Development of a Humanized HLA-A2.1/DP4 Transgenic Mouse Model and the Use of This Model to Map HLA-DP4-Restricted Epitopes of HBV Envelope Protein

A new homozygous humanized transgenic mouse strain, HLA-A2.1+/+HLA-DP4+/+ hCD4+/+mCD4−/−IAβ−/−β2m−/− (HLA-A2/DP4), was obtained by crossing the previously characterized HLA-A2+/+β2m−/− (A2) mouse and our previously created HLA-DP4+/+ hCD4+/+mCD4−/−IAβ−/− (DP4) mouse. We confirmed that the transgenes (HLA-A2, HLA-DP4, hCD4) inherited from the parental A2 and DP4 mice are functional in the HLA-A2/DP4 mice. After immunizing HLA-A2/DP4 mice with a hepatitis B DNA vaccine, hepatitis B virus-specific antibodies, HLA-A2-restricted and HLA-DP4-restricted responses were observed to be similar to those in naturally infected humans. Therefore, the present study demonstrated that HLA-A2/DP4 transgenic mice can faithfully mimic human cellular responses. Furthermore, we reported four new HLA-DP4-restricted epitopes derived from HBsAg that were identified in both vaccinated HLA-A2/DP4 mice and HLA-DP4-positive human individuals. The HLA-A2/DP4 mouse model is a promising preclinical animal model carrying alleles present to more than a quarter of the human population. This model should facilitate the identification of novel HLA-A2- and HLA-DP4-restricted epitopes and vaccine development as well as the characterization of HLA-DP4-restricted responses against infection in humans

Etude structurale du gene de la pyruvate kinase L et expression des sequences repetitives de type identificatrices ID

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Exploitation d un modèle expérimentale préclinique de souris HLA transgénique pour l identification des épitopes T HLA-restreint afin de concevoir des vaccins poly-epitopiques

Une nouvelle lignée homozygote de souris humanisé HLA transgéniques : HLA-A2.1+/+HLA-DP4+/+hCD4+/+mCD4-/-IAb-/-b2m-/- (HLA-A2/DP4), a été obtenue en croisant entre les souris HLA transgéniques HLA-A2.1+/+b2m-/-(A2) et les souris HLA transgéniques HLA-DP4+/+hCD4+/+mCD4-/-IAb-/-(DP4). Chez les souris HLA-A2/DP4, les réponses cellulaire T HLA-A2 restreint ou HLA-DP4 restreint contre l antigène HBs du virus de l Hépatite B suite à une immunisation avec le vaccin anti-AgHBs sont similaires à ceux observés chez les souris A2, chez les souris DP4, chez les humains infectés par le virus ou immunisés avec le même vaccin. Ces résultats montrent que les réponses cellulaires induites les souris HLA-A2/DP4 miment fidèlement les réponses homologues humaines. Ainsi, ces souris représentent un excellent modèle d expérimentations précliniques animal pour évaluer ou comparer l efficacité des réponses humain induites in vivo par des candidates vaccins. Le modèle facilitera également l'identification de nouvelles épitopes HLA-A2 et HLA-DP4 restreints, qui constituera de futurs réactives de suivi clinique des réponses contre l'infection chez les humains.En exploitant ces souris HLA-A2/DP4, nous avons identifié quatre nouveaux HLA-DP4-restricted épitopes issus de l'AgHBs et deux nouveaux HLA-A2 restreint épitopes dérivés de protéines M1.A new homozygous humanized HLA transgenic mouse strain, HLA-A2.1+/+HLA-DP4+/+hCD4+/+mCD4-/-IAb-/-b2m-/- (HLA-A2/DP4), was obtained by crossing the HLA transgenic HLA-A2.1+/+b2m-/-(A2) mice and HLA transgenic HLA-DP4+/+hCD4+/+mCD4-/-IAb-/-(DP4) mice. In HLA-A2/DP4 mice, HLA-A2 restricted or HLA-DP4 restricted T cell responses against HBs antigen of hepatitis B virus after immunization with the HBsAg vaccine are similar to those induced in A2 mice, in DP4 mice, in HBV-infected or HBsAg-vaccinated humans. These results show that cellular responses induced in HLA-A2/DP4 mice faithfully mimic human responses counterparts. Thus, these mice represent an excellent animal model for preclinical experimentations to evaluate or compare the effectiveness of responses "human" induced in vivo by candidate vaccines. The model will also facilitate the identification of new epitopes HLA-A2 and HLA-DP4 restricted, which will be of future reactive for clinical monitoring response against infection in humans. By exploiting these HLA-A2/DP4 mice, we identified four new HLA-DP4-restricted epitopes from HBsAg and two new HLA-A2 restricted epitopes derived from protein M1.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Antimicrobial peptides, novel solution for the treatment of precancerous disease acne -A review

International audienceAcne is one of the most common epithelial diseases affecting approximately 80% of the world's population between the ages of 16 and 35. It is caused by multiple factors such as genetic predisposition and hormonal alteration including growth factor IGF-I, among others. Acne being related to IGF-I expression, is involved in possible apparition of malignant diseases. The pathology of acne is limited to the pilosebaceous unit. The evolution is governed by the increase in colonization of the bacteria Propionibacterium acnes (P. acnes). Acne is clinically manifested by the appearance of comedones with a tendency to inflammation. Finally causes scarring damaging self-esteem and quality of life of those who suffer it. As proposed therapies, external treatments have been developed such as inhibitors of IGF-I among others. As an internal treatment, the innate response of the patient's immune system to the presence of an invading microorganism has been studied, highlighting anti-microbial peptides as the host's own defense molecules. This work shows a compilation of the most relevant and current antimicrobial peptides that could be used as potential therapeutic agents against microorganisms located in the skin and related to acne disease

Optimisation of secretion of recombinant HBsAg virus-like particles: Impact on the development of HIV-1/HBV bivalent vaccines.

International audienceThe hepatitis B surface antigen (HBsAg) assembles into virus-like particles (VLPs) that can be used as carrier of immunogenic peptides for the development of bivalent vaccine candidates. It is shown here that by respecting certain qualitative features of mammalian preS1 and preS2 protein domains upstream of HBsAg, foreign sequences can be inserted in their place while maintaining efficient secretion of VLPs. A polyepitope bearing HIV-1 epitopes restricted to the HLA-A*0201 class I allele was optimised for secretion as an HBsAg fusion protein by counterbalancing the generally hydrophobic class I epitopes with hydrophilic spacers, eliminating epitopes bearing cysteine residues, limiting the number of internal methionine residues to a minimum and adopting Homo sapiens codon usage. The optimised HIV-1 polyepitope-HBsAg recombinant protein with up to 138 residues assembled into efficiently secreted recombinant VLPs. DNA immunisation in HLA-A*0201 and HLA-A*0201/HLA-DR1 transgenic mice resulted in the recovery of humoral response against the carrier and enhanced levels of HIV-1 specific CD8(+) T lymphocyte activation. Efficient self-assembly of recombinant HBsAg VLPs opens up the possibility of making efficient bivalent HBV/HIV vaccine candidates, which is particularly apposite given that the two viruses are frequently associated