APRANK: Computational Prioritization of Antigenic Proteins and Peptides From Complete Pathogen Proteomes.

Availability of highly parallelized immunoassays has renewed interest in the discovery of serology biomarkers for infectious diseases. Protein and peptide microarrays now provide a rapid, high-throughput platform for immunological testing and validation of potential antigens and B-cell epitopes. However, there is still a need for tools to prioritize and select relevant probes when designing these arrays. In this work we describe a computational method called APRANK (Antigenic Protein and Peptide Ranker) which integrates multiple molecular features to prioritize potentially antigenic proteins and peptides in a given pathogen proteome. These features include subcellular localization, presence of repetitive motifs, natively disordered regions, secondary structure, transmembrane spans and predicted interaction with the immune system. We trained and tested this method with a number of bacteria and protozoa causing human diseases: Borrelia burgdorferi (Lyme disease), Brucella melitensis (Brucellosis), Coxiella burnetii (Q fever), Escherichia coli (Gastroenteritis), Francisella tularensis (Tularemia), Leishmania braziliensis (Leishmaniasis), Leptospira interrogans (Leptospirosis), Mycobacterium leprae (Leprae), Mycobacterium tuberculosis (Tuberculosis), Plasmodium falciparum (Malaria), Porphyromonas gingivalis (Periodontal disease), Staphylococcus aureus (Bacteremia), Streptococcus pyogenes (Group A Streptococcal infections), Toxoplasma gondii (Toxoplasmosis) and Trypanosoma cruzi (Chagas Disease). We have evaluated this integrative method using non-parametric ROC-curves and made an unbiased validation using Onchocerca volvulus as an independent data set. We found that APRANK is successful in predicting antigenicity for all pathogen species tested, facilitating the production of antigen-enriched protein subsets. We make APRANK available to facilitate the identification of novel diagnostic antigens in infectious diseases.

Indirect immunofluorescence to demonstrate lichen planus specific antigen (LPSA) in lichen planus.

BACKGROUND: Current evidence suggests that lichen planus is an immunological disease. Cytotoxic CD8+ cells in the lesional epidermis recognize a unique antigen called lichen planus specific antigen. This antigen could be demonstrated by indirect immunofluorescence using the patient's serum and autologous lesional skin. AIM: To study indirect immunofluorescence pattern in lichen planus, among Indian patients. METHODS: Twenty-five consecutive patients with the clinical diagnosis of lichen planus were enrolled in the study. Direct immunofluorescence was done in all patients. Indirect immunofluorescence using lesional skin as substrate was done in all 25 patients and five patients with other dermatoses. RESULTS: A specific fluorescence pattern corresponding to the distribution of lichen planus specific antigen was observed in the stratum spinosum and granulosum in 22 (88%) patients. It was absent from other parts of the epidermis, dermis and in patients with other dermatoses. CONCLUSION: Indirect immunofluorescence is a useful adjuvant test in lichen planus, particularly in atypical cases.

La serología en lepra: últimos avances, potencial, limitaciones y perspectivas: revision del estado del arte

Los anticuerpos específicos pueden ser usados como un marcador indirecto para la carga bacterial en la lepra. Las pruebas para descubrir anticuerpos pueden ser usadas para (i) la clasificación de pacientes por objetivos del tratamiento [la ma yoría de los pacientes multibacilares (MB) son seropositivos, la mayoría de pacientes paucibacilares (PB) no lo son], (ii) para la predicción de un riesgo aumentado de recaída y (iii) la identificación de contactos que presentan un riesgo aumentado de desarrollar lepra. Con la llegada de tests serológicos rápidos, seguros y fáciles de realizar como la prueba del flujo lateral, la aglutinación y técnicas tipo tarjeta, el uso de la seroogy en el campo para estos objetivos adopta una perspectiva factible. De momento presentamos una descripción de los conocimiento actuales y novedades en esta área y se comenta el potencial, limitaciones y las posibles' sutilidades de detección de anticuerpos en la investigación de lepra y su control (AU)

Pesquisa de antígenos ABH em eritrócitos e na saliva de pacientes hansenianos / ABH antigens research in erythrocytes and at leprosy patients saliva

Os poucos estudos já publicados sobre a determinaçäo de fenótipo secretor dos antígenos ABH na saliva de hansenianos têm demonstrado näo haver uma correlaçäo significativa entre estas substâncias e a suscetibilidade à doença. No presente estudo avaliamos 74 pacientes, sendo 27 virchovianos, 23 tuberculóides e 24 dimorfos, quanto à presença de antíngenos ABH nos eritrócitos e na saliva, pela reaçäo de aglutinaçäo em tubo e inibiçäo de aglutinaçäo. A frequência dos grupos sanguineos ABO e do fenótipo secretor e näo secretor nestes pacientes e no grupo controle foram: O= 40,5(por cento) 49(por cento); AB= 6,8(por cento) 3,6(por cento) e näo secretor= 31,1(por cento) 17,5(por cento). Analisando-se os resultados apresentados nos hansenianos, observamos que näo houve antígenos ABH pesquisados nos eritrócitos e na saliva

Detection of S-100 antigen and anti ceramide antibody in sera of leprosy patients with and without reaction.

Levels of anticeramide antibodies and S-100 antigen in leprosy patients with and without reaction are compared in this study. The increase in levels of IgM anti ceramide antibody in the tuberculoid group of patients with reaction, when compared to those without reaction, is significant (P < 0.05). Similarly, significant increase (P < 0.01) was observed in the borderline group with reaction. No significant change in anti ceramide antibody level was observed in the lepromatous group of patients with and without reaction. Mean levels of S-100 were slightly lower in all three groups of patients with reaction, but the differences were not statistically significant.

The humoral autoimmune response to vasectomy described by immunoblotting from two-dimensional gels and demonstration of a human spermatozoal antigen immunochemically crossreactive with the D2 adhesion molecule.

The specificity of human serum antispermatozoal antibodies was analysed by immunoblotting after two-dimensional electrophoretic separation (IEF/PAGE) of human spermatozoal proteins. Spermatozoal proteins with Mr 20-200 kDa and pI between 4.5 and 7.8 were analysed for antigenicity. Fifteen sera (four female and 11 male) were analysed for antisperm IgG antibodies. Individual IgG binding patterns were observed. The antisperm antibody response to ligation of the vas deferens was described by immunoblotting analysis of sera taken pre- and post-operatively at regular intervals from three men undergoing vasectomy. The high resolution of spermatozoal antigens allowed a specific description of the humoral response to vasectomy. Both appearance and disappearance of spots were observed in the postoperative period, indicating induction of new antibody producing clones and binding of former free antibodies in circulating immunocomplexes. In one patient five glycosylated proteins induced an IgM response 2 weeks after vasectomy. Four of these autoantigens with Mr of 122 kDa, 119 kDa, 104 kDa and 77 kDa and pI of 5.9, 6.1, 7.7 and 6.0, respectively, have previously been shown to be intrinsic membrane proteins (Naaby-Hansen, (1990) J., Reprod. Immunol. 17). An observed immunochemical crossreactivity between the interneuronal adhesion molecule, D2-protein and an antigen extracted from human sperm and teratomas is discussed.

[Antigen spectrum of allergic rhinitis (author's transl)]. / Antigenspektrum der allergischen Rhinitis (Ubersicht und eigene Untersuchungen)

The results of 10.000 individual tests have shown that it is necessary to revise and supplement the influences and the emergence of new antigens support this demand. Refined testing for grass pollen seems to be of particular importance, whereby cross reactions must be taken into account. The test program we must, furthermore, take into consideration the geographical incidence distribution of trees and herbs. In Austria, a considerable amount of ragweed pollen has recently been ascertained to be a cause of pollinosis and asthma. The grain pollens are of great importance and so is household dust, which contains regionally different antigens. Animal hairs and epithelia must be tested if the case history indicates possible involvement of these factors. Special mention is made of the increasing significance of mold spores and bacteria. The variety of listed antigens, each of which may cause allergic rhinitis, shows the importance of supplementing the Hansen test. The new priorities in the test programme are incorporated in, and juxtaposed to the Hansen scheme (see Table 1) for clarification.

[The diangostic value of skin tests with tissue-extracts, especially in lepra and sarcoidosis (author's transl)]. / Der Stellenwert von Hauttesten mit Gewebeextrakten insbesondere bei Lepra und Sarkoidose

The immunological aspects of lepra (India, Germany) and Sarcoidosis are presented under consideration of cutaneous reaction to lepromin and Kveim-extracts. Patients with lepra, erythema nodosum, sarcoidosis and different dermatoses have been tested with lepromin, Kveim-Antigen and tuberculin. The specifity of the results has been discussed. Patients with tuberculoid lepra did not react on Kveim-test, but patients with sarcoidosis can give positive reaction on lepromin. Patients with erythema nodosum without clinical signs of sarcoidosis are Kveim negativ and a positive lepromin-test is an exception. The positive Kveim-test is bound to a histological examination. The positive lepromin-test in non lepraendemic countries should be interpreted also by histological examination. Granulomatous dermatoses can show positive lepromin-tests, but the histological picture is different from the lepromin reaction in tuberculoid lepra. The positive reactions on tissue extracts are not combined with positive immunfluorescence results. Intracutaneous injection of lepra-bacilli in lepromin extract can be presented days to weeks after intracutaneous application in biopsies.