Loss of marginal zone B-cells in SHIVSF162P4 challenged rhesus macaques despite control of viremia to low or undetectable levels in chronic infection
VIROLOGY
Authors: Demberg, Thorsten; Mohanram, Venkatramanan; Musich, Thomas; Brocca-Cofano, Egidio; McKinnon, Katherine M.; Venzon, David; Robert-Guroff, Marjorie
Abstract
Marginal zone (MZ) B cells generate T-independent antibody responses to pathogens before T-dependent antibodies arise in germinal centers. They have been identified in cynomolgus monkeys and monitored during acute SIV infection, yet have not been well-studied in rhesus macaques. Here we characterized rhesus macaque MZ B cells, present in secondary lymphoid tissue but not peripheral blood, as CD19(+), CD20(+), CD21(hi), IgM(+), CD22(+), CD38(+), BTLA(+), CD40(+), CCR6(+) and BCL-2(+). Compared to healthy macaques, SHIVSF162P4-infected animals showed decreased total B cells and MZ B cells and increased MZ B cell Ki-67 expression early in chronic infection. These changes persisted in late chronic infection, despite viremia reductions to low or undetectable levels. Expression levels of additional phenotypic markers and RNA PCR array analyses were in concert with continued low-level activation and diminished function of MZ B cells. We conclude that MZ B-cell dysregulation and dysfunction associated with SIV/HIV infection are not readily reversible. Published by Elsevier Inc.
Tumor Necrosis Factor Superfamily in Innate Immunity and Inflammation
COLD SPRING HARBOR PERSPECTIVES IN BIOLOGY
Authors: Sedy, Johns; Bekiaris, Vasileios; Ware, Carl F.
Abstract
The tumor necrosis factor superfamily (TNFSF) and its corresponding receptor superfamily (TNFRSF) form communication pathways required for developmental, homeostatic, and stimulus-responsive processes in vivo. Although this receptor-ligand system operates between many different cell types and organ systems, many of these proteins play specific roles in immune system function. The TNFSF and TNFRSF proteins lymphotoxins, LIGHT (homologous to lymphotoxins, exhibits inducible expression, and competes with HSV glycoprotein D for herpes virus entry mediator [ HVEM], a receptor expressed by T lymphocytes), lymphotoxin-b receptor (LT-bR), and HVEM are used by embryonic and adult innate lymphocytes to promote the development and homeostasis of lymphoid organs. Lymphotoxin-expressing innate-acting B cells construct microenvironments in lymphoid organs that restrict pathogen spread and initiate interferon defenses. Recent results illustrate howthe communication networks formed among these cytokines and the coreceptors B and T lymphocyte attenuator (BTLA) and CD160 both inhibit and activate innate lymphoid cells (ILCs), innate gd T cells, and natural killer (NK) cells. Understanding the role of TNFSF/TNFRSF and interacting proteins in innate cells will likely reveal avenues for future therapeutics for human disease.