Evolution: the paradox of sperm leviathans

Sexual selection theory predicts that sperm competition will push males to produce more, smaller sperm. Paradoxically, in the fruitfly Drosophila bifurca sperm competition is rife but males produce few, giant sperm--the largest known. A recent study reconciles the evolution of giant sperm with theory.     

MARCKS actin-binding capacity mediates actin filament assembly during mitosis in human hepatic stellate cells

Cross-linking between the actin cytoskeleton and plasma membrane actin-binding proteins is a key interaction responsible for the mechanical properties of the mitotic cell. Little is known about the identity, the localization, and the function of actin filament-binding proteins during mitosis in human hepatic stellate cells (hHSC). The aim of the present study was to identify and analyze the cross talk between actin and myristoylated alanine-rich kinase C substrate (MARCKS), an important PKC substrate and actin filament-binding protein, during mitosis in primary hHSC. Confocal analysis and chromosomal fraction analysis of mitotic hHSC demonstrated that phosphorylated (P)-MARCKS displays distinct phase-dependent localizations, accumulates at the perichromosomal layer, and is a centrosomal protein belonging to the chromosomal cytosolic fraction. Aurora B kinase (AUBK), an important mitotic regulator, β-actin, and P-MARCKS concentrate at the cytokinetic midbody during cleavage furrow formation. This localization is critical since MARCKS-depletion in hHSC is characterized by a significant loss in cytosolic actin filaments and cortical β-actin that induces cell cycle inhibition and dislocation of AUBK. A depletion of AUBK in hHSC affects cell cycle, resulting in multinucleation. Quantitative live cell imaging demonstrates that the actin filament-binding capacity of MARCKS is key to regulate mitosis since the cell cycle inhibitory effect in MARCKS-depleted cells caused abnormal cell morphology and an aberrant cytokinesis, resulting in a significant increase in cell cycle time. These findings implicate that MARCKS, an important PKC substrate, is essential for proper cytokinesis and that MARCKS and its partner actin are key mitotic regulators during cell cycle in hHSC.     

Factors Influencing the Measurement of Lysosomal Enzymes Activity in Human Cerebrospinal Fluid

Measurements of the activities of lysosomal enzymes in cerebrospinal fluid have recently been proposed as putative biomarkers for Parkinson''s disease and other synucleinopathies. To define the operating procedures useful for ensuring the reliability of these measurements, we analyzed several pre-analytical factors that may influence the activity of β-glucocerebrosidase, α-mannosidase, β-mannosidase, β-galactosidase, α-fucosidase, β-hexosaminidase, cathepsin D and cathepsin E in cerebrospinal fluid. Lysosomal enzyme activities were measured by well-established fluorimetric assays in a consecutive series of patients (n = 28) with different neurological conditions, including Parkinson''s disease. The precision, pre-storage and storage conditions, and freeze/thaw cycles were evaluated. All of the assays showed within- and between-run variabilities below 10%. At −20°C, only cathepsin D was stable up to 40 weeks. At −80°C, the cathepsin D, cathepsin E, and β-mannosidase activities did not change significantly up to 40 weeks, while β-glucocerebrosidase activity was stable up to 32 weeks. The β-galactosidase and α-fucosidase activities significantly increased (+54.9±38.08% after 4 weeks and +88.94±36.19% after 16 weeks, respectively). Up to four freeze/thaw cycles did not significantly affect the activities of cathepsins D and E. The β-glucocerebrosidase activity showed a slight decrease (−14.6%) after two freeze/thaw cycles. The measurement of lysosomal enzyme activities in cerebrospinal fluid is reliable and reproducible if pre-analytical factors are accurately taken into consideration. Therefore, the analytical recommendations that ensue from this study may contribute to the establishment of actual values for the activities of cerebrospinal fluid lysosomal enzymes as putative biomarkers for Parkinson''s disease and other neurodegenerative disorders.     

MF59?-Adjuvanted H5N1 Vaccine Induces Immunologic Memory and Heterotypic Antibody Responses in Non-Elderly and Elderly Adults

Background

Pathogenic avian influenza virus (H5N1) has the potential to cause a major global pandemic in humans. Safe and effective vaccines that induce immunologic memory and broad heterotypic response are needed.

Methods and Findings

Healthy adults aged 18–60 and >60 years (n = 313 and n = 173, respectively) were randomized (1∶1) to receive two primary and one booster injection of 7.5 μg or 15 μg doses of a subunit MF59-adjuvanted H5N1 (A/Vietnam/1194/2004) (clade 1) vaccine. Safety was monitored until 6 months after booster. Immunogenicity was assessed by hemagglutination inhibition (HI), single radial hemolysis (SRH) and microneutralization assays (MN). Mild injection-site pain was the most common adverse reaction. No serious adverse events relating to the vaccine were reported. The humoral immune responses to 7.5 μg and 15 μg doses were comparable. The rates for seroprotection (HI>40; SRH>25mm²; MN ≥40) after the primary vaccination ranged 72–87%. Six months after primary vaccination with the 7.5 μg dose, 18% and 21% of non-elderly and elderly adults were seroprotected; rates increased to 90% and 84%, respectively, after the booster vaccination. In the 15 μg group, seroprotection rates among non-elderly and elderly adults increased from 25% and 62% after primary vaccination to 92% and 88% after booster vaccination, respectively. A heterologous immune response to the H5N1/turkey/Turkey/05 strain was elicited after second and booster vaccinations.

Conclusions

Both formulations of MF59-adjuvanted influenza H5N1 vaccine were well tolerated. The European Union requirement for licensure for pre-pandemic vaccines was met by the lower dose tested. The presence of cross-reactive antibodies to a clade 2 heterologous strain demonstrates that this vaccine may be appropriate for pre-pandemic programs.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00311480","term_id":"NCT00311480"}}NCT00311480     

Probiotics Reduce Inflammation in Antiretroviral Treated,HIV-Infected Individuals: Results of the “Probio-HIV” Clinical Trial

Background

HIV infection results in damage to the gastrointestinal (GI) tract, microbial translocation and immune activation. These are not completely normalized with combined antiretroviral therapy (cART). Moreover, increate morbidity and mortality of cART-treated HIV-infected individuals is associated with inflammation.

Methods

In order to enhance GI tract immunity, we recruited and treated 20 HIV-infected humans with cART supplemented with probiotics and followed inflammation and immunological parameters (clinical trial number NCT02164344). 11 HIV seronegative subjects were included as control group. The enumeration of CD4+, CD8+, CD38+ and HLA-DR+ lymphocytes were evaluated on peripheral blood; HIV-RNA levels, sCD14, d-dimer, C-reactive protein (CRP) high sensitivity C-reactive protein (hsCRP), IL-6 and Lipopolysaccharide Binding Protein (LBP) were assayed on plasma.

Results

We observe that cART does not normalize the levels of immune activation in HIV positive patients anyway inflammation and markers of microbial translocation were significantly reduced with probiotic supplementation. Patients show a clear and statistically significant reduction in the levels of immune activation on CD4 T-lymphocytes, for both markers CD38 and HLA-DR and their simultaneous expression, LBP and hsCRP plasma levels after probiotic diet supplementation settling to values comparable to controls.

Conclusions

Supplementing cART with probiotics in HIV-infected individuals may improve GI tract immunity and there by mitigate inflammatory sequelae, ultimately improving prognosis.

Trial Registration

ClinicalTrials.gov NCT02164344     

Apolipoprotein C-II deficiency: detection of immunoreactive apolipoprotein C-II in the intestinal mucosa of two patients

Recent data suggest that mutant immunoreactive forms of apolipoprotein C-II (apoC-II) can be detected in the plasma of patients with the apoC-II deficiency syndrome. We studied the possible presence of apoC-II mutants in the plasma of two patients with apoC-II deficiency by immunological means. The patients were hypertriglyceridemic, and apoC-II was undetectable in plasma as determined by radial immunodiffusion, electroimmunoassay, and immunonephelometry. Furthermore, apoC-II was undetectable either by electrophoresis or by immunoblotting in the plasma of the probands, while apoC-II was present in the plasma of their parents, although at less than half-normal concentration. Immunochemical localization of apoC-II, however, showed that the apoprotein could be detected within the enterocytes obtained from the intestinal mucosa of the patients. From these data we conclude that the patients synthesize apoC-II, at least in the intestine.     

Copia and Gypsy retrotransposons activity in sunflower (Helianthus annuus L.)

Background  

Retrotransposons are heterogeneous sequences, widespread in eukaryotic genomes, which refer to the so-called mobile DNA. They resemble retroviruses, both in their structure and for their ability to transpose within the host genome, of which they make up a considerable portion. Copia- and Gypsy-like retrotransposons are the two main classes of retroelements shown to be ubiquitous in plant genomes. Ideally, the retrotransposons life cycle results in the synthesis of a messenger RNA and then self-encoded proteins to process retrotransposon mRNA in double stranded extra-chromosomal cDNA copies which may integrate in new chromosomal locations.