Complement Defects in Patients with Chronic Rhinosinusitis

The complement system is an important part of our immune system, and complement defects lead generally to increased susceptibility to infections and autoimmune diseases. We have studied the role of complement activity in relation with chronic rhinosinusitis (CRS), and more specifically studied whether complement defects collectively predispose individuals for CRS or affect CRS severity. The participants comprised 87 CRS patients randomly selected from the general population, and a control group of 150 healthy blood donors. The CRS patients were diagnosed according to the European Position Paper on Rhinosinusitis and nasal Polyps criteria, and severity was evaluated by the Sino-nasal Outcome Test-22. Serum samples were analysed by ELISA for activity of the respective pathways of complement, and subsequently for serum levels of relevant components. We found that the frequency of complement defects was significantly higher among CRS patients than among healthy control subjects. A majority of Mannan-binding lectin deficient CRS patients was observed. The presence of complement defects had no influence on the severity of subjective symptoms. Our studies show that defects in the complement system collectively may play an immunological role related to the development of CRS. However, an association between severity of symptoms and presence of complement defects could not be demonstrated.     

Clinical-grade manufacturing of autologous mature mRNA-electroporated dendritic cells and safety testing in acute myeloid leukemia patients in a phase I dose-escalation clinical trial

Background aimsRNA-electroporated dendritic cell (DC)-based vaccines are rapidly gaining interest as therapeutic cancer vaccines. We report on a phase I dose-escalation trial using clinical-grade manufactured mature RNA-electroporated DC in acute myeloid leukemia (AML) patients.MethodsCD14⁺ cells were isolated from leukapheresis products by immunomagnetic CliniMACS separation and differentiated into mature DC (mDC). mDC were electroporated with clinical-grade mRNA encoding the Wilm's tumor (WT1) antigen, and tested for viability, phenotype, sterility and recovery. To test product safety, increasing doses of DC were administered intradermally four times at 2-week intervals in 10 AML patients.ResultsIn a pre-clinical phase, immunomagnetic monocyte isolation proved superior over plastic adherence in terms of DC purity and lymphocyte contamination. We also validated a simplified DC maturation protocol yielding a consistent phenotype, migration and allogeneic T-cell stimulatory capacity in AML patients in remission. In the clinical trial, highly purified CD14⁺ cells (94.5 ± 3.4%) were obtained from all patients. A monocyte-to-mDC conversion factor of 25 ± 10% was reached. All DC preparations exhibited high expression of mDC markers. Despite a decreased cell recovery of mDC after a combination of mRNA electroporation and cryopreservation, successful vaccine preparations were obtained in all AML patients. DC injections were well tolerated by all patients.ConclusionsOur method yields a standardized, simplified and reproducible preparation of multiple doses of clinical-grade mRNA-transfected DC vaccines from a single apheresis with consistent mature phenotype, recovery, sterility and viability. Intradermal injection of such DC vaccines in AML patients is safe.     

Shaping the phylogenetic tree of influenza by cross-immunity

Cross-immunity among related strains can account for the selection producing the slender phylogenetic tree of influenza A and B in humans. Using a model of seasonal influenza epidemics with drift (Andreasen, 2003. Dynamics of annual influenza A epidemics with immuno-selection. J. Math. Biol. 46, 504-536), and assuming that two mutants arrive in the host population sequentially, we determine the threshold condition for the establishment of the second mutant in the presence of partial cross-protection caused by the first mutant and their common ancestors. For fixed levels of cross-protection, the chance that the second mutant establishes increases with rho the basic reproduction ratio and some temporary immunity may be necessary to explain the slenderness of flu's phylogenetic tree. In the presence of moderate levels of temporary immunity, an asymmetric situation can arise in the season after the two mutants were introduced and established: if the offspring of the new mutant arrives before the offspring of the resident type, then the mutant-line may produce a massive epidemic suppressing the original lineage. However, if the original lineage arrives first then both strains may establish and the phylogenetic tree may bifurcate.     

The SIRC model and influenza A

We develop a simple ordinary differential equation model to study the epidemiological consequences of the drift mechanism for influenza A viruses. Improving over the classical SIR approach, we introduce a fourth class (C) for the cross-immune individuals in the population, i.e., those that recovered after being infected by different strains of the same viral subtype in the past years. The SIRC model predicts that the prevalence of a virus is maximum for an intermediate value of R(0), the basic reproduction number. Via a bifurcation analysis of the model, we discuss the effect of seasonality on the epidemiological regimes. For realistic parameter values, the model exhibits a rich variety of behaviors, including chaos and multi-stable periodic outbreaks. Comparison with empirical evidence shows that the simulated regimes are qualitatively and quantitatively consistent with reality, both for tropical and temperate countries. We find that the basins of attraction of coexisting cycles can be fractal sets, thus predictability can in some cases become problematic even theoretically. In accordance with previous studies, we find that increasing cross-immunity tends to complicate the dynamics of the system.     

Nucleotide sequence of an endo-β-1,4-glucanase gene fromBacillus subtilis CK-2

The gene encoding endo--1,4-glucanase inBacillus subtilis CK-2 was cloned intoEscherichia coli DH5, and the nucleotide sequence determined. The 1500 bp gene encodes a protein of 499 amino-acid residues with a calculated molecular mass of 55 261, and is equipped with a typicalB. subtilis signal peptide. Nucleotide sequence comparison revealed only 2 basepairs deviation between this gene and the endo--1,4-glucanase gene ofB. subtilis PAP115, and 93% to 95% homology was found between the amino acid sequences of these enzymes and otherB. subtilis endo--1,4-glucanases. Regions of similarity were also observed between the carboxy-terminal part of these enzymes and the part of theB. lautus PL236celA enzyme constituting the cellulose-binding domain.     

Comparison and definition of spleen and lymph node: a phylogenetic analysis

The hitherto largely unsolved problem with a biological definition of spleen versus lymph node seems possible to solve from a phylogenetic point of view. Thus, it is suggested that the spleen be defined as a hemopoietic organ which is able to filter blood with sinusoids. In contradistinction, a lymph node is defined as a hemopoietic organ which is able to filter lymph with sinusoids. Comparative anatomical studies show that the spleen appears as a condensation of the lymphomyeloid complex in the spiral fold of the gut in cyclostomes. The spiral fold spleen vanishes with the bony fishes, while in cartilaginous fishes a similar spleen appears in the dorsal mesentery. The dorsal spleen remains in a retroperitoneal position in higher vertebrates and is regarded as a specialized blood vessel compartment closely connected with the blood stream. In "higher" vertebrates the spleen is a stagnated organ because splenic functions are gradually transferred to other sites. The bone marrow takes over the erythro-, thrombo- and granulocytopoiesis while the lymph nodes take over the lymphocytopoiesis. This transfer of the splenic functions is first seen in anurans and seems to be a marvelous adaptation to life on land where the need for local defence against a large number of antigens is necessary before spread of the antigens to central parts of the body. In higher vertebrates, the great number of lymph nodes at peripheral positions, derived from the lymphatic vessels, are able to do so. It is demonstrated that the definitions of spleen and lymph nodes as hemopoietic organs which by their sinusoids are able to filter blood and lymph, respectively, are not only of semantic interest but also useful in regard the immunohematological system as an entity.     

The Acute Effect of Ammonium Acetate on Levels of Amino Acids in the Intact and Decorticated Rat Neostriatum

Unilateral frontal cortex ablations were performed in rats so that the glutamate terminals in the ipsilateral rostral neostriatum were removed. At 1 or 7 days later, intraperitoneal injections of ammonium acetate induced different changes in amino acid concentrations in the intact and deafferentated neostriatum. After 1 day, the level of glutamate decreased only in the intact side, whereas that of glutamine increased and that of aspartate decreased to the same extent on both sides following ammonia injection. After 7 days, the glutamate level decreased more in the intact than the decorticated side in both nonconvulsing and convulsing rats. The concentration of alanine increased most in the intact neostriatum, whereas glutamine levels increased and aspartate levels decreased to the same extent on both sides in nonconvulsing and convulsing rats. The results indicate that ammonia has a more pronounced effect on neuronal than glial glutamate pools.     

Dynamics of annual influenza A epidemics with immuno-selection

 The persistence of Influenza A in the human population relies on continual changes in the viral surface antigens allowing the virus to reinfect the same hosts every few years. The epidemiology of such a drifting virus is modeled by a discrete season-to-season map. During the epidemic season only one strain is present and its transmission dynamics follows a standard epidemic model. After the season, cross-immunity to next year's virus is determined from the proportion of hosts that were infected during the season. A partial analysis of this map shows the existence of oscillations where epidemics occur at regular or irregular intervals. Received: 16 February 2001 / Revised version: 11 June 2002 / Published online: 28 February 2003 Key words or phrases: Infectious disease – Influenza drift – Cross-immunity – Seasonal epidemics – Iterated map