Tumor biomarker glycoproteins in the seminal plasma of healthy human males are endogenous ligands for DC-SIGN.

DC-SIGN is an immune C-type lectin that is expressed on both immature and mature dendritic cells associated with peripheral and lymphoid tissues in humans. It is a pattern recognition receptor that binds to several pathogens including HIV-1, Ebola virus, Mycobacterium tuberculosis, Candida albicans, Helicobacter pylori, and Schistosoma mansoni. Evidence is now mounting that DC-SIGN also recognizes endogenous glycoproteins, and that such interactions play a major role in maintaining immune homeostasis in humans and mice.

Carbohydrate-mediated binding and induction of acrosomal exocytosis in a boar sperm-somatic cell adhesion model.

The molecular basis underlying the binding of spermatozoa to their homologous eggs and the subsequent induction of acrosomal exocytosis remain a major unresolved issue in mammalian fertilization. Novel cell adhesion systems are now being explored to advance this research. Triantennary and tetraantennary N-glycans have previously been implicated as the major carbohydrate sequences that mediate the initial binding of spermatozoa to the specialized egg coat (zona pellucida) in the murine and porcine models.

Age-related changes in mature CD4+ T cells: cell cycle analysis.

T cell proliferative responses decrease with age, but the mechanisms responsible are unknown. We examined the impact of age on memory and naive CD4(+) T cell entry and progression through the cell cycle using acridine orange to identify cell cycle stage. For both subsets, fewer stimulated cells from old donors were able to enter and progress through the first cell cycle, with an increased number of cells arrested in G(0) and fewer cells in post G(0) phases.

CpG DNA rescue of murine B lymphoma cells from anti-IgM-induced growth arrest and programmed cell death is associated with increased expression of c-myc and bcl-xL.

One of the principal mechanisms thought to maintain B cell tolerance to self Ags is deletion of cells bearing functional IgM receptors for self Ag via apoptosis in the bone marrow. Because of its characteristic growth arrest and apoptosis in response to surface IgM cross-linking, the B cell line WEHI-231 has been a useful model system for studies of Ag receptor-mediated apoptosis. Unmethylated CpG dinucleotides in oligonucleotides (CpG DNA) can be strong B cell mitogens.

Alteration of cell cycle kinetics and immunoglobulin gene transcription as the result of multiple agonist stimulation of murine B cells.

Several laboratories have established that anti-IgM can inhibit polyclonal B cell activation by LPS or LPS/DxS. The use of intact anti-IgM results in an inhibition of both proliferation and differentiation, whereas F(ab')2 fragments inhibit only differentiation. Since signal transduction by both alpha-Ig's (intact and F(ab')2 fragments) is known to be mediated by PIP2 hydrolysis, we have investigated the effects of A23187 and PMA on LPS/DxS activation of splenic B cells.