Alterations in Immunophenotype of Autoimmune-prone Hypomorphic RAG-deficient Patients with CID-G/AI Phenotype
Poster May 08, 2018
Thomas Pennix, Matthew Stowell, Boglarka Ujhazi, Taco Kuijpers, Olajumoke Fadugba, John Sleasman, Benedict Neven, Waleed Al-Herz, Manish Butte, Elisabeth G. Hoyte, Joseph D. Hernandez, Janet S. Chou9, Raif S. Geha, Luigi D. Notarangelo, Eric Meffre, Krisztian Csomos, Jolan E. Walter
Rationale: Patients with partial deficiency of recombination-activating genes 1 or 2 (RAG1/2) can present with a wide spectrum of primary immunodeficiencies including combined immunodeficiency with granuloma and/or autoimmunity (CID-G/AI). Prior case reports have highlighted alterations in B and T cell compartments; however comprehensive characterization of these cell populations with focus on autoreactive-prone subsets has not been reported.
Methods: Multiparametric flow cytometry approach was used to characterize B and T cell subsets of RAG CID-G/AI patients' peripheral blood. Major B cell subsets were identified based on CD19, CD21, CD24, CD27, CD38, CD138, IgD and IgM expression, while regulatory (Treg) and follicular helper T (Tfh) cells were determined as CD3+CD4+CD25highCD127low and CD3+CD4+PD-1+CXCR5+ cells, respectively.
Results: Based on the analysis of our cohort of six hypomorphic RAG-deficient patients with CID-G/AI phenotype, we noted significantly lower ratio of transitional and naïve mature B cells, while memory B cells were enriched as compared to healthy controls. Interestingly, marginal zone and CD21−/low anergic B cells were represented in significantly higher frequencies in our cohort compared to healthy controls. Furthermore, RAG-deficient patients had fewer Tregs and increased frequency of circulating Tfh cells.
Conclusions: Alterations among B cell subsets patients may be related to partial developmental block in bone marrow and peripheral clonal expansion of memory, marginal zone B cells or anergic autoreactive-prone CD21−/low B cells. Decreased frequency of Tregs and expansion of Tfh cells, may contribute to immune dysregulation and autoimmunity observed in these patients.
Primary Human Hepatocyte (PHH) culture provides the closest in vitro model to human liver that can produce a metabolic profile of a given drug very similar to that found in vivo. Recently we have developed an easy-to-assemble user-friendly in vitro Primary Human Hepatocyte (PHH) 3D-spheroid modelREAD MORE