APOBEC3G rescues cells from the deleterious effects of DNA damage.

Human apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3G (hA3G), a member of the APOBEC family, was described as an anti-HIV-1 restriction factor, deaminating reverse transcripts of the HIV-1 genome. Several types of cancer cells that express high levels of A3G, such as diffuse large B-cell lymphoma cells and glioblastomas, show enhanced cell survival after ionizing radiation and chemotherapy treatments. Previously, we showed that hA3G promotes (DNA) double-strand breaks repair in cultured cells and rescues transgenic mice from a lethal dose of ionizing radiation.

Increased expression with differential subcellular location of cytidine deaminase APOBEC3G in human CD4(+) T-cell activation and dendritic cell maturation.

APOBEC3G (apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G; A3G) is an innate defense protein showing activity against retroviruses and retrotransposons. Activated CD4(+) T cells are highly permissive for HIV-1 replication, whereas resting CD4(+) T cells are refractory. Dendritic cells (DCs), especially mature DCs, are also refractory.

ISA virus regulates the generation of reactive oxygen species and p47phox expression in a p38 MAPK-dependent manner in Salmo salar.

Several viruses, including Orthomyxovirus, utilize cellular reactive oxygen species (ROS) for viral genomic replication and survival within host cells. However, the role of ROS in early events of viral entry and signal induction has not been elucidated. Here, we show that ISA virus (ISAV) induces ROS production very early during infection of CHSE-214 and SHK-1Ycells, and that production is sustained over the observed 24h post-infection.

Increased alpha-defensins 1-3 production by dendritic cells in HIV-infected individuals is associated with slower disease progression.

Background: Defensins are natural endogenous antimicrobial peptides with potent anti-HIV activity and immuno-modulatory effects. We recently demonstrated that immature dendritic cells (DC) produce alpha-defensins1-3 and that alpha-defensins1-3 modulate DC generation and maturation. Since DC-HIV interaction plays a critical role during the first steps of HIV infection, we investigated the possible impact of alpha-defensins1-3 production by DC on disease progression.

Immunological dysfunction in HIV-1-infected individuals caused by impairment of adenosine deaminase-induced costimulation of T-cell activation.

The cell surface association between CD26 and adenosine deaminase (ADA) has a costimulatory function during T-cell activation. Several studies have revealed correlations among CD4(+) CD26(+) T-cell depletion, increased serum levels of ADA, and the evolution of human immunodeficiency virus (HIV) infection, implicating CD26 and ADA in HIV disease progression. In this context, we aimed to determine whether ADA costimulation could be altered during HIV infection.

Impact of alpha-defensins1-3 on the maturation and differentiation of human monocyte-derived DCs. Concentration-dependent opposite dual effects.

alpha-defensins1-3 are potent antimicrobial molecules that also link innate and adaptive immunity, depending on the concentration range. However, their effects on the biology of human DCs remain largely unknown. We analyzed the impact of different concentrations of alpha-defensins1-3 on the maturation and differentiation of monocyte-derived DCs (MDDCs).

Immunodominant role of CCHA subunit of Concholepas hemocyanin is associated with unique biochemical properties.

Hemocyanin, the oxygen transporter metallo-glycoprotein from mollusks, shows strong relationship between its notable structural features and intrinsic immunomodulatory effects. Here we investigated the individual contribution of CCHA and CCHB subunits from Concholepas hemocyanin (CCH) to in vivo humoral immune response and their pre-clinical evaluation as immunotherapeutic agent in a mice bladder cancer model, in relation to their biochemical properties. To this end, subunits were purified and well characterized.

Human immature monocyte-derived dendritic cells produce and secrete alpha-defensins 1-3.

Defensins are effector molecules of the innate immunity with a broad antimicrobial spectrum, including HIV. They also link innate and adaptive immunity, displaying chemotactic activity for monocytes, T cells, and dendritic cells (DCs). alpha-Defensins 1-3 are mainly produced by neutrophils, but their production by other leukocyte subsets has also been reported.

Expression and function of the IL-2 receptor in activated human plasmacytoid dendritic cells.

Human and mouse plasmacytoid dendritic cells (PDC) express IL-2 mRNA specifically upon TLR stimulation, but not under CD40L stimulation. Even though the expression of the IL-2R by PDC has been described, the functional implications of this expression remain unknown. Here, we investigated the expression and function of the IL-2R in activated human PDC.

Glutamate released by dendritic cells as a novel modulator of T cell activation.

Adaptive immune responses begin after productive immunosynaptic contacts formation established in secondary lymphoid organs by dendritic cells (DC) presenting the Ag to T lymphocytes. Despite its resemblance to the neurosynapse, the participation of soluble small nonpeptidic mediators in the intercellular cross-talk taking place during T cell-DC interactions remains poorly studied. In this study, we show that human DC undergoing maturation and in contact with T cells release significant amounts of glutamate, which is the main excitatory neurotransmitter in mammalians.

Tacrolimus treatment of plasmacytoid dendritic cells inhibits dinucleotide (CpG-)-induced tumour necrosis factor-alpha secretion.

Tacrolimus is a widely used immunosuppressive agent. Although T cells are the main targets of these pharmacological drugs, antigen presentation may also be affected. Among antigen-presenting cells, plasmacytoid dendritic cells (PDCs) are the main source of type I interferons upon microbial challenge, and are involved in several diseases and autoimmune disorders.

Hemocyanin of the molluscan Concholepas concholepas exhibits an unusual heterodecameric array of subunits.

We describe here the structure of the hemocyanin from the Chilean gastropod Concholepas concholepas (CCH), emphasizing some attributes that make it interesting among molluscan hemocyanins. CCH exhibits a predominant didecameric structure as revealed by electron microscopy and a size of 8 MDa by gel filtration, and, in contrast with other mollusc hemocyanins, its stabilization does not require additional Ca(2+) and/or Mg(2+) in the medium. Polyacrylamide gel electrophoresis studies, analyses by a MonoQ FPLC column, and Western blots with specific monoclonal antibodies showed that CCH is made by two subunits noncovalently linked, named CCH-A and CCH-B, with molecular masses of 405 and 350 kDa, respectively.

Monoclonal antibodies to molluskan hemocyanin from Concholepas concholepas demonstrate common and specific epitopes among subunits.

We studied the reactivity of mouse monoclonal antibodies (MAbs) against the hemocyanin from the Chilean marine gastropod Concholepas concholepas (CCH). This protein has been successfully used as a carrier to produce antibodies to haptens and peptides. All MAbs (13) belonging to IgG subclass exhibit dissociation constants (K(d)) from 1 x 10(-7) M to 1 x 10(-9) M.