Modern medicine has established three central antimicrobial therapeutic concepts: vaccination, antibiotics, and, recently, the use of active immunotherapy to enhance the immune response toward specific pathogens. The efficacy of vaccination and antibiotics is limited by the emergence of new pathogen strains and the increased incidence of antibiotic resistance. To date, immunotherapy development has focused mainly on cytokines. Here we report the successful therapeutic application of a complement component, a recombinant form of properdin (P n ), with significantly higher activity than native properdin, which promotes complement activation via the alternative pathway, affording protection against N. menigitidis and S. pneumoniae. In a mouse model of infection, we challenged C57BL/6 WT mice with N. menigitidis B-MC58 6 h after i.p. administration of P n (100 μg/mouse) or buffer alone. Twelve hours later, all control mice showed clear symptoms of infectious disease while the P n treated group looked healthy. After 16 hours, all control mice developed sepsis and had to be culled, while only 10% of P n treated mice presented with sepsis and recoverable levels of live Meningococci. In a parallel experiment, mice were challenged intranasally with a lethal dose of S. pneumoniae D39. Mice that received a single i.p. dose of P n at the time of infection showed no signs of bacteremia at 12 h postinfection and had prolonged survival times compared with the salinetreated control group (P < 0.0001). Our findings show a significant therapeutic benefit of P n administration and suggest that its antimicrobial activity could open new avenues for fighting infections caused by multidrug-resistant neisserial or streptococcal strains.

SummarySera from a large panel of normal subjects were typed for three common polymorphisms, one in C3 (R102G) and two in Factor H (V62I and Y402H), that influence predisposition to age-related macular degeneration and to some forms of kidney disease. Three groups of sera were tested; those that were homozygous for the three risk alleles; those that were heterozygous for all three; and those homozygous for the low-risk alleles. These groups vary in their response to the addition of exogenous Factor I when the alternative complement pathway is activated by zymosan. Both the reduction in the maximum amount of iC3b formed and the rate at which the iC3b is converted to C3dg are affected. For both reactions the at-risk complotype requires higher doses of Factor I to produce similar down-regulation. Because iC3b reacting with the complement receptor CR3 is a major mechanism by which complement activation gives rise to inflammation, the breakdown of iC3b to C3dg can be seen to have major significance for reducing complement-induced inflammation. These findings demonstrate for the first time that sera from subjects with different complement alleles behave as predicted in an in-vitro assay of the down-regulation of the alternative complement pathway by increasing the concentration of Factor I. These results support the hypothesis that exogenous Factor I may be a valuable therapeutic aid for down-regulating hyperactivity of the C3b feedback cycle, thereby providing a treatment for age-related macular degeneration and other inflammatory diseases of later life.

AIM:To determine the laryngeal H+K+-ATPase and pharyngeal pH in patients with laryngopharyngeal reflux (LPR)-symptoms as well as to assess the symptom scores during PPI therapy. METHODS:Endoscopy was performed to exclude neoplasia and to collect biopsies from the posterior cricoid area (immunohistochemistry and PCR analysis).Immunohistochemical staining was performed with monoclonal mouse antibodies against human H+K+-ATPase. Quantitative real-time RT-PCR for each of the H+K+-ATPase subunits was performed. The pH values were assessed in the aerosolized environment of the oropharynx (DxpH Catheter) and compared to a subsequently applied combined pH/MII measurement. RESULTS:Twenty patients with LPR symptoms were included. In only one patient, the laryngeal H+K+-ATPase was verified by immunohistochemical staining. In another patient, real-time RT-PCR for each H+K+-ATPase subunit was positive. Fourteen out of twenty patients had pathological results in DxpH, and 6/20 patients had pathological results in pH/MII. Four patients had pathological results in both functional tests. Nine out of twenty patients responded to PPIs. CONCLUSION:The laryngeal H+K+-ATPase can only be sporadically detected in patients with LPR symptoms and is unlikely to cause the LPR symptoms. Alternative hypotheses for the pathomechanism are needed. The role of pharyngeal pH-metry remains unclear Prospective Study ORIGINAL ARTICLEBecker V et al . Pathomechansim and diagnosis of LPR and its use can only be recommended for patients in a research study setting. Core tip: The pathophysiology and objective diagnosis of laryngopharyngeal reflux (LPR) is still unclear. The response to standard therapy (proton pump inhibitors) is poor. Laryngeal proton pumps (H+K+-ATPase) are often considered to be potential causes of LPR. The clinical significance of laryngeal proton pumps (H+K+-ATPase) is unclear. We present the first prospective series evaluating the laryngeal H+K+-ATPase, pharyngeal pH and symptom scores in patients with LPR symptoms. Laryngeal H+K+-ATPases can only be sporadically detected, and they are unlikely to cause LPR symptoms. The role of pharyngeal pH-metry remains unclear and its use can only be recommended for patients in the research study setting.Becker V, Drabner R, Graf S, Schlag C, Nennstiel S, Buchberger AM, Schmid RM, Saur D, Bajbouj M. New aspects in the pathomechanism and diagnosis of the laryngopharyngeal reflux-clinical impact of laryngeal proton pumps and pharyngeal pH metry in extraesophageal gastroesophageal reflux disease. World J Gastroenterol 2015; 21(3): 982-987 Available from:

SummaryIn this paper we have extended our earlier studies of the action of increasing Factor I concentration on complement activation by using a soluble activator, lipopolysaccharide (LPS) endotoxin, and using human erythrocytes as a source of CR1 -the co-factor needed for the final clip of iC3b to C3dg by Factor I. Using this more physiological system, the results show that we can predict that a quite modest increase in Factor I concentration -22 mg/ml of extra Factor I -will convert the activity of the highest risk sera to those of the lowest risk. Preliminary experiments have been performed with erythrocytes allotyped for CR1 number. While we have not been able to perform an adequate study of their co-factor activities in our assays, preliminary experiments suggest that when Factor I levels are increased the difference produced by different allotypes of red cells is largely overcome. This suggests that in patients with paroxysmal nocturnal haemoglobinuria (PNH) treated with eculizumab, additional treatment with Factor I may be very useful in reducing the need for blood transfusion. We have also explored the age-related allele frequency for the two polymorphisms of Factor H and the polymorphism of C3. In our population, unlike the 1975 study, we found no age variation in the allele frequency in these polymorphisms. This may, however, reflect that the Cambridge BioResource volunteers do not include many very young or very elderly patients, and in general comprise a population not greatly at risk of death from infectious disease.