Molecular complementation of IL-12Rbeta1 deficiency reveals functional differences between IL-12Rbeta1 alleles including partial IL-12Rbeta1 deficiency.
Patients with mutations in IL12RB1, the gene encoding IL-12Rbeta1, suffer from combined IL-12R/IL-23R deficiency and are unusually susceptible to nontuberculous mycobacteria and salmonellae. The functional effects of amino acid changes in IL-12Rbeta1, however, have not been determined at the molecular level. Molecular complementation studies are essential to demonstrate how structural amino acid changes affect IL-12Rbeta1 function, and whether functionally different IL-12Rbeta1 alleles can be distinguished. Thirteen different IL-12Rbeta1 alleles, including 11 amino acid substitutions and the two major haplotypes (214Q-365M-378G and 214R-365T-378R), were retrovirally transduced in IL-12Rbeta1 deficient human T cells. We provide functional evidence that L77P, R173P, C186S, R213W and Y367C are deleterious mutations leading to non-functional proteins. Conversely, S74R, R156H, H438Y, A525T and G594E are fully functional IL-12Rbeta1 variants. The C198R mutation leads to a partially functional IL-12Rbeta1, representing the first molecularly proven partial IL-12Rbeta1 deficiency. Interleukin-12 (IL-12) induced not only Interferon-gamma but also IL-10 in all responder but not in null-mutant alleles, with intermediate levels in C198R. The QMG allele was found to be a higher IL-12 responder allele compared with the RTR allele. These results have implications for understanding IL-12R/IL-23R structure-function and the role of IL-12R/IL-23R in human disease.
van de Vosse
Esther
E
Department of Infectious Diseases, Leiden University Medical Center, The Netherlands. e.van_de_vosse@lumc.nl
de Paus
Roelof A
RA
van Dissel
Jaap T
JT
Ottenhoff
Tom H M
TH
D000483:Alleles; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D004357:Drug Synergism; D005816:Genetic Complementation Test; D014644:Genetic Variation; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000494:pharmacology; D020382:Interleukin-18 / Q000494:pharmacology; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins / Q000494:pharmacology; D009154:Mutation; D018123:Receptors, Interleukin / Q000172:deficiency* / Q000235:genetics*; D053707:Receptors, Interleukin-12; D012190:Retroviridae / Q000235:genetics; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology; D014161:Transduction, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
C508438:IL12RB1 protein, human; C508840:IL23A protein, human; D020382:Interleukin-18; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins; D018123:Receptors, Interleukin; D053707:Receptors, Interleukin-12; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma