Search

Recent developments in artificial nucleic acid and drug delivery systems present possibilities for the symbiotic engineering of therapeutic oligonucleotides, such as antisense oligonucleotides (ASOs) and small interfering ribonucleic acids (siRNAs). Employing these technologies, triplex-forming oligonucleotides (TFOs) or peptide nucleic acids (PNAs) can be applied to the development of symbiotic genome-targeting tools as well as a new class of oligonucleotide drugs, which offer conceptual advantages over antisense as the antigene target generally comprises two gene copies per cell rather than multiple copies of mRNA that are being continually transcribed. Further, genome editing by TFOs or PNAs induces permanent changes in the pathological genes, thus facilitating the complete cure of diseases. Nuclease-based gene-editing tools, such as zinc fingers, CRISPR-Cas9, and TALENs, are being explored for therapeutic applications, although their potential off-target, cytotoxic, and/or immunogenic effects may hinder their in vivo applications. Therefore, this review is aimed at describing the ongoing progress in TFO and PNA technologies, which can be symbiotic genome-targeting tools that will cause a near-future paradigm shift in drug development. [ABSTRACT FROM AUTHOR]

Recent developments in artificial nucleic acid and drug delivery systems present possibilities for the symbiotic engineering of therapeutic oligonucleotides, such as antisense oligonucleotides (ASOs) and small interfering ribonucleic acids (siRNAs). Employing these technologies, triplex-forming oligonucleotides (TFOs) or peptide nucleic acids (PNAs) can be applied to the development of symbiotic genome-targeting tools as well as a new class of oligonucleotide drugs, which offer conceptual advantages over antisense as the antigene target generally comprises two gene copies per cell rather than multiple copies of mRNA that are being continually transcribed. Further, genome editing by TFOs or PNAs induces permanent changes in the pathological genes, thus facilitating the complete cure of diseases. Nuclease-based gene-editing tools, such as zinc fingers, CRISPR-Cas9, and TALENs, are being explored for therapeutic applications, although their potential off-target, cytotoxic, and/or immunogenic effects may hinder their in vivo applications. Therefore, this review is aimed at describing the ongoing progress in TFO and PNA technologies, which can be symbiotic genome-targeting tools that will cause a near-future paradigm shift in drug development.

The recent development of mRNA vaccines against the SARS-CoV-2 infection has turned the spotlight on the potential of nucleic acids as innovative prophylactic agents and as diagnostic and therapeutic tools. Until now, their use has been severely limited by their reduced half-life in the biological environment and the difficulties related to their transport to target cells. These limiting aspects can now be overcome by resorting to chemical modifications in the drug and using appropriate nanocarriers, respectively. Oligonucleotides can interact with complementary sequences of nucleic acid targets, forming stable complexes and determining their loss of function. An alternative strategy uses nucleic acid aptamers that, like the antibodies, bind to specific proteins to modulate their activity. In this review, the authors will examine the recent literature on nucleic acids-based strategies in the COVID-19 era, focusing the attention on their applications for the prophylaxis of COVID-19, but also on antisense- and aptamer-based strategies directed to the diagnosis and therapy of the coronavirus pandemic. [ABSTRACT FROM AUTHOR]

The humoral and cellular immune response to an infection is highly complex. With the help of self-made and appealing models, the essential characteristics of the immune defense are imparted in a clear and comprehensible way to learners from the 7th grade onwards and to scientifically interested laymen. The three most important cells of the immune defense system - B cells, killer cells and T helper cells - are used as comic-like models made of styrofoam balls and papier-mâché. A modified vacuum cleaner serves as model for scavenger cells (macrophages), hands function as antigens and mittens of different sizes represent antibodies. With the help of a flexible wooden hand, mutations of viral surface proteins are made clear. How an antibody and an antigen test work in principle is demonstrated by hands of shop window mannequins fastened on to a wooden board, mittens and luminous clothes pegs. [ABSTRACT FROM AUTHOR]

Peptide nucleic acids (PNAs) are getting prodigious interest currently in the biomedical and diagnostic field as an extremely powerful tool because of their potentiality to hybridize with natural nucleic acids. Although PNA has strong affinity and sequence specificity to DNA/RNA, there is a considerable ongoing effort to further enhance their special chemical and biological properties for potential application in numerous fields, notably in the field of therapeutics. The toolbox for backbone modified PNAs synthesis has been extended substantially in recent decades, providing a more efficient synthesis of peptides with numerous scaffolds and modifications. This paper reviews the various strategies that have been developed so far for the modification of the PNA backbone, challenging the search for new PNA systems with improved chemical and physical properties lacking in the original aegPNA backbone. The various practical issues and limitations of different PNA systems are also summarized. The focus of this review is on the evolution of PNA by its backbone modification to improve the cellular uptake, sequence specificity, and compatibility of PNA to bind to DNA/RNA. Finally, an insight was also gained into major applications of backbone modified PNAs for the development of biosensors. [ABSTRACT FROM AUTHOR]

Peptide nucleic acid (PNA) is an amide based structural nucleic acid mimic with potential applications in gene therapeutic drug discovery. In the present study, we evaluated and compared the effects on gene expression, cell viability and apoptosis of two antisense PNA- d -octaarginine conjugates, targeting sequences at the AUG translation start site or the 5′-UTR of the TdT (terminal deoxynucleotidyl transferase) gene, as well as a sense oligomer corresponding to the 5′-UTR-antisense, in Molt-4 cells. The protein level of TdT was determined by flow cytometry, and qPCR was used for mRNA expression analysis. Mismatch PNAs were used as control to address the sequence/target spcifity of the biological effects. The results showed that treatment with the AUG- and to slightly lesser extent with the 5′-UTR-antisense PNAs reduced the TdT mRNA as wel as the protein level, whereas only very low effect was observed for the 5′-UTR-sense PNA. A parallel effect was observed on reduced cell survival and increased rate of apoptosis. Our findings suggest that antisense PNAs can inhibit expression of the TdT gene and induce apoptosis in Molt-4 cells. [ABSTRACT FROM AUTHOR]

Peptide nucleic acids (PNA) are synthetic analog of DNA with a repeating N-(2-aminoethyl)-glycine peptide backbone connected to purine and pyrimidine nucleobases via a linker. Considering the unique properties of PNA, including resistance to enzymatic digestion, higher biostability combined with great hybridization affinity toward DNA and RNA, it has attracted great attention toward PNA- based technology as a promising approach for gene alteration. However, an important challenge in utilizing PNA is poor intracellular uptake. Therefore, some strategies have been developed to enhance the delivery of PNA in order to reach cognate site. Although PNAs primarily demonstrated to act as an antisense and antigene agents for inhibition of transcription and translation of target genes, more therapeutic applications such as splicing modulation and gene editing are also used to produce specific genome modifications. Hence, several approaches based on PNAs technology have been designed for these purposes. This review briefly presents the properties and characteristics of PNA as well as different gene modulation mechanisms. Thereafter, current status of successful therapeutic applications of PNA as gene therapeutic intervention in different research areas with special interest in medical application in particular, anti-cancer therapy are discussed. Then it focuses on possible use of PNA as anti-mir agent and PNA-based strategies against clinically important bacteria.

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Les filarioses constituent des entités infectieuses d'origine parasitaire, rares en France métropolitaine. Elles sont majoritairement importées d'Afrique, mais existent aussi en Asie et en Amérique centrale et du Sud. De ce fait, leur diagnostic doit s'envisager avant tout chez les sujets migrants originaires des pays tropicaux ou chez les expatriés ayant séjourné en zone d'endémie devant des signes cliniques évocateurs qui s'accompagnent bien souvent d'une hyperéosinophilie sanguine. En fonction de l'espèce filarienne qui est initialement suspectée, la recherche directe, l'identification et le dénombrement des larves (microfilaires) se réalisent dans le sang (par état frais, frottis sanguin et goutte épaisse, ou leucoconcentration) ou dans le suc dermique (par biopsie cutanée exsangue ou scarification). Différentes précautions relatives au prélèvement doivent être préalablement associées à l'analyse technique pour en optimiser le rendement diagnostique. Encore aujourd'hui, il semble évident que l'expertise microscopique joue un rôle clé dans la détermination d'espèce. Les méthodes indirectes, comme la sérologie, peuvent constituer de bonnes alternatives aux insuffisances des techniques directes, mais se heurtent à des limites de spécificité. Il ne s'agit donc que d'un élément diagnostique d'appoint. Au final, les directives de la prise en charge thérapeutique sont étroitement liées à la précision du diagnostic de laboratoire. Filariasis is a parasite infection that is rare in Europe. It is mostly imported from Africa, but also from Asia or Central and South America. Therefore in light of suggestive clinical signs and blood eosinophilia, its diagnosis should be primarily considered in migrant subjects or expatriates who have stayed in an endemic area. Depending on the species of filaria that is initially suspected, the direct search of microfilariae larvae has to be carried out in blood (by fresh mounting, thick and thin smear, or buffy coat concentration) or in derma (by snip test or scarification). Different sampling precautions must be associated to optimize the diagnostic performance. Even nowadays in the 21st century, microscopic expertise still plays a key-role in determining species and in counting the number of larva (microfilaria). Indirect methods, such as serology, may be good alternatives to the shortcomings of direct laboratory techniques, but they suffer from lack of specificity. Eventually, one should remember that the guidelines for therapeutic management are closely linked to the accuracy of the laboratory diagnosis. [ABSTRACT FROM AUTHOR]

Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Etlik Veteriner Mikrobiyoloji Dergisi is the property of Veteriner Kontrol Merkez Arastirma Enstitusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peptide nucleic acids (PNA) are synthetic analog of DNA with a repeating N-(2-aminoethyl)-glycine peptide backbone connected to purine and pyrimidine nucleobases via a linker. Considering the unique properties of PNA, including resistance to enzymatic digestion, higher biostability combined with great hybridization affinity toward DNA and RNA, it has attracted great attention toward PNA- based technology as a promising approach for gene alteration. However, an important challenge in utilizing PNA is poor intracellular uptake. Therefore, some strategies have been developed to enhance the delivery of PNA in order to reach cognate site. Although PNAs primarily demonstrated to act as an antisense and antigene agents for inhibition of transcription and translation of target genes, more therapeutic applications such as splicing modulation and gene editing are also used to produce specific genome modifications. Hence, several approaches based on PNAs technology have been designed for these purposes. This review briefly presents the properties and characteristics of PNA as well as different gene modulation mechanisms. Thereafter, current status of successful therapeutic applications of PNA as gene therapeutic intervention in different research areas with special interest in medical application in particular, anti-cancer therapy are discussed. Then it focuses on possible use of PNA as anti-mir agent and PNA-based strategies against clinically important bacteria. [ABSTRACT FROM AUTHOR]

Abstract: Protein biomarkers in blood have been widely used in the early diagnosis of disease. However, simultaneous detection of many biomarkers in a single sample remains challenging. Herein, we show that the combination of a sandwich assay and DNA‐assisted nanopore sensing could unambiguously identify and quantify several antigens in a mixture. We use five barcode DNAs to label different gold nanoparticles that can selectively bind specific antigens. After the completion of the sandwich assay, barcode DNAs are released and subject to nanopore translocation tests. The distinct current signatures generated by each barcode DNA allow simultaneous quantification of biomarkers at picomolar level in clinical samples. This approach would be very useful for accurate and multiplexed quantification of cancer‐associated biomarkers within a very small sample volume, which is critical for non‐invasive early diagnosis of cancer. [ABSTRACT FROM AUTHOR]

Abstract: Sialyl‐Tn (STn) is a tumor‐associated carbohydrate antigen (TACA) rarely observed on healthy tissues. We synthesized two fully synthetic N‐acetyl and N‐propionyl STn trimer (triSTn) vaccines possessing a T‐helper epitope and a TLR2 agonist, since the clustered STn antigens are highly expressed on many cancer cells. Immunization of both vaccines in mice induced the anti‐triSTn IgG antibodies, which recognized triSTn‐expressing cell lines PANC‐1 and HepG2. The N‐propionyl triSTn vaccine induced the triSTn‐specific IgGs, while IgGs induced by the N‐acetyl triSTn vaccine were less specific. These results illustrated that N‐propionyl triSTn is a valuable unnatural TACA for anticancer vaccines. [ABSTRACT FROM AUTHOR]

Peptide Nucleic Acids (PNAs) are the DNA/RNA analogues in which sugar-phosphate backbone is replaced by N -2-aminoethylglycine repeating units. PNA contains neutral backbone hence due to the absence of electrostatic repulsion, its hybridization shows remarkable stability towards complementary oligonucleotides. PNAs are highly resistant to cleavage by chemicals and enzymes due to the substrate specific nature of enzymes and therefore not degraded inside the cells. PNAs are emerging as new tools in the market due to their applications in antisense and antigene therapies by inhibiting translation and transcription respectively. Hence, several methods based on PNAs have been developed for designing various anticancer and antigene drugs, detection of mutations or modulation of PCR reactions. The duplex homopurine sequence of DNA may also be recognized by PNA, forming firm PNA/DNA/PNA triplex through strand invasion with a looped-out DNA strand. PNAs have also been found to replace DNA probes in varied investigative purposes. There are several disadvantages regarding cellular uptake of PNA, so modifications in PNA backbone or covalent coupling with cell penetrating peptides is necessary to improve its delivery inside the cells. In this review, hybridization properties along with potential applications of PNA in the field of diagnostics and pharmaceuticals are elaborated. [ABSTRACT FROM AUTHOR]

Here we report the synthesis of new PNA monomers for pseudocomplementary PNA (pcPNA) that are fully compatible with standard Fmoc chemistry. The thiocarbonyl group of the 2-thiouracil (sU) monomer was protected with the 4-methoxy-2-methybenzyl group (MMPM), while the exocyclic amino groups of diaminopurine (D) were protected with Boc groups. The newly synthesized monomers were incorporated into a 10-mer PNA oligomer using standard Fmoc chemistry for solid-phase synthesis. Oligomerization proceeded smoothly and the HPLC and MALDI-TOF MS analyses indicated that there was no remaining MMPM on the sU nucleobase. The new PNA monomers reported here would facilitate a wide range of applications, such as antigene PNAs and DNA nanotechnologies. [ABSTRACT FROM AUTHOR]

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin de la Société de Pathologie Exotique is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] We report the synthesis of a peptide nucleic acid (PNA) monomer containing N 4-bis(aminomethyl)benzoylated cytosine (BzC2+ base). The BzC2+ monomer was incorporated into PNA oligomers using Fmoc-based solid-phase synthesis. The BzC2+ base in PNA had two positive charges and exhibited greater affinity for DNA G base than the natural C base. The BzC2+ base stabilized PNA-DNA heteroduplexes through electrostatic attractions, even in high salt conditions. The two positive charges on the BzC2+ residue did not compromise the sequence specificity of PNA oligomers. These insights will aid the future design of cationic nucleobases. [ABSTRACT FROM AUTHOR]

Résumé Il a été démontré que la fixation de l'antigène aux IgE liées au récepteur de haute affinité, FcɛRI sur les mastocytes et les basophiles induit une réaction inflammatoire. Le second récepteur engagé par les IgE est le récepteur de faible affinité, CD23/FcɛRII. CD23 est principalement exprimé à la surface des lymphocytes B et régulerait négativement la réponse à l'IgE. Les mécanismes qui régulent le ciblage des deux récepteurs et leur rôle respectif dans les processus allergiques inflammatoires et de l'homéostasie ne sont cependant pas encore bien compris. Ici, nous avons étudié plusieurs mécanismes relatifs aux IgE à leurs récepteurs ainsi qu'à l'impact de la liaison de l'antigène aux IgE spécifiques dans les différents types de cellules exprimant ces récepteurs. Nous avons pu montrer que les IgE libres se lient préférentiellement au FcɛRI, alors que les complexes immuns à IgE (CI-IgE) sont capturés préférentiellement par le CD23. La liaison des CI-IgE au CD23 sur les lymphocytes B permet, d'une part, de réguler les IgE sériques et d'empêcher l'activation des cellules effectrices et, d'autre part, de faciliter la présentation de l'antigène en délivrant cet antigène aux cellules dendritiques. Abstract IgE cross-linking is known to trigger inflammatory reactions to antigens after binding FcɛRI, a high-affinity IgE receptor present on mast cells or basophils. The second receptor engaged by IgE is the low-affinity IgE receptor, CD23/FcɛRII, most prominently expressed in B cells, which is thought to negatively regulate IgE levels. However, the mechanisms that regulate the targeting of the two receptors and the respective function of the two pathways in inflammation or homeostasis are not yet understood. We investigated several mechanisms related to the binding of IgE and antigen to both receptors, as well as the influence of such binding on different immune cells expressing the receptors. We showed that free IgE preferentially binds to FcɛRI whereas IgE immune complexes (IgE-ICs) are preferentially captured by CD23. Binding of IgE-ICs to CD23 on B cells can regulate serum IgE and prevent effector cell activation on one hand while on the other hand it can facilitate antigen presentation by delivering antigen to dendritic cells. [ABSTRACT FROM AUTHOR]

A peptide nucleic acid (PNA) is a synthetic nucleic acid mimic in which the sugar-phosphate backbone is replaced by a peptide backbone. PNAs hybridize to complementary DNA and RNA with higher affinity and superior sequence selectivity compared to DNA. PNAs are resistant to nucleases and proteases and have a low affinity for proteins. These properties make PNAs an attractive agent for biological and medical applications. To improve the antisense and antigene properties of PNAs, many backbone modifications of PNAs have been explored under the concept of preorganization. This review focuses on chiral PNAs bearing a substituent in the N-(2-aminoethyl)glycine backbone. Syntheses, properties, and applications of chiral PNAs are described.

The sequence-specific formation of triplex DNA offers a potential basis for genome-targeting technologies. In an antiparallel triplex DNA, the sequence-specificity is established by the formation of specific base triplets (G−GC, A−AT, and T−AT) between a triplex-forming oligonucleotide (TFO) and a duplex DNA. However, there are no natural nucleosides that can selectively recognize the inverted CG and TA base pairs. Therefore, the recognition of the CG and TA inversion sites to form a stable triplex DNA has been a long-standing goal for the triplex-forming technology. We now describe the design and synthesis of pseudo-deoxycytidine (ΨdC) derivatives for selective recognition of the CG base pair to expand the triplex-forming sequence. The aminopyridine-bearing ΨdC derivatives showed high selectivity and affinity toward the CG base pair in all neighboring base contexts. Remarkably, 3-methyl-2-aminopyridinyl−ΨdC (MeAP−ΨdC) formed a stable triplex with the promoter sequence of the hTERT gene containing four CG inversion sites, and effectively inhibited its transcription in human cancer cells. Thus, MeAP−ΨdC is expected to serve as a new starting point of triplex-forming oligonucleotides for a wide variety of genome-targeting applications. [ABSTRACT FROM AUTHOR]

The roles of the immune system are recognized in the interaction between the host and the external environment, functionality and features dependent on a multitude of genetic and environmental factors. Specific and nonspecific immunity undergo a maturation throughout early childhood - crucial step in the further development of the organism. Cellular and molecular mechanisms are deciphering in the era of molecular medicine and their understanding is essential for effective therapeutic approach in pediatric pathology. [ABSTRACT FROM AUTHOR]

Résumé La vaccination consiste à introduire, chez un individu sain, un produit biologique fabriqué à partir de virus ou bactéries. Le vaccin obtenu n'a pas la capacité d'entraîner la maladie mais conserve celle d'induire une réponse immunitaire. La vaccination s'appuie donc sur la propriété de mémoire du système immunitaire adaptatif et permet de développer une immunité à long terme contre les antigènes d'agents pathogènes spécifiques. Summary Vaccination consists in introducing, into a healthy individual, a biological product made from a virus or bacteria. The vaccine obtained is not able to cause disease but induces an immune response. Vaccination is therefore based on the adaptive immune system's immunological memory and enables long-term immunity to be developed against the antigens of specific pathogenic agents. [ABSTRACT FROM AUTHOR]

All Enterobacteriaceae express a polysaccharide known as enterobacterial common antigen (ECA), which is an attractive target for the development of universally acting immunotherapies. The first chemical synthesis of ECA-derived oligosaccharides for the development of such therapies is described. A number of synthetic challenges had to be addressed, including the development of concise synthetic procedures for unusual monosaccharides, the selection of appropriate orthogonal protecting groups, the development of stereoselective glycosylation methods, appropriate timing for the introduction of the carboxylic acid groups on the Man pNAcA moieties, and the selection of appropriate conditions for the reduction of multiple azido moieties. The synthetic compounds were employed to uncover immunodominant moieties of ECA. Furthermore, a monoclonal antibody (mAb) was developed that binds to ECA and can selectively recognize a wide range of Enterobacteriaceae species. [ABSTRACT FROM AUTHOR]

The existence of an antitumor immunity, which involves multiple effectors belonging both to adaptative and innate immunity, has been clearly established. The inhibition of this immunosurveillance is a prerequisite to a tumor development and will follow a Darwinian selection of minimal immunogenic tumor clones which will succeed in escaping our immune system. The restoration of this antitumor immunity is a key therapeutic challenge as it will not only provide antitumor activity but also hope for a specific targeting of tumors and moreover allow a sustained efficacy by assuring an immune memory. [ABSTRACT FROM AUTHOR]

Nach allgemeiner Annahme wird die Immunogenität von Kohlenhydraten stark von deren Modifikationen beeinflusst. Kapselpolysaccharide (KPS) von pathogenen Bakterien enthalten häufig ein Pyruvat, das als Acetal die 4,6 ‐ , 3,4 ‐ oder 2,3 ‐ Positionen überbrücken kann. Das KPS von Serotyp 4 Streptococcus pneumoniae (ST4) ist mit einem trans ‐ 2,3 ‐ verknüpften Pyruvat modifiziert. Um die immunologische Bedeutung dieser Modifikation zu untersuchen, wurde die Wiederholungseinheit dieses Polysaccharids erstmals chemisch synthetisiert. Bei der Analyse von Antikörpern gegen ST4 ‐ KPS mithilfe eines Kohlenhydratmikroarrays, der verschiedene Substrukturen des KPS enthält, konnte eine exklusive Bindung an die Wiederholungseinheit mit Pyruvat festgestellt werden. Das Pyruvatacetal ist somit ein Schlüsselmotiv für die Entwicklung minimaler synthetischer Kohlenhydratimpfstoffe gegen ST4. Ungewöhnlich protektiv: Bei der Suche nach dem protektiven Glykanepitop von Serotyp 4 Streptococcus pneumoniae war die Totalsynthese der Wiederholungseinheit (siehe Struktur) der Schlüsselschritt zur Identifikation des Pyruvats als immunologische Determinante auf dem Weg zu einem neuen Impfstoffkandidat für dieses Bakterium. [ABSTRACT FROM AUTHOR]

Résumé Les tests de diagnostic rapide dont l’intérêt réside dans leur mise en œuvre sans matériel spécifique par du personnel non spécialisé se sont beaucoup développés ces quinze dernières années pour le diagnostic du paludisme avec la détection de protéines plasmodiales spécifiques, PfHRP2 et pLDH principalement. Si la détection de la PfHRP2 présente une très bonne sensibilité pour le diagnostic des accès palustres à Plasmodium falciparum , les recherches de la pLDH ou de l’aldolase sont moins performantes pour les autres espèces, imposant de conserver le diagnostic microscopique de référence. Cette méthodologie est également appliquée maintenant au diagnostic de la filariose lymphatique avec la recherche d’un antigène spécifique. Parallèlement, la détection d’anticorps spécifiques s’est développée pour la maladie de Chagas, et la leishmaniose viscérale et récemment, la bilharziose. Ces tests possèdent des sensibilités et des spécificités variables, dont le biologiste doit avoir connaissance avant de choisir le réactif qu’il mettra en œuvre dans son laboratoire. Summary Rapid diagnostic tests whose interest lies in their implementation without specific equipment by unskilled personnel have grown significantly over the past fifteen years to malaria diagnosis with detection of specific Plasmodium proteins, mainly PfHRP2 and pLDH. If the detection of PfHRP2 makes a very good sensitivity for the diagnosis of Plasmodium falciparum malaria attacks, research pLDH or aldolase are lower for other species, imposing retain microscopic diagnosis reference. This methodology is now being applied to the diagnosis of lymphatic filariasis as well. At the same time, the detection of specific antibody developed for Chagas disease and visceral leishmaniasis and recently schistosomiasis. These tests have sensitivities and specificities variables, the biologist must know before choosing the reagent that will implement in his laboratory. [ABSTRACT FROM AUTHOR]

An evaluation of trypanosomosis prevalence was carried out in Guinea on sera originating from the serum bank of the veterinary laboratory of the National Livestock Services. Nine hundred and twenty-eight sera sampled on N’dama cattle were randomly selected and analyzed for antibody and antigen detection of Trypanosoma spp. Results obtained in the first test revealed Trypanosoma spp. antibodies in 67% of the cattle, with rates of 72% in the High Guinea area, 68% in Lower Guinea, 63% in Forest Guinea, and 62% in Middle Guinea. Among the animals, 69% of the females were infected or had been in contact with the infectious agent, against 62% of the males. The animals were infected regardless of their age. Infection rates were 71, 43, 61, 63, 59, and 74% in cattle under one year of age, 1-2 years old, 2-3 years old, 3-4 years old, 4-5 years old, over 5 years old, respectively. The second test showed the presence of antigens against T. brucei (16% of the sera), T. congolense (11%) and T. vivax ( 2%). The distribution of the results of both tests showed that 2% of the animals were positive for one, two or three antigens without the presence of antibodies, 17% were positive for both antigen(s) and antibodies, and 50% were positive for antibodies only.

Dans le présent article est décrite une technique rapide de diagnostic de la peste équine dès la période d'incubation de la maladie. Il s'agit d'un test ELISA indirect en sandwich qui permet la détection des antigènes viraux liés aux lymphocytes circulants ou aux globules rouges. Sur les prélèvements sanguins récoltés durant la phase virémique des chevaux malades, les lymphocytes circulants ont donné de meilleurs résultats en comparaison avec les globules rouges. La possibilité d'application de cette technique comme technique de diagnostic rapide et d'épidémiosurveillance de la peste équine en zone non infectée comme en zone enzootique est discutée.

Un ELISA de détection des antigènes circulants de Trypanosoma vivax mis au point par Nantulya et Lindqvist en 1989, a été comparé à celle du test de Woo lors d'infections expérimentales de deux moutons avec une souche guyanaise de T. vivax. Quelle que soit la période d'infection, que la parasitémie soit détectable ou non, la sensibilité du test ELISA a été très basse. L'association des deux techniques n'apporte aucune sensibilité supplémentaire. Déjà observé au Burkina Faso et en Gambie, ce défaut de sensibilité risque d'affecter fortement les résultats des enquêtes épidémiologiques entreprises avec ces réactifs en Afrique. Il est nécessaire de développer de nouveaux anticorps monoclonaux afin de mettre au point un test de détection des antigènes de T. vivax dont la sensibilité soit plus satisfaisante.

Multivalente synthetische Vakzine wurden durch Festphasensynthese von tumorassoziierten MUC1 ‐ Glycopeptidantigenen und deren Kupplung an ein Pam3Cys ‐ Lipopeptid durch Klick ‐ Reaktion gewonnen. Diese Vakzine lösen in Mäusen Immunreaktionen aus, ohne dass externe Adjuvantien angewendet werden. Die vier MUC1 ‐ Sialyl ‐ TN ‐ Antigene enthaltende Vakzine zeigte einen signifikanten Cluster ‐ Effekt. Sie induzierte in Mäusen vorwiegend IgG2a ‐ Antikörper, die an MCF ‐ 7 ‐ Brusttumorzellen binden und diese Tumorzellen durch Aktivierung des Complement ‐ abhängigen Cytotoxizitätskomplexes (CDC) abtöten. Eine Serie multivalenter MUC1 ‐ Glycopeptid ‐ Vakzine mit dem STn ‐ Antigen wurde synthetisiert und immunologisch geprüft. Die in Mäusen induzierten Immunantworten hingen von der Valenz der Glycopeptide ab. Die Antiseren banden stark an Tumorzellen, was zu deren Abtöten führte. Dieser neue Effekt der geclusterten multivalenten Vakzine ist dem veränderten Spektrum der induzierten Antikörperisotypen zuzuschreiben. [ABSTRACT FROM AUTHOR]

Background and aims: The prevalence of hydatid cyst in patients with cancer is lower than those of normal population. In this study the effect of different extractions of hydatid cyst antigens on growth of Hella cancer cells has been investigated in vitro. Methods: In this experimental study, crude protoscolices antigen, protoscolices ES antigen and hydatid fluid antigen were prepared and fractions of these antigens were using salting out method. These fractions were added to Hella cell line and incubated for 48h. Then the number of alive and dead cells was counted in comparison to appropriate control. Analysis of data was carried out using SPSS software and Jonckheere-Terpstra test. P<0.05 was considered as significant. Results: In cell cultures treated with mentioned fractions, all 3 fractions significantly decrease the growth of Hella cancer in comparison to control cell culture. Also fractions of crude protoscolices antigen significantly increase the growth of Hella cancer cells. Conclusion: Different extracts of hydatid cyst antigens inhibitory effects on Hella cell's growth in culture medium. Further work is recommended an anti-cancer property of these antigens. [ABSTRACT FROM AUTHOR]

The article deals with those immunological concepts from the first half of the 20th century that influenced the terminology of molecular genetics that was to come. They comprise mainly explanations of the contact between antibodies and antigens and clarifications of the fact that organisms are able to produce a huge variety of specific antibodies. This paper focuses on the term "template," which geneticists adopted from immunology. The term "template" went through an appreciable semantic change, which came between the 1930s and the 1950s. This change documents the earliest development of molecular genetics. [ABSTRACT FROM AUTHOR]