Updates on Databases of Allergens and Allergen-Epitopes

The increasing prevalence of allergic diseases is of great public health concern. Environmental and food allergens are the major triggers of allergic diseases via respiratory or gastrointestinal routes, respectively. A major setback in the clinical management of allergies is the unavailability of purified allergens required for diagnostic purposes. Furthermore, manipulation of allergen sequences and structures by employing protein-engineering approaches is needed to design immunotherapeutic vaccines. All these approaches rely upon the sequence, structure, and epitope location of allergens. A number of databases have therefore been developed that serve as repositories of molecular information of allergens. In this chapter, we discuss the five most important widely used allergen databases that might be helpful for the research community working on molecular allergology.

Computational Vaccine Design for Common Allergens

In this chapter, the steps of designing candidate vaccine molecules for allergen-specific immunotherapy (AIT) using immunoinformatics are described. The most modern approach of AIT deals with carrier-bound B cell epitope and multi-epitope vaccine molecules. The strategy for designing these molecules and the bioinformatics tools and servers used for that are discussed in detail here.

Designing Next-Generation Vaccines Against Common Pan-Allergens Using In Silico Approaches

Next-generation allergy vaccines refer to allergen-derived attenuated molecules that can boost allergen-blocking IgG response. These IgG antibodies are specifically directed toward the IgE epitope of allergens and interfere in allergen-IgE interaction. Our study is a computational approach to design such vaccines against four widespread pan-allergens families. Pan-allergens display extensive immunological cross-reactivity due to the presence of conserved IgE epitope and T cell epitope. In this study, the vaccine design is based on hapten-carrier concept in which the carrier protein is an immunogenic component providing T cell help. Either PreS protein of hepatitis B or cholera enterotoxin B (CTB) fused with three tetanus toxoid fragments (TTFrC) was used here as the carrier. The hapten components are nonanaphylactic peptides (NAPs) derived from experimentally determined antigenic regions of the allergens. The charged residues of NAPs are selectively modified to obliterate IgE, as well as T cell reaction, and hence, are safe to apply in allergy patients. Various combinations of vaccine constructs (PreS/CTB+TTFrC and NAPs) were designed with intermediate linker motifs. Screening of constructs was performed through a three-step method such as physicochemical parameters, secondary structures, and tertiary structures using various bioinformatic tools. The final construct with best quality and stability was selected for each allergen family. Suitability of these constructs for being expressed in recombinant form was checked at DNA, RNA, and protein level. Presence of putative epitopes inducing tolerogenic interleukin-10 was also predicted for these constructs. The present work led to the design of putative vaccines with immunotherapeutic potential and broad applicability for allergic diseases caused by a wide array of cross-reactive allergens.

AB0399 COMPARISON OF RITUXIMAB VERSUS LEFLUNOMIDE IN COMBINATION WITH METHOTREXATE IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS DESPITE METHOTREXATE TREATMENT- AN OPEN LABEL, RANDOMISED CONTROLLED TRIAL

Background

Active rheumatoid arthritis (RA) despite methotrexate monotherapy is seen in about 43% of patients1. The current American College of Rheumatology (ACR) guidelines recommend adding a biologic or targeted synthetic Disease Modifying Anti-rheumatic Drug (DMARD) to methotrexate (MTX) therapy in such cases. The European Alliance of Associations for Rheumatology (EULAR) guidelines recommend combination DMARDs but the most commonly used combination is that of MTX with sulphasalazine and hydroxychloroquine. In a resource limited country like ours, it is not always possible to give a biological or a targeted synthetic DMARD, and a more cost effective method needs to be implemented. Often, leflunomide (LEF) is added in such cases and is effective.

Objectives

We aimed to study if LEF with MTX combination is non inferior to rituximab (RTX) and MTX combination in patients with active RA despite MTX.

Methods

This open label, randomised controlled trial, carried out on patients with moderate to high disease activity despite MTX therapy for atleast 3 months (Clinical Trials Registry- India - REF/2021/04/042755) was conducted in a tertiary care centre in India. Patients were randomised to receive either LEF (10-20mg/day) or RTX (2 doses of 1gm, 2 weeks apart) along with background MTX (10-25mg/week) and followed up at 12, 18 and 24 weeks. The primary outcome ACR20 response at 24 weeks and secondary outcomes were ACR50 and 70 responses at 24 weeks.

Results

There were 21 patients in each arm. At baseline, all patients in both groups had seropositive RA and had high disease activity according to Disease Activity Score (DAS)28 scores. The ACR20 response at 24 weeks was achieved by 14 (66.6%) and 16 (76.19%) patients respectively in the LEF and RTX arms. The ACR50 response was achieved by 11 (52.38%) patients in both groups and ACR70 response by 4 (19%) and 7 (33.3%) in the LEF and RTX arms respectively (Figure 1). The mean dose of LEF at week 24 was 17.6 mg/day. Improvement of various parameters at week 24 as compared to the baseline values were similar in both groups (Table 1). No major adverse events were noted. Two patients receiving RTX had a mild infusion reaction. Elevation in liver enzymes (<3 times the upper limit of normal) were noted in 4 patients in the LEF arm which normalised subsequently. No patient required drug withdrawal.

Table 1.

Responses in both groups at week 24 (p= Not significant for all)

Leflunomide, n=21Rituximab, n=21Mean ±SD reduction in SJC-4.57 ± 3.4-5.43 ± 4.6Mean ±SD reduction in TJC-6.2 ± 3.9-7.1 ± 6.1Mean ±SD reduction in PhGA-3.42 ± 1.8-4.04 ± 2.5Mean ±SD reduction in PGA-3.05 ± 1.8-3.42 ± 2.4Mean ±SD reduction in pain VAS-33.57 ± 23.2-38.57 ± 24.4Mean ±SD reduction in DAS28-ESR-1.95 ± 1.2-2.08 ± 1.4Mean ±SD reduction in DAS28-CRP-1.81 ± 1.2-2.07 ± 1.4Mean ±SD reduction in HAQ-DI-0.65 ± 0.5-0.82 ± 0.6EULAR good response (%)1 (4.76%)1 (4.76%)EULAR moderate response (%)15 (71.43%)14 (66.6%)EULAR non-responders (%)5 (23.81%)6 (28.57%)

CRP, C- Reactive Protein; DAS, Disease Activity Score; ESR, Erythrocyte Sedimentation Rate; HAQ-DI, Healthy Assessment Questionnaire-Disability Index; PGA, Patient’s global assessment of disease activity; PhGA, Physician’s global assessment of disease activity; SJC, Swollen Joint Count; TJC, Tender Joint Count; VAS, Visual analogue scale.

Figure 1.

Number of patients achieving ACR20, 50 and 70 responses at week 24

Conclusion

In our study, LEF was comparable to RTX for achievement of ACR20/50/70 responses at 24 weeks. LEF can be considered as an add-on option to MTX instead of more expensive biologic agents in MTX refractory RA. Larger studies are needed to confirm this hypothesis.

References

[1]Sergeant JC, Hyrich KL, Anderson J, et al. Prediction of primary non-response to methotrexate therapy using demographic, clinical and psychosocial variables: results from the UK Rheumatoid Arthritis Medication Study (RAMS). Arthritis Res Ther. 2018;20(1):147. Published 2018 Jul 13.

Disclosure of Interests

None declared

Comprehensive characterization and molecular insights into the salt tolerance of a Cu, Zn-superoxide dismutase from an Indian Mangrove, Avicennia marina

Superoxide dismutases are important group of antioxidant metallozyme and play important role in ROS homeostasis in salinity stress. The present study reports the biochemical properties of a salt-tolerant Cu, Zn-superoxide from Avicennia marina (Am_SOD). Am_SOD was purified from the leaf and identified by mass-spectrometry. Recombinant Am_SOD cDNA was bacterially expressed as a homodimeric protein. Enzyme kinetics revealed a high substrate affinity and specific activity of Am_SOD as compared to many earlier reported SODs. An electronic transition in 360–400 nm spectra of Am_SOD is indicative of Cu²⁺-binding. Am_SOD activity was potentially inhibited by diethyldithiocarbamate and H₂O₂, a characteristic of Cu, Zn-SOD. Am_SOD exhibited conformational and functional stability at high NaCl concentration as well in alkaline pH. Introgression of Am_SOD in E. coli conferred tolerance to oxidative stress under highly saline condition. Am_SOD was moderately thermostable and retained functional activity at ~ 60 °C. In-silico analyses revealed 5 solvent-accessible N-terminal residues of Am_SOD that were less hydrophobic than those at similar positions of non-halophilic SODs. Substituting these 5 residues with non-halophilic counterparts resulted in > 50% reduction in salt-tolerance of Am_SOD. This indicates a cumulative role of these residues in maintaining low surface hydrophobicity of Am_SOD and consequently high salt tolerance. The molecular information on antioxidant activity and salt-tolerance of Am_SOD may have potential application in biotechnology research. To our knowledge, this is the first report on salt-tolerant SOD from mangrove.

Molecular characterization of a fungal cyclophilin allergen Rhi o 2 and elucidation of antigenic determinants responsible for IgE-cross-reactivity

Cyclophilins are structurally conserved pan-allergens showing extensive cross-reactivity. So far, no precise information on cross-reactive IgE-epitopes of cyclophilins is available. Here, an 18-kDa IgE-reactive cyclophilin (Rhi o 2) was purified from Rhizopus oryzae, an indoor mold causing allergic sensitization. Based on LC-MS/MS-derived sequences of natural Rhi o 2, the full-length cDNA was cloned, and expressed as recombinant (r) allergen. Purified rRhi o 2 displayed IgE-reactivity and basophil degranulation with sera from all cyclophilin-positive patients. The melting curve of properly folded rRhi o 2 showed partial refolding after heat denaturation. The allergen displayed monomeric functional peptidyl-prolyl cis-trans isomerase (PPIase) activity. In IgE-inhibition assays, rRhi o 2 exhibited extensive cross-reactivity with various other cyclophilins reported as allergens from diverse sources including its homologous human autoantigen. By generating a series of deletion mutants, a conserved 69-residue (Asn⁸¹-Asn¹⁴⁹) fragment at C terminus of Rhi o 2 was identified as crucial for IgE-recognition and cross-reactivity. Grafting of the Asn⁸¹-Asn¹⁴⁹ fragment within the primary structure of yeast cyclophilin CPR1 by replacing its homologous sequence resulted in a hybrid molecule with structural folds similar to Rhi o 2. The IgE-reactivity and allergenic activity of the hybrid cyclophilin were greater than that of CPR1. Therefore, the Asn⁸¹-Asn¹⁴⁹ fragment can be considered as the site of IgE recognition of Rhi o 2. Hence, Rhi o 2 serves as a candidate antigen for the molecular diagnosis of mold allergy, and determination of a major cross-reactive IgE-epitope has clinical potential for the design of next-generation immunotherapeutics against cyclophilin-induced allergies.

Spectrum of Allergens and Allergen Biology in India

The growing prevalence of allergy and asthma in India has become a major health concern with symptoms ranging from mild rhinitis to severe asthma and even life-threatening anaphylaxis. The "allergen repertoire" of this subcontinent is highly diverse due to the varied climate, flora, and food habits. The proper identification, purification, and molecular characterization of allergy-eliciting molecules are essential in order to facilitate an accurate diagnosis and to design immunotherapeutic vaccines. Although several reports on prevalent allergens are available, most of these studies were based on preliminary detection and identification of the allergens. Only a few of these allergen molecules have been characterized by recombinant technology and structural biology. The present review first describes the composition, distribution pattern, and natural sources of the predominant allergens in India along with the prevalence of sensitization to these allergens across the country. We go on to present a comprehensive report on the biochemical, immunological, and molecular information on the allergens reported so far from India. The review also covers the studies on allergy- related biosafety assessment of transgenic plants. Finally, we discuss the allergen-specific immunotherapy trials performed in India.

Cari p 1, a Novel Polygalacturonase Allergen From Papaya Acting as Respiratory and Food Sensitizer

Papaya has been reported to elicit IgE-mediated hypersensitivity via pollen inhalation and fruit consumption. Certain papaya sensitive patients with food allergy were found to experience recurrent respiratory distresses even after quitting the consumption of fruits. This observation prompted us to investigate the allergens commonly present in fruits and pollen grains of papaya. A discovery approach consisting of immunoproteomic detection followed by molecular characterization led to the identification of a novel papaya allergen designated as Cari p 1. This allergen was detected as a 56 kDa IgE-reactive protein from pollen as well as fruit proteome through serological analysis. The protein was identified as an endopolygalacturonase by tandem mass spectrometry. Full length Cari p 1 cDNA was isolated from papaya pollen, cloned in expression vector, and purified as recombinant allergen. The recombinant protein was monomeric and displayed pectinolytic activity. Recombinant Cari p 1 reacted with IgE-antibodies of all the papaya sensitized patient sera. In addition to IgE-reactivity, rCari p 1 displayed allergenic activity by stimulating histamine release from IgE-sensitized granulocytes. CD-spectroscopy of rCari p 1 revealed the presence of predominantly β-sheet characters. The melting curve of the allergen showed partial refolding from a fully denatured state indicating the possible presence of conformational IgE-epitopes characteristic of inhalant allergens in addition to the linear IgE-epitopes of food allergens. The expression of this allergen in papaya fruits was detected by immunoblot with anti-Cari p 1 rabbit IgG and reconfirmed by PCR. In an in vivo mouse model, rCari p 1 exhibited a comparable level of inflammatory responses in the lung and duodenum tissues explaining the dual role of Cari p 1 allergen in respiratory sensitization via pollen inhalation and sensitization of gut mucosa via fruit consumption. Purified rCari p 1 can be used a marker allergen for component-resolved molecular diagnosis. Further immunological studies on Cari p 1 are warranted to design immunotherapeutic vaccine for the clinical management of papaya allergy.

Cardiac tamponade in systemic lupus erythematosus

BACKGROUND

Cardiac tamponade is a rare but life-threatening complication of systemic lupus erythematosus (SLE).

AIMS/OBJECTIVES

To describe incidence, risk factors and treatment of cardiac tamponade in a large cohort of Indian patients with SLE.

METHODS

This retrospective study was conducted at the Department of Rheumatology, IPGMER, Kolkata, India from May 2014 to December 2016 on admitted patients with SLE. Lupus-related serositis was diagnosed after excluding other causes, such as infection, malignancy or heart failure.

RESULTS

Of 409 patients with SLE, pericarditis was diagnosed in 25.4% (104/409) and cardiac tamponade in 5.9% (24/409). Tamponade was the presenting feature of SLE in 50% (12/24). Tamponade occurred in 77.8% (14/18) of large effusions and in 11.63% (10/86) of small-to-moderate effusions. The commonest autoantibody in serum and pericardial fluid was anti-nucleosme antibody. Large pericardial effusion (>20 mm) (Odd's ratio (OR): 93.2, 95% confidence interval (CI): 11.1-782.5, P < 0.001) predicted tamponade. In the subset of patients with small-to-moderate sized pericardial effusion, tamponade was associated with pleuritis (OR: 44.5, 95% CI: 1.6-1243, P = 0.025), anti-nucleosome antibody (OR: 42.9, 95% CI: 1.6-1176, P = 0.026) and size of pericardial effusion (OR: 1.36, 95% CI: 1.04-1.76, P = 0.025). Repeated pericardiocentesis was required in 3 patients and one needed surgical intervention. Immunosuppressives used were: prednisolone with monthly intravenous cyclophosphamide (in 33.33%) and intravenous methylprednisolone with monthly cyclophosphamide (in 50%).

CONCLUSIONS

Pleuritis, anti-nucleosome antibody and size of pericardial effusion predicted development of tamponade. High dose immunosuppression (methylprednisolone and IV cyclophosphamide) alleviated need for surgery in majority.

Epitope Mapping of Rhi o 1 and Generation of a Hypoallergenic Variant: A CANDIDATE MOLECULE FOR FUNGAL ALLERGY VACCINES

Efficacy of allergen-specific immunotherapy is often severely impaired by detrimental IgE-mediated side effects of native allergen during vaccination. Here, we present the molecular determinants for IgE recognition of Rhi o 1 and eventually converting the allergen into a hypoallergenic immunogen to restrain health hazards during desensitization. Rhi o 1 is a respiratory fungal allergen. Despite having cross-reactivity with cockroach allergen, we observed that non-cross-reactive epitope predominantly determined IgE binding to Rhi o 1. Denaturation and refolding behavior of the allergen confirmed that its IgE reactivity was not essentially conformation-dependent. A combinatorial approach consisting of computational prediction and a peptide-based immunoassay identified two peptides ((44)TGEYLTQKYFNSQRNN and (311)GAEKNWAGQYVVDCNK) of Rhi o 1 that frequently reacted with IgE antibodies of sensitized patients. Interestingly, these peptides did not represent purely linear IgE epitopes but were presented in a conformational manner by forming a spatially clustered surface-exposed epitope conferring optimal IgE-binding capacity to the folded allergen. Site-directed alanine substitution identified four residues of the IgE epitope that were crucial for antibody binding. A multiple mutant (T49A/Y52A/K314A/W316A) showing 100-fold lower IgE binding and reduced allergenic activity was generated. The TYKW mutant retained T-cell epitopes, as evident from its lymphoproliferative capacity but down-regulated pro-allergic IL-5 secretion. The TYKW mutant induced enhanced focusing of blocking IgG antibodies specifically toward the IgE epitope of the allergen. Anti-TYKW mutant polyclonal IgG antibodies competitively inhibited binding of IgE antibodies to Rhi o 1 up to 70% and suppressed allergen-mediated histamine release by 10-fold. In conclusion, this is a simple yet rational strategy based on epitope mapping data to develop a genetically modified hypoallergenic variant showing protective antibody response for immunotherapeutic applications.

Data on mass spectrometry based identification of allergens from sunflower (Helianthus annuus L.) pollen proteome

Allergy is a type of abnormal immune reactions, which is triggered by environmental antigens or allergens and mediated by IgE antibodies. Now-a-days mass spectrometry is the method of choice for allergen identification based on homology searching. Here, we provide the mass spectrometry dataset associated with our previously published research article on identification of sunflower pollen allergens (Ghosh et al., 2015 [1]). In this study allergenicity of sunflower (Helianthus annuus) pollen grains were primarily investigated by clinical studies followed by detailed immunobiochemical and immunoproteomic analyses. The mass spectrometry data for the identification of allergens were deposited to ProteomeXchange Consortium via PRIDE partner repository with the dataset identifier PXD002397.

Purification, Cloning and Immuno-Biochemical Characterization of a Fungal Aspartic Protease Allergen Rhi o 1 from the Airborne Mold Rhizopus oryzae

BACKGROUND

Fungal allergy is considered as serious health problem worldwide and is increasing at an alarming rate in the industrialized areas. Rhizopus oyzae is a ubiquitously present airborne pathogenic mold and an important source of inhalant allergens for the atopic population of India. Here, we report the biochemical and immunological features of its 44 kDa sero-reactive aspartic protease allergen, which is given the official designation 'Rhi o 1'.

METHOD

The natural Rhi o 1 was purified by sequential column chromatography and its amino acid sequence was determined by mass spectrometry and N-terminal sequencing. Based on its amino acid sequence, the cDNA sequence was identified, cloned and expressed to produce recombinant Rhi o 1. The allergenic activity of rRhi o 1 was assessed by means of its IgE reactivity and histamine release ability. The biochemical property of Rhi o 1 was studied by enzyme assay. IgE-inhibition experiments were performed to identify its cross-reactivity with the German cockroach aspartic protease allergen Bla g 2. For precise characterization of the cross-reactive epitope, we used anti-Bla g 2 monoclonal antibodies for their antigenic specificity towards Rhi o 1. A homology based model of Rhi o 1 was built and mapping of the cross-reactive conformational epitope was done using certain in silico structural studies.

RESULTS

The purified natural nRhi o 1 was identified as an endopeptidase. The full length allergen cDNA was expressed and purified as recombinant rRhi o 1. Purified rRhi o 1 displayed complete allergenicity similar to the native nRhi o 1. It was recognized by the serum IgE of the selected mold allergy patients and efficiently induced histamine release from the sensitized PBMC cells. This allergen was identified as an active aspartic protease functional in low pH. The Rhi o 1 showed cross reactivity with the cockroach allergen Bla g 2, as it can inhibit IgE binding to rBla g 2 up to certain level. The rBla g 2 was also found to cross-stimulate histamine release from the effector cells sensitized with anti-Rhi o 1 serum IgE. This cross-reactivity was found to be mediated by a common mAb4C3 recognizable conformational epitope. Bioinformatic studies revealed high degree of structural resemblances between the 4C3 binding sites of both the allergens.

CONCLUSION/SIGNIFICANCE

The present study reports for the first time anew fungal aspartic protease allergen designated as Rhi o 1, which triggers IgE-mediated sensitization leading to various allergic diseases. Here we have characterized the recombinant Rhi o 1 and its immunological features including cross-reactive epitope information that will facilitate the component-resolved diagnosis of mold allergy.

Mining Novel Allergens from Coconut Pollen Employing Manual De Novo Sequencing and Homology-Driven Proteomics

Coconut pollen, one of the major palm pollen grains is an important constituent among vectors of inhalant allergens in India and a major sensitizer for respiratory allergy in susceptible patients. To gain insight into its allergenic components, pollen proteins were analyzed by two-dimensional electrophoresis, immunoblotted with coconut pollen sensitive patient sera, followed by mass spectrometry of IgE reactive proteins. Coconut being largely unsequenced, a proteomic workflow has been devised that combines the conventional database-dependent analysis of tandem mass spectral data and manual de novo sequencing followed by a homology-based search for identifying the allergenic proteins. N-terminal acetylation helped to distinguish "b" ions from others, facilitating reliable sequencing. This led to the identification of 12 allergenic proteins. Cluster analysis with individual patient sera recognized vicilin-like protein as a major allergen, which was purified to assess its in vitro allergenicity and then partially sequenced. Other IgE-sensitive spots showed significant homology with well-known allergenic proteins such as 11S globulin, enolase, and isoflavone reductase along with a few which are reported as novel allergens. The allergens identified can be used as potential candidates to develop hypoallergenic vaccines, to design specific immunotherapy trials, and to enrich the repertoire of existing IgE reactive proteins.

Search for Allergens from the Pollen Proteome of Sunflower (Helianthus annuus L.): A Major Sensitizer for Respiratory Allergy Patients

BACKGROUND

Respiratory allergy triggered by pollen allergens is increasing at an alarming rate worldwide. Sunflower pollen is thought to be an important source of inhalant allergens. Present study aims to identify the prevalence of sunflower pollinosis among the Indian allergic population and characterizes the pollen allergens using immuno-proteomic tools.

METHODOLOGY

Clinico-immunological tests were performed to understand the prevalence of sensitivity towards sunflower pollen among the atopic population. Sera from selected sunflower positive patients were used as probe to detect the IgE-reactive proteins from the one and two dimensional electrophoretic separated proteome of sunflower pollen. The antigenic nature of the sugar moiety of the glycoallergens was studied by meta-periodate modification of IgE-immunoblot. Finally, these allergens were identified by mass-spectrometry.

RESULTS

Prevalence of sunflower pollen sensitization was observed among 21% of the pollen allergic population and associated with elevated level of specific IgE and histamine in the sera of these patients. Immunoscreening of sunflower pollen proteome with patient sera detected seven IgE-reactive proteins with varying molecular weight and pI. Hierarchical clustering of 2D-immunoblot data highlighted three allergens characterized by a more frequent immuno-reactivity and increased levels of IgE antibodies in the sera of susceptible patients. These allergens were considered as the major allergens of sunflower pollen and were found to have their glycan moiety critical for inducing IgE response. Homology driven search of MS/MS data of these IgE-reactive proteins identified seven previously unreported allergens from sunflower pollen. Three major allergenic proteins were identified as two pectate lyases and a cysteine protease.

CONCLUSION

Novelty of the present report is the identification of a panel of seven sunflower pollen allergens for the first time at immuno-biochemical and proteomic level, which substantiated the clinical evidence of sunflower allergy. Further purification and recombinant expression of these allergens will improve component-resolved diagnosis and therapy of pollen allergy.

Allergic asthma biomarkers using systems approaches

Asthma is characterized by lung inflammation caused by complex interaction between the immune system and environmental factors such as allergens and inorganic pollutants. Recent research in this field is focused on discovering new biomarkers associated with asthma pathogenesis. This review illustrates updated research associating biomarkers of allergic asthma and their potential use in systems biology of the disease. We focus on biomolecules with altered expression, which may serve as inflammatory, diagnostic and therapeutic biomarkers of asthma discovered in human or experimental asthma model using genomic, proteomic and epigenomic approaches for gene and protein expression profiling. These include high-throughput technologies such as state of the art microarray and proteomics Mass Spectrometry (MS) platforms. Emerging concepts of molecular interactions and pathways may provide new insights in searching potential clinical biomarkers. We summarized certain pathways with significant linkage to asthma pathophysiology by analyzing the compiled biomarkers. Systems approaches with this data can identify the regulating networks, which will eventually identify the key biomarkers to be used for diagnostics and drug discovery.

In silico prediction of allergenic proteins

Currently, the prediction of new allergens is becoming important due to use of genetically modified (GM) foods and biopharmaceuticals. In this chapter, we describe how to use four popular allergenic prediction servers: (1) Structural Database of Allergenic Proteins (SDAP), (2) Allermatch, (3) Evaller 2, and (4) AlgPred. The first two prediction servers are based on traditional approaches, whereas Evaller 2 and AlgPred use sophisticated machine learning techniques.

Allergen databases

In this chapter, five popular allergen databases have been described: (1) Allergome is based on basic and clinical information on allergens causing an IgE-mediated disease; (2) AllergenOnline allows online search of peer-reviewed allergen list; (3) International Union of Immunological Societies Allergen nomenclature subcommittee database contains systematic nomenclature and molecular details of well-characterized allergens; (4) AllFam allows classifying allergens into protein families based on domain information; and (5) SDAP provides in detail structural information of the allergens.

Clinical features, epidemiology, and short-term outcomes of proliferative lupus nephritis in Eastern India

Race and ethnicity are important predictors of prognosis in lupus nephritis. This study was conducted to determine the clinical features, epidemiological profile, and short-term outcomes in patients of lupus nephritis from a single center in Eastern India. A total of 86 patients of class III/IV lupus nephritis were studied. Seventy-eight of them received cyclophosphamide for induction and eight of them received mycophenolate. The patients were evaluated for response, estimated glomerular filtration rate (eGFR), and proteinuria at 6 months. About 44% patients had a partial or complete response at 6 months and 64% at 1 year. The factors correlating with response at 6 months were older age at diagnosis, hypertension, activity, and chronicity indices and duration of symptoms prior to therapy. Chronicity index and hypertension were the predictors of response by logistic regression at 6 months. Compared to the Caucasian and African American patients, patients with proliferative lupus in Eastern India presented with a lower eGFR, lower proteinuria, and higher chronicity scores. Older age at diagnosis, hypertension, activity, chronicity indices, and duration of symptoms correlated with response. Short-term outcomes were similar to those described in Caucasian patients.

Identification of aero-allergens from Rhizopus oryzae: an immunoproteomic approach

Airborne fungal spores bearing allergens are the causative agent for inducing immediate hypersensitive reaction in sensitive individuals. In this study the potential aeroallergens have been reported for the first time from Rhizopus oryzae a common airborne mold. Clinical data based on SPT was further confirmed by ELISA. IgE reactive bands were revealed by one-dimensional immunoblotting. A 44 kDa major reactive band was found in all immunoblots. For precise identification of allergens, an immuno-proteomic approach was taken with a combination of 2-Dimensional gel electrophoresis and Mass-spectrometry. 2D map of spore-mycelial protein was confronted with pooled sera and several IgE reactive spots were detected, most of which were glycoproteins and except for one, which has no antigenic determinacy after metaperiodate modification. Each of those spots was identified by MALDI-TOF-TOF. Some bioinformatic approaches were taken to predict the signal peptide and subcellular localization of each protein. Major 44 kDa allergen was identified as Aspartyl endopeptidase. Sequence information was extracted from MS/MS spectra of two tryptic peptides generated from the 44 kDa endopeptidase. Multiple alignments with other reported aspartyl protease allergens showed significant homology. Allergenicity assessment of this protein was performed in silico and identified as a potential putative allergen.