Killer cell Immunoglobulin-like Receptor (KIR) genes are a family of genes located together within the leukocyte receptor cluster on human chromosome 19q13.4. To date, 17 KIR genes have been ...identified including nine inhibitory genes (2DL1/L2/L3/L4/L5A/L5B, 3DL1/L2/L3), six activating genes (2DS1/S2/S3/S4/S5, 3DS1) and two pseudogenes (2DP1, 3DP1) classified into group A (KIR A) and group B (KIR B) haplotypes. The number and the nature of KIR genes vary between the individuals. In addition, these KIR genes are known to be polymorphic at allelic level (907 alleles described in July 2017). KIR genes encode for receptors which are predominantly expressed by Natural Killer (NK) cells. KIR receptors recognize HLA class I molecules and are able to kill residual recipient leukemia cells, and thus reduce the likelihood of relapse. KIR alleles of Hematopoietic Stem Cell (HSC) donor would require to be known (Alicata et al. Eur J Immunol 2016) because the KIR allele polymorphism may affect both the KIR+ NK cell phenotype and function (Gagne et al. Eur J Immunol 2013; Bari R, et al. Sci Rep 2016) as well as HSCT outcome (Boudreau et al. JCO 2017). The introduction of the Next Generation Sequencing (NGS) has overcome current conventional DNA sequencing method limitations, known to be time consuming. Recently, a novel NGS KIR allele typing approach of all KIR genes was developed by our team in Nantes from 30 reference DNAs (Maniangou et al. Front in Immunol 2017). This NGS KIR allele typing approach is simple, fast, reliable, specific and showed a concordance rate of 95% for centromeric and telomeric KIR genes in comparison with high-resolution KIR typing obtained to those published data using exome capture (Norman PJ et al. Am J Hum Genet 2016). This NGS KIR allele typing approach may also be used in reproduction and to better study KIR+ NK cell implication in the control of viral infections.
Les gènes Killer cell Immunoglobulin-like Receptor (KIR) sont une famille de 15 gènes, localisés chez l’homme sur le bras long du chromosome 19. Ces gènes KIR peuvent être inhibiteurs (2DL1/L2/L3/L4/L5A/L5B, 3DL1/L2/L3) ou activateurs (2DS1/S2/S3/S4/S5, 3DS1) et sont organisés en deux groupes d’haplotypes : haplotype A ou B. Le nombre et la nature des gènes KIR présents varient selon les individus. De plus, ces gènes KIR sont connus pour être polymorphes au niveau allélique (907 allèles décrits en juillet 2017). Les gènes KIR codent pour des récepteurs KIR inhibiteurs ou activateurs, exprimés principalement sur les cellules tueuses naturelles (NK). Les récepteurs KIR ont pour ligands les molécules HLA de classe I et sont capables de lyser les cellules leucémiques résiduelles des patients après greffe de cellules souches hématopoïétiques (CSH). Le contenu en allèles KIR de chaque donneur de CSH nécessiterait d’être connu (Alicata et al. Eur J Immunol 2016) car ce polymorphisme allélique KIR peut affecter le phénotype et la fonction des cellules NK KIR+ (Gagne et al. Eur J Immunol 2013; Bari R, et al. Sci Rep 2016) ainsi que le devenir des greffes de CSH (Boudreau et al. JCO 2017). L’arrivée de nouvelles technologies de séquençage à haut débit (NGS) a permis d’aller au-delà des limites des techniques de séquençages conventionnelles, connues pour prendre plus de temps car spécifique d’un seul locus KIR. Récemment, une nouvelle approche NGS de typage allélique de tous les gènes KIR en entier a été développée par notre équipe nantaise à partir de 30 ADNs de référence (Maniangou et al. Front in Immunol 2017). Cette approche NGS.KIR est simple, rapide, fiable, spécifique et a montré une concordance des résultats alléliques KIR proche de 95 % avec ceux effectués sur les mêmes ADN dans une étude de l’exome aux États-Unis (Norman PJ et al. Am J Hum Genet 2016). Cette approche NGS de typage des allèles KIR peut aussi être utilisée en reproduction et pour étudier plus finement l’implication des cellules NK KIR+ dans le contrôle des infections virales.
Adeno Associated virus serotype 8 (AAV8) is of particular interest as a vector for pre-clinical and clinical trial for Duchenne Muscular Dystrophy (DMD). In several cell lines, this vector has been ...shown to enter cells through clathrin-mediated endocytosis followed by a trafficking through the microtubule network in various endosomal compartments toward the nucleus. To efficiently transduce cells, AAV must undergo multiple levels of regulation in these cellular compartments. In DMD, dystrophin deficiency results in disturbed balance of cellular events i.e., fiber centronucleation, disorganized cytoskeleton, presence of fibrosis. We have recently described a loss of virion genomes from both dogs and mice models of DMD treated with therapeutic molecules vectorized in AAV. Indeed, the pathophysiological state of DMD muscle should impact on virions fate and subsequently affect crucial steps for AAV effectiveness as viral uncoating, viral genome maintenance and consequently, the transduction efficiency of AAV. Our project aims to characterize cellular uptake and intracellular transport of AAV8 in DMD muscular cells, with the goal of optimizing AAV vector use to get the best transduction efficiency with the lowest AAV dose. Our first data showed that AAV8-GFP was less efficient to transduce DMD and control primary muscular cells compared to HeLa cells. Moreover, AAV8 traffics through same endosomal compartment in DMD and control myoblasts, but at different rates during early time points of the transduction. These results suggest that in muscle cells, AAV8 uses different entry and trafficking pathways from those previously described in HeLa cells and that dystrophic cellular status could affect subcellular processing of the vector particles. We will specify the relationship between AAV8 vector entry, trafficking, uncoating, and transduction efficiency in vitro in primary myoblasts/myotubes of DMD patients and controls.
Adeno Associated virus serotype 8 (AAV8) is of particular interest as a vector for pre-clinical and clinical trial for Duchenne Muscular Dystrophy (DMD). In several cell lines, this vector has been ...shown to enter cells through clathrin-mediated endocytosis followed by a trafficking through the microtubule network in various endosomal compartments toward the nucleus. To efficiently transduce cells, AAV must undergo multiple levels of regulation in these cellular compartments. In DMD, dystrophin deficiency results in disturbed balance of cellular events i.e., fiber centronucleation, disorganized cytoskeleton, presence of fibrosis. We have recently described a loss of virion genomes from both dogs and mice models of DMD treated with therapeutic molecules vectorized in AAV. Indeed, the pathophysiological state of DMD muscle should impact on virions fate and subsequently affect crucial steps for AAV effectiveness as viral uncoating, viral genome maintenance and consequently, the transduction efficiency of AAV. Our project aims to characterize cellular uptake and intracellular transport of AAV8 in DMD muscular cells, with the goal of optimizing AAV vector use to get the best transduction efficiency with the lowest AAV dose. Our first data showed that AAV8-GFP was less efficient to transduce DMD and control primary muscular cells compared to HeLa cells. Moreover, AAV8 traffics through same endosomal compartment in DMD and control myoblasts, but at different rates during early time points of the transduction. These results suggest that in muscle cells, AAV8 uses different entry and trafficking pathways from those previously described in HeLa cells and that dystrophic cellular status could affect subcellular processing of the vector particles. We will specify the relationship between AAV8 vector entry, trafficking, uncoating, and transduction efficiency in vitro in primary myoblasts/myotubes of DMD patients and controls.
