Insights into the functional mechanism of the non-specific lipid transfer protein nsLTP in Kalanchoe fedtschenkoi (Lavender scallops).

Plant non-specific lipid transfer protein (nsLTP) is able to bind and transport lipids and essential oils, as well as engage in various physiological processes, including defense against phytopathogens. Kalanchoe fedtschenkoi (Lavender Scallops) is an attractive and versatile succulent. To investigate the functional mechanism of Kalanchoe fedtschenkoi nsLTP (Ka-nsLTP), we expressed, purified and successfully obtained monomeric Ka-nsLTP. Mutational experiments revealed that the C6A variant retained the same activity as the wild-type (WT) Ka-nsLTP. Ka-nsLTP showed weak antiphytopathogenic bacterial activity, but inhibited fungal growth. Ka-nsLTP possessed a hydrophobic cavity effectively binding lauric acid. Our results offer novel molecular insights into the functional mechanism of nsLTP, which broadens our knowledge of the biological function of nsLTP in crops and provides a useful locus for genetic improvement of plants.

Co-sensitizations to Gibberellin Regulated Proteins (GRPs) in Italy: results of a polycentric study.

Summary: Background. Gibberellin Regulated Proteins (GRPs) are small glycoproteins that induce allergy to various types of fruit. This study aimed to evaluate co-sensitization to cypress pollen and other molecules responsible for fruit allergy, such as nsLTP (Pru p 3), PR-10 (Bet v1), and Profilin (Bet v2). Methods. Sixty subjects sensitized to peach GRP (Pru p 7) were consecutively recruited from four Italian centers: 28 males and 32 females (mean age 37.9 years; range 11-79). Specific IgE for Pru p 7, Pru p 3, Bet v 1, Bet v 2, cypress pollen extract (Cup s), and Cup a 1 were determined in all subjects. Results. Sensitization rates to Cup s, Cup a 1, Pru p 3, Bet v 1, and Bet v 2 in the entire studied population were 90.0%, 83.3%, 45.8%, 40.0%, and 30.0%, respectively. In subjects residing in Northern Italy, the respective sensitization rates were 96.4%, 80.0%, 50.0%, 73.3%, and 40.0%, while in those residing in Southern Italy, they were 83.3%, 86.7%, 40.0%, 6.7%, and 20.0%. The only significant difference was observed for PR-10 (p less than 0.0001) Co-sensitization to PR-10 was found to be associated with a reduced risk of anaphylaxis (OR: 0.125). Allergic reactions were most commonly triggered by peach (26/40), followed by orange (12/40), with other foods being less frequently implicated. Conclusions. This study confirms a high association between sensitization to Pru p 7 and cypress pollen and highlights a high percentage of co-sensitization to nsLTP, PR-10, and profilin. PR-10 emerged as a protective factor against anaphylaxis.

Non-Specific Lipid Transfer Protein Amb a 6 Is a Source-Specific Important Allergenic Molecule in Ragweed Pollen.

Pollen from common ragweed is an important allergen source worldwide and especially in western and southern Romania. More than 100 million patients suffer from symptoms of respiratory allergy (e.g., rhinitis, asthma) to ragweed pollen. Among the eleven characterized allergens, Amb a 6 is a non-specific lipid transfer protein (nsLTP). nsLTPs are structurally stable proteins in pollen and food from different unrelated plants capable of inducing severe reactions. The goal of this study was to produce Amb a 6 as a recombinant and structurally folded protein (rAmb a 6) and to characterize its physicochemical and immunological features. rAmb a 6 was expressed in Spodoptera frugiperda Sf9 cells as a secreted protein and characterized by mass spectrometry and circular dichroism (CD) spectroscopy regarding molecular mass and fold, respectively. The IgE-binding frequency towards the purified protein was evaluated using sera from 150 clinically well-characterized ragweed-allergic patients. The allergenic activities of rAmb a 6 and the nsLTP from the weed Parietaria judaica (Par j 2) were evaluated in basophil activation assays. rAmb a 6-specific IgE reactivity was associated with clinical features. Pure rAmb a 6 was obtained by insect cell expression. Its deduced molecular weight corresponded to that determined by mass spectrometry (i.e., 10,963 Da). rAmb a 6 formed oligomers as determined by SDS-PAGE under non-reducing conditions. According to multiple sequence comparisons, Amb a 6 was a distinct nsLTP with less than 40% sequence identity to currently known plant nsLTP allergens, except for nsLTP from Helianthus (i.e., 52%). rAmb a 6 is an important ragweed allergen recognized by 30% of ragweed pollen allergic patients. For certain patients, rAmb a 6-specific IgE levels were higher than those specific for the major ragweed allergen Amb a 1 and analysis also showed a higher allergenic activity in the basophil activation test. rAmb a 6-positive patients suffered mainly from respiratory symptoms. The assumption that Amb a 6 is a source-specific ragweed allergen is supported by the finding that none of the patients showing rAmb a 6-induced basophil activation reacted with Par j 2 and only one rAmb a 6-sensitized patient had a history of plant food allergy. Immunization of rabbits with rAmb a 6 induced IgG antibodies which strongly inhibited IgE binding to rAmb a 6. Our results demonstrate that Amb a 6 is an important source-specific ragweed pollen allergen that should be considered for diagnosis and allergen-specific immunotherapy of ragweed pollen allergy.

Role of Small Molecule Ligands in IgE-Mediated Allergy.

PURPOSE OF REVIEW: A significant fraction of allergens bind small molecular ligands, and many of these compounds are classified as lipids. However, in most cases, we do not know the role that is played by the ligands in the allergic sensitization or allergic effector phases. RECENT FINDINGS: More effort is dedicated toward identification of allergens' ligands. This resulted in identification of some lipidic compounds that can play active immunomodulatory roles or impact allergens' molecular and allergic properties. Four allergen families (lipocalins, NPC2, nsLTP, and PR-10) are among the best characterized in terms of their ligand-binding properties. Allergens from these four families are able to bind many chemically diverse molecules. These molecules can directly interact with human immune system and/or affect conformation and stability of allergens. While there is more data on the allergens and their small molecular ligands, we are just starting to understand their role in allergy.

Characterization of non-specific lipid transfer protein (nsLtp) gene families in the Brassica napus pangenome reveals abundance variation.

BACKGROUND: Brassica napus is an important agricultural species, improving stress resistance was one of the main breeding goals at present. Non-specific lipid transfer proteins (nsLTPs) are small, basic proteins which are involved in some biotic or abiotic stress responses. B. napus is susceptible to a variety of fungal diseases, so identify the BnLTPs and their expression in disease responses is very important. The common reference genome of B. napus does not contain all B. napus genes because of gene presence/absence variations between individuals. Therefore, it was necessary to search for candidate BnLTP genes in the B. napus pangenome. RESULTS: In the present study, the BnLTP genes were identified throughout the pangenome, and different BnLTP genes were presented among varieties. Totally, 246 BnLTP genes were identified and could be divided into five types (1, 2, C, D, and G). The classification, phylogenetic reconstruction, chromosome distribution, functional annotation, and gene expression were analyzed. We also identified potential cis-elements that respond to biotic and abiotic stresses in the 2 kb upstream regions of all BnLTP genes. RNA sequencing analysis showed that the BnLTP genes were involved in the response to Sclerotinia sclerotiorum infection. We identified 32 BnLTPs linked to blackleg resistance quantitative trait locus (QTL). CONCLUSION: The identification and analysis of LTP genes in the B. napus pangenome could help to elucidate the function of BnLTP family members and provide new information for future molecular breeding in B. napus.

Genome-Wide Identification and Expression Analysis of nsLTP Gene Family in Rapeseed (Brassica napus) Reveals Their Critical Roles in Biotic and Abiotic Stress Responses.

Non-specific lipid transfer proteins (nsLTPs) are small cysteine-rich basic proteins which play essential roles in plant growth, development and abiotic/biotic stress response. However, there is limited information about the nsLTP gene (BnLTP) family in rapeseed (Brassica napus). In this study, 283 BnLTP genes were identified in rapeseed, which were distributed randomly in 19 chromosomes of rapeseed. Phylogenetic analysis showed that BnLTP proteins were divided into seven groups. Exon/intron structure and MEME motifs both remained highly conserved in each BnLTP group. Segmental duplication and hybridization of rapeseed's two sub-genomes mainly contributed to the expansion of the BnLTP gene family. Various potential cis-elements that respond to plant growth, development, biotic/abiotic stresses, and phytohormone signals existed in BnLTP gene promoters. Transcriptome analysis showed that BnLTP genes were expressed in various tissues/organs with different levels and were also involved in the response to heat, drought, NaCl, cold, IAA and ABA stresses, as well as the treatment of fungal pathogens (Sclerotinia sclerotiorum and Leptosphaeria maculans). The qRT-PCR assay validated the results of RNA-seq expression analysis of two top Sclerotinia-responsive BnLTP genes, BnLTP129 and BnLTP161. Moreover, batches of BnLTPs might be regulated by BnTT1 and BnbZIP67 to play roles in the development, metabolism or adaptability of the seed coat and embryo in rapeseed. This work provides an important basis for further functional study of the BnLTP genes in rapeseed quality improvement and stress resistance.

Structural insights into the lipid transfer mechanism of a non-specific lipid transfer protein.

The non-specific lipid transfer proteins (nsLTPs) are multifunctional seed proteins engaged in several different physiological processes. The nsLTPs are stabilized by four disulfide bonds and exhibit a characteristic hydrophobic cavity, which is the primary lipid binding site. While these proteins are known to transfer lipids between membranes, the mechanism of lipid transfer has remained elusive. Four crystal structures of nsLTP from Solanum melongena, one in the apo-state and three myristic acid bound states were determined. Among the three lipid bound states, two lipid molecules were bound on the nsLTP surface at different positions and one was inside the cavity. The lipid-dependent conformational changes leading to opening of the cavity were revealed based on structural and spectroscopic data. The surface-bound lipid represented a transient intermediate state and the lipid ultimately moved inside the cavity through the cavity gate as revealed by molecular dynamics simulations. Two critical residues in the loop regions played possible 'gating' role in the opening and closing of the cavity. Antifungal activity and membrane permeabilization effect of nsLTP against Fusarium oxysporum suggested that it could possibly involve in bleaching out the lipids. Collectively, these studies support a model of lipid transfer mechanism by nsLTP via intermediate states.

Allergens and their associated small molecule ligands-their dual role in sensitization.

Many allergens feature hydrophobic cavities that allow the binding of primarily hydrophobic small-molecule ligands. Ligand-binding specificities can be strict or promiscuous. Serum albumins from mammals and birds can assume multiple conformations that facilitate the binding of a broad spectrum of compounds. Pollen and plant food allergens of the family 10 of pathogenesis-related proteins bind a variety of small molecules such as glycosylated flavonoid derivatives, flavonoids, cytokinins, and steroids in vitro. However, their natural ligand binding was reported to be highly specific. Insect and mammalian lipocalins transport odorants, pheromones, catecholamines, and fatty acids with a similar level of specificity, while the food allergen ß-lactoglobulin from cow's milk is notably more promiscuous. Non-specific lipid transfer proteins from pollen and plant foods bind a wide variety of lipids, from phospholipids to fatty acids, as well as sterols and prostaglandin B2, aided by the high plasticity and flexibility displayed by their lipid-binding cavities. Ligands increase the stability of allergens to thermal and/or proteolytic degradation. They can also act as immunomodulatory agents that favor a Th2 polarization. In summary, ligand-binding allergens expose the immune system to a variety of biologically active compounds whose impact on the sensitization process has not been well studied thus far.

A Lipid Transfer Protein has Antifungal and Antioxidant Activity and Suppresses Fusarium Head Blight Disease and DON Accumulation in Transgenic Wheat.

Trichothecene mycotoxins such as deoxynivalenol (DON) are virulence factors of Fusarium graminearum, which causes Fusarium head blight, one of the most important diseases of small grain cereals. We previously identified a nonspecific lipid transfer protein (nsLTP) gene, AtLTP4.4, which was overexpressed in an activation-tagged Arabidopsis line resistant to trichothecin, a type B trichothecene in the same class as DON. Here we show that overexpression of AtLTP4.4 in transgenic wheat significantly reduced F. graminearum growth in 'Bobwhite' and 'RB07' lines in the greenhouse and reduced fungal lesion size in detached leaf assays. Hydrogen peroxide accumulation was attenuated on exposure of transgenic wheat plants to DON, indicating that AtLTP4.4 may confer resistance by inhibiting oxidative stress. Field testing indicated that disease severity was significantly reduced in two transgenic 'Bobwhite' lines expressing AtLTP4.4. DON accumulation was significantly reduced in four different transgenic 'Bobwhite' lines expressing AtLTP4.4 or a wheat nsLTP, TaLTP3, which was previously shown to have antioxidant activity. Recombinant AtLTP4.4 purified from Pichia pastoris exhibited potent antifungal activity against F. graminearum. These results demonstrate that overexpression of AtLTP4.4 in transgenic wheat suppresses DON accumulation in the field. Suppression of DON-induced reactive oxygen species by AtLTP4.4 might be the mechanism by which fungal spread and mycotoxin accumulation are inhibited in transgenic wheat plants.

Genome-wide identification and characterization of nonspecific lipid transfer protein (nsLTP) genes in Arachis duranensis.

Nonspecific lipid transfer proteins (nsLTPs) play vital roles in lipid metabolism, cell apoptosis and biotic and abiotic stresses in plants. However, the distribution of nsLTPs in Arachis duranensis has not been fully characterized. In this study, we identified 64 nsLTP genes in A. duranensis (designated AdLTPs), which were classified into six subfamilies and randomly distributed along nine chromosomes. Tandem and segmental duplication events were detected in the evolution of AdLTPs. The Ks and ω values differed significantly between Types 1 and D subfamilies, and eight AdLTPs were under positive selection. The expression levels of AdLTPs were changed after salinity, PEG, low-temperature and ABA treatments. Three AdLTPs were associated with resistance to nematode infection, and DOF and WRI1 transcription factors may regulate the AdLTP response to nematode infection. Our results may provide valuable genomic information for the breeding of peanut cultivars that are resistant to biotic and abiotic stresses.

Structural Characterization of Act c 10.0101 and Pun g 1.0101-Allergens from the Non-Specific Lipid Transfer Protein Family.

(1) Background: Non-specific lipid transfer proteins (nsLTPs), which belong to the prolamin superfamily, are potent allergens. While the biological role of LTPs is still not well understood, it is known that these proteins bind lipids. Allergen nsLTPs are characterized by significant stability and resistance to digestion. (2) Methods: nsLTPs from gold kiwifruit (Act c 10.0101) and pomegranate (Pun g 1.0101) were isolated from their natural sources and structurally characterized using X-ray crystallography (3) Results: Both proteins crystallized and their crystal structures were determined. The proteins have a very similar overall fold with characteristic compact, mainly α-helical structures. The C-terminal sequence of Act c 10.0101 was updated based on our structural and mass spectrometry analysis. Information on proteins' sequences and structures was used to estimate the risk of cross-reactive reactions between Act c 10.0101 or Pun g 1.0101 and other allergens from this family of proteins. (4) Conclusions: Structural studies indicate a conformational flexibility of allergens from the nsLTP family and suggest that immunoglobulin E binding to some surface regions of these allergens may depend on ligand binding. Both Act c 10.0101 and Pun g 1.0101 are likely to be involved in cross-reactive reactions involving other proteins from the nsLTP family.

A lipid transfer protein variant with a mutant eight-cysteine motif causes photoperiod- and thermo-sensitive dwarfism in rice.

Plant height is an important trait for architecture patterning and crop yield improvement. Although the pathways involving gibberellins and brassinosteroids have been well studied, there are still many gaps in our knowledge of the networks that control plant height. In this study, we determined that a dominant photoperiod- and thermo-sensitive dwarf mutant is caused by the active role of a mutated gene Photoperiod-thermo-sensitive dwarfism 1 (Ptd1), the wild-type of which encodes a non-specific lipid transfer protein (nsLTP). Ptd1 plants showed severe dwarfism under long-day and low-temperature conditions, but grew almost normal under short-day and high-temperature conditions. These phenotypic variations were associated with Ptd1 mRNA levels and accumulation of the corresponding protein. Furthermore, we found that the growth inhibition in Ptd1 may result from the particular protein conformation of Ptd1 due to loss of two disulfide bonds in the eight-cysteine motif (8-CM) that is conserved among nsLTPs. These results contribute to our understanding of the novel function of disulfide bonds in the 8-CM, and provide a potential new strategy for regulation of cell development and plant height by modifying the amino acid residues involved in protein conformation patterning.

Performance of basophil activation test and specific IgG4 as diagnostic tools in nonspecific lipid transfer protein allergy: Antwerp-Barcelona comparison.

BACKGROUND: Recent studies show that nsLTP sensitization is not limited to the Mediterranean basin and can present diverse clinical phenotypes. It remains challenging to predict clinical outcome when specific IgE antibodies (sIgE) to nsLTPs are present. This study compares both clinical and in vitro allergy characteristics but also diagnostic performance of a basophil activation test (BAT) and sIgG4 in nsLTP-sensitized patients from Antwerp (ANT, Belgium) and Barcelona (BCN, Spain). METHODS: Adult subjects with positive sIgE rPru p 3 and/or rMal d 3 ≥ 0.10 kUA /L (n = 182) and healthy controls (n = 37) were included. NsLTP-sensitized individuals were stratified according to clinical symptoms with peach/apple, respectively. BAT rPru p 3 and rMal d 3 were performed and sIgG4 antibodies to both components quantified. RESULTS: In BCN, only ratios of sIgG4/sIgE rMal d 3 and BAT rMal d 3 (0.001 µg/mL) can identify clinically relevant Mal d 3 sensitization (sensitivity of 60%-63% and a specificity of 75%-67%, respectively). In ANT, only the sIgE/total IgE rPru p 3 ratio shows added value (sensitivity 60% and specificity 83%). Finally, it appears that symptomatic patients in BCN are more sensitive to lower allergen concentrations compared to ANT. In addition, it was shown that ANT patients were more often sensitized to pollen and that specific pollen sources differed between regions. CONCLUSIONS: NsLTP-related allergy profiles and diagnostic performance differ significantly between regions and are component-specific, which makes extrapolation of data difficult to do. In addition, it seems that basophil sensitivity might show geographical differences. Additional research is needed to confirm these findings.

Phenotyping peach-allergic patients sensitized to lipid transfer protein and analysing severity biomarkers.

BACKGROUND: Patients with peach allergy due to nsLTP sensitization constitute a heterogeneous group in terms of sensitization profile and severity. This could be due to the presence of additional allergies to pollens. The aim of this study was to analyse the clinical characteristics, sensitization profile and severity of reactions in peach-allergic patients sensitized to nsLTP from two Mediterranean areas with different pollen exposure. METHODS: Patients with diagnosis of LTP allergy from the Allergy Unit of Hospital Regional Universitario de Malaga (HRUM) and Hospital Clinic de Barcelona (HCB) were prospectively included and classified into two groups; (a) LTP-monoallergic: those that presented reaction only with peach and (b) LTP-Allergy: those that presented reaction with peach and at least another plant-food containing LTP. RESULTS: A total of 252 patients were included, 235 (93.2%) had LTP-syndrome and 17 (6.8%) were LTP-monoallergic. We found a higher percentage of anaphylaxis and delayed onset of symptoms in the LTP-monoallergic group (P = .02 and P = .04, respectively). Moreover, anaphylaxis was less frequent in patients with profilin sensitization (P = .03). The comparison of patients' data from HRUM with data from HCB showed differences in sensitization to olive tree pollen and profilin (P = .01 and P = .001, respectively). CONCLUSION: This study was undertaken to characterize two large group of subjects from to two regions with differing exposures to pollen. We found that more than 90% of peach-allergic patients in both populations evolved to LTP-Allergy and showed an early onset. Profilin sensitization could be more useful as a severity biomarker than the number of nsLTP, aeroallergen sensitizations or sIgE levels. This could provide clues regarding sensitization and severity patterns that might be relevant in other geographical areas.

A triticale tapetal non-specific lipid transfer protein (nsLTP) is translocated to the pollen cell wall.

KEY MESSAGE: A Triticeae type III non-specific lipid transfer protein (nsLTP) was shown for the first time to be translocated from the anther tapetum to the pollen cell wall. Two anther-expressed non-specific lipid transfer proteins (nsLTPs) were identified in triticale (× Triticosecale Wittmack). LTPc3a and LTPc3b contain a putative signal peptide sequence and eight cysteine residues in a C-Xn-C-Xn-CC-Xn-CXC-Xn-C-Xn-C pattern. These proteins belong to the type III class of nsLTPs which are expressed exclusively in the inflorescence of angiosperms. The level of LTPc3 transcript in the anther was highest at the tetrad and uninucleate microspore stages, and absent in mature pollen. In situ hybridization showed that LTPc3 was expressed in the tapetal layer of the developing triticale anther. The expression of the LTPc3 protein peaked at the uninucleate microspore stage, but was also found to be associated with the mature pollen. Accordingly, an LTPc3a::GFP translational fusion expressed in transgenic Brachypodium distachyon first showed activity in the tapetum, then in the anther locule, and later on the mature pollen grain. Altogether, these results represent the first detailed characterization of a Triticeae anther-expressed type III nsLTP with possible roles in pollen cell wall formation.

Genome-wide identification, characterization and expression analysis of the non-specific lipid transfer proteins in potato.

BACKGROUND: Plant non-specific lipid transfer proteins (nsLTPs) are small, basic proteins that are abundant in higher plants. They have been reported to play an important role in various plant physiological processes, such as lipid transfer, signal transduction, and pathogen defense. To date, a comprehensive analysis of the potato nsLTP gene family is still lacking after the completion of potato (Solanum tuberosum L.) genome sequencing. A genome-wide characterization, classification and expression analysis of the StnsLTP gene family was performed in this study. RESULTS: In this study, a total of 83 nsLTP genes were identified and categorized into eight types based on Boutrot's method. Multiple characteristics of these genes, including phylogeny, gene structures, conserved motifs, protein domains, chromosome locations, and cis-elements in the promoter sequences, were analyzed. The chromosome distribution and the collinearity analyses suggested that the expansion of the StnsLTP gene family was greatly enhanced by the tandem duplications. Ka/Ks analysis showed that 47 pairs of duplicated genes tended to undergo purifying selection during evolution. Moreover, the expression of StnsLTP genes in various tissues was analyzed by using RNA-seq data and verified by quantitative real-time PCR, revealing that the StnsLTP genes were mainly expressed in younger tissues. These results indicated that StnsLTPs may played significant and functionally varied roles in the development of different tissues. CONCLUSION: In this study, we comprehensively analyzed nsLTPs in potato, providing valuable information to better understand the functions of StnsLTPs in different tissues and pathways, especially in response to abiotic stress.

Identification and molecular characterization of allergenic non-specific lipid-transfer protein from durum wheat (Triticum turgidum).

BACKGROUND: Common wheat (Triticum aestivum) and durum wheat (T. turgidum) are both involved in Baker's asthma (BA) and food allergy (FA) including wheat-dependent exercise-induced asthma (WDEIA). However, allergens in durum wheat have not been described, and the over-expression of T. turgidum non-specific lipid-transfer protein (nsLTPs) is considered to increase resistance to phytopathogens. OBJECTIVE: To identify and assess the allergenicity of nsLTP from T. turgidum. METHODS: Recombinant T. turgidum nsLTP Tri tu 14 was generated and tested for structural integrity (circular dichroism-spectroscopy) and purity (SDS-PAGE). Thirty-two wheat allergic patients were enrolled: 20 Spanish patients (BA) with positive bronchial challenge to wheat flour, and 12 Italian patients (wheat FA/WDEIA) with positive double-blind placebo-controlled food challenge/open food challenge (OFC) to pasta. IgE values to wheat, Tri tu 14, Tri a 14 (T. aestivum) and Pru p 3 (P. persica) were determined by ImmunoCAP testing. Allergenic potency (in vitro mediator release) and IgE cross-reactivity were investigated. RESULTS: Tri tu 14 was found to share 49% and 52% amino acid identity with Tri a 14 and Pru p 3, respectively. Among 25 Tri a 14 CAP positive sera, 23 (92%) were reactive to wheat extract, 22 (88%) to Tri tu 14 and 20 (80%) to Pru p 3. The correlation between Tri a 14 and Tri tu 14 specific IgE levels was r = 0.97 (BA) and r = 0.93 (FA/WDEIA), respectively. FA/WDEIA patients showed higher specific IgE values to Tri tu 14 and Pru p 3 than BA patients. Tri tu 14 displayed allergenic activity by mediator release from effector cells and IgE cross-reactivity with Pru p 3. The degree of IgE cross-reactivity between the two wheat nsLTPs varied between individual patients. CONCLUSIONS AND CLINICAL RELEVANCE: Sensitization to Tri tu 14 likely appears to be more important in wheat FA/WDEIA than in BA. Over-expression of Tri tu 14 in wheat would represent a risk for patients with nsLTP-mediated FA.

An atlas of IgE sensitization patterns in different Italian areas. A multicenter, cross-sectional study.

Summary: Background. The development of recombinant technology supported the allergy diagnostic work-up in the daily clinical practice, representing a useful tool for epidemiological studies. Methods. An atlas of the IgE sensitization profiles found throughout Italy was prepared from a nationwide, multicenter, cross-sectional study. Results. 6052 unselected consecutive individuals, belonging to North-West [NW], North-East [NE], Centre [C], South [S], and Islands subset [Is] were evaluated by means of the ImmunoCAP ISAC test. The top-ranked sensitizations found were Cup a 1 in [C] (58.1%) and [S] (53.6%), Phl p 1 in the North (from 46.1% to 49%), and Cyn d 1 in [Is] (44.2%). High frequency of house dust mite group 2 molecules sensitization was found in [C] (36.9%) and [S] Italy (40.8%), whilst low level of reactivity was recorded in [NW] (20%). Pellitory hypersensitivity was mainly found in [C], [S], and [Is], whilst ragweed Amb a 1 sensitivity was particularly found in [NW] Italy. IgE recognition of PR-10, Profilin, and nsLTP was mutually exclusive in 69.1% of cases, PR-10 reactivity mostly occurring in [NE], Profilin in [NW], and nsLTP molecules recognition mainly recorded in [C] and [S]. Conclusions. Divergent IgE sensitization patterns were found along Italy, possibly linked to the distinct geographical locations, indicating multiplex system IgE analysis as a reliable approach for epidemiological evaluation even in small geographical areas.

Storage molecules from tree nuts, seeds and legumes: relationships and amino acid identity among homologue molecules.

Summary: The families of seed storage proteins, together with profilins, oil-bodies-associated oleosins, and pathogenesis-related (PR) proteins like PR-10 (Bet v 1-like), PR-12 (defensins) and PR-14 (non-specific lipid transfer protein), are the main causes of IgE sensitization to tree nuts, legumes and seeds. All these allergens, with the exclusion of profilins and of PR-10, are heat-stable and possibly responsible for fatal or almost fatal adverse reactions to such foods. In this short review, we will discuss the relationship and amino acid identities among some of the seed storage homologue molecules identified to date from tree nuts, seeds and legumes.

Lipid transfer proteins: classification, nomenclature, structure, and function.

The non-specific lipid transfer proteins (LTPs) constitute a large protein family found in all land plants. They are small proteins characterized by a tunnel-like hydrophobic cavity, which makes them suitable for binding and transporting various lipids. The LTPs are abundantly expressed in most tissues. In general, they are synthesized with an N-terminal signal peptide that localizes the protein to spaces exterior to the plasma membrane. The in vivo functions of LTPs are still disputed, although evidence has accumulated for a role in the synthesis of lipid barrier polymers, such as cuticular waxes, suberin, and sporopollenin. There are also reports suggesting that LTPs are involved in signaling during pathogen attacks. LTPs are considered as key proteins for the plant's survival and colonization of land. In this review, we aim to present an overview of the current status of LTP research and also to discuss potential future applications of these proteins. We update the knowledge on 3D structures and lipid binding and review the most recent data from functional investigations, such as from knockout or overexpressing experiments. We also propose and argument for a novel system for the classification and naming of the LTPs.