Correlation between allergic rhinitis or hay fever and lung cancer: A systematic review and meta-analysis

BACKGROUND

The association between allergies and cancer is contradictory, whereas some forms of cancer have inverse associations with allergies. Allergic rhinitis (AR) is the most prevalent form of allergy, and lung cancer is one of the most prevalent forms of cancer with the highest mortality rate. Recent studies have reported a positive association between asthma and lung cancer; however, this association is inconclusive. Furthermore, AR is positively associated with asthma; therefore, our research question was to explore whether there is any correlation between AR and lung cancer epidemiologically.

METHODS

After a rigorous search of PubMed, Google Scholar, and ScienceDirect, 7 eligible articles were included in this systematic review and meta-analysis, including 4724 cases and 9059 controls, 5 from the USA, and one each from Canada and Germany.

RESULTS

Pooled analysis (OR, 0.55; 95% CI: 0.45-0.68; P value < .00001) showed a strong inverse relationship between AR and lung cancer.

CONCLUSION

The current meta-analysis suggests an inverse relationship between AR and lung cancer; however, new epidemiological studies are required to observe the current scenario more comprehensively.

Time- and cost-effective production of untagged recombinant MVA by flow virometry and direct virus sorting

BACKGROUND

Recombinant MVAs (rMVAs) are widely used both in basic and clinical research. Our previously developed Red-to-Green Gene Swapping Method (RGGSM), a cytometry-based Cell-Sorting protocol, revolves around the transient expression of a green fluorescent cytoplasmic marker, to subsequently obtain purified untagged rMVA upon loss of that marker by site-specific recombination. The standard RGSSM is quite costly in terms of bench work, reagents, and Sorting Facility fees. Although faster than other methods to obtain recombinant MVAs, the standard RGSSM still is time-consuming, taking at least 25 days to yield the final product.

METHODS

The direct sorting of fluorescent virions is made amenable by the marker HAG, a flu hemagglutinin/EGFP fusion protein, integrated into the external envelope of extracellular enveloped virions (EEVs). Fluorescent EEVs-containing supernatants of infected cultures are used instead of purified virus. Direct Virus-Sorting was performed on BD FACSAria Fusion cell sorter equipped with 4 lasers and a 100-mm nozzle, with 20 psi pressure and a minimal flow rate, validated using Megamix beads.

RESULTS

Upon infection of cells with recombinant EEVs, at the first sorting step virions that contain HAG are harvested and cloned, while the second sorting step yields EEVs that have lost HAG, allowing to clone untagged rMVA. Because only virion-containing supernatants are used, no virus purification steps and fewer sortings are necessary. Therefore, the final untagged rMVA product can be obtained in a mere 8 days.

CONCLUSIONS

Altogether, we report that the original RGSSM has been markedly improved in terms of time- and cost efficiency by substituting Cell-Sorting with direct Virus-Sorting from the supernatants of infected cells. The improved virometry-based RGGSM may find wide applicability, considering that rMVAs hold great promise to serve as personalized vaccines for therapeutic intervention against cancer and various types of infectious diseases.

Research Advances in Mast Cell Biology and Their Translation Into Novel Therapies for Anaphylaxis

Anaphylaxis is an acute, potentially life-threatening systemic allergic reaction for which there are no known reliable preventative therapies. Its primary cell mediator, the mast cell, has several pathophysiologic roles and functions in IgE-mediated reactions that continue to be poorly understood. Recent advances in the understanding of allergic mechanisms have identified novel targets for inhibiting mast cell function and activation. The prevention of anaphylaxis is within reach with new drugs that could modulate immune tolerance, mast cell proliferation and differentiation, and IgE regulation and production. Several US Food and Drug Administration-approved drugs for chronic urticaria, mastocytosis, and cancer are also being repurposed to prevent anaphylaxis. New therapeutics have not only shown promise in potential efficacy for preventing IgE-mediated reactions, but in some cases, they are able to inform us about mast cell mechanisms in vivo. This review summarizes the most recent advances in the treatment of anaphylaxis that have arisen from new pharmacologic tools and our current understanding of mast cell biology.

The Very Low IgE Producer: Allergology, Genetics, Immunodeficiencies, and Oncology

Opposite to other immunoglobulin (Ig) classes and subclasses, there is no consensus on the definition of normal levels of serum total IgE. However, longitudinal studies on birth cohorts produced growth charts of total IgE levels in helminth-free and never atopic children and defining the normal ranges of total serum IgE concentration at the individual, rather than population, level. Accordingly, very 'low IgE producers' (i.e., children whose tIgE level belong to the lowest percentiles) became atopic while keeping their total IgE levels in a range considered 'normal' if compared to the general age-matched population but 'abnormally high' if projected on the tIgE growth chart against the trajectory of that child's own percentile levels. In 'low IgE producers', the IgE-specific activity, i.e., the ratio between allergen-specific and total IgE, is more important than the absolute specific IgE levels to confirm causality between allergen exposure and allergic symptoms. Patients with allergic rhinitis or peanut anaphylaxis but low or undetectable allergen-specific IgE levels must therefore be reconsidered considering their total IgE levels. Low IgE producers have been also associated with common variable immunodeficiency, lung diseases, and malignancies. A few epidemiological studies have shown a higher risk of malignancies in very low IgE producers, leading to a debated hypothesis proposing a novel, evolutionistic-relevant function for IgE antibodies for antitumor immune surveillance.

Anti-cancer pro-inflammatory effects of an IgE antibody targeting the melanoma-associated antigen chondroitin sulfate proteoglycan 4

Outcomes for half of patients with melanoma remain poor despite standard-of-care checkpoint inhibitor therapies. The prevalence of the melanoma-associated antigen chondroitin sulfate proteoglycan 4 (CSPG4) expression is ~70%, therefore effective immunotherapies directed at CSPG4 could benefit many patients. Since IgE exerts potent immune-activating functions in tissues, we engineer a monoclonal IgE antibody with human constant domains recognizing CSPG4 to target melanoma. CSPG4 IgE binds to human melanomas including metastases, mediates tumoricidal antibody-dependent cellular cytotoxicity and stimulates human IgE Fc-receptor-expressing monocytes towards pro-inflammatory phenotypes. IgE demonstrates anti-tumor activity in human melanoma xenograft models engrafted with human effector cells and is associated with enhanced macrophage infiltration, enriched monocyte and macrophage gene signatures and pro-inflammatory signaling pathways in the tumor microenvironment. IgE prolongs the survival of patient-derived xenograft-bearing mice reconstituted with autologous immune cells. No ex vivo activation of basophils in patient blood is measured in the presence of CSPG4 IgE. Our findings support a promising IgE-based immunotherapy for melanoma.

Increased Hazard Risk of First Malignancy in Adults with Undetectable Serum IgE: a Retrospective Cohort Study

PURPOSE

The clinical relevance of IgE-deficiency is not established. Previous studies have postulated a relationship between absent serum IgE and the incidence of specific malignancies. We sought to examine the relationship between undetectable total serum IgE (< 3 IU/mL) and first malignancy, considering both general all-cause malignancy risk and risk of specific malignancy subtypes in adult subjects.

METHODS

Retrospective cohort study at a single center of 39,965 adults aged 18 or older (median age 51, 65.1% female) with at least one serum total IgE measurement from 1998 to 2020. Analytics included chi² table and logistic regression modeling of the main outcome measures, which include diagnosis of first malignancy and first diagnosis of specific malignancy subtype.

RESULTS

Of the entire cohort, 2584 subjects (6.5%) developed a first malignancy and 2516 (6.3%) had an undetectable IgE. Of those with undetectable IgE levels, 8.9% developed a first malignancy versus 6.3% with detectable IgE measurements. After adjusting for risk factors, there was a significant association between undetectable IgE and risk/hazard of first malignancy (relative risk 1.49, 95% confidence interval (CI) 1.27-1.75) (hazard ratio 1.28, 95% CI 1.08-1.52). Results were similar in multiple sensitivity analyses. For type of malignancy developed, undetectable IgE was associated with increased risk of hematologic malignancy (relative risk 2.07, 95% CI 1.29-3.30) and skin malignancy (relative risk 1.52, 95% CI 1.13-2.05).

CONCLUSION

Compared to individuals with detectable IgE levels, patients with undetectable total serum IgE had increased risk and hazard of first malignancy in general, and increased risk of hematologic malignancy in particular.

Molecular links between allergy and cancer

Epidemiologic studies show both positive and negative associations between allergies and cancer. Allergic diseases may protect against tumorigenesis by promoting the immune surveillance, while carcinogenesis may be promoted through inflammatory responses from allergies. Histamine receptor antagonists are the focus of recent cancer studies because of their promising beneficial effect on tumor development. Also, cytokines, particularly IL-4 or IL-33, IgE as well as allergy-related immune cells such as eosinophils can contribute to tumor growth suppression. Depending on cancer types, cancer therapy may be more beneficial when considering combinatorial immunotherapy. In this review, we give an overview on molecular links between allergies and cancer.

Mast Cells and Dendritic Cells as Cellular Immune Checkpoints in Immunotherapy of Solid Tumors

The immune checkpoint inhibitors have revolutionized cancer immunotherapy. These inhibitors are game changers in many cancers and for many patients, sometimes show unprecedented therapeutic efficacy. However, their therapeutic efficacy is largely limited in many solid tumors where the tumor-controlled immune microenvironment prevents the immune system from efficiently reaching, recognizing, and eliminating cancer cells. The tumor immune microenvironment is largely orchestrated by immune cells through which tumors gain resistance against the immune system. Among these cells are mast cells and dendritic cells. Both cell types possess enormous capabilities to shape the immune microenvironment. These capabilities stage these cells as cellular checkpoints in the immune microenvironment. Regaining control over these cells in the tumor microenvironment can open new avenues for breaking the resistance of solid tumors to immunotherapy. In this review, we will discuss mast cells and dendritic cells in the context of solid tumors and how these immune cells can, alone or in cooperation, modulate the solid tumor resistance to the immune system. We will also discuss how this modulation could be used in novel immunotherapeutic modalities to weaken the solid tumor resistance to the immune system. This weakening could then help other immunotherapeutic modalities engage against these tumors more efficiently.

Basophils as a potential therapeutic target in cancer

Basophils, which are considered as redundant relatives of mast cells and the rarest granulocytes in peripheral circulation, have been neglected by researchers in the past decades. Previous studies have revealed their vital roles in allergic diseases and parasitic infections. Intriguingly, recent studies even reported that basophils might be associated with cancer development, as activated basophils synthesize and release a variety of cytokines and chemokines in response to cancers. However, it is still subject to debate whether basophils function as tumor-protecting or tumor-promoting components; the answer may depend on the tumor biology and the microenvironment. Herein, we reviewed the role of basophils in cancers, and highlighted some potential and promising therapeutic strategies.

Remodeling of the tumor microenvironment via disrupting Blimp1+ effector Treg activity augments response to anti-PD-1 blockade

BACKGROUND

Accumulation of Foxp3⁺ regulatory T (Treg) cells in the tumor often represents an important mechanism for cancer immune evasion and a critical barrier to anti-tumor immunity and immunotherapy. Many tumor-infiltrating Treg cells display an activated phenotype and express the transcription factor Blimp1. However, the specific impact of these Blimp1⁺ Treg cells and their follicular regulatory T (T_FR) cell subset on tumor and the underlying mechanisms of action are not yet well-explored.

METHODS

Various transplantable tumor models were established in immunocompetent wild-type mice and mice with a Foxp3-specific ablation of Blimp1. Tumor specimens from patients with metastatic melanoma and TCGA datasets were analyzed to support the potential role of Treg and T_FR cells in tumor immunity. In vitro culture assays and in vivo adoptive transfer assays were used to understand how Treg, T_FR cells and antibody responses influence tumor control. RNA sequencing and NanoString analysis were performed to reveal the transcriptome of tumor-infiltrating Treg cells and tumor cells, respectively. Finally, the therapeutic effects of anti-PD-1 treatment combined with the disruption of Blimp1⁺ Treg activity were evaluated.

RESULTS

Blimp1⁺ Treg and T_FR cells were enriched in the tumors, and higher tumoral T_FR signatures indicated increased risk of melanoma metastasis. Deletion of Blimp1 in Treg cells resulted in impaired suppressive activity and a reprogramming into effector T-cells, which were largely restricted to the tumor-infiltrating Treg population. This destabilization combined with increased anti-tumor effector cellular responses, follicular helper T-cell expansion, enhanced tumoral IgE deposition and activation of macrophages secondary to dysregulated T_FR cells, remodeled the tumor microenvironment and delayed tumor growth. The increased tumor immunogenicity with MHC upregulation improved response to anti-PD-1 blockade. Mechanistically, Blimp1 enforced intratumoral Treg cells with a unique transcriptional program dependent on Eomesodermin (Eomes) expression; deletion of Eomes in Blimp1-deficient Treg cells restored tumor growth and attenuated anti-tumor immunity.

CONCLUSIONS

These findings revealed Blimp1 as a new critical regulator of tumor-infiltrating Treg cells and a potential target for modulating Treg activity to treat cancer. Our study has also revealed two FCERIA-containing immune signatures as promising diagnostic or prognostic markers for melanoma patients.

Insights from IgE Immune Surveillance in Allergy and Cancer for Anti-Tumour IgE Treatments

IgE, the predominant antibody class of the allergic response, is known for its roles in protecting against parasites; however, a growing body of evidence indicates a significant role for IgE and its associated effector cells in tumour immunosurveillance, highlighted by the field of AllergoOncology and the successes of the first-in-class IgE cancer therapeutic MOv18. Supporting this concept, substantial epidemiological data ascribe potential roles for IgE, allergy, and atopy in protecting against specific tumour types, with a corresponding increased cancer risk associated with IgE immunodeficiency. Here, we consider how epidemiological data in combination with functional data reveals a complex interplay of IgE and allergy with cancer, which cannot be explained solely by one of the existing conventional hypotheses. We furthermore discuss how, in turn, such data may be used to inform future therapeutic approaches, including the clinical management of different patient groups. With epidemiological findings highlighting several high-risk cancer types protected against by high IgE levels, it is possible that use of IgE-based therapeutics for a range of malignant indications may offer efficacy to complement that of established IgG-class antibodies.

Is There a Clinical Significance of Very Low Serum Immunoglobulin E Level?

PURPOSE

High serum immunoglobulin (Ig) E levels are associated with allergies, parasitic infections, and some immune deficiencies; however, the potential effects and clinical implications of low IgE levels on the human immune system are not well-known. This study aims to determine the disorders accompanying very low IgE levels in children and adults.

METHODS

The patients whose IgE levels were determined between January 2015 and September 2020 were analyzed, and the patients with an IgE level < 2 IU/mL were included in this study. Demographic data, immunoglobulin levels, autoantibody results, and the diagnoses of the patients were noted from the electronic recording system of the hospital.

RESULT

The IgE levels were measured in 34,809 patients (21,875 children, 12,934 adults), and 130 patients had IgE levels < 2 IU/mL. Fifty-seven patients were children (0.26%); 73 were adults (0.56%). There was a malignant disease in 34 (9 of them children) (26%), autoimmune diseases in 20 (3 of them children) (15.4%), and immunodeficiency in 17 (14 of them children) (13.1%) of the patients. The most common reasons were other diseases, immunodeficiency and malignancy in children, and malignancy, autoimmune disorders, and other diseases in the adults, in rank order. The IgE level did not show any correlation with the levels of other immunoglobulins.

CONCLUSION

Although rare, a low IgE level has been shown to accompany malignancies, autoimmune disorders, and immune deficiencies. Patients with very low IgE levels should be carefully monitored for systemic disorders.

Novel Approaches in the Inhibition of IgE-Induced Mast Cell Reactivity in Food Allergy

Allergy is an IgE-dependent type-I hypersensitivity reaction that can lead to life-threatening systemic symptoms such as anaphylaxis. In the pathogenesis of the allergic response, the common upstream event is the binding of allergens to specific IgE, inducing cross-linking of the high-affinity FcεRI on mast cells, triggering cellular degranulation and the release of histamine, proteases, lipids mediators, cytokines and chemokines with inflammatory activity. A number of novel therapeutic options to curb mast cell activation are in the pipeline for the treatment of severe allergies. In addition to anti-IgE therapy and allergen-specific immunotherapy, monoclonal antibodies targeted against several key Th2/alarmin cytokines (i.e. IL-4Rα, IL-33, TSLP), active modification of allergen-specific IgE (i.e. inhibitory compounds, monoclonal antibodies, de-sialylation), engagement of inhibitory receptors on mast cells and allergen-specific adjuvant vaccines, are new promising options to inhibit the uncontrolled release of mast cell mediators upon allergen exposure. In this review, we critically discuss the novel approaches targeting mast cells limiting allergic responses and the immunological mechanisms involved, with special interest on food allergy treatment.

Eosinophils, a Jack of All Trades in Immunity: Therapeutic Approaches for Correcting Their Functional Disorders

BACKGROUND AND OBJECTIVE

Eosinophils are primitive myeloid cells derived from bonemarrow precursors and require the intervention of interleukin (IL)-5 for their survival and persistence in blood and tissues. Under steady-state conditions, they contribute to immune regulation and homeostasis. Under pathological circumstances, eosinophils are involved in host protection against parasites and participate in allergy and inflammation.

DISCUSSION

Mostly, in asthma, eosinophils provoke airway damage via the release of granule contents and IL-13 with mucus hypersecretion and differentiation of goblet cells. Then, tissue remodeling follows with the secretion of transforming growth factor-β. Eosinophils are able to kill helminth larvae acting as antigen-presenting cells with the involvement of T helper (h)-2 cells and subsequent antibody response. However, they also exert pro-worm activity with the production of suppressive cytokine (IL- 10 and IL-4) and inhibition of nitric oxide. Eosinophils may play a pathogenic role in the course of chronic and autoimmune disease, e.g., inflammatory bowel disease and eosinophilic gastroenteritis, regulating Th2 responses and promoting a profibrotic effect. In atopic dermatitis, eosinophils are commonly detected and may be associated with disease severity. In cutaneous spontaneous urticaria, eosinophils participate in the formation of wheals, tissue remodeling and modifications of vascular permeability. With regard to tumor growth, it seems that IgE can exert anti-neoplastic surveillance via mast cell and eosinophil-mediated cytotoxicity, the so-called allergo-oncology. From a therapeutic point of view, monoclonal antibodies directed against IL-5 or the IL-5 receptors have been shown to be very effective in patients with severe asthma. Finally, as an alternative treatment, polyphenols for their anti-inflammatory and anti-allergic activities seem to be effective in reducing serum IgE and eosinophil count in bronchoalveolar lavage in murine asthma.

CONCLUSION

Eosinophils are cells endowed with multiple functions and their modulation with monoclonal antibodies and nutraceuticals may be effective in the treatment of chronic disease.

Mast Cells and Skin and Breast Cancers: A Complicated and Microenvironment-Dependent Role

Mast cells are important sentinel cells in host defense against infection and major effector cells in allergic disease. The role of these cells in cancer settings has been widely debated. The diverse range of mast cell functions in both immunity and tissue remodeling events, such as angiogenesis, provides multiple opportunities for mast cells to modify the tumor microenvironment. In this review, we consider both skin and breast cancer settings to address the controversy surrounding the importance of mast cells in the host response to tumors. We specifically address the key mediators produced by mast cells which impact tumor development. The role of environmental challenges in modifying mast cell responses and opportunities to modify mast cell responses to enhance anti-tumor immunity are also considered. While the mast cell's role in many cancer contexts is complicated and poorly understood, the activities of these tissue resident and radioresistant cells can provide important opportunities to enhance anti-cancer responses and limit cancer development.

The other side of the coin: IgE deficiency, a susceptibility factor for malignancy occurrence

Since the discovery of IgE, almost all attention was given to conditions with elevated specific or total IgE levels such as atopy, type I hypersensitivity reactions, or parasitic infestations. Recent prospective and retrospective studies show that having very low IgE levels, such as those seen in IgE deficiency (IgE<2.5 kU/L), is not without clinical consequences. Patients with ultra-low IgE levels have an elevated risk of cancer of any type. These results are in agreement with murine models research which demonstrated that grafted tumors grow faster and bigger on an IgE knockout background. The novel finding that IgE deficiency is a susceptibility factor for cancer, fits very well with the AllergoOncology concept. The reports on a beneficial, cytotoxic function of IgE, in cooperation with its high (FcεRI) and low (FcεRII, CD23) affinity IgE receptors resulting in tumor cell phagocytosis, propose a role of IgE in cancer surveillance. It appears that not only deficiency of serum IgE, but also lack of tissue-bound IgE is important in malignancy susceptibility in these patients. As such, IgE deficient individuals with absent serum and cell-bound IgE as suggested by negative type I hypersensitivity skin tests, are at the highest risk for a malignancy diagnosis. In contrast, IgE deficient individuals with cell-bound IgE depicted through positive type I hypersensitivity skin tests, have lower rates of malignancy diagnosis. The present report discusses the evidence and potential role of ultra-low IgE as a novel biomarker for cancer susceptibility.

Effects of omalizumab on basophils: Potential biomarkers in asthma and chronic spontaneous urticaria

Omalizumab is an anti-IgE humanized monoclonal antibody approved for the treatment of severe asthma and chronic spontaneous urticaria. Omalizumab binds free serum IgE and antagonizes its interaction with FcεRI, which is considered the main pharmacodynamic mechanism responsible for the clinical response to the treatment. The reduction of IgE serum concentration down-regulates the cellular expression of FcεRI on basophils. However, the biological events occurring on basophils during the therapy with omalizumab are multiple and complex. Here we review the current evidence regarding the specific biological effects of omalizumab on basophils in patients with asthma and chronic spontaneous urticaria. In addition to the modulation of IgE receptors, omalizumab may affect basophils homeostasis, intra-cellular signaling, cellular responsiveness/activation and cytokine release. These effects may be partially responsible for the clinical success of omalizumab and potentially provide useful biological markers for future assessment of the clinical response to the treatment. However, further investigation is required to better elucidate the role of basophils during the treatment with omalizumab.

AllergoOncology: ultra-low IgE, a potential novel biomarker in cancer-a Position Paper of the European Academy of Allergy and Clinical Immunology (EAACI)

Elevated serum IgE levels are associated with allergic disorders, parasitosis and specific immunologic abnormalities. In addition, epidemiological and mechanistic evidence indicates an association between IgE-mediated immune surveillance and protection from tumour growth. Intriguingly, recent studies reveal a correlation between IgE deficiency and increased malignancy risk. This is the first review discussing IgE levels and links to pathological conditions, with special focus on the potential clinical significance of ultra-low serum IgE levels and risk of malignancy. In this Position Paper we discuss: (a) the utility of measuring total IgE levels in the management of allergies, parasitosis, and immunodeficiencies, (b) factors that may influence serum IgE levels, (c) IgE as a marker of different disorders, and d) the relationship between ultra-low IgE levels and malignancy susceptibility. While elevated serum IgE is generally associated with allergic/atopic conditions, very low or absent IgE may hamper anti-tumour surveillance, indicating the importance of a balanced IgE-mediated immune function. Ultra-low IgE may prove to be an unexpected biomarker for cancer risk. Nevertheless, given the early stage of investigations conducted mostly in patients with diseases that influence IgE levels, in-depth mechanistic studies and stratification of malignancy risk based on associated demographic, immunological and clinical co-factors are warranted.

Harnessing Therapeutic IgE Antibodies to Re-educate Macrophages against Cancer

Currently, IgG is the only class of antibodies employed for cancer therapy. However, harnessing the unique biological properties of a different class ( e.g., IgE) could engender potent effector cell activation, and unleash previously untapped immune mechanisms against cancer. IgE antibodies are best known for pathogenic roles in allergic diseases and for protective effector functions against parasitic infestation, often mediated by IgE Fc receptor-expressing macrophages. Notably, IgE possess a very high affinity for cognate Fc receptors expressed by tumor-associated macrophages (TAMs). This paper reviews pre-clinical studies, which indicate control of cancer growth by tumor antigen-specific IgE that recruit and re-educate TAMs towards activated profiles. The clinical development harnessing the antitumor potential of recombinant IgE antibodies in cancer patients is also discussed.

AllergoOncology: High innate IgE levels are decisive for the survival of cancer-bearing mice

Background

Atopics have a lower risk for malignancies, and IgE targeted to tumors is superior to IgG in fighting cancer. Whether IgE-mediated innate or adaptive immune surveillance can confer protection against tumors remains unclear.

Objective

We aimed to investigate the effects of active and passive immunotherapy to the tumor-associated antigen HER-2 in three murine models differing in Epsilon-B-cell-receptor expression affecting the levels of expressed IgE.

Methods

We compared the levels of several serum specific anti-HER-2 antibodies (IgE, IgG1, IgG2a, IgG2b, IgA) and the survival rates in low-IgE ΔM1M2 mice lacking the transmembrane/cytoplasmic domain of Epsilon-B-cell-receptors expressing reduced IgE levels, high-IgE KN1 mice expressing chimeric Epsilon-Gamma1-B-cell receptors with 4-6-fold elevated serum IgE levels, and wild type (WT) BALB/c. Prior engrafting mice with D2F2/E2 mammary tumors overexpressing HER-2, mice were vaccinated with HER-2 or vehicle control PBS using the Th2-adjuvant Al(OH)₃ (active immunotherapy), or treated with the murine anti-HER-2 IgG1 antibody 4D5 (passive immunotherapy).

Results

Overall, among the three strains of mice, HER-2 vaccination induced significantly higher levels of HER-2 specific IgE and IgG1 in high-IgE KN1, while low-IgE ΔM1M2 mice had higher IgG2a levels. HER-2 vaccination and passive immunotherapy prolonged the survival in tumor-grafted WT and low-IgE ΔM1M2 strains compared with treatment controls; active vaccination provided the highest benefit. Notably, untreated high-IgE KN1 mice displayed the longest survival of all strains, which could not be further extended by active or passive immunotherapy.

Conclusion

Active and passive immunotherapies prolong survival in wild type and low-IgE ΔM1M2 mice engrafted with mammary tumors. High-IgE KN1 mice have an innate survival benefit following tumor challenge.

Mast Cells and Natural Killer Cells-A Potentially Critical Interaction

Natural killer (NK) cells play critical roles in host defense against infectious agents or neoplastic cells. NK cells provide a rapid innate immune response including the killing of target cells without the need for priming. However, activated NK cells can show improved effector functions. Mast cells are also critical for early host defense against a variety of pathogens and are predominately located at mucosal surfaces and close to blood vessels. Our group has recently shown that virus-infected mast cells selectively recruit NK cells and positively modulate their functions through mechanisms dependent on soluble mediators, such as interferons. Here, we review the possible consequences of this interaction in both host defense and pathologies involving NK cell and mast cell activation.

A new look at IgE beyond allergies

Immunoglobulin E (IgE), though constitutively present at low levels, is most commonly studied in atopic disease where it plays a vital role in mast cell degranulation and in initiating a T helper 2 (Th2) response. With the advent of better detection assays, however, researchers are discovering the importance of IgE in actively contributing to many disease states and pathologies. This review will discuss the latest findings in IgE beyond its role in allergies and recently discovered roles for IgE in its cell-bound form on FcεRI-expressing effector cells like monocytes and dendritic cells. In terms of parasites, we will discuss helminth-induced IgE that appears to protect the worms from immune recognition and a tick-borne illness that elicits an IgE response against red meat. Next, we describe recent findings of how auto-reactive IgE can contribute to the progression of lupus and induce organ damage. Finally, we summarize the emerging roles of IgE in tumor surveillance and antibody-dependent cytotoxicity. We additionally discuss recent or ongoing clinical trials that either target harmful IgE or use the unique characteristics of the isotype.

Hapten-mediated recruitment of polyclonal antibodies to tumors engenders antitumor immunity

Uptake of tumor antigens by tumor-infiltrating dendritic cells is limiting step in the induction of tumor immunity, which can be mediated through Fc receptor (FcR) triggering by antibody-coated tumor cells. Here we describe an approach to potentiate tumor immunity whereby hapten-specific polyclonal antibodies are recruited to tumors by coating tumor cells with the hapten. Vaccination of mice against dinitrophenol (DNP) followed by systemic administration of DNP targeted to tumors by conjugation to a VEGF or osteopontin aptamer elicits potent FcR dependent, T cell mediated, antitumor immunity. Recruitment of αGal-specific antibodies, the most abundant naturally occurring antibodies in human serum, inhibits tumor growth in mice treated with a VEGF aptamer-αGal hapten conjugate, and recruits antibodies from human serum to human tumor biopsies of distinct origin. Thus, treatment with αGal hapten conjugated to broad-spectrum tumor targeting ligands could enhance the susceptibility of a broad range of tumors to immune elimination.

Mast cells, basophils and eosinophils: From allergy to cancer

Basophils, eosinophils and mast cells were first recognized by Paul Ehrlich in the late 19th century. These cells have common, but non-redundant roles, in the pathogenesis of allergic diseases and in the protection against parasites. Nevertheless, in virtue of their shared-adeptness to produce a huge variety of immunological mediators and express membrane-bound receptors, they are able to interact with immune and non-immune components of the tissue microenvironment, contributing to the regulation of tissue homeostasis and immune response while participating to further deregulation of tissues transforming into neoplasia.

B Cell Intrinsic Mechanisms Constraining IgE Memory

Memory B cells and long-lived plasma cells are key elements of adaptive humoral immunity. Regardless of the immunoglobulin class produced, these cells can ensure long-lasting protection but also long-lasting immunopathology, thus requiring tight regulation of their generation and survival. Among all antibody classes, this is especially true for IgE, which stands as the most potent, and can trigger dramatic inflammatory reactions even when present in minute amounts. IgE responses and memory crucially protect against parasites and toxic components of venoms, conferring selective advantages and explaining their conservation in all mammalian species despite a parallel broad spectrum of IgE-mediated immunopathology. Long-term memory of sensitization and anaphylactic responses to allergens constitute the dark side of IgE responses, which can trigger multiple acute or chronic pathologic manifestations, some punctuated with life-threatening events. This Janus face of the IgE response and memory, both necessary and potentially dangerous, thus obviously deserves the most elaborated self-control schemes.

Therapeutic Antibodies: What Have We Learnt from Targeting CD20 and Where Are We Going?

Therapeutic monoclonal antibodies (mAbs) have become one of the fastest growing classes of drugs in recent years and are approved for the treatment of a wide range of indications, from cancer to autoimmune disease. Perhaps the best studied target is the pan B-cell marker CD20. Indeed, the first mAb to receive approval by the Food and Drug Administration for use in cancer treatment was the CD20-targeting mAb rituximab (Rituxan®). Since its approval for relapsed/refractory non-Hodgkin's lymphoma in 1997, rituximab has been licensed for use in the treatment of numerous other B-cell malignancies, as well as autoimmune conditions, including rheumatoid arthritis. Despite having a significant impact on the treatment of these patients, the exact mechanisms of action of rituximab remain incompletely understood. Nevertheless, numerous second- and third-generation anti-CD20 mAbs have since been developed using various strategies to enhance specific effector functions thought to be key for efficacy. A plethora of knowledge has been gained during the development and testing of these mAbs, and this knowledge can now be applied to the design of novel mAbs directed to targets beyond CD20. As we enter the "post-rituximab" era, this review will focus on the lessons learned thus far through investigation of anti-CD20 mAb. Also discussed are current and future developments relating to enhanced effector function, such as the ability to form multimers on the target cell surface. These strategies have potential applications not only in oncology but also in the improved treatment of autoimmune disorders and infectious diseases. Finally, potential approaches to overcoming mechanisms of resistance to anti-CD20 therapy are discussed, chiefly involving the combination of anti-CD20 mAbs with various other agents to resensitize patients to treatment.