The co-stimulatory molecule CD28 is essential for activation of helper T cells. Despite this critical role, it is not known whether CD28 has functions in maintaining T cell responses following activation. To determine the role for CD28 after T cell priming, we generated a strain of mice where CD28 is removed from CD4(+) T cells after priming. We show that continued CD28 expression is important ...

BACKGROUND/AIMS CEL-MODY is a monogenic form of diabetes and exocrine pancreatic insufficiency due to mutations in the carboxyl-ester lipase (CEL) gene. We aimed to investigate endocrine and exocrine pancreatic function in CEL knockout mice (CELKO). METHODS A knockout mouse model with global targeted deletion of CEL was investigated physiologically and histopathologically, and compared to lit...

Antigen-specific helper T cells are required in the generation of cytotoxic T cells from thymocyte precursors. We have demonstrated that these alloantigen-specific helper cells can be generated in vitro and that both the quantity and quality of the helpers appear to be superior to the help obtained from unprimed spleen cells. Optimal helper cell activity is produced at day two of culture when C...

B e c a u s e of t h e b u r s t i n e s s of v i d e o trajgic, a v e r y large s a m p l i n g i n t e r v a l is needed t o o b t a i n acceptable cell loss probab i l i t y . P r e v i o u s s t u d i e s repor t ed v e r y h i g h cel l loss probab i l i t i e s f o r we l l -behaved s o u r c e s w h e n u s i n g t h e L e a k y B u c k e t m e c h a n a s m (LB) t o po l ice VBR v i d e...

It has long been known that thymus-derived lymphocytes (T cells) can produce cytokines that have powerful effects on hematopoiesis. All major classes of T cells--CD4 T helper cells, CD4 regulatory T cells, CD8 T cells, gammadelta T cells and NKT cells--produce a number of cytokines and chemokines that can modulate hematopoiesis. More recent research has shown that specific T helper cell types, ...

Previous studies using chemical modification approach have shown the importance of arginine residues in bile salt activation of carboxyl ester lipase (CEL) activity. However, the x-ray crystal structure of CEL failed to show the involvement of arginine residues in CEL-bile salt interaction. The current study used a site-specific mutagenesis approach to determine the role of arginine residues 63...

Advanced glycation endproducts (AGEs) in food products may pose health risks, and thermal processing of foods accelerates the formation of AGEs. The effects of heat treatments (65-100 °C, 0-60 min) on the formation of AGEs including N(ε)-carboxymethyllysine (CML) and N(ε)-carboxyethyllysine (CEL) in ground beef were investigated. The levels of CML and CEL in ground beef steadily increased with ...

Major histocompatibility complex-restricted helper T cell clones against "minor" antigens expressed on B cell and macrophage surfaces, when confronted with appropriate T cell-depleted spleen cells, are induced to proliferation and, in turn, activate "target-responder" B cells to polyclonal growth and maturation. Irradiation of helper cell populations, however, demonstrates that their effector f...

A patient with acquired agammaglobulinemia was treated with plasmapheresis. The rationale for this procedure was based on the presence of a cytotoxic autoantibody with specificity for helper (TH2-) T lymphocytes. Plasmapheresis reduced the autoantibody concentration to undetectable levels, which resulted in an increase number of helper T cells. These T cells provided normal in vitro helper acti...