362 research outputs found
‘O sibling, where art thou?’ – a review of avian sibling recognition with respect to the mammalian literature
Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where ‘mixing potential’ of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through ‘direct familiarisation’ (commonly known as associative learning or familiarity); future experiments should also incorporate tests for ‘indirect familiarisation’ (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic
Matched sizes of activating and inhibitory receptor/ligand pairs are required for optimal signal integration by human Natural Killer cells
It has been suggested that receptor-ligand complexes segregate or co-localise within immune synapses according to their size, and this is important for receptor signaling. Here, we set out to test the importance of receptor-ligand complex dimensions for immune surveillance of target cells by human Natural Killer (NK) cells. NK cell activation is regulated by integrating signals from activating receptors, such as NKG2D, and inhibitory receptors, such as KIR2DL1. Elongating the NKG2D ligand MICA reduced its ability to trigger NK cell activation. Conversely, elongation of KIR2DL1 ligand HLA-C reduced its ability to inhibit NK cells. Whereas normal-sized HLA-C was most effective at inhibiting activation by normal-length MICA, only elongated HLA-C could inhibit activation by elongated MICA. Moreover, HLA-C and MICA that were matched in size co-localised, whereas HLA-C and MICA that were different in size were segregated. These results demonstrate that receptor-ligand dimensions are important in NK cell recognition, and suggest that optimal integration of activating and inhibitory receptor signals requires the receptor-ligand complexes to have similar dimensions
ESLpred2: improved method for predicting subcellular localization of eukaryotic proteins
<p>Abstract</p> <p>Background</p> <p>The expansion of raw protein sequence databases in the post genomic era and availability of fresh annotated sequences for major localizations particularly motivated us to introduce a new improved version of our previously forged eukaryotic subcellular localizations prediction method namely "ESLpred". Since, subcellular localization of a protein offers essential clues about its functioning, hence, availability of localization predictor would definitely aid and expedite the protein deciphering studies. However, robustness of a predictor is highly dependent on the superiority of dataset and extracted protein attributes; hence, it becomes imperative to improve the performance of presently available method using latest dataset and crucial input features.</p> <p>Results</p> <p>Here, we describe augmentation in the prediction performance obtained for our most popular ESLpred method using new crucial features as an input to Support Vector Machine (SVM). In addition, recently available, highly non-redundant dataset encompassing three kingdoms specific protein sequence sets; 1198 fungi sequences, 2597 from animal and 491 plant sequences were also included in the present study. First, using the evolutionary information in the form of profile composition along with whole and N-terminal sequence composition as an input feature vector of 440 dimensions, overall accuracies of 72.7, 75.8 and 74.5% were achieved respectively after five-fold cross-validation. Further, enhancement in performance was observed when similarity search based results were coupled with whole and N-terminal sequence composition along with profile composition by yielding overall accuracies of 75.9, 80.8, 76.6% respectively; best accuracies reported till date on the same datasets.</p> <p>Conclusion</p> <p>These results provide confidence about the reliability and accurate prediction of SVM modules generated in the present study using sequence and profile compositions along with similarity search based results. The presently developed modules are implemented as web server "ESLpred2" available at <url>http://www.imtech.res.in/raghava/eslpred2/</url>.</p
Visual Information Alone Changes Behavior and Physiology during Social Interactions in a Cichlid Fish (Astatotilapia burtoni)
Social behavior can influence physiological systems dramatically yet the sensory
cues responsible are not well understood. Behavior of male African cichlid fish,
Astatotilapia burtoni, in their natural habitat suggests
that visual cues from conspecifics contribute significantly to regulation of
social behavior. Using a novel paradigm, we asked whether visual cues alone from
a larger conspecific male could influence behavior, reproductive physiology and
the physiological stress response of a smaller male. Here we show that just
seeing a larger, threatening male through a clear barrier can suppress dominant
behavior of a smaller male for up to 7 days. Smaller dominant males being
“attacked” visually by larger dominant males through a clear barrier
also showed physiological changes for up to 3 days, including up-regulation of
reproductive- and stress-related gene expression levels and lowered plasma
11-ketotestesterone concentrations as compared to control animals. The smaller
males modified their appearance to match that of non-dominant males when exposed
to a larger male but they maintained a physiological phenotype similar to that
of a dominant male. After 7 days, reproductive- and stress- related gene
expression, circulating hormone levels, and gonad size in the smaller males
showed no difference from the control group suggesting that the smaller male
habituated to the visual intruder. However, the smaller male continued to
display subordinate behaviors and assumed the appearance of a subordinate male
for a full week despite his dominant male physiology. These data suggest that
seeing a larger male alone can regulate the behavior of a smaller male but that
ongoing reproductive inhibition depends on additional sensory cues. Perhaps,
while experiencing visual social stressors, the smaller male uses an
opportunistic strategy, acting like a subordinate male while maintaining the
physiology of a dominant male
Integrated Genomic and Gene Expression Profiling Identifies Two Major Genomic Circuits in Urothelial Carcinoma
Similar to other malignancies, urothelial carcinoma (UC) is characterized by specific recurrent chromosomal aberrations and gene mutations. However, the interconnection between specific genomic alterations, and how patterns of chromosomal alterations adhere to different molecular subgroups of UC, is less clear. We applied tiling resolution array CGH to 146 cases of UC and identified a number of regions harboring recurrent focal genomic amplifications and deletions. Several potential oncogenes were included in the amplified regions, including known oncogenes like E2F3, CCND1, and CCNE1, as well as new candidate genes, such as SETDB1 (1q21), and BCL2L1 (20q11). We next combined genome profiling with global gene expression, gene mutation, and protein expression data and identified two major genomic circuits operating in urothelial carcinoma. The first circuit was characterized by FGFR3 alterations, overexpression of CCND1, and 9q and CDKN2A deletions. The second circuit was defined by E3F3 amplifications and RB1 deletions, as well as gains of 5p, deletions at PTEN and 2q36, 16q, 20q, and elevated CDKN2A levels. TP53/MDM2 alterations were common for advanced tumors within the two circuits. Our data also suggest a possible RAS/RAF circuit. The tumors with worst prognosis showed a gene expression profile that indicated a keratinized phenotype. Taken together, our integrative approach revealed at least two separate networks of genomic alterations linked to the molecular diversity seen in UC, and that these circuits may reflect distinct pathways of tumor development
Influence of Cytokines on HIV-Specific Antibody-Dependent Cellular Cytotoxicity Activation Profile of Natural Killer Cells
There is growing interest in HIV-specific antibody-dependent cellular cytotoxicity (ADCC) as an effective immune response to prevent or control HIV infection. ADCC relies on innate immune effector cells, particularly NK cells, to mediate control of virus-infected cells. The activation of NK cells (i.e., expression of cytokines and/or degranulation) by ADCC antibodies in serum is likely subject to the influence of other factors that are also present. We observed that the HIV-specific ADCC antibodies, within serum samples from a panel of HIV-infected individuals induced divergent activation profiles of NK cells from the same donor. Some serum samples primarily induced NK cell cytokine expression (i.e., IFNγ), some primarily initiated NK cell expression of a degranulation marker (CD107a) and others initiated a similar magnitude of responses across both effector functions. We therefore evaluated a number of HIV-relevant soluble factors for their influence on the activation of NK cells by HIV-specific ADCC antibodies. Key findings were that the cytokines IL-15 and IL-10 consistently enhanced the ability of NK cells to respond to HIV-specific ADCC antibodies. Furthermore, IL-15 was demonstrated to potently activate “educated” KIR3DL1+ NK cells from individuals carrying its HLA-Bw4 ligand. The cytokine was also demonstrated to activate “uneducated” KIR3DL1+ NK cells from HLA-Bw6 homozygotes, but to a lesser extent. Our results show that cytokines influence the ability of NK cells to respond to ADCC antibodies in vitro. Manipulating the immunological environment to enhance the potency of NK cell-mediated HIV-specific ADCC effector functions could be a promising immunotherapy or vaccine strategy
Assessing Perceived Risk and STI Prevention Behavior: A National Population-Based Study with Special Reference to HPV
Aim: This thesis aims to provide a multidimensional assessment of infection risks and
to evaluate strategies for HPV prevention including vaccination with quadrivalent HPVvaccines,
dose-level vaccine effectiveness and condom use in high STI risk situations.
Methods: Multiple population-based registers and questionnaire responses provided data
for this thesis. Various multivariable and univariate regression models were fit.
Findings: Overall, quadrivalent HPV-vaccination was highly effective against genital
warts (GW) also referred to as condyloma, which is the first HPV disease endpoint
possible to measure. However, effectiveness was contingent upon young age-at-first
vaccination, with effectiveness declining steadily the older the age-at-first vaccination.
Among women above 20 years of age there was low to immeasurable effectiveness and
suggestive evidence vaccinations in this age group tended to reach women at high GW
risk. There were marked socioeconomic disparities in the opportunistic (on-demand with
co-pay) vaccination strategy evaluated, with women and girls who have parents with
the highest education level compared to the lowest having a 15 times greater likelihood
to be vaccinated (Study III). Once vaccination was initiated, however, high parental
education level was unrelated to vaccination completion. Maximum protection against
GW was found among girls vaccinated under the age of 17 who had received three doses
of the vaccine. No differences in effectiveness were found for girls who received twodoses
between ages 10-16 with that of those who received three-doses between ages 17-
19 (Study IV). GW affects more men than women in Sweden as of 2010 with 453 per
100 000 men and 365 per 100 000 women treated. A decline between 25-30% was seen
between 2006 and 2010 among women in the age groups with the highest vaccination
coverage. No decline was found amongst men and their GW incidence has steadily
increased between 2006 and 2010 (Study II). Reported condom use in high risk situations
was low among both men and women, with 41% of men and 34% of women reporting
always/almost always condom use with temporary partners. STI risk perception was also
low, with approximately 10% of sexually active respondents considering themselves at
large risk of contracting an STI. There was no association between men’s condom use and
their STI risk perception but there was an association for women (Study I).
Conclusions: Results suggest that males bear a substantial burden of HPV-related
condyloma where incidence has dropped among women. When planning HPVvaccination
among females, efforts should target girls under age 14 for maximum
effectiveness. Quadrivalent HPV-vaccination offers most protection against condyloma at
three doses. Gross social inequity was found with opportunistic HPV-vaccination. There
were large gender differences in factors associated with condom use in high risk situations
and STI risk perceptions
Ubiquitin fusion expression and tissue-dependent targeting of hG-CSF in transgenic tobacco
<p>Abstract</p> <p>Background</p> <p>Human granulocyte colony-stimulating factor (hG-CSF) is an important human cytokine which has been widely used in oncology and infection protection. To satisfy clinical needs, expression of recombinant hG-CSF has been studied in several organisms, including rice cell suspension culture and transient expression in tobacco leaves, but there was no published report on its expression in stably transformed plants which can serve as a more economical expression platform with potential industrial application.</p> <p>Results</p> <p>In this study, hG-CSF expression was investigated in transgenic tobacco leaves and seeds in which the accumulation of hG-CSF could be enhanced through fusion with ubiquitin by up to 7 fold in leaves and 2 fold in seeds, leading to an accumulation level of 2.5 mg/g total soluble protein (TSP) in leaves and 1.3 mg/g TSP in seeds, relative to hG-CSF expressed without a fusion partner. Immunoblot analysis showed that ubiquitin was processed from the final protein product, and ubiquitination was up-regulated in all transgenic plants analyzed. Driven by <it>CaMV </it>35S promoter and phaseolin signal peptide, hG-CSF was observed to be secreted into apoplast in leaves but deposited in protein storage vacuole (PSV) in seeds, indicating that targeting of the hG-CSF was tissue-dependent in transgenic tobacco. Bioactivity assay showed that hG-CSF expressed in both seeds and leaves was bioactive to support the proliferation of NFS-60 cells.</p> <p>Conclusions</p> <p>In this study, the expression of bioactive hG-CSF in transgenic plants was improved through ubiquitin fusion strategy, demonstrating that protein expression can be enhanced in both plant leaves and seeds through fusion with ubiquitin and providing a typical case of tissue-dependent expression of recombinant protein in transgenic plants.</p
- …