[Effect of Jinzhen Oral Liquid on cough after lipopolysaccharide-induced infection in rats and mechanism].

This study aims to explore the effect of Jinzhen Oral Liquid(JOL) on cough after infection in rats and the mechanism. To be specific, a total of 60 male SD rats were classified into 6 groups: normal group(equivalent volume of distilled water, ig), model group(equivalent volume of distilled water, ig), Dextromethorphan Hydrobromide Oral Solution group(3.67 mL·kg~(-1), ig), high-, medium-, and low-dose JOL groups(11.34, 5.67, and 2.84 mL·kg~(-1), respectively, ig). Lipopolysaccharide(LPS, nasal drip), smoking, and capsaicin(nebulization) were employed to induce cough after infection in rats except the normal group. Administration began on the 19 th day and lasted 7 days. Capsaicin(nebulization) was used to stimulate cough 1 h after the last administration and the cough frequency and cough incubation period in rats were recorded. The pathological morphology of lung tissue was observed based on hematoxylin-eosin(HE) staining. Immunohistochemistry(IHC) was used to detect the specific expression of transient receptor potential vanilloid 1(Trpv1), nerve growth factor(NGF), tropomyosin receptor kinase A(TrkA), and phosphorylated-p38 mitogen-activated protein kinase(p-p38 MAPK) in lung tissue, Western blot the protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue, and real-time fluorescent quantitative polymerase chain reaction(real-time PCR) the mRNA expression of Trpv1, NGF, and TrkA. The results showed that model group demonstrated significantly high cough frequency, obvious proliferation and inflammatory cell infiltration in lung tissue, significantly enhanced positive protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue and significant increase in the mRNA expression of Trpv1, NGF, and TrkA compared with the normal group. Compared with the model group, JOL can significantly reduce the cough frequency, alleviate the pathological changes of lung tissue, and decrease the protein expression of Trpv1, NGF, TrkA, and p-p38 MAPK in lung tissue, and high-dose and medium-dose JOL can significantly lower the mRNA expression of Trpv1, NGF, and TrkA. This study revealed that JOL can effectively inhibit Trpv1 pathway-related proteins and improve cough after infection. The mechanism is that it reduces the expression of NGF, TrkA, and p-p38 MAPK in lung tissue, thereby decreasing the expression of Trpv1 and cough sensitivity.

Tropomyosin: A panallergen that causes a worldwide allergic problem.

Background: Panallergens are proteins that take part in key processes of organisms and, therefore, are ubiquitously distributed with highly conserved sequences and structures. One class of these panallergens is composed of the tropomyosins. The highly heat-stable tropomyosins comprise the major allergens in crustaceans and mollusks, which make them important food allergens in exposed populations. Tropomyosins are responsible for a widespread immunoglobulin E cross-reactivity among allergens from different sources. Allergic tropomyosins are expressed in many species, including parasites and insects. Methods: This panallergen class is divided, according to it capacity of induced allergic symptoms, into allergenic or nonallergenic tropomyosin. Although vertebrate tropomyosins share ∼55% of sequence homology with invertebrate tropomyosins, it has been thought that the invertebrate tropomyosins would not have allergic properties. Nevertheless, in recent years, this opinion has been changed. In particular, tropomyosin has been recognized as a major allergen in many insects. Results: A high grade of homology has been shown among tropomyosins from different species, such as crustaceans and insects, which supports the hypothesis of cross-reactivity among tropomyosins from divergent species. Moreover, the emerging habit of consuming edible insects has drawn the attention of allergists to invertebrate tropomyosin protein due to its potential allergenic risk. Nevertheless, evidence about tropomyosin involvement in clinical allergic response is still scarce and deserves more investigation. Conclusion: This review intended to report allergic reactions associated with different tropomyosins when considering house dust mites, parasites, seafood, and insects, and to summarize our current knowledge about its cross-reactivity because this could help physicians to accurately diagnose patients with food allergy.

Investigation of glycated shrimp tropomyosin as a hypoallergen for potential immunotherapy.

Tropomyosin (TM) is the most important allergen in shrimps that could cause food allergy. Glycation is reported to be effective in reducing TM allergenicity and produce hypoallergen; however, up to now, there are very few reports on the potential of hypoallergenic glycated TM (GTM) as allergen immunotherapy for shrimp TM-induced food allergy. This study investigated the glycation of TM-produced hypoallergen and the immunotherapeutic efficacy of GTM + Al(OH)3 as potential allergen immunotherapy. Compared to TM, the TM glycated by glucose (TM-G), maltotriose (TM-MTS), maltopentaose (TM-MPS) and maltoheptaose (TM-MHS) had weaker allergy activation on mast cells and mouse model as a hypoallergen. However, the TM glycated by maltose (TM-M) insignificantly affected the allergenicity. In addition, the GTM absorbed into Al(OH)3 could be efficacious as potential allergen immunotherapy, particularly for the TM glycated by the saccharides having larger molecular size (e.g., TM-MHS), which could provide preclinical data to develop GTM + Al(OH)3 as a candidate immunotherapy for shrimp allergic patients.

[Myofibrillar protein tropomyosin and allergic cross-reactivity].

Myofibrillar protein tropomyosin (TM) is a normal physiological protein participating in regulation of muscular contraction. It is widely prevalent among living organisms. This explains cross-reactivity of allergic patients to home dust, sea fish, cockroaches, etc. The presence of similar IgE-binding epitopes in TM of different origin is a key factor in development of cross-reactivity (CR). CR to TM is a general biological phenomenon. We consider modified TM as a basic component in design of allergovaccines of a new generation.

New insights into seafood allergy.

PURPOSE OF REVIEW: Seafood plays an important role in human nutrition worldwide, sustained by international trade of a variety of new seafood products. Increased production and consumption have resulted in more frequent reports of adverse reactions, highlighting the need for more specific diagnosis and treatment of seafood allergy. This review discusses recent literature in this field. RECENT FINDINGS: The most recent prevalence data from Asia highlight seafood as a significant sensitizer in up to 40% of children and 33% of adults. Furthermore, the demonstration of species-specific sensitization to salt-water and fresh-water prawns and processed prawn extract should improve diagnosis. Studies on humans demonstrated for the first time that biologically active fish allergens can be detected in serum samples as early as 10 min after ingestion. These studies highlight that minute amounts of ingested seafood allergens can quickly trigger allergic symptoms; also, inhaled airborne allergens seem to induce sensitization and reactions. In the past 2 years, over 10 additional seafood allergens have been characterized. Allergen-specific detection assays in food products are available for crustacean tropomyosin; however, many specific mollusk and some fish allergens are not readily identified. SUMMARY: Although cross-reactivity between crustacean and mollusks as well as mites is demonstrated, the often poor correlation of IgE reactivity and clinical symptoms calls for more detailed investigations. The recent development of hypoallergenic parvalbumin from carp could form the basis for safer vaccination products for treatment of fish allergy. Molecular characterization of more universal marker allergens for the three major seafood groups will improve current component-resolved clinical diagnosis and have a significant impact on the management of allergic patients, on food labeling and on future immunotherapy for seafood allergy.

Evolutionary distance from human homologs reflects allergenicity of animal food proteins.

BACKGROUND: In silico analysis of allergens can identify putative relationships among protein sequence, structure, and allergenic properties. Such systematic analysis reveals that most plant food allergens belong to a restricted number of protein superfamilies, with pollen allergens behaving similarly. OBJECTIVE: We have investigated the structural relationships of animal food allergens and their evolutionary relatedness to human homologs to define how closely a protein must resemble a human counterpart to lose its allergenic potential. METHODS: Profile-based sequence homology methods were used to classify animal food allergens into Pfam families, and in silico analyses of their evolutionary and structural relationships were performed. RESULTS: Animal food allergens could be classified into 3 main families--tropomyosins, EF-hand proteins, and caseins--along with 14 minor families each composed of 1 to 3 allergens. The evolutionary relationships of each of these allergen superfamilies showed that in general, proteins with a sequence identity to a human homolog above approximately 62% were rarely allergenic. Single substitutions in otherwise highly conserved regions containing IgE epitopes in EF-hand parvalbumins may modulate allergenicity. CONCLUSION: These data support the premise that certain protein structures are more allergenic than others. Contrasting with plant food allergens, animal allergens, such as the highly conserved tropomyosins, challenge the capability of the human immune system to discriminate between foreign and self-proteins. Such immune responses run close to becoming autoimmune responses. CLINICAL IMPLICATIONS: Exploiting the closeness between animal allergens and their human homologs in the development of recombinant allergens for immunotherapy will need to consider the potential for developing unanticipated autoimmune responses.

[Cross reactivity between fish and shellfish]. / Reactividad cruzada entre pescados y mariscos.

In Spain, fish allergy represents 18 % of all cases of food allergy in children while reactions caused by crustacea and mollusks account for 3.8 % and 1.6 % respectively. Cross-reactivity is defined as the recognition of distinct antigens by the same IgE antibody, demonstrable by in vivo and in vitro tests, which clinically manifests as reactions caused by antigens homologous to different species. Subclinical sensitization can also occur, giving rise to patients sensitized to particular fish or shellfish but who do not present symptoms on consumption.Cod and shrimp have been the models used to study allergy to fish and crustacea respectively. The major allergens responsible for cross-reactivity among distinct species of fish and amphibians are proteins that control calcium flow in the muscular sarcoplasm of these animals, called parvalbumins, with a molecular weight of approximately 12 kD and an isoelectric point of 4.75, resistant to the action of heat and enzymatic digestion. Recently, recombinant carp parvalbumin has been reproduced, confirming that this allergen contains 70 % of the IgE epitopes present in natural extract of cod, tuna and salmon, which makes it a valid tool in the diagnosis of patients with fish allergy. Moreover, this recombinant allergen could constitute the basis for the development of immunotherapy against food allergy. In the case of shellfish, a non-taxonomic group that includes crustacea and mollusks, the major allergen is tropomyosin, an essential protein in muscle contraction both in invertebrates and vertebrates. In invertebrates, tropomyosins, which have a molecular weight of between 38 and 41 kD, show great homology in their amino acid sequence and are the panallergens responsible for cross-reactions between crustacea, insects, mites, nematodes, and different classes of mollusks. It is estimated that 50 % of individuals allergic to some type of fish are at risk for reacting to a second species, while those allergic to some type of crustacea present a risk of 75 % due to the greater similarity among tropomyosins than among parvalbumins. In addition, up to 40 % of patients sensitized to one or more fish do not present symptoms on consuming other species, the best tolerated of which belong to the Scombroidea family (which includes tuna).

Tropomyosin: an invertebrate pan-allergen.

Among food allergens, crustaceans, such as shrimp, crab, crawfish and lobster, are a frequent cause of adverse food reactions in allergic individuals. The major allergen has been identified as the muscle protein tropomyosin. This molecule belongs to a family of highly conserved proteins with multiple isoforms found in both muscle and nonmuscle cells of all species of vertebrates and invertebrates. Its native structure consists of two parallel alpha-helical tropomyosin molecules that are wound around each other forming a coiled-coil dimer. Allergenic tropomyosins are found in invertebrates such as crustaceans (shrimp, lobster, crab, crawfish), arachnids (house dust mites), insects (cockroaches), and mollusks (e.g. squid), whereas vertebrate tropomyosins are nonallergenic. Studies of cross-reactivities among crustaceans and the high degree of sequence identity among them suggest that tropomyosin is probably the common major allergen in crustaceans. Furthermore, immunological relationships between crustaceans, cockroaches and housedust mites have been established and may suggest tropomyosin as an important cross-sensitizing pan allergen.

Aumento de sensibilidad alérgica a la ingesta de mariscos en pacientes bajo protocolos de inmunoterapia específica [SIT] para ácaros / Increase of allergic sensitization to shellfish consumption in patients treated with specific immunotherapy [SIT] for mites

Seis pacientes que consultaron por síntomas respiratorios alérgicos (RSP y ASMA) diagnosticados por Skin prick test (SPT), fueron tratados con inmunoterapia específica (SIT) para ácaros por un lapso promedio de 23,3 meses. Tres (N2, N4 y N5) referían a su ingreso, síntomas leves a la ingesta de mariscos y se hizo SPT e IgE específica por Radio Allergo Sorbent Test (RAST) para "pool" de mariscos antes de la SIT. Ante la aparición y/o intensificación de síntomas en estos 6 pacientes por ingesta de frutos de mar luego de SIT prolongada, se realizó RAST clase 1 y 2 para N4 y N2; y N1 entre clase 0 y 1 (0,35 PRU/ml). El SPT de N2 se mantuvo positivo y el de N5 negativo, tal como antes de SIT. Sólo N4 cambió a SPT positivo al "pool" de marisco. Doce controles asintomáticos con SIT similares fueron negativos a la provocación oral, al SPT y al RAST. La presencia de un antígeno común a ambos alergenos (tropomiosina) al ser administrado en SIT para ácaros, provocaría una sensibilización nueva o aumentada en estos pacientes aunque no se pudo descartar sensibilización por ingesta habitual de mariscos