.

CD39 Produced from Human GMSCs Regulates the Balance of Osteoclasts and Osteoblasts through the Wnt/ß-Catenin Pathway in Osteoporosis.

Osteoporosis is a disease in which the density and quality of bone are reduced, causing bones to become weak and so brittle that a fall or even mild stresses can cause a fracture. Current drug treatment consists mainly of antiresorptive agents that are unable to stimulate new bone formation. Our recent studies have defined a critical role of gingiva-derived mesenchymal stem cells (GMSCs) in attenuating autoimmune arthritis through inhibition of osteoclast formation and activities, but it remains to be ruled out whether the administration of GMSCs to patients with osteoporosis could also regulate osteoblasts and eventually affect bone formation and protection. With the use of an ovariectomized mouse model, we here demonstrated that adoptive transfer of GMSCs regulated the balance of osteoclasts and osteoblasts, eventually contributing to dynamic bone formation. Validation by RNA sequencing (RNA-seq), single-cell sequencing, revealed a unique population of CD39+ GMSC that plays an important role in promoting bone formation. We further demonstrated that CD39 produced from GMSC exerted its osteogenic capacity through the Wnt/ß-catenin pathway. Our results not only establish a previously unidentified role and mechanism of GMSC for bone promotion but also a potential therapeutic target for management of patients with osteoporosis and other bone loss conditions.

Treg Cells and Epigenetic Regulation.

The discovery of the epigenetic regulation of Treg cells, a cell population with fundamental immunoregulatory properties, has shed considerable insights into an understanding of the role of these cells in health and disease. Research over the past several years has shown that the interaction of Treg cells with the gut microbiota are critical not only for the development of Treg function in health but also for abnormalities of Treg function that play a critical role in the pathogenesis of human diseases such as the allergic diseases, the autoimmune disorders, and cancer. The equilibrium between phenotypic plasticity and stability of Treg cells is defined by the fine-tuned transcriptional and epigenetic events required to ensure stable expression of Foxp3 in Treg cells. In this chapter, we discuss the molecular events that control Foxp3 gene expression and address the importance of DNA methylation as an important molecular switch that regulates the genetic expression of Treg induction and the possible implications of these findings for the treatment of human diseases characterized by abnormalities of Treg cell function.

COVID-19 vaccines and vaccine hesitancy: Role of the allergist/immunologist in promotion of vaccine acceptance.

Background: Vaccine hesitancy has been defined as a delay in acceptance or refusal of vaccines, despite the availability of vaccine services. In the past, despite an impressive record of vaccine effectiveness in the United States, several factors have contributed to a decreased acceptance of vaccines that has resulted in outbreaks of infectious diseases, e.g., measles. More recently, vaccine hesitancy has spread to coronavirus disease 2019 (COVID-19) vaccines. There are many causes of vaccine hesitancy, such as misinformation, fallacies, and myths, that have contributed to vaccine hesitancy. Objective: The purpose of the present report is to address the many causes of vaccine hesitancy and to suggest ways that the allergist/immunologist can be involved in the promotion of vaccine acceptance. Methods: The current COVID-19 vaccines were reviewed, together with their mechanisms(s) of action and adverse reactions to them. Results: The many causes of vaccine hesitancy include many doubts and concerns related to COVID-19 vaccines as well as a diminished level of confidence and trust by segments of the public in the nation's leaders in government, medical, and business communities, that those groups once enjoyed. Conclusion: Vaccination with COVID-19 vaccines is the only way that COVID-19 will be eliminated or at least controlled today, and vaccine hesitancy is the potential nemesis. The present report describes how the allergist/immunologist not only plays a major role in the delivery of specialized therapy of COVID-19 but also in educating the public with regard to the importance of COVID-19 vaccines, in dispelling misinformation, and in promoting trust for vaccine acceptance but must be informed with the most accurate and current information to do so.

COVID-19 in children: Pathogenesis and current status.

Background: Since its initial description in December 2019 in Wuhan, China, coronavirus disease 2019 (COVID-19) has rapidly progressed into a worldwide pandemic, which has affected millions of lives. Unlike the disease in adults, the vast majority of children with COVID-19 have mild symptoms and are largely spared from severe respiratory disease. However, there are children who have significant respiratory disease, and some may develop a hyperinflammatory response similar to that seen in adults with COVID-19 and in children with Kawasaki disease (KD), which has been termed multisystem inflammatory syndrome in children (MIS-C). Objective: The purpose of this report was to examine the current evidence that supports the etiopathogenesis of COVID-19 in children and the relationship of COVID-19 with KD and MIS-C as a basis for a better understanding of the clinical course, diagnosis, and management of these clinically perplexing conditions. Results: The pathogenesis of COVID-19 is carried out in two distinct but overlapping phases of COVID-19: the first triggered by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) itself and the second by the host immune response. Children with KD have fewer of the previously described COVID-19-associated KD features with less prominent acute respiratory distress syndrome and shock than children with MIS-C. Conclusion: COVID-19 in adults usually includes severe respiratory symptoms and pathology, with a high mortality. It has become apparent that children are infected as easily as adults but are more often asymptomatic and have milder disease because of their immature immune systems. Although children are largely spared from severe respiratory disease, they can present with a SARS-CoV-2-associated MIS-C similar to KD.

Studies of mitochondrial and nuclear DNA released from food allergen-activated neutrophils. Implications for non-IgE food allergy.

Background: Although adverse food reactions are commonly divided into immunoglobulin E (IgE) mediated food allergy (FA), and non-IgE FA, the current literature is providing support for the role of innate immune responses as an important component of non-IgE FA. Using a commercially available leukocyte activation (LA) assay, a recent quantitative study of total extracellular DNA released in cellular supernatants of human peripheral blood mononuclear cells exposed either to positive or negative tested foods demonstrated that leukocytes exposed to foods with positive LA test results showed higher DNA content than those exposed to foods with negative LA test results. In humans, the origin of DNA might be either the nucleus or the mitochondria. Analysis of emerging data from several laboratories, including our own, suggests that mitochondrial DNA induces inflammatory responses through induction of proinflammatory cytokines. Objective: This pilot study was designed primarily to convey the finding, and relevance of, mitochondrial DNA in the form of neutrophil extracellular traps (NET) as a new pathogenetic mechanism for innate immune-mediated non-IgE FA. Methods: The study population consisted of a total of six subjects, four in a major FA study group and two in a subgroup. Neutrophils were isolated and treated with food antigens that elicited positive and negative LA responses, and the released free DNA was analyzed for the cellular site of origin by using real-time polymerase chain reaction and for leukocyte calprotectin and S100 calcium-binding protein A12 (S100A12) proteins as markers of NETs. Results: We showed that cellular supernatants from neutrophils treated with foods that elicit positive LA responses can contain increased DNA levels of nuclear as well as mitochondrial origin. Supernatants from neutrophils treated with negative tested food (LA) responses did not induce the release of nuclear or mitochondrial DNA. Conclusion: Analysis of our data suggested that the induction of NETs that contain proinflammatory mitochondrial DNA may provide the critical link necessary for a better understanding of the pathogenesis of non-IgE-mediated FA. These discoveries may not only facilitate better diagnostic tests of FA but should also improve clinical management of allergic and other inflammatory diseases.

Effects of myeloid and plasmacytoid dendritic cells on ILC2s in patients with allergic rhinitis.

BACKGROUND: Group 2 innate lymphoid cells (ILC2s) were reported to serve a critical role in allergic diseases. Myeloid dendritic cells (mDCs) and plasmacytoid DCs (pDCs) play significant roles in allergic immune response. However, effects of DCs on ILC2s in allergic diseases, especially for patients with allergic rhinitis (AR), remain unclear. OBJECTIVE: We sought to address the roles of mDCs and pDCs in regulating ILC2 function in AR. METHODS: mDCs and pDCs were cocultured with human PBMCs isolated from patients with AR or ILC2s to measure soluble or intracellular TH2 cytokines, transcription factors, signaling pathways in ILC2s, and the following mechanisms were further investigated. The levels of peripheral IL-33+mDCs, pDCs, and ILC2s were studied in patients under an inhaled allergen challenge. RESULTS: We confirmed the presence of ILC2s, mDCs, and pDCs in the nasal mucosa of patients with AR. Both allogenic and autologous mDCs were found to activate ILC2s from patients with AR to produce TH2 cytokines, and increase the levels of GATA-3 and signal transducer and activator of transcription signaling pathways, in which IL-33-producing mDCs exerted the major role by binding on ST2 on ILC2s. We further identified high levels of IL-33+mDCs and ILC2s in patients with AR under antigen challenge. Activated pDCs inhibited the cytokine production of ILC2s isolated from patients with AR by secretion of IL-6. CONCLUSIONS: mDCs promote ILC2 function by the IL-33/ST2 pathway, and activation of pDCs suppresses ILC2 function through IL-6 in patients with AR. Our findings provide new understanding of the interplay between DCs and ILC2s in allergic diseases.

Combination of human umbilical cord mesenchymal stem (stromal) cell transplantation with IFN-γ treatment synergistically improves the clinical outcomes of patients with rheumatoid arthritis.

OBJECTIVES: To clarify the key role of circulating interferon-γ (IFN-γ) and to improve the clinical efficacy of mesenchymal stem cell (MSC) transplantation (MSCT) in patients with rheumatoid arthritis (RA). METHODS: Study of wild-type or IFN-γR-/- MSCT was first evaluated in a murine model of collagen-induced arthritis (CIA) following which a phase 1/2 randomised controlled study was conducted in 63 patients with RA who responded poorly to regular clinical treatments. Subjects were randomly assigned to an MSCT monotherapy group (n=32) or an MSCT plus recombinant human IFN-γ treatment group (n=31), with 1 year of follow-up. The primary end points consisted of efficacy as assessed as good or moderate EULAR response rates and the proportion of patients at 3 months attaining American College of Rheumatology 20 (ACR20) response rates. RESULTS: In the murine studies, wild-type MSCT significantly improved the clinical severity of CIA, while IFN-γR-/- MSCT aggravated synovitis, and joint and cartilage damage. Transitioning from the murine to the clinical study, the 3-month follow-up results showed that the efficacy and ACR20 response rates were attained in 53.3% patients with MSCT monotherapy and in 93.3% patients with MSCT combined with IFN-γ treatment (p<0.05). No new or unexpected safety issues were encountered in 1-year follow-up for either treatment group. CONCLUSIONS: The results of this study show that IFN-γ is a key factor in determining the efficacy of MSCT in the treatment of RA, and that an MSC plus IFN-γ combination therapeutic strategy can greatly improve the clinical efficacy of MSC-based therapy in RA patients.

Human gingiva-derived mesenchymal stem cells are therapeutic in lupus nephritis through targeting of CD39-CD73 signaling pathway.

Cell specific and cytokine targeted therapeutics have underperformed in systemic lupus erythematosus (SLE). Mesenchymal stem cells (MSCs) have emerged as a novel therapy to address the dysregulation in autoimmune diseases but also have limitations. Human gingiva derived MSCs (GMSCs) are superior in regulating immune responses. Here, we demonstrate that the adoptive transfer of GMSCs homes to and maintains in the kidney and has a robust therapeutic effect in a spontaneous lupus nephritis model. Specifically, GMSCs limits the development of autoantibodies as well as proteinuria, decreases the frequency of plasma cells and lupus nephritis histopathological scores by directly suppressing B cells activation, proliferation and differentiation. The blockage of CD39-CD73 pathway dramatically abrogates the suppressive capacities of GMSCs in vitro and in vivo and highlights the significance of this signaling pathway in SLE. Collectively, manipulation of GMSCs provides a promising strategy for the treatment of patients with SLE and other autoimmune diseases.