As there is limited knowledge regarding the longitudinal development and early ontogeny of naïve and regulatory CD4(+) T-cell subsets during the first postnatal year, we sought to evaluate the changes in proportion of naïve (thymic and central) and regulatory (resting and activated) CD4(+) T-cell populations during the first postnatal year. Blood samples were collected and analyzed at birth, 6 ...

Effective accumulation and interaction of mature dendritic cells (DCs) and naïve T cells within lymph nodes (LNs), driven by the CCR7-CCL19/CCL21 axis, are critical for the induction of adaptive T cell immunity. Human natural killer (NK) cells activated by IL-18 exhibit unique ‘helper’ activity in promoting productive DC-T cell interactions, inducing dendritic cell (DC) maturation and the type-...

Abstract Background Primary biliary cholangitis (PBC), an autoimmune liver disease, presents with progressive damage to the intrahepatic bile ducts infiltrating mononuclear cells and appearance of anti‐mitochondrial antibodies (AMAs). The initiation disease is permissively mediated by dysfunctional regulatory T (Treg cells). Naïve CD4 + cultured splenic B220 without additional cytokines or chem...

Naïve CD4 T cells are triggered to undergo spontaneous proliferation, a proliferative response induced in response to homeostatic stimulation, when exposed to severe lymphopenic environments. They spontaneously acquire proinflammatory effector phenotypes, playing a major role in inducing chronic inflammation in the intestine that is believed to be induced by T cell recognition of commensal anti...

B-1a cells constitutively secrete natural antibody that provides immediate protection against microbial pathogens and functions homeostatically to speed removal of apoptotic cell debris. Although B-1a cells are especially prominent in the peritoneal and pleural cavities, some B-1a cells reside in the spleen. A small subset of splenic B-1a cells in naïve, unimmunized mice express CD138, a recogn...

Activation of immune cells (but not B cells) with lectins is widely known. We used the structurally defined interaction between influenza hemagglutinin (HA) and its cell surface receptor sialic acid (SA) to identify a B cell receptor (BCR) activation modality that proceeded through non-cognate interactions with antigen. Using a new approach to reconstitute antigen-receptor interactions in a hum...

NK cells are known as innate immune cells that lack immunological memory. Recently, it has been shown that NK cells remember encounters with chemical haptens that induce contact hypersensitivity and cytomegalovirus infection. Here, we show the existence of NK cell memory following HSV-2 infection. Stimulation with HSV-2 Ags led to higher IFNγ production in NK cells that were exposed 30 days pre...

Abstract Flow cytometry is valuable for identifying and monitoring B cell subsets in patients with humoral immune disorders treated immunotherapies targeting cells. We have designed a 13-color cFluor ®B Cell Monitoring panel that identifies plasmablasts/plasma cells (CD19 +CD20 −CD27 +CD38 ++), naïve (CD27 −IgD +), IgG class switched memory +IgG +) unswitched +IgD +and/or IgM +). Additionally, ...

DURING PREGNANCY, THE MATERNAL IMMUNE SYSTEM FACES A DOUBLE DILEMMA: tolerate the growing semi-allogeneic fetus and at the same time protect the mother and the progeny against pathogens. This requires a fine and extremely regulated equilibrium between immune activation and tolerance. As professional antigen presenting cells, B cells and in particular B-1a B cells, can activate or tolerize T cel...