Germline hypomorphic CARD11 mutations in severe atopic disease

Chi A Ma, Jeffrey R Stinson, Yuan Zhang, Jordan K Abbott, Michael A Weinreich, Pia J Hauk, Paul R Reynolds, Jonathan J Lyons, Celeste G Nelson, Elisa Ruffo, Batsukh Dorjbal, Salomé Glauzy, Natsuko Yamakawa, Swadhinya Arjunaraja, Kelsey Voss, Jennifer Stoddard, Julie Niemela, Yu Zhang, Sergio D Rosenzweig, Joshua J McElwee, Thomas DiMaggio, Helen F Matthews, Nina Jones, Kelly D Stone, Alejandro Palma, Matías Oleastro, Emma Prieto, Andrea R Bernasconi, Geronimo Dubra, Silvia Danielian, Jonathan Zaiat, Marcelo A Marti, Brian Kim, Megan A Cooper, Neil Romberg, Eric Meffre, Erwin W Gelfand, Andrew L Snow, Joshua D Milner

Few monogenic causes for severe manifestations of common allergic diseases have been identified. Through next-generation sequencing on a cohort of patients with severe atopic dermatitis with and without comorbid infections, we found eight individuals, from four families, with novel heterozygous mutations in CARD11, which encodes a scaffolding protein involved in lymphocyte receptor signaling. Disease improved over time in most patients. Transfection of mutant CARD11 expression constructs into T cell lines demonstrated both loss-of-function and dominant-interfering activity upon antigen receptor-induced activation of nuclear factor-κB and mammalian target of rapamycin complex 1 (mTORC1). Patient T cells had similar defects, as well as low production of the cytokine interferon-γ (IFN-γ). The mTORC1 and IFN-γ production defects were partially rescued by supplementation with glutamine, which requires CARD11 for import into T cells. Our findings indicate that a single hypomorphic mutation in CARD11 can cause potentially correctable cellular defects that lead to atopic dermatitis.