HLA TYPING AS A QUALITY CONTROL FOR PURITY IN CELLULAR THERAPY PRODUCTS

WILDFEUER GUSTAVO; GAMBA CECILIA; ROCA VALERIA

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias 2019; 2019

Sociedad Argentina de Investigación Clínica

Abstract/Resumen: Research on advanced therapies holdsgreat therapeutic potential. Among them, cell therapy, based ontransplantation of live cells, frequently relies on in vitro cultureswith or without genetic modifications. Cross-contamination withunrelated cells and/or with microorganisms are among the mostfrequent risks related to cell culture. According to local andinternational standards, cellular therapy productscharacterization, even those intended for pre-clinical research,should include testing for identity, purity, potency, and viability.Short tandem repeats (STR) analysis is recommended for geneticcell line authentication for research but there is no clearconsensus on the analysis for products intended for cell therapy.Our goal is to evaluate whether human leukocyte antigen (HLA)typing, by sequence-specific oligonucleotide (SSO) technology,could be use as a quality control to guarantee cell purity,particularly lack of cross-contamination with unrelated cells thatwill not be revealed by phenotypic characterization ormorphological differences. We chose HLA typing because it is ahighly polymorphic set of genes and this technology is commonlyused in many typing laboratories including ours. Genomic DNAfrom 4 mesenquimal cell lines (MSC) was obtained and used toperformed SSO-PCR for HLA-A; HLA-B and HLA-DRB1 andLuminex analysis according to standard protocols. To test theability to detect cross-contamination, we performed gDNA mixesbetween samples (1:1 - 1:100). For the analysis, we comparedthe number of positive and negative beads in each sample and inthe mixes. We set a minimum of 3 different beads as criteria todefine contamination. All 4 cell lines showed a unique HLA profilefor HLA-A; HLA-B and HLA-DRB1. Also, we were able to detectcross-contamination in all the mixes assayed up to 1:4 by meansof at least 3 different beads for each gene. Cell contaminationslower than 20 % were not detected. HLA typing by SSO-PCRtechnology is effective to determine lack of cross-contaminationwith unrelated cells and may be a suitable assay for cellulartherapy products.