A multistage-polyepitope vaccine protects against Mycobacterium tuberculosis infection in HLA-DR3 transgenic mice

Mycobacterium tuberculosis (Mtb) is responsible for almost 2 million deaths annually. BCG, currently the only TB vaccine, induces variable protection and does not protect against reactivation of latent TB. Thus, efficient vaccines to supplement BCG are required urgently. Since Mtb's proteome differs qualitatively and quantitatively during bacterial replication stages from that expressed during dormancy, improved TB vaccines should drive immune responses to Mtb antigens expressed during multiple stages of infection. Consequently, such “multistage” vaccines should be composed of (immunodominant) antigens expressed during different phases of Mtb infection. As a concept multistage vaccine, we constructed a polyepitope by fusing five HLA-DR3-restricted T-cell epitopes derived from different Mtb proteins either expressed highly by replicating bacteria (Ag85B, hsp65, 19 kDa lipoprotein), or abundantly expressed by dormant bacilli and recognized preferentially by TST⁺ individuals (hsp16, Rv1733c). PBMC of HLA-DR3⁺ but not HLA-DR3⁻ cured TB patients and TST⁺ individuals responded well to the multistage-polyepitope in vitro. The in vivo immunogenicity and protective efficacy of the multistage-polyepitope were analyzed using HLA-DR3 transgenic mice lacking endogenous murine class II as a model. Immunization with the multistage-polyepitope adjuvanted with CpG generated high IgG levels as well as polyfunctional CD4⁺ T-cells producing IFN-γ, TNF and IL-2, specific for these HLA-DR3-restricted epitopes. Importantly, multistage-polyepitope immunization reduced the number of bacilli in the lungs after Mtb challenge when administered as prophylactic vaccine. Given the extensive repertoire of potential Mtb antigens available for immune recognition, the data of our model demonstrate the potential of multistage-polyepitope vaccines to protect against TB.     

Chronic intestinal pseudoobstruction in young children

We studied 8 young children (4 boys and 4 girls) with chronic intestinal pseudoobstruction. Intestinal pseudoobstruction, recurrent urinary tract infections, and dysuria occurred between the ages of a few weeks to 5 yr old. All had marked dilatation of the entire gastrointestinal tract distal to the esophagus, and megacystis. Conventional pathologic examinations of the full-thickness specimens of the gastrointestinal tract were normal in 5 and abnormal in 2 patients. The abnormalities included increased fibrosis and lipofuscin pigment in the smooth muscle cells. Myenteric plexus examination, using the Smith's method in 2 patients, was normal. Biopsy specimens from urinary bladders examined in 3 patients revealed separation of individual smooth muscle cells by collagen fibers. Intestinal manometric studies performed in 3 patients showed only weak and infrequent contractions during fasting and after feeding. Severe and extensive dysfunction of the gastrointestinal and urinary tracts with relatively normal histologic appearance are typical for these children.     

Darstellung der Wirkung des Lobelins und der Kohlensäure auf die Atmung des Menschen in der Narkose

Ohne ZusammenfassungDie Arbeit wurde durchgeführt mit Unterstützung des Kuratoriums der Freiburger Wissenschaftlichen Gesellschaft, der auch an dieser Stelle gedankt sei.     

cGMP-Dependent Protein Kinase Type I Is Implicated in the Regulation of the Timing and Quality of Sleep and Wakefulness

Many effects of nitric oxide (NO) are mediated by the activation of guanylyl cyclases and subsequent production of the second messenger cyclic guanosine-3′,5′-monophosphate (cGMP). cGMP activates cGMP-dependent protein kinases (PRKGs), which can therefore be considered downstream effectors of NO signaling. Since NO is thought to be involved in the regulation of both sleep and circadian rhythms, we analyzed these two processes in mice deficient for cGMP-dependent protein kinase type I (PRKG1) in the brain. Prkg1 mutant mice showed a strikingly altered distribution of sleep and wakefulness over the 24 hours of a day as well as reductions in rapid-eye-movement sleep (REMS) duration and in non-REM sleep (NREMS) consolidation, and their ability to sustain waking episodes was compromised. Furthermore, they displayed a drastic decrease in electroencephalogram (EEG) power in the delta frequency range (1–4 Hz) under baseline conditions, which could be normalized after sleep deprivation. In line with the re-distribution of sleep and wakefulness, the analysis of wheel-running and drinking activity revealed more rest bouts during the activity phase and a higher percentage of daytime activity in mutant animals. No changes were observed in internal period length and phase-shifting properties of the circadian clock while chi-squared periodogram amplitude was significantly reduced, hinting at a less robust oscillator. These results indicate that PRKG1 might be involved in the stabilization and output strength of the circadian oscillator in mice. Moreover, PRKG1 deficiency results in an aberrant pattern, and consequently a reduced quality, of sleep and wakefulness, possibly due to a decreased wake-promoting output of the circadian system impinging upon sleep.