Search Results - (Author, Cooperation:O. Maza)

2014-09-19

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Anti-Bacterial Agents/pharmacology ; Aspartame/adverse effects ; Body Weight/drug effects ; Diet, High-Fat ; Dietary Fats/pharmacology ; Feces/microbiology ; Female ; Gastrointestinal Tract/*drug effects/*microbiology ; Germ-Free Life ; Glucose/metabolism ; Glucose Intolerance/*chemically induced/metabolism/*microbiology ; Humans ; Male ; Metabolic Syndrome X/chemically induced/metabolism/microbiology ; Mice ; Mice, Inbred C57BL ; Microbiota/*drug effects ; Saccharin/administration & dosage/adverse effects ; Sucrose/adverse effects/analogs & derivatives ; Sweetening Agents/*adverse effects ; Waist-Hip Ratio

2018-05-08

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Using a haemolytic plaque assay for y-interferon (IFN-γ) secretion we found that in vitro Epstein-Barr virus (EBV) exposure of peripheral blood mononuclear cells from EBV immune individuals led to IFN-y secretion, which was apparent wiihin 6 h after virus coniact and peaked 12–24 h after induction. Live, ultraviolel-light-irradiaicd and heat-inactivated virions all caused IFN-γ secretion. In contrast, blood mononuclear cells from EBV non-immune adults or neonates could not be activated to IFN-y production by EBV.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Controversy concerning the immunologic role of antigen-binding cells (ABO has prompted us to attempt to quantitate the proportion of stimulable ABC, in immunized animals, which are precursors for cells producing antibody specific for the antigen bound. Using a lipopolysaccharide (LPS)-driven limiting dilution analysis system, the precursor frequency (PF) of cells secreting IgM and IgG and sheep erythrocyte (SRBQ-specific IgM and IgG was established for highly purified SRBC antigen-binding cell (SRBC-ABC) and unfractionated populations taken from CBA/J mouse spleens on days 5, 12 and 180 of the in vivo primary immune response to SRBC. At all these times, almost all SRBC-ABC spontaneously secreting immunoglobulin (Ig) secreted SRBC-specific Ig, and almost all precursors of Ig-secreting cells in the ABC populations were precursors of cells secreting specific anti-SRBC antibody. In SRBC-ABC populations, the PF for total and SRBC-specific Ig secretion was seen to decrease on days 5 and 12 after immunization and to increase to 3.5 to 7 times nonimmune levels 180 days after immunization. The absolute number of precursors, within the SRBC-ABC population, for the secretion of SRBC-specific Ig decreased on day 12 after immunization. In the unfractionated population, the PF for SRBC-specific Ig secretion temporarily increased after immunization, reaching peak levels 5 days (IgM) and 12 days (IgG) after immunization. These two changes may be related, representing the progress of stimulated cells out of the ABC pool as they lose receptors en roule to full maturation. The small clone sizes on days 5 and 12 indicate that ABC divide less in response to LPS when already engaged in a response to antigen. In contrast, the PF for total IgM and IgG secretion in the unfractionated population was not greatly affected by immunization.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The clonal selection theory, as formulated by Burnet, predicts that a lymphocyte bearing receptors for a given antigen will, upon activation, produce antibody to that same antigen. This prediction has for the first time been quantitatively confirmed, by precursor frequency analysis of highly purified sheep erythrocyte antigen-binding cells (SRBC-ABC), isolated from the spleens of non-immune mice, by means of an LPS-driven limiting dilution micro-culture system. These precursor frequencies indicated that virtually every non-immune SRBC-ABC that was a precursor for the secretion of IgM (or IgG) was also a precursor for the secretion of SRBC-specific IgM (or SRBC-specific JgG), after correction for non-SRBC-ABC B cells contaminating the SRBC-ABC preparations. These data help to clarify the relationship between antigen-binding cells and the antigen-reactive cells of the clonal selection theory. In the course of making this observation, it was also shown that the precursor frequency of purified non-immune SRBC-ABC for IgG production was the same as that of unfractionated cells, whereas the precursor frequency for IgM production and LPS-induced thymidine incorporation were both lower in the ABC. The clone size estimates for IgM and IgG precursors in ABC and unfractionated cells all fell within a narrow range (1 to 2 doublings).

Electronic Resource

0014-4827

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource