Expression of HIV-1 broadly neutralizing antibodies mediated by recombinant adeno-associated virus 8 in vitro and in vivo

Publication date: December 2016
Source:Molecular Immunology, Volume 80
Author(s): Yongjiao Yu, Lu Fu, Xiaoyu Jiang, Shanshan Guan, Ziyu Kuai, Wei Kong, Yuhua Shi, Yaming Shan
Despite unremitting efforts since the discovery of human immunodeficiency virus type 1 (HIV-1), an effective vaccine has not been generated. Viral vector-mediated transfer for expression of HIV-1 broadly neutralizing antibodies (BnAbs) is an attractive strategy. In this study, a recombinant adeno-associated virus 8 (rAAV8) vector was used to encode full-length antibodies against HIV-1 in 293T cells and Balb/c mice after gene transfer. The 10E8 or NIH45-46 BnAb was expressed from a single open reading frame by linking the heavy and light chains with a furin cleavage and a 2A self-processing peptide (F2A). The results showed that the BnAbs could be expressed in the 293T cell culture medium. A single intramuscular injection of rAAV8 led to long-term expression of BnAbs in Balb/c mice. The expressed antibodies in the supernatant of 293T cells and in Balb/c mice showed neutralization effects against HIV-1 pseudoviruses. Combined immunization of rAAV8 expressing 10E8 and rAAV8 expressing NIH45-46 in Balb/c mice could increase these neutralization effects on strains of HIV-1 sensitive to 10E8 or NIH45-46 antibody compared with a single injection of rAAV8 expressing either antibody alone. Therefore, the combined immunization may be a potential vaccine approach against HIV-1.



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Regulated localization of an AID complex with E2A, PAX5 and IRF4 at the Igh locus

Publication date: December 2016
Source:Molecular Immunology, Volume 80
Author(s): Jannek Hauser, Christine Grundström, Ramesh Kumar, Thomas Grundström
Activation-induced cytidine deaminase (AID) is the key mutagenic enzyme that initiates somatic hypermutation (SH) and class switch recombination (CSR) by deaminating cytosine to uracil. The targeting of AID and therefore SH and CSR to Ig genes is a central process of the immune system, but the trans-acting factors mediating the specific targeting have remained elusive. Here we show that defective calmodulin inhibition of the transcription factor E2A after activation of the B cell receptor (BCR) leads to reduced BCR, IL4 plus CD40 ligand stimulated CSR to IgE and instead CSR to other Ig classes. AID that initiates CSR is shown to be in a complex with the transcription factors E2A, PAX5 and IRF4 on key sequences of the Igh locus. Calmodulin shows proximity with each of them after BCR stimulation. BCR signaling reduces binding of the proteins to some of the target sites on the Igh locus, and calmodulin resistance of E2A blocks these reductions. AID binds directly to the bHLH domain of E2A and to the PD domain of PAX5. E2A, AID, PAX5 and IRF4 are components of a CSR complex that is redistributed on the Igh locus by BCR signaling through calmodulin binding.

Graphical abstract

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Effects of Bothrops atrox venom and two isolated toxins on the human complement system: Modulation of pathways and generation of anaphylatoxins

Publication date: December 2016
Source:Molecular Immunology, Volume 80
Author(s): Danilo L. Menaldo, Carolina P. Bernardes, Anna L. Jacob-Ferreira, Cíntia G. Nogueira-Santos, Tania M. Casare-Ogasawara, Luciana S. Pereira-Crott, Suely V. Sampaio
The complement system plays important biological roles, including the activation of inflammatory processes in response to the generation of proteolytic fragments of its components. Here we evaluated the effects of Bothrops atrox venom and two of its toxins (the P-I metalloprotease Batroxase and the acidic phospholipase A2 BatroxPLA2) on the human complement system, evaluating their effects on the classical (CP), lectin (LP) and alternative (AP) pathways, as well as on different complement components associated to the generation of anaphylatoxins. Primarily, the venom and both toxins modulated the hemolytic activity of the complement CP, with the venom and Batroxase reducing this activity and BatroxPLA2 increasing it. ELISA deposition assays indicated that B. atrox venom and Batroxase were also capable of modulating all three activation pathways (CP, LP and AP), reducing their activity after incubation with normal human serum (NHS), while BatroxPLA2 apparently only interfered with AP. Additionally, the venom and Batroxase, but not BatroxPLA2, promoted significant degradation of the components C3, C4, Factor B and C1-Inhibitor, as shown by Western blot and SDS-PAGE analyses, also generating anaphylatoxins C3a, C4a and C5a. Therefore, B. atrox venom and Batroxase were able to activate the complement system by direct proteolytic action on several components, generating anaphylatoxins and affecting the activation pathways, while BatroxPLA2 only interfered with the hemolysis induced by CP and the C3 deposition related to AP. Our results indicate that Batroxase and possibly other metalloproteases should be the main toxins in B. atrox venom to induce pronounced effects on the complement system.



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O022 The relationship between asthma and food deserts in the hampton roads area

Publication date: November 2016
Source:Annals of Allergy, Asthma & Immunology, Volume 117, Issue 5, Supplement
Author(s): D. Preston, M. Morales, A. Plunk




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Transnasal, Transethmoidal Endoscopic Removal of a Foreign Body in the Medial Extraconal Orbital Space

Intraorbital foreign bodies are located within the orbit but outside the ocular globe. Though not uncommon, removal of these objects poses a challenge for surgeons. External approaches have been the most frequently used but are associated with increased complications and morbidity. An endoscopic endonasal approach can be an appropriate and less complicated technique in these cases. We report a case of a chronic intraorbital foreign body located within the medial extraconal space lateral to the lamina papyracea and behind the lacrimonasal duct, which was successfully removed using a transnasal, transethmoidal endoscopic technique. Neither postoperative complications nor ocular impairment was reported. The patient improved and remains asymptomatic. The transnasal transethmoidal endoscopic approach can be used as a safer and less invasive alternative when removing foreign bodies from the medial orbital compartment.

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Angiofibroma Originating outside the Nasopharynx: A Management Dilemma

Background. Angiofibroma is a benign tumor, consisting of fibrous tissue with varying degrees of vascularity, characterized by proliferation of stellate and spindle cells around the blood vessels. It most commonly arises from the nasopharynx, although it may rarely arise in extranasopharyngeal sites. Case Report. A 46-year-old male presented with left side nasal obstruction and epistaxis for one month. Clinical nasal examination revealed left sided polypoidal mass arising from the vestibular region of the lateral nasal wall. Results. CT scan and MRI showed highly vascular soft tissue mass occupying the anterior part of the left nostril. Preoperative selective embolization followed by transnasal excision was performed. Histopathological examination confirmed the diagnoses of nasal vestibular angiofibroma. Conclusion. Extranasopharyngeal angiofibroma is a very rare pathology. It should be kept in mind as a differential diagnosis with any unilateral nasal vestibular mass causing nasal obstruction and epistaxis. A biopsy without further investigation can cause life threatening bleeding in the patient.

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Axiographic results of CAD/CAM-assisted microvascular, fibular free flap reconstruction of the mandible: A prospective study of 21 consecutive cases

Publication date: Available online 12 November 2016
Source:Journal of Cranio-Maxillofacial Surgery
Author(s): Lucas M. Ritschl, Thomas Mücke, Andreas M. Fichter, Maximilian Roth, Clemens Kaltenhauser, Jean Marc Pho Duc, Marco R. Kesting, Klaus-Dietrich Wolff, Denys J. Loeffelbein
Virtual planning and guided reconstruction of the mandible following ablative surgery have become standard procedures in reconstructive surgery. Many advantages regarding operation time, morphology, bony fit, and consolidation have been described, but analyses of the functional outcome of virtually planned mandibular reconstructions are lacking. We prospectively analyzed 21 consecutive cases of mandibular reconstructions using CAD/CAM-assisted microvascular, fibular free flaps in operations between July 2014 and January 2016 at a single center. Axiographic measurements were performed preoperatively and at 10 days and 3 months postoperatively and were correlated with clinical findings. Uni- and multivariate regression analyses were performed to determine the association between possible predictor variables on functional outcomes. Overall, no statistical differences between the t1 and t3 measurements were seen in the analyzed variables. The univariate analysis showed a significant influence of indication and pre- and postoperative irradiation only on mouth opening (p=0.018, p=0.026, and p=0.049). Timing, the number of osteotomies, and the incidence of wound healing disturbances had no significant influence on postoperative function (p=0.753, p=0.69 and p=0.776). In particular, cases without malignancy or preoperative irradiation benefitted from the integration of the CAD/CAM technique and showed good functional outcomes.



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