Browsing by Subject "CyTOF"

Now showing 1 - 3 of 3
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    Early innate and adaptive immune perturbations determine long-term severity of chronic virus and Mycobacterium tuberculosis coinfection
    (Elsevier, 2021) Xu, Wenxi; Snell, Laura M.; Guo, Mengdi; Boukhaled, Giselle; Macleod, Bethany L.; Li, Ming; Tullius, Michael V.; Guidos, Cynthia J.; Tsao, Ming-Sound; Divangahi, Maziar; Horwitz, Marcus A.; Liu, Jun; Brooks, David G.; Microbiology and Immunology, School of Medicine
    Chronic viral infections increase severity of Mycobacterium tuberculosis (Mtb) coinfection. Here, we examined how chronic viral infections alter the pulmonary microenvironment to foster coinfection and worsen disease severity. We developed a coordinated system of chronic virus and Mtb infection that induced central clinical manifestations of coinfection, including increased Mtb burden, extra-pulmonary dissemination, and heightened mortality. These disease states were not due to chronic virus-induced immunosuppression or exhaustion; rather, increased amounts of the cytokine TNFα initially arrested pulmonary Mtb growth, impeding dendritic cell mediated antigen transportation to the lymph node and subverting immune-surveillance, allowing bacterial sanctuary. The cryptic Mtb replication delayed CD4 T cell priming, redirecting T helper (Th) 1 toward Th17 differentiation and increasing pulmonary neutrophilia, which diminished long-term survival. Temporally restoring CD4 T cell induction overcame these diverse disease sequelae to enhance Mtb control. Thus, Mtb co-opts TNFα from the chronic inflammatory environment to subvert immune-surveillance, avert early immune function, and foster long-term coinfection.
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    Neonatal Osteomacs and Bone Marrow Macrophages Differ in Phenotypic Marker Expression and Function
    (Wiley, 2021) Mohamad, Safa F.; Gunawan, Andrea; Blosser, Rachel; Childress, Paul; Aguilar-Perez, Alexandra; Ghosh, Joydeep; Hong, Jung Min; Liu, Jianyun; Kanagasabapathy, Deepa; Kacena, Melissa A.; Srour, Edward F.; Bruzzaniti, Angela; Medicine, School of Medicine
    Osteomacs (OM) are specialized bone-resident macrophages that are a component of the hematopoietic niche and support bone formation. Also located in the niche are a second subset of macrophages, namely bone marrow-derived macrophages (BM Mφ). We previously reported that a subpopulation of OM co-express both CD166 and CSF1R, the receptor for macrophage colony-stimulating factor (MCSF), and that OM form more bone-resorbing osteoclasts than BM Mφ. Reported here are single-cell quantitative RT-PCR (qRT-PCR), mass cytometry (CyTOF), and marker-specific functional studies that further identify differences between OM and BM Mφ from neonatal C57Bl/6 mice. Although OM express higher levels of CSF1R and MCSF, they do not respond to MCSF-induced proliferation, in contrast to BM Mφ. Moreover, receptor activator of NF-κB ligand (RANKL), without the addition of MCSF, was sufficient to induce osteoclast formation in OM but not BM Mφ cultures. OM express higher levels of CD166 than BM Mφ, and we found that osteoclast formation by CD166-/- OM was reduced compared with wild-type (WT) OM, whereas CD166-/- BM Mφ showed enhanced osteoclast formation. CD110/c-Mpl, the receptor for thrombopoietin (TPO), was also higher in OM, but TPO did not alter OM-derived osteoclast formation, whereas TPO stimulated BM Mφ osteoclast formation. CyTOF analyses demonstrated OM uniquely co-express CD86 and CD206, markers of M1 and M2 polarized macrophages, respectively. OM performed equivalent phagocytosis in response to LPS or IL-4/IL-10, which induce polarization to M1 and M2 subtypes, respectively, whereas BM Mφ were less competent at phagocytosis when polarized to the M2 subtype. Moreover, in contrast to BM Mφ, LPS treatment of OM led to the upregulation of CD80, an M1 marker, as well as IL-10 and IL-6, known anti-inflammatory cytokines. Overall, these data reveal that OM and BM Mφ are distinct subgroups of macrophages, whose phenotypic and functional differences in proliferation, phagocytosis, and osteoclast formation may contribute physiological specificity during health and disease.
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    The transcription factor IRF2 drives interferon-mediated CD8+ T cell exhaustion to restrict anti-tumor immunity
    (Elsevier, 2022-12-13) Lukhele, Sabelo; Rabbo, Diala Abd; Guo, Mengdi; Shen, Jian; Elsaesser, Heidi J.; Quevedo, Rene; Carew, Madeleine; Gadalla, Ramy; Snell, Laura M.; Mahesh, Lawanya; Ciudad, M. Teresa; Snow, Bryan E.; You-Ten, Annick; Haight, Jillian; Wakeham, Andrew; Ohashi, Pamela S.; Mak, Tak W.; Cui, Weiguo; McGaha, Tracy L.; Brooks, David G.; Microbiology and Immunology, School of Medicine
    Type I and II interferons (IFNs) stimulate pro-inflammatory programs that are critical for immune activation, but also induce immune-suppressive feedback circuits that impede control of cancer growth. Here, we sought to determine how these opposing programs are differentially induced. We demonstrated that the transcription factor interferon regulatory factor 2 (IRF2) was expressed by many immune cells in the tumor in response to sustained IFN signaling. CD8+ T cell-specific deletion of IRF2 prevented acquisition of the T cell exhaustion program within the tumor and instead enabled sustained effector functions that promoted long-term tumor control and increased responsiveness to immune checkpoint and adoptive cell therapies. The long-term tumor control by IRF2-deficient CD8+ T cells required continuous integration of both IFN-I and IFN-II signals. Thus, IRF2 is a foundational feedback molecule that redirects IFN signals to suppress T cell responses and represents a potential target to enhance cancer control.