Phylogeny, genetic variability and colour polymorphism of an emerging animal model: the short-lived annual Nothobranchius fishes from southern Mozambique

Nothobranchius are a group of small, extremely short-lived killifishes living in temporary savannah pools in Eastern Africa and that survive annual desiccation of their habitat as dormant eggs encased in dry mud. One mitochondrial (COI) and three nuclear (CX32.2, GHITM, PNP) loci were used to investigate the phylogenetic relationship of Nothobranchius species from southern and central Mozambique. This group shows marked variation in captive lifespan at both the inter- and intraspecific levels; lifespan varies from a few months to over a year. As their distribution encompasses a steep gradient between semi-arid and humid habitats, resulting in contrasting selection pressures on evolution of lifespan and associated life history traits, Mozambican Nothobranchius spp. have recently become a model group in studies of ageing, age-related disorders and life history evolution. Consequently, intraspecific genetic variation and male colour morph distribution was also examined in the recovered clades. Using Bayesian species tree reconstruction and single loci analyses, three large clades were apparent and their phylogenetic substructure was revealed at the inter- and intra-specific levels within those clades. The Nothobranchius furzeri and Nothobranchius orthonotus clades were strongly geographically structured. Further, it was demonstrated that male colour has no phylogenetic signal in N. furzeri, where colour morphs are sympatric, but is associated with two reciprocally monophyletic groups in Nothobranchius rachovii clade, where colour morphs are parapatric. Finally, our analysis showed that a polymorphism in the Melanocortin1 receptor gene (which controls pigmentation in many vertebrates and was a candidate gene of male colouration in N. furzeri) is unrelated to colour phenotypes of the study species. Our results raise significant implications for future comparative studies of the species and populations analysed in the present work.     

Profiling of Humoral Response to Influenza A(H1N1)pdm09 Infection and Vaccination Measured by a Protein Microarray in Persons with and without History of Seasonal Vaccination

Background

The influence of prior seasonal influenza vaccination on the antibody response produced by natural infection or vaccination is not well understood.

Methods

We compared the profiles of antibody responses of 32 naturally infected subjects and 98 subjects vaccinated with a 2009 influenza A(H1N1) monovalent MF59-adjuvanted vaccine (Focetria®, Novartis), with and without a history of seasonal influenza vaccination. Antibodies were measured by hemagglutination inhibition (HI) assay for influenza A(H1N1)pdm09 and by protein microarray (PA) using the HA1 subunit for seven recent and historic H1, H2 and H3 influenza viruses, and three avian influenza viruses. Serum samples for the infection group were taken at the moment of collection of the diagnostic sample, 10 days and 30 days after onset of influenza symptoms. For the vaccination group, samples were drawn at baseline, 3 weeks after the first vaccination and 5 weeks after the second vaccination.

Results

We showed that subjects with a history of seasonal vaccination generally exhibited higher baseline titers for the various HA1 antigens than subjects without a seasonal vaccination history. Infection and pandemic influenza vaccination responses in persons with a history of seasonal vaccination were skewed towards historic antigens.

Conclusions

Seasonal vaccination is of significant influence on the antibody response to subsequent infection and vaccination, and further research is needed to understand the effect of annual vaccination on protective immunity.     

Protease inhibitors clitocypin and macrocypin are differentially expressed within basidiomycete fruiting bodies

Clitocypin and macrocypin are cysteine protease inhibitors of the mycocypin family which is unique to basidiomycetes. We have established that Clitocybe nebularis and Macrolepiota procera each contain genes for both macrocypin and clitocypin. Both are expressed in M. procera but only clitocypin in C. nebularis. Further analysis of mycocypin expression at the mRNA and protein levels in mature fruiting bodies of M. procera revealed that clitocypin is expressed evenly throughout the fruiting body, while the level of expression of macrocypins varies, and, at the protein level, is much higher in the veil fragments and the ring. The expression patterns of various mycocypins were determined in Coprinopsis cinerea, using promoters linked to a reporter gene. The expression profile of the clitocypin promoter was similar to that of the constitutive promoter gpdII from Agaricus bisporus, while that of the macrocypin 4 promoter was limited to the outer edges of the fruiting body throughout development. In addition, the activity of the macrocypin 3 promoter was different, indicating different regulation of expression for different macrocypin genes. The complex, tissue specific expression patterns for mycocypin genes suggest different biological roles for the products, either in regulation of endogenous proteases or in defense against pathogens or predators.     

The rising incidence and mortality of prostate cancer in Belgrade population

The purpose of this study was to analyze the epidemiological situation of prostate cancer in Belgrade population. Morbidity data were obtained from the Institute of Public Health of Serbia for the period 1999-2005. Mortality data for the period 1990-2006, were derived from the Statistical Office of Republic of Serbia. Average standardized incidence and mortality rates for the prostate cancer were 33.57 and 11.86 respectively. Standardized incidence rates of prostate cancer steadily increased from 29.34 per 100,000 in 1999 to 36.86 per 100,000 in 2005. In the observed period, the mortality rates significantly increased in the age groups 50-59 (y = 2.77+0.42x, p = 0.015), 70-79 (y = 61.92+10.70x, p = 0.000) and 80+ (y = 183.08+19.99x, p = 0.000). The average annual percentage of changes (AAPC) was the highest (7.2%) for the 70-79 age group, the lowest (0.1%) for the youngest group (< or = 50), and 5% for the total. The increase of prostate cancer incidence and mortality during the observed period in Belgrade population indicate urgent need for Serbian health professionals to adopt existing evidence-based cancer control and preventive measures. A national policy including prostate specific antigen (PSA) screening should be considered.     

Repeated in vivo stimulation of T and B cell responses in old mice generates protective immunity against lethal West Nile virus encephalitis

Older adults exhibit higher morbidity and mortality from infectious diseases compared with those of the general population. The introduction and rapid spread of West Nile virus (WNV) throughout the continental United States since 1999 has highlighted the challenge of protecting older adults against emerging pathogens: to this day there is no therapy or vaccine approved for human use against West Nile encephalitis. In this study, we describe the characterization of T and B cell responses in old mice after vaccination with RepliVAX WN, a novel West Nile encephalitis vaccine based on single-cycle flavivirus particles. In adult mice, RepliVAX WN induced robust and long-lasting CD4(+) and CD8(+) T cell and Ab (B cell) responses against natural WNV epitopes, similar to those elicited by primary WNV infection. Primary and memory T and B cell responses in old mice against RepliVAX WN vaccination were significantly lower than those seen in younger mice, similar to the response of old mice to infection with WNV. Surprisingly, both the quality and the quantity of the recall Ab and T cell responses in vaccinated old mice were improved to equal or exceed those in adult animals. Moreover, these responses together (but not individually) were sufficient to protect both old and adult mice from severe WNV disease upon challenge. Therefore, at least two cycles of in vivo restimulation are needed for selection and expansion of protective lymphocytes in older populations, and live, single-cycle virus vaccines that stimulate both cellular and humoral immunity can protect older individuals against severe viral disease.     

Functional CD8 T cell memory responding to persistent latent infection is maintained for life

Aging is associated with depressed naive T cell responses, but it is less clear whether T cell memory established early in life also becomes impaired with age. This is particularly important for T cells responding to latent persistent infection, which need to remain functional and capable of controlling the infection over the lifetime; however, repeated stimulation over the lifetime may dysregulate their maintenance or function, potentially contributing to impaired immunity in the elderly. Systemic infection with HSV-1, a persistent latent virus, is associated with memory inflation of virus-specific CD8 T cells. We tested how these inflated memory cells are maintained from adulthood into old age. We found no significant differences in the numbers (i.e., blood, spleen), ex vivo Ag-specific IFN-γ production, and in vivo recall response to HSV-1 (i.e., proliferation, IFN-γ production, cytolysis) between adult and old memory T cells. There was a discrete shift from dominantly effector memory phenotype in the adults to a central memory-like phenotype in the old mice, with fewer old cells expressing the killer cell lectin-like receptor G1 (KLRG1). Adult and old KLRG1(+) memory CD8 T cells were functionally identical: both produced IFN-γ but could minimally proliferate in response to viral challenge. Interestingly, regardless of age, KLRG1(+) cells retained the ability to proliferate and survive in response to homeostatic signals, both in vitro (culture with IL-7 and IL-15) and in vivo (expansion following transfer into lymphopenic recipients). This finding demonstrates that functional effector memory T cells, including those expressing KLRG-1, are maintained and are functional for life, despite the presence of persistent viral infection.     

Structural investigations on native collagen type I fibrils using AFM

This study was carried out to determine the elastic properties of single collagen type I fibrils with the use of atomic force microscopy (AFM). Native collagen fibrils were formed by self-assembly in vitro characterized with the AFM. To confirm the inner assembly of the collagen fibrils, the AFM was used as a microdissection tool. Native collagen type I fibrils were dissected and the inner core uncovered. To determine the elastic properties of collagen fibrils the tip of the AFM was used as a nanoindentor by recording force-displacement curves. Measurements were done on the outer shell and in the core of the fibril. The structural investigations revealed the banding of the shell also in the core of native collagen fibrils. Nanoindentation experiments showed the same Young's modulus on the shell as well as in the core of the investigated native collagen fibrils. In addition, the measurements indicate a higher adhesion in the core of the collagen fibrils compared to the shell.     

Immune Protection against Virus Challenge in Aging Mice Is Not Affected by Latent Herpesviral Infections

Latent herpesvirus infections alter immune homeostasis. To understand if this results in aging-related loss of immune protection against emerging infections, we challenged old mice carrying latent mouse cytomegalovirus (CMV), herpes simplex virus 1 (HSV-1), and/or murine gammaherpesvirus 68 (MHV-68) with influenza virus, West Nile virus (WNV), or vesicular stomatitis virus (VSV). We observed no increase in mortality or weight loss compared to results seen with herpesvirus-negative counterparts and a relative but not absolute reduction in CD8 responses to acute infections. Therefore, the presence of herpesviruses does not appear to increase susceptibility to emerging infections in aging patients.