Infection of mice with cytopathic foot-and-mouth disease virus (FMDV) induces a rapid and specific thymus-independent (TI) neutralizing antibody response that promptly clears the virus. Herein, it is shown that FMDV-infected dendritic cells (DCs) directly stimulate splenic innate-like CD9(+) B lymphocytes to rapidly (3 days) produce neutralizing anti-FMDV immunoglobulin M antibodies without T-l...

Background: Hematogones are normal B-cell precursor which can be seen in different physiological and pathological conditions. Due to variation in B-cell acute lymphoblastic leukemia (B-ALL) blasts immunophenotyping and interference of hematogones in minimal residual disease (MRD) assessment, precise discrimination of hematogones is very crucial.  The purpose of this study was to evaluate the ex...

Transgenic mouse lines were created that express FcgRIIA on platelets and macrophages at human physiologic levels, and they were used to explore the consequences in vivo of activating antiplatelet antibodies. Anti-CD9 antibody activated platelets of FcgRIIA transgenic (tg) mice and, following injection in vivo, caused more rapid severe thrombocytopenia than nonactivating antiplatelet antibody. ...

STING (stimulator of IFN genes) activates the IFN-dependent innate immune response to infection on sensing the presence of DNA in cytosol. The quantity of STING accumulating in cultured cells varies; it is relatively high in some cell lines [e.g., HEp-2, human embryonic lung fibroblasts (HEL), and HeLa] and low in others (e.g., Vero cells). In a preceding publication we reported that STING was ...

EWI-2, a cell surface IgSF protein, is highly expressed in normal human brain but is considerably diminished in glioblastoma tumors and cell lines. Moreover, loss of EWI-2 expression correlated with a shorter survival time in human glioma patients, suggesting that EWI-2 might be a natural inhibitor of glioblastoma. In support of this idea, EWI-2 expression significantly impaired both ectopic an...

Transgenic mouse lines were created that express FcgRIIA on platelets and macrophages at human physiologic levels, and they were used to explore the consequences in vivo of activating antiplatelet antibodies. Anti-CD9 antibody activated platelets of FcgRIIA transgenic (tg) mice and, following injection in vivo, caused more rapid severe thrombocytopenia than nonactivating antiplatelet antibody. ...

Sperm-egg fusion is a cell-cell membrane fusion event essential for the propagation of sexually reproducing organisms. In gamete fusion, as in other fusion events, such as virus-cell and intracellular vesicle fusion, membrane fusion is a two-step process. Attachment of two membranes through cell-surface molecules is followed by the physical merger of the plasma membrane lipids. Recent progress ...

Altered natural killer (NK) cell function is a component of the global immune dysregulation that occurs in advanced malignancies. Another condition associated with altered NK homeostasis is normal pregnancy, where robust infiltration with CD16- CD9+ NK cells can be identified in decidual tissues, along with a concomitant expansion of CD16- NK cells in the maternal peripheral blood. In metastati...

ononuclear phagocytes can fuse to form osteoclasts or multinuclear giant cells. The latter are hallmarks of Crohn’s disease, granulomas, tumors, and fungal and HIV infections. Though the precise function of these syncytia remains unclear, Takeda et al. (page 945) now provide important new insights into phagocyte fusion, suggesting that the process may differ considerably from other types of cel...