Acinar Cell Basal-Lateral Membrane—Endomembrane Traffic May Mediate Interactions with Both T Cells and B Cells

Abstract

The lacrimal glands are normally populated by significant numbers of IgA-producing plasma cells and T lymphocytes, with CD8 cells in twofold excess over CD4 cells. The numbers of these cells increase during normal aging, and there has been speculation that they may exacerbate the lacrimal dysfunction of primary lacrimal deficiency. Lymphocytic infiltration increases much more dramatically in Sjögren’s syndrome, an immune system disorder in which CD4 cells dominate the T lymphocyte population, and the antibody-producing population includes large numbers of B cells. The B cell infiltrates are polyclonal and often produce IgG and IgM against intracellular antigens, such as the ribonuclear proteins Ro and La and a variety of Golgi proteins. Because of the severity of the ocular surface disease and the debilitating and potentially life-threatening nature of the systemic manifestations of Sjögren’s syndrome, it is important to identify the mechanisms that lead to CD4 cell and B cell proliferation in the lacrimal glands.