Reduced MCMV Δm157 viral clearance in the absence of TSAd.

The T cell specific adapter protein (TSAd) is expressed in activated T cells and NK cells. While TSAd is beginning to emerge as a critical regulator of Lck and Itk activity in T cells, its role in NK cells has not yet been explored. Here we have examined susceptibility to virus infections in a murine model using various viral infection models. We report that TSAd-deficient mice display reduced clearance of murine cytomegalovirus (MCMV) that lack the viral MHC class I homologue m157, which is critical for Ly49H-mediated NK cell recognition of infected cells. In this infection model, NK cells contribute in the early stages of the disease, whereas CD8+ T cells are critical for viral clearance. We found that mice infected with MCMV Δm157 displayed reduced viral clearance in the spleen as well as reduced proliferation in spleen NK cells and CD8+ T cells in the absence of TSAd. Though no other immunophenotype was detected in the infection models tested, these data suggests that in the absence of the Ly49H ligand activation, NK cell and CD8+ T cell responses may be compromised in TSAd-deficient mice.

Plasma lipoproteins in healthy octogenarians: lack of reduced high density lipoprotein cholesterol levels: results from the Framingham Heart Study.

Genetic low density lipoprotein (LDL) deficiency and high density lipoprotein (HDL) excess have been associated with enhanced longevity. This investigation assessed the prevalence of lipoprotein abnormalities in octogenarians free of clinical evidence of cardiovascular disease (CVD) in the Framingham Heart Study. Plasma lipid and lipoprotein cholesterol determinations were carried out by standard techniques between 1971 and 1974. Participants who were free of clinical evidence of CVD in an examination approximately 10 years later (1981 to 1982) had their lipoprotein values tabulated based on the earlier examination. There were 106 women and 57 men who met these criteria, with mean ages of 83.3 and 82.9 years, respectively, at examination 16 (called cases). Mean levels (+/- SEM) of LDL cholesterol in cases were 152 +/- 3 mg/dL for women, and 147 +/- 5 mg/dL for men. For HDL cholesterol, these values were 57 +/- mg/dL for women and 46 +/- 2 mg/dL for men. These values were not statistically different from those of other study subjects (who did not meet the CVD criteria or were decreased) or middle-aged controls. In contrast, HDL cholesterol levels below the tenth percentile of normal were not observed in any male cases and in only 1.0% of female cases (P less than .05) as compared with observations in control subjects. The data are consistent with the concept that there is not an overrepresentation of either decreased LDL cholesterol or elevated HDL cholesterol values in subjects who subsequently become healthy octogenarians, but that these subjects are exceedingly unlikely to have reduced HDL cholesterol levels.