How to hit the allergy target: A critical appraisal of intralymphatic immunotherapy with practical recommendations on ultrasound-guided injections.

BACKGROUND: Intralymphatic immunotherapy (ILIT) represents a promising novel approach treating allergic diseases. However, no standardized procedures or recommendations have been established or reported, despite the recognized fact that treatment efficacy relies on the ability to inject the allergen intranodally. OBJECTIVE: We aim to provide a critical appraisal of ILIT as a method of allergen immunotherapy and to deliver practical recommendations for accurate ILIT. METHODS: One hundred and seventy-three ILIT injections were performed in 28 (47%) women and 32 (53%) men with median age of 29 years (21-59). The injections were ultrasound-guided and recorded for retrospective analysis with respect to injection location, needle visibility, medication release, and patient characteristics. RESULTS: The results show that the correct positioning of the needle within the lymph node (LN) was most critical. If the whole length of the needle bevel was not inserted into the LN, substance backflush into the interstitium was observed. Selecting a more superficial LN and inserting the needle at a smaller angle towards the LN significantly improved needle visibility in the ultrasound. Longitudinal results showed that continuous practice significantly correlated with improved needle visibility and more accurate ILIT injections. CONCLUSION: Based on our results and practical experience, we propose several recommendations for LN selection and the correct handling of ultrasound probe and needle. We are confident that ILIT standardization and training will be important as to meet the goals of good safety and efficacy of ILIT.

Strain matters in mouse models of peanut-allergic anaphylaxis: Systemic IgE-dependent and Ara h 2-dominant sensitization in C3H mice.

BACKGROUND: Peanut allergy accounts for the majority of food-induced hypersensitivity reactions and can lead to lethal anaphylaxis. Animal models can provide an insight into the immune mechanisms responsible for sensitization and allergic anaphylaxis. However, different mouse strains and sensitization protocols can influence the successful development of a peanut allergic mouse model. OBJECTIVE: We aimed at developing a systemic anaphylaxis model of peanut allergy that resembles human anaphylaxis. We compared the immunological and clinical responses in genetically different mouse strains. METHODS: Female BALB/c, C57BL/6, and C3H mice were intraperitoneally sensitized and later challenged with peanut proteins. Allergen-specific serology was done by ELISA, and anaphylaxis was evaluated by monitoring changes in body temperature upon systemic challenge. RESULTS: Sensitization to peanut was successful in C3H mice and triggered production of allergen-specific antibodies, cytokines and anaphylaxis. Allergic reactions were characterized by the release of allergic mediators and by changes in leukocyte populations in blood and in the peritoneal cavity. Among the identified major peanut allergens, Ara h 2 showed the strongest anaphylactic potential. Much lower or no trigger of peanut-specific antibodies was observed in BALB/c and C57BL/6 mice, which experienced no hypersensitivity reactions. CONCLUSIONS: Mouse strain matters for testing of peanut protein allergens. We identified C3H mice as a suitable strain for the development of a mouse model of peanut-allergic anaphylaxis. Pre-clinical, humoural and cellular responses resembled the responses observed in human patients. The described model can be useful for further studies on peanut allergy and for the development of new therapeutic strategies.

Targeting Ara h 2 with human-derived monoclonal antibodies prevents peanut-induced anaphylaxis in mice.

BACKGROUND: Peanut allergy is a type-I hypersensitivity immune reaction mediated by the binding of peanut allergens to IgE-FcεRI complexes on mast cells and basophils and by their subsequent cellular degranulation. Of all major peanut allergens, Ara h 2 is considered the most anaphylactic. With few options but allergen avoidance, effective treatment of allergic patients is needed. Passive immunotherapy (herein called PIT) based on prophylactic administration of peanut-specific monoclonal antibodies (mAbs) may present a promising treatment option for this under-served disease. METHOD: Fully human recombinant anti-peanut IgG mAbs were tested in mice sensitized to peanut allergen extract. Allergic mice received intravenous immunotherapy with anti-peanut Ara h 2-specific IgG1 or IgG4 mAbs cocktails, and were then challenged by a systemic injection of high-dose peanut allergen extract. The protection from allergic anaphylaxis was measured by monitoring the core body temperature. RESULTS: PIT with peanut-specific mAbs was associated with a significant and dose-dependent reduction of anaphylactic reactions in peanut-sensitized mice challenged with peanut allergen extract. Complete protection was observed at doses approximately 0.3-0.6 mg mAbs. Mixtures of mAbs were more effective than single mAbs, and effective treatment could be obtained with mAbs of both IgG1 and IgG4 subclasses. The therapeutic effect of anti-Ara h 2 mAbs was based on allergen neutralization and independent of the Fcγ receptor and mast-cell inhibition. CONCLUSION: This is the first report that shows that human-derived anti-peanut mAbs can prevent allergic anaphylaxis in mice. The study demonstrates that neutralizing allergenic epitopes on Ara h 2 by mAbs may represent a promising treatment option in peanut-allergy.

Potential Cost Savings by Switching from Subcutaneous to Intralymphatic Insect Venom Immunotherapy.

INTRODUCTION: IgE-mediated bee venom allergy can be treated with allergen-specific immunotherapy (AIT). Subcutaneous immunotherapy (SCIT) is time and cost intensive due to the repeated consultations, but the costs are justified by the high risk of potentially life-threatening allergic reactions, including anaphylaxis. However, intralymphatic immunotherapy (ILIT) offers potential to reduce treatment costs due to a significant reduction in injections and a shorter duration of therapy. Therefore, we calculated the cost savings that arise when switching from SCIT to ILIT. METHODS: Treatment protocols for ILIT were based on previous ILIT studies. Treatment protocols for SCIT were based on routine treatment at the University Hospital Zurich (USZ). The treatment costs were calculated based on the internal hospital information system (KISIM). RESULTS: The calculations revealed a potential two-fold reduction in treatment costs if ILIT is used instead of SCIT in patients with bee venom allergy. The costs could be reduced from EUR 11,612.59 with SCIT to EUR 5,942.15 with ILIT over 5 years. CONCLUSIONS: This study shows that bee venom ILIT has a cost-benefit potential for health insurances and patients, which should encourage further ILIT studies and which should be taken into account when considering future implementation of ILIT in the standard care of venom allergy.

Intralymphatic immunotherapy with one or two allergens renders similar clinical response in patients with allergic rhinitis due to birch and grass pollen.

INTRODUCTION: There is a need for a fast, efficient and safe way to induce tolerance in patients with severe allergic rhinitis. Intralymphatic immune therapy has been shown to be effective. METHODS: Patients with severe birch and timothy allergy were randomized and received three doses of 0.1 ml of birch and 5-grass allergen extracts (10,000 SQ units/ml, ALK-Abelló), or birch and placebo or 5-grass and placebo by ultrasound-guided injections into inguinal lymph nodes at monthly intervals. Rhinoconjunctivitis total symptom score, medication score and rhinoconjunctivitis quality of life questionnaire were evaluated before treatment and after each birch and grass pollen season during three subsequent years. Circulating proportions of T helper subsets and allergen-induced cytokine and chemokine production were analysed by flow cytometry and Luminex. RESULTS: The three groups reported fewer symptoms, lower use of medication and improved quality of life during the birch and grass pollen seasons each year after treatment at an almost similar rate independently of treatment with one or two allergens. Mild local pain was the most common adverse event. IgE levels to birch decreased, whereas birch-induced IL-10 secretion increased in all three groups. IgG4 levels to birch and timothy and skin prick test reactivity remained mainly unchanged. Conjunctival challenge tests with timothy extract showed a higher threshold for allergen. In all three groups, regulatory T cell frequencies were increased 3 years after treatment. CONCLUSIONS: Intralymphatic immunotherapy with one or two allergens in patients with grass and birch pollen allergy was safe, effective and may be associated with bystander immune modulatory responses. CLINICAL TRIAL REGISTRATION: EudraCT (2013-004726-28).

BATF3-dependent dendritic cells drive both effector and regulatory T-cell responses in bacterially infected tissues.

The gastric lamina propria of mice that have been experimentally infected with the pathobiont Helicobacter pylori hosts a dense network of myeloid cells that includes BATF3-dependent CD103+ dendritic cells (DCs). We show here that CD103+ DCs are strictly required for gastric Th1 responses to H. pylori and for H. pylori infection control. A similar dependence of type 1 immunity on CD103+ DCs is observed in a Mycobacterium bovis BCG infection model, and in a syngeneic colon cancer model. Strikingly, we find that not only the expansion and/or recruitment of Th1 cells, but also of peripherally induced, neuropilin-negative regulatory T-cells to sites of infection requires BATF3-dependent DCs. A shared feature of the examined models is the strongly reduced production of the chemokines and CXCR3 ligands CXCL9, 10 and 11 in BATF3-deficient mice. The results implicate BATF3-dependent DCs in the recruitment of CXCR3+ effector and regulatory T-cells to target tissues and in their local expansion.

A dual role for hepatocyte-intrinsic canonical NF-κB signaling in virus control.

BACKGROUND & AIMS: Hepatic innate immune control of viral infections has largely been attributed to Kupffer cells, the liver-resident macrophages. However, hepatocytes, the parenchymal cells of the liver, also possess potent immunological functions in addition to their known metabolic functions. Owing to their abundance in the liver and known immunological functions, we aimed to investigate the direct antiviral mechanisms employed by hepatocytes. METHODS: Using lymphocytic choriomeningitis virus (LCMV) as a model of liver infection, we first assessed the role of myeloid cells by depletion prior to infection. We investigated the role of hepatocyte-intrinsic innate immune signaling by infecting mice lacking canonical NF-κB signaling (IkkßΔHep) specifically in hepatocytes. In addition, mice lacking hepatocyte-specific interferon-α/ß signaling-(IfnarΔHep), or interferon-α/ß signaling in myeloid cells-(IfnarΔMyel) were infected. RESULTS: Here, we demonstrate that LCMV activates NF-κB signaling in hepatocytes. LCMV-triggered NF-κB activation in hepatocytes did not depend on Kupffer cells or TNFR1 signaling but rather on Toll-like receptor signaling. LCMV-infected IkkßΔHep livers displayed strongly elevated viral titers due to LCMV accumulation within hepatocytes, reduced interferon-stimulated gene (ISG) expression, delayed intrahepatic immune cell influx and delayed intrahepatic LCMV-specific CD8+ T cell responses. Notably, viral clearance and ISG expression were also reduced in LCMV-infected primary hepatocytes lacking IKKß, demonstrating a hepatocyte-intrinsic effect. Similar to livers of IkkßΔHep mice, enhanced hepatocytic LCMV accumulation was observed in livers of IfnarΔHep mice, whereas IfnarΔMyel mice were able to control LCMV infection. Hepatocytic NF-κB signaling was also required for efficient ISG induction in HDV-infected dHepaRG cells and interferon-α/ß-mediated inhibition of HBV replication in vitro. CONCLUSIONS: Together, these data show that hepatocyte-intrinsic NF-κB is a vital amplifier of interferon-α/ß signaling, which is pivotal for strong early ISG responses, immune cell infiltration and hepatic viral clearance. LAY SUMMARY: Innate immune cells have been ascribed a primary role in controlling viral clearance upon hepatic infections. We identified a novel dual role for NF-κB signaling in infected hepatocytes which was crucial for maximizing interferon responses and initiating adaptive immunity, thereby efficiently controlling hepatic virus replication.

Microcrystalline Tyrosine and Aluminum as Adjuvants in Allergen-Specific Immunotherapy Protect from IgE-Mediated Reactivity in Mouse Models and Act Independently of Inflammasome and TLR Signaling.

Allergen immunotherapy (AIT) is the only modality that can modify immune responses to allergen exposure, but therapeutic coverage is low. One strategy to improve AIT safety and efficacy is the use of new or improved adjuvants. This study investigates immune responses produced by microcrystalline tyrosine (MCT)-based vaccines as compared with conventional aluminum hydroxide (alum). Wild-type, immune-signaling-deficient, and TCR-transgenic mice were treated with different Ags (e.g., OVA and cat dander Fel d 1), plus MCT or alum as depot adjuvants. Specific Ab responses in serum were measured by ELISA, whereas cytokine secretion was measured both in culture supernatants by ELISA or by flow cytometry of spleen cells. Upon initiation of AIT in allergic mice, body temperature and further clinical signs were used as indicators for anaphylaxis. Overall, MCT and alum induced comparable B and T cell responses, which were independent of TLR signaling. Alum induced stronger IgE and IL-4 secretion than MCT. MCT and alum induced caspase-dependent IL-1ß secretion in human monocytes in vitro, but inflammasome activation had no functional effect on inflammatory and Ab responses measured in vivo. In sensitized mice, AIT with MCT-adjuvanted allergens caused fewer anaphylactic reactions compared with alum-adjuvanted allergens. As depot adjuvants, MCT and alum are comparably effective in strength and mechanism of Ag-specific IgG induction and induction of T cell responses. The biocompatible and biodegradable MCT seems therefore a suitable alternative adjuvant to alum-based vaccines and AIT.

Distinct T helper cell dependence of memory B-cell proliferation versus plasma cell differentiation.

Several memory B-cell subclasses with distinct functions have been described, of which the most effective is the class-switched (CS) memory B-cell population. We have previously shown, using virus-like particles (VLPs), that the proliferative potential of these CS memory B cells is limited and they fail to re-enter germinal centres (GCs). However, VLP-specific memory B cells quickly differentiated into secondary plasma cells (PCs) with the virtue of elevated antibody production compared with primary PCs. Whereas the induction of VLP+ memory B cells was strongly dependent on T helper cells, we were wondering whether re-stimulation of VLP+ memory B cells and their differentiation into secondary PCs would also require T helper cells. Global absence of T helper cells led to strongly impaired memory B cell proliferation and PC differentiation. In contrast, lack of interleukin-21 receptor-dependent follicular T helper cells or CD40 ligand signalling strongly affected proliferation of memory B cells, but differentiation into mature secondary PCs exhibiting increased antibody production was essentially normal. This contrasts with primary B-cell responses, where a strong dependence on CD40 ligand but limited importance of interleukin-21 receptor was seen. Hence, T helper cell dependence differs between primary and secondary B-cell responses as well as between memory B-cell proliferation and PC differentiation.

Photosensitizer and Light Pave the Way for Cytosolic Targeting and Generation of Cytosolic CD8 T Cells Using PLGA Vaccine Particles.

The generation of CTLs is crucial in the immunological fight against cancer and many infectious diseases. To achieve this, vaccine Ags need to be targeted to the cytosol of dendritic cells, which can activate CD8 T cells via MHC class I (MHCI). Therefore, such targeting has become one of the major objectives of vaccine research. In this study, we aimed to bypass the unwanted and default MHC class II Ag presentation and trigger MHCI presentation by using a photosensitizer that, upon light activation, would facilitate cytosolic targeting of codelivered Ag. Poly(lactide-co-glycolide) microparticles ∼1 µm size were loaded with OVA and the photosensitizer tetraphenyl chlorine disulphonate (TPCS2a) and administered intradermally in mice, which were illuminated 1 d later for activation of the photosensitizer. Immunization in the presence of TPCS2a significantly increased activation of CD8 T cells compared with immunization without TPCS2a and as measured by CD8 T cell proliferation, production of proinflammatory IFN-γ, TNF-α, and IL-2, and prevention of tumor growth. Cytotoxicity was demonstrated by granzyme B production in vitro and by in vivo killing of CFSE-labeled targets. CD4-dependent Ab responses were abrogated in mice immunized with TPCS2a-containing particles, suggesting that photosensitization facilitated a shift from default MHC class II toward MHCI Ag presentation. Hence, vaccine particles with Ag and photosensitizers proved an effective vehicle or adjuvant for stimulation of CTLs, and they may find potential application in therapeutic cancer vaccination and in prophylactic and therapeutic vaccination against intracellular infections.

Development of Adaptive Coping From Mid to Late Life: A 70-Year Longitudinal Study of Defense Maturity and Its Psychosocial Correlates.

The present study examines changes in defense maturity from mid to late life using data from an over 70-year longitudinal study. A sample of 72 men was followed beginning in late adolescence. Participants' childhoods were coded for emotional warmth. Defense mechanisms were coded by independent raters using the Q-Sort of Defenses (, Ego mechanisms of defense: A guide for clinicians and researchers 217-233) based on interview data gathered at approximately ages 52 and 75. We examined psychosocial correlates of defenses at midlife, late life, and changes in defense from mid to late life. Overall, defenses grew more adaptive from midlife to late life. However, results differed on the basis of the emotional warmth experienced in the participants' childhoods. In midlife, men who experienced warm childhoods used more adaptive (mature) defenses; yet by late life, this difference in defensive maturity had disappeared. Men who experienced less childhood warmth were more likely to show an increase in adaptive defenses during the period from mid to late life.

Cytosolic Delivery of Liposomal Vaccines by Means of the Concomitant Photosensitization of Phagosomes.

One of the greatest pharmaceutical challenges in vaccinology is the delivery of antigens to the cytosol of antigen-presenting cells (APCs) in order to allow for the stimulation of major histocompatibility complex (MHC) class I-restricted CD8(+) T-cell responses, which may act on intracellular infections or cancer. Recently, we described a novel method for cytotoxic T-lymphocyte (CTL) vaccination by combining antigens with a photosensitizer and light for cytosolic antigen delivery. The goal of the current project was to test this immunization method with particle-based formulations. Liposomes were prepared from dipalmitoylphosphatidylcholine and cholesterol, and the antigen ovalbumin (OVA) or the photosensitizer tetraphenyl chlorine disulfonate (TPCS2a) was separately encapsulated. C57BL/6 mice were immunized intradermally with OVA liposomes or a combination of OVA and TPCS2a liposomes, and light was applied the next day for activation of the photosensitizer resulting in cytosolic release of antigen from phagosomes. Immune responses were tested both after a prime only regime and after a prime-boost scheme with a repeat immunization 2 weeks post priming. Antigen-specific CD8(+) T-cell responses and antibody responses were analyzed ex vivo by flow cytometry and ELISA methods. The physicochemical stability of liposomes upon storage and light exposure was analyzed in vitro. Immunization with both TPCS2a- and OVA-containing liposomes greatly improved CD8(+) T-cell responses as compared to immunization without TPCS2a and as measured by proliferation in vivo and cytokine secretion ex vivo. In contrast, OVA-specific antibody responses (IgG1 and IgG2c) were reduced after immunization with TPCS2a-containing liposomes. The liposomal formulation protected the photosensitizer from light-induced inactivation during storage. In conclusion, the photosensitizer TPCS2a was successfully formulated in liposomes and enabled a shift from MHC class II to MHC class I antigen processing and presentation for stimulation of strong CD8(+) T-cell responses. Therefore, photosensitive particulate vaccines may have the potential to add to current vaccine practice a new method of vaccination that, as opposed to current vaccines, can stimulate strong CD8(+) T-cell responses.

TLR4- and TRIF-dependent stimulation of B lymphocytes by peptide liposomes enables T cell-independent isotype switch in mice.

Immunoglobulin class switching from IgM to IgG in response to peptides is generally T cell-dependent and vaccination in T cell-deficient individuals is inefficient. We show that a vaccine consisting of a dense array of peptides on liposomes induced peptide-specific IgG responses totally independent of T-cell help. Independency was confirmed in mice lacking T cells and in mice deficient for MHC class II, CD40L, and CD28. The IgG titers were high, long-lived, and comparable with titers obtained in wild-type animals, and the antibody response was associated with germinal center formation, expression of activation-induced cytidine deaminase, and affinity maturation. The T cell-independent (TI) IgG response was strictly dependent on ligation of TLR4 receptors on B cells, and concomitant TLR4 and cognate B-cell receptor stimulation was required on a single-cell level. Surprisingly, the IgG class switch was mediated by TIR-domain-containing adapter inducing interferon-ß (TRIF), but not by MyD88. This study demonstrates that peptides can induce TI isotype switching when antigen and TLR ligand are assembled and appropriately presented directly to B lymphocytes. A TI vaccine could enable efficient prophylactic and therapeutic vaccination of patients with T-cell deficiencies and find application in diseases where induction of T-cell responses contraindicates vaccination, for example, in Alzheimer disease.

Inflammasome activation and IL-1ß target IL-1α for secretion as opposed to surface expression.

Interleukin-1α (IL-1α) and -ß both bind to the same IL-1 receptor (IL-1R) and are potent proinflammatory cytokines. Production of proinflammatory (pro)-IL-1α and pro-IL-1ß is induced by Toll-like receptor (TLR)-mediated NF-κB activation. Additional stimulus involving activation of the inflammasome and caspase-1 is required for proteolytic cleavage and secretion of mature IL-1ß. The regulation of IL-1α maturation and secretion, however, remains elusive. IL-1α exists as a cell surface-associated form and as a mature secreted form. Here we show that both forms of IL-1α, the surface and secreted form, are differentially regulated. Surface IL-1α requires NF-κB activation only, whereas secretion of mature IL-1α requires additional activation of the inflammasome and caspase-1. Surprisingly, secretion of IL-1α also required the presence of IL-1ß, as demonstrated in IL-1ß-deficient mice. We further demonstrate that IL-1ß directly binds IL-1α, thus identifying IL-1ß as a shuttle for another proinflammatory cytokine. These results have direct impact on selective treatment modalities of inflammatory diseases.

A murine model of peanut-allergic asthma.

Objectives: Peanut allergy is an IgE-mediated food allergy that is associated with asthma in certain patients. With increasing prevalence, its great impact on the quality of life, and a lack of treatment options, the need for new therapy options is a given. Hence, models for research and development are required. This study aimed to establish a murine model of allergic airway inflammation induced by peanut allergens. Methods: C3H mice were sensitised by intraperitoneal injections of peanut allergen extract and challenged by an intranasal application of the same extract. The assessment of airway inflammation involved the analysis of immune cells in the bronchoalveolar lavage fluid as measured by flow cytometry. Inflammatory reactions in the lung tissue were also studied by histology and quantitative PCR. Moreover, peanut-specific immune responses were studied after re-stimulation of spleen cells in vitro. Results: Sensitisation led to allergen-specific IgE, IgA, and IgG1 seroconversion. Subsequent nasal exposure led to allergic airway inflammation as manifested by structural changes such as bronchial smooth muscle hypertrophy, mucus cell hyperplasia, infiltration of eosinophil cells and T cells, as well as an upregulation of genes expressing IL-4, IL-5, IL-13, and IFN-γ. Upon re-stimulation of splenocytes with peanut allergen, increased secretion of both T-helper type 2 (Th2) and Th1 cytokines was observed. Conclusion: We successfully established a peanut-associated asthma model that exhibited many features characteristic of airway inflammation in human patients with allergic asthma. The model holds potential as a tool for investigating novel therapeutic approaches aimed at preventing the development of allergic asthma.

Cyclodextrin microneedles for the delivery of a nanoparticle-based peptide antigen vaccine.

In recent years, microneedles (MNs) have gained considerable interest in drug formulation due to their non-invasive and patient-friendly nature. Dissolving MNs have emerged as a promising approach to enhance drug delivery across the skin in a painless manner without generating sharp waste and providing the possibility for self-administration. Cyclodextrins, a group of cyclic oligosaccharides, are well-established in pharmaceutical products due to their safety and unique ability to form inclusion complexes with various drug molecules. In this manuscript, we report the development and characterization of dissolving MNs composed of cyclodextrins for intradermal delivery of a cyclodextrin-based nanoparticulate vaccine. Different cyclodextrins were tested and the most promising candidates were fabricated into MNs by micromolding. The MNs' piercing effectiveness and drug permeation across the skin were tested ex vivo. Furthermore, in vivo studies were carried out to assess the skin's tolerance to cyclodextrin-based MNs, and to evaluate the immune response using a model peptide antigen in a mouse model. The data revealed that the MNs were well-tolerated and effective, even leading to dose-sparing effects. This study highlights the potential of cyclodextrin-based dissolving MNs as a versatile platform for intradermal vaccine delivery, providing a compatible matrix for nanoparticulate formulations to enhance immune responses.

T cell independent antibody responses with class switch and memory using peptides anchored on liposomes.

Vaccines generally require T lymphocytes for B-cell activation and immunoglobulin class switching in response to peptide or protein antigens. In the absence of T cells, limited IgG class switch takes place, germinal centers are short-lived, and the B cells lack memory. Here, immunization of mice with liposomes containing 15mer peptides and monophosphoryl lipid A (MPLA) as adjuvant, induced T-cell independent (TI) IgG class switch within three days, as well as germinal center formation. The antibody responses were long-lived, strictly dependent on Toll-like receptor 4 (TLR4) signaling, partly dependent on Bruton's tyrosine kinase (BTK) signal transmission, and independent of signaling through T-cell receptors, MHC class II and inflammasome. The antibody response showed characteristics of both TI type 1 and TI type 2. All IgG subclasses could be boosted months after primary immunization, and the biological function of the secreted antibodies was demonstrated in murine models of allergic anaphylaxis and of bacterial infection. Moreover, antibody responses after immunization with peptide- and MPLA-loaded liposomes could be triggered in neonatal mice and in mice receiving immune-suppressants. This study demonstrates T-cell independent endogenous B-cell memory and recall responses in vivo using a peptide antigen. The stimulation of these antibody responses required a correct and dense assembly and administration of peptide and adjuvant on the surface of liposomes. In the future, TI vaccines may prove beneficial in pathological conditions in which T-cell immunity is compromised through disease or medicines or when rapid, antibody-mediated immune protection is needed.

The antihistamines clemastine and desloratadine inhibit STAT3 and c-Myc activities and induce apoptosis in cutaneous T-cell lymphoma cell lines.

Mycosis fungoides and its leukaemic counterpart Sézary syndrome are the most frequent cutaneous T-cell lymphomas (CTCL), and there is no cure for these diseases. We evaluated the effect of clinically approved antihistamines on the growth of CTCL cell lines. CTCL cell lines as well as blood lymphocytes from patients with Sézary syndrome were cultured with antihistamines, and the cell were analysed for proliferation, apoptosis and expression of programmed death molecules and transcription factors. The two antihistamines clemastine and desloratadine, currently used for symptom alleviation in allergy, induced potent reduction of the activities of the constitutively active transcription factors c-Myc, STAT3, STAT5a and STAT5b in mycosis fungoides and Sézary syndrome cell lines. This inhibition was followed by apoptosis and cell death, especially in the Sézary syndrome-derived cell line Hut78 that also showed increased expression of the programmed death-1 (PD-1) after clemastine treatment. In lymphocytes isolated from Sézary syndrome patients, the CD4-positive fraction underwent apoptosis after clemastine treatment, while CD4-negative lymphocytes were little affected. Because both c-Myc and STAT transcription factors are highly expressed in proliferating tumours, their inhibition by clemastine, desloratadine and other inhibitors could complement established chemotherapies not only for cutaneous T-cell lymphomas but perhaps also other cancers.