A glutamic acid at residue 69(Glu69) in the HLA-DPB1 gene (Glu69) is associated with chronic beryllium disease (CBD) and possibly beryllium sensitization (BeS). This study tested the hypothesis that MHC class II polymorphisms are important in susceptibility to BeS and CBD and that the Glu69 variant is related to markers of disease severity. Genomic DNA was obtained from BeS (n = 50), CBD (n = 104), and beryllium-exposed nondiseased (Be-nondiseased) (n = 125) subjects. HLA-DPB1, -DRB1, and -DQB1 genotypes were determined by (sequence-specific primers) PCR. Disease severity was assessed by pulmonary function and exercise testing. A higher frequency of the DPB1 Glu69 gene was found in CBD and BeS compared with the Be-nondiseased subjects, with odds ratios of 10.1 for CBD vs Be-nondiseased and 9.5 for BeS vs Be-nondiseased. The majority of BeS and CBD subjects displayed non-0201 Glu69 alleles. Glu69 homozygosity was higher in the CBD subjects, while BeS subjects were intermediate and Be-nondiseased lowest. DRB1*01 and DQB1*05 phenotypes were reduced in CBD vs Be-nondiseased subjects, while DRB1*13 and DQB1*06 were associated with CBD in the absence of Glu69. Markers of disease severity, including a lower forced vital capacity, diffusion capacity for carbon monoxide, PaO2 at rest, maximum workload on exercise testing, and a higher arterial-alveolar gradient at rest, were associated with Glu69 homozygosity. We conclude that DPB1 Glu69 is a marker of sensitization and not specific for disease. Glu69 homozygosity acts as a functional marker associated with markers of CBD severity.

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This review updates the basic biology of lung DCs and their functions. Lung DCs have taken center stage as cellular therapeutic targets in new vaccine strategies for the treatment of diverse human disorders, including asthma, allergic lung inflammation, lung cancer, and infectious lung disease. The anatomical distribution of lung DCs, as well as the division of labor between their subsets, aids their ability to recognize and endocytose foreign substances and to process antigens. DCs can induce tolerance in or activate naïve T cells, making lung DCs well-suited to their role as lung sentinels. Lung DCs serve as a functional signaling/sensing unit to maintain lung homeostasis and orchestrate host responses to benign and harmful foreign substances.

Infection of endothelial cells by bacteria may be an important component of the bacteria's ability to escape host defenses and cause disease. Listeria monocytogenes causes sepsis and central nervous system infection in domesticated animals and immunocompromised humans, suggesting that this bacterium interacts with endothelial cells in a significant fashion. The experiments presented here tested the hypothesis that L. monocytogenes can invade and replicate within human endothelial cells. We found that L. monocytogenes grows readily in umbilical vein endothelial cells and that its intracellular life cycle involves phagosomal escape, F-actinbased motility, and cell-to-cell spread. We found that L. monocytogenes invaded endothelial cells by cell-to-cell spread from adherent mononuclear phagocytes which were previously infected by this bacterium. Interestingly, L. monocytogenes mutants lacking the invasion protein, internalin, bound less well to endothelial cells than did wild-type bacteria in the absence, but not the presence, of serum, and their invasion of endothelial cells was diminished under both conditions. Thus, endothelial cell infection by L. monocytogenes can occur by two distinct mechanisms: direct bacterial invasion of the endothelial cells in an internalin-mediated fashion or cell-to-cell spread from adherent, infected mononuclear phagocytes. These data support the idea that endothelial cell infection by L. monocytogenes is an important event in the pathogenesis of listeriosis.