Age-related adiposity has been linked to chronic inflammatory diseases in late-life. To date, the studies on adipose tissue leukocytes and aging have not taken into account the heterogeneity of adipose tissue macrophages (ATMs), nor have they examined how age impacts other leukocytes such as T cell in fat. Therefore, we have performed a detailed examination of ATM subtypes in young and old mice using state of the art techniques. Our results demonstrate qualitative changes in ATMs with aging that generate a decrease in resident Type 2 (M2) ATMs. The profile of ATMs in old fat shifts towards a pro-inflammatory environment with increased numbers of CD206-CD11c- (double negative) ATMs. The mechanism of this aging-induced shift in the phenotypic profile of ATMs was found to be related to a decrease in PPARγ expression in ATMs and alterations in chemokine/chemokine receptor expression profiles. Furthermore, we have revealed a profound and unexpected expansion of adipose tissue T (ATT) cells in visceral fat with aging that includes a significant induction of regulatory T cells (Tregs) in fat. Our findings demonstrate a unique inflammatory cell signature in the physiologic context of aging adipose tissue that differs from those induced in setting of diet-induced obesity.

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Epidemic respiratory infections are responsible for extensive morbidity and mortality within both military and civilian populations. We describe a high-throughput method to simultaneously identify and genotype species of bacteria from complex mixtures in respiratory samples. The process uses electrospray ionization mass spectrometry and base composition analysis of PCR amplification products from highly conserved genomic regions to identify and determine the relative quantity of pathogenic bacteria present in the sample. High-resolution genotyping of specific species is achieved by using additional primers targeted to highly variable regions of specific bacterial genomes. This method was used to examine samples taken from military recruits during respiratory disease outbreaks and for follow up surveillance at several military training facilities. Analysis of respiratory samples revealed high concentrations of pathogenic respiratory species, including Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pyogenes. When S. pyogenes was identified in samples from the epidemic site, the identical genotype was found in almost all recruits. This analysis method will provide information fundamental to understanding the polymicrobial nature of explosive epidemics of respiratory disease.genotyping ͉ group A streptococci ͉ infectious disease ͉ Streptococcus pyogenes ͉ pneumonia

This study identified multiple novel c-Abl–mediated nmMLCK phosphorylation sites by mass spectroscopy and examined their influence on nmMLCK function and human lung endothelial barrier regulation. The data indicate an essential role for Abl kinase in vascular barrier regulation via phosphorylation of nmMLCK and the actin-binding protein cortactin.

Aging is associated with a progressive dysregulation of immune responses. Whether these changes are solely responsible for the observed increased mortality and morbidity amongst the elderly is uncertain. Recent advances have highlighted the age-associated changes that occur beyond T and B lymphocytes. Additionally, multiple human and animal studies have identified a relationship between chronic low-grade inflammation and geriatric syndromes, such as frailty, suggesting that the phenomenon of "inflamm-aging" may provide a rationale for the increased vulnerability to chronic inflammatory diseases in older adults. In the present review, we broadly summarize our current understanding of age-dependent changes in leukocyte function and their contribution to aging-related disease processes.