Biallelic mutations in IRF8 impair human NK cell maturation and function

Human NK cell deficiencies are rare yet result in severe and often fatal disease, particularly as a result of viral susceptibility. NK cells develop from hematopoietic stem cells, and few monogenic errors that specifically interrupt NK cell development have been reported. Here we have described biallelic mutations in IRF8, which encodes an interferon regulatory factor, as a cause of familial NK cell deficiency that results in fatal and severe viral disease. Compound heterozygous or homozygous mutations in IRF8 in 3 unrelated families resulted in a paucity of mature CD56dim NK cells and an increase in the frequency of the immature CD56bright NK cells, and this impairment in terminal maturation was also observed in Irf8–/–, but not Irf8+/–, mice. We then determined that impaired maturation was NK cell intrinsic, and gene expression analysis of human NK cell developmental subsets showed that multiple genes were dysregulated by IRF8 mutation. The phenotype was accompanied by deficient NK cell function and was stable over time. Together, these data indicate that human NK cells require IRF8 for development and functional maturation and that dysregulation of this function results in severe human disease, thereby emphasizing a critical role for NK cells in human antiviral defense

Functionally Distinct Subpopulations of CpG-Activated Memory B Cells

During the human B cell (Bc) recall response, rapid cell division results in multiple Bc subpopulations. The TLR-9 agonist CpG oligodeoxynucleotide, combined with cytokines, causes Bc activation and division in vitro and increased CD27 surface expression in a sub-population of Bc. We hypothesized that the proliferating CD27lo subpopulation, which has a lower frequency of antibody-secreting cells (ASC) than CD27hi plasmablasts, provides alternative functions such as cytokine secretion, costimulation, or antigen presentation. We performed genome-wide transcriptional analysis of CpG activated Bc sorted into undivided, proliferating CD27lo and proliferating CD27hi subpopulations. Our data supported an alternative hypothesis, that CD27lo cells are a transient pre-plasmablast population, expressing genes associated with Bc receptor editing. Undivided cells had an active transcriptional program of non-ASC B cell functions, including cytokine secretion and costimulation, suggesting a link between innate and adaptive Bc responses. Transcriptome analysis suggested a gene regulatory network for CD27lo and CD27hi Bc differentiation

Serous macular detachment, yellow macular deposits, and prominent middle limiting membrane in multiple myeloma

Berna Dogan,1 Muhammet Kazim Erol,1 Devrim Toslak,1 Deniz Turgut Coban,1 Mehmet Bulut,1 Ayse Cengiz,1 Esin Sogutlu Sari2 1Antalya Training and Research Hospital, Eye Clinic, Antalya, Turkey; 2Balikesir University Medicine Faculty, Eye Clinic, Balikesir, Turkey Abstract: Bone marrow-derived multiple myeloma is a type of plasma cell tumor that may be associated with ocular complications. A 52-year-old male patient was admitted to our eye clinic with the complaint of sudden visual loss and a visual acuity of 20/50 in the right eye and 20/800 in the left eye. Fundus examination revealed common flame-shaped hemorrhages, venous dilatation and tortuosity, Roth spots, serous macular detachment, and yellow macular deposits in both eyes. Evaluation with fundus fluorescein angiography, fundus autofluorescence, and spectral-domain optical coherence tomography resulted in suspicion of hyperviscosity retinopathy and referral to the hematology clinic. After hematology consultation confirmed a diagnosis of multiple myeloma, chemotherapy and plasmapheresis were initiated. Four months after presentation, best-corrected visual acuity was 20/20 in both eyes and improvement in hyperviscosity retinopathy, serous macular detachment, and yellow macular deposits was observed. Keywords: serous macular detachment, yellow macular deposit, prominent middle limiting membrane, multiple myelom