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.
Background
Insect‐bite hypersensitivity (IBH) in horses is a chronic allergic dermatitis caused by insect bites. Horses suffer from pruritic skin lesions, caused by type‐I/type‐IV allergic reactions ...accompanied by prominent eosinophil infiltration into the skin. Interleukin‐5 (IL‐5) is the key cytokine for eosinophils and we have previously shown that targeting IL‐5 by vaccination reduces disease symptoms in horses.
Objective
Here, we analyzed the potential for long‐term therapy by assessing a second follow‐up year of the previously published study.
Methods
The vaccine consisted of equine IL‐5 (eIL‐5) covalently linked to a cucumber mosaic virus‐like particle (VLP) containing a universal T cell epitope (CuMVTT) using a semi‐crossover design to follow vaccinated horses during a second treatment season. Thirty Icelandic horses were immunized with 300 μg of eIL‐5‐CuMVTT without adjuvant.
Results
The vaccine was well tolerated and did not reveal any safety concerns throughout the study. Upon vaccination, all horses developed reversible anti‐eIL‐5 auto‐antibody titers. The mean course of eosinophil levels was reduced compared to placebo treatment leading to significant reduction of clinical lesion scores. Horses in their second vaccination year showed a more pronounced improvement of disease symptoms when compared to first treatment year, most likely due to more stable antibody titers induced by a single booster injection. Hence, responses could be maintained over two seasons and the horses remained protected against disease symptoms.
Conclusion
Yearly vaccination against IL‐5 may be a long‐term solution for the treatment of IBH and other eosinophil‐mediated diseases in horses and other species including humans.
Basic vaccination regimen consisting of three vaccine injections in the first treatment year induces sufficient antibody titers leading to significant improvement of insect bite hypersensitivity (IBH) lesion scores. A single booster vaccine injection in the second treatment year re‐induces anti‐IL‐5 antibody titers leading to enhanced improvement of IBH lesion scores. Anti‐IL‐5 vaccination in horses significantly reduces eosinophil levels in blood.
Extensive studies have been undertaken to describe naive B cells differentiating into memory B cells at a cellular and molecular level. However, relatively little is known about the fate of memory B ...cells upon Ag re-encounter. We have previously established a system based on virus-like particles (VLPs), which allows tracking of VLP-specific B cells by flow cytometry as well as histology. Using allotype markers, it is possible to adoptively transfer memory B cells into a naive mouse and track responses of naive and memory B cells in the same mouse under physiological conditions. We have observed that VLP-specific memory B cells quickly differentiated into plasma cells that drove the early onset of a strong humoral IgG response. However, neither IgM(+) nor IgG(+) memory B cells proliferated extensively or entered germinal centers. Remarkably, plasma cells derived from memory B cells preferentially homed to the bone marrow earlier and secreted increased levels of Abs when compared with primary plasma cells derived from naive B cells. Hence, memory B cells have the unique phenotype to differentiate into highly effective secondary plasma cells.
Optimal vaccine strategies must be identified for improving T‐cell vaccination against infectious and malignant diseases. MelQbG10 is a virus‐like nano‐particle loaded with A‐type ...CpG‐oligonucleotides (CpG‐ODN) and coupled to peptide16–35 derived from Melan‐A/MART‐1. In this phase IIa clinical study, four groups of stage III‐IV melanoma patients were vaccinated with MelQbG10, given (i) with IFA (Montanide) s.c.; (ii) with IFA s.c. and topical Imiquimod; (iii) i.d. with topical Imiquimod; or (iv) as intralymph node injection. In total, 16/21 (76%) patients generated ex vivo detectable Melan‐A/MART‐1‐specific T‐cell responses. T‐cell frequencies were significantly higher when IFA was used as adjuvant, resulting in detectable T‐cell responses in all (11/11) patients, with predominant generation of effector‐memory‐phenotype cells. In turn, Imiquimod induced higher proportions of central‐memory‐phenotype cells and increased percentages of CD127+ (IL‐7R) T cells. Direct injection of MelQbG10 into lymph nodes resulted in lower T‐cell frequencies, associated with lower proportions of memory and effector‐phenotype T cells. Swelling of vaccine site draining lymph nodes, and increased glucose uptake at PET/CT was observed in 13/15 (87%) of evaluable patients, reflecting vaccine triggered immune reactions in lymph nodes. We conclude that the simultaneous use of both Imiquimod and CpG‐ODN induced combined memory and effector CD8+ T‐cell responses.
Background
Insect bite hypersensitivity (IBH) is the most common seasonal pruritic allergic dermatitis of horses occurring upon insect bites. In recent years, a major role for IL‐31 in allergic ...pruritus of humans, monkeys, dogs, and mice was acknowledged. Here, we investigate the role of IL‐31 in IBH of horses and developed a therapeutic vaccine against equine IL‐31 (eIL‐31).
Methods
IL‐31 levels were quantified in allergen‐stimulated peripheral blood mononuclear cells (PBMCs) and skin punch biopsies of IBH lesions and healthy skin from IBH‐affected and healthy horses. The vaccine consisted of eIL‐31 covalently coupled to a virus‐like particle (VLP) derived from cucumber mosaic virus containing a tetanus toxoid universal T‐cell epitope (CuMVTT). Eighteen IBH‐affected horses were recruited and immunized with 300 μg of eIL‐31‐CuMVTT vaccine or placebo and IBH severity score was recorded.
Results
IL‐31 was increased in PBMCs and exclusively detectable in skin lesions of IBH‐affected horses. Vaccination against eIL‐31 reduced delta clinical scores when compared to previous untreated IBH season of the same horses and to placebo‐treated horses in the same year. The vaccine was well tolerated without safety concerns throughout the study.
Conclusion
TH2‐derived IL‐31 is involved in IBH pathology and accordingly the immunotherapeutic vaccination approach targeting IL‐31 alleviated clinical scores in affected horses.
Equine IL‐31 is detectable in insect bite hypersensitivity (IBH) skin lesions upon insect bites and mediates pruritus by targeting peripheral nerves. IL‐31 is absent in skin biopsies from nonlesional or healthy skin. eIL‐31‐CuMVTT vaccine successfully induces autoantibodies against IL‐31 and reduces lesion scores in horses.
Insect-bite hypersensitivity is the most common allergic dermatitis in horses. Excoriated skin lesions are typical symptoms of this seasonal and refractory chronic disease. On a cellular level, the ...skin lesions are characterized by massive eosinophil infiltration caused by an underlying allergic response.
To target these cells and treat disease, we developed a therapeutic vaccine against equine IL-5 (eIL-5), the master regulator of eosinophils.
The vaccine consisted of eIL-5 covalently linked to a virus-like particle derived from cucumber mosaic virus containing the tetanus toxoid universal T-cell epitope tt830-843 (CMVTT). Thirty-four Icelandic horses were recruited and immunized with 400 μg of eIL-5–CMVTT formulated in PBS without adjuvant (19 horses) or PBS alone (15 horses).
The vaccine was well tolerated and did not reveal any safety concerns but was able to induce anti–eIL-5 autoantibody titers in 17 of 19 horses. This resulted in a statistically significant reduction in clinical lesion scores when compared with previous season levels, as well as levels in placebo-treated horses. Protection required a minimal threshold of anti–eIL-5 antibodies. Clinical improvement by disease scoring showed that 47% and 21% of vaccinated horses reached 50% and 75% improvement, respectively. In the placebo group no horse reached 75% improvement, and only 13% reached 50% improvement.
Our therapeutic vaccine inducing autoantibodies against self IL-5 brings biologics to horses, is the first successful immunotherapeutic approach targeting a chronic disease in horses, and might facilitate development of a similar vaccine against IL-5 in human subjects.
Display omitted
Cat allergy in human subjects is usually caused by the major cat allergen Fel d 1 and is found in approximately 10% of the Western population. Currently, there is no efficient and safe therapy for ...cat allergy available. Allergic patients usually try to avoid cats or treat their allergy symptoms.
We developed a new strategy to treat Fel d 1–induced allergy in human subjects by immunizing cats against their own major allergen, Fel d 1.
A conjugate vaccine consisting of recombinant Fel d 1 and a virus-like particle derived from the cucumber mosaic virus containing the tetanus toxin–derived universal T-cell epitope tt830-843 (CuMVTT) was used to immunize cats. A first tolerability and immunogenicity study, including a boost injection, was conducted by using the Fel-CuMVTT vaccine alone or in combination with an adjuvant.
The vaccine was well tolerated and had no overt toxic effect. All cats induced a strong and sustained specific IgG antibody response. The induced anti–Fel d 1 antibodies were of high affinity and exhibited a strong neutralization ability tested both in vitro and in vivo. A reduction in the endogenous allergen level and a reduced allergenicity of tear samples, were observed.
Vaccination of cats with Fel-CuMVTT induces neutralizing antibodies and might result in reduced symptoms of allergic cat owners. Both human subjects and animals could profit from this treatment because allergic cat owners would reduce their risk of developing chronic diseases, such as asthma, and become more tolerant of their cats, which therefore could stay in the households and not need to be relinquished to animal shelters.
Display omitted
Protamine is a natural cationic peptide mixture used as a drug for the neutralization of heparin and in formulations of slow-release insulin. In addition, Protamine can be used for the stabilization ...and delivery of nucleic acids (antisense, small interfering RNA (siRNA), immunostimulatory nucleic acids, plasmid DNA, or messenger RNA) and is therefore included in several compositions that are in clinical development. Notably, when mixed with RNA, protamine spontaneously generates particles in the size range of 20-1000 nm depending on the formulation conditions (concentration of the reagents, ratio, and presence of salts). These particles are being used for vaccination and immuno-stimulation. Several grades of protamine are available, and we compared them in the context of complex formation with messenger RNA (mRNA). We found that the different available protamine preparations largely vary in their composition and capacity to transfect mRNA. Our data point to the source of protamine as an important parameter for the production of therapeutic protamine-based complexes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
30.
Intralymphatic immunotherapy Senti, Gabriela; Kündig, Thomas M
The World Allergy Organization journal,
03/2015, Letnik:
8, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Gold Standard allergen-specific immunotherapy is associated with low efficacy because it requires either many subcutaneous injections of allergen or even more numerous sublingual allergen ...administrations to achieve amelioration of symptoms. Intralymphatic vaccination can maximize immunogenicity and hence efficacy. We and others have demonstrated that as few as three low dose intralymphatic allergen administrations are sufficient to effectively alleviate symptoms. Results of recent prospective and controlled trials suggest that this strategy may be an effective form of allergen immunotherapy.
PDF
