scholarly journals Molecular basis of organ-specific selection of viral variants during chronic infection.

1991 ◽  
Vol 65 (8) ◽  
pp. 4242-4247 ◽  
Author(s):  
R Ahmed ◽  
C S Hahn ◽  
T Somasundaram ◽  
L Villarete ◽  
M Matloubian ◽  
...  
1988 ◽  
Vol 167 (5) ◽  
pp. 1719-1724 ◽  
Author(s):  
R Ahmed ◽  
M B Oldstone

This study demonstrates organ specific selection of viral variants during chronic lymphocytic choriomeningitis virus (LCMV) infection in its natural host. Isolates with different biological properties were present in the central nervous system (CNS) and lymphoid tissues of carrier mice infected at birth with the wt Armstrong strain of LCMV. Viral isolates from the CNS were similar to the wt Armstrong strain and induced potent virus-specific cytotoxic T lymphocyte (CTL) responses in adult mice and the infection was cleared within 2 wk. In contrast, LCMV isolates derived from the lymphoid tissues caused a chronic infection in adult mice associated with suppressed CTL responses. Revertants with wt Armstrong phenotype were present in the CNS of mice infected with a spleen isolate showing unequivocally the importance of host tissues in the selection of viral variants. These results provide a possible mechanism by which viral variants emerge in nature and suggest that tissue- and cell-specific selection is an important aspect of virus evolution.


Biology Open ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. bio055632

ABSTRACTFirst Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Komal Panchal is first author on ‘Miro, a Rho GTPase genetically interacts with Alzheimer's disease-associated genes (Tau, Aβ42 and Appl) in Drosophila melanogaster’, published in BiO. Komal is a PhD student in the lab of Dr Anand K. Tiwari at the Institute of Advanced Research (IAR), Koba Institutional Area, Gujarat, India, investigating the possible molecular basis of Alzheimer's disease.


1965 ◽  
Vol 13 (6) ◽  
pp. 510-514 ◽  
Author(s):  
JAMES L. CONKLIN ◽  
EDWARD J. NEBEL

Malate dehydrogenase fractions of the chick embryo were demonstrated after starch gel electrophoresis of homogenates of liver, brain and spleen. A total of seven malate dehydrogenase fractions were observed to occur in the chick embryo in an organ specific pattern. Treatment of the homogenates with urea, sodium chloride-sodium phosphate, and p-chloromercuribenzoate prior to electrophoresis revealed that only three distinct malate dehydrogenase-active proteins were presence. Two of these proteins exhibited properties similar to those previously reported for the supernatant malate dehydrogenase and mitochondrial malate dehydrogenase of other species. Becuase of the differing properties of chick malate and lactate dehydrogenase it is concluded that the molecular basis for malate dehydrogenase isozymes is different from that reported for lactate dehydrogenase isozymes.


Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 557 ◽  
Author(s):  
Alexander N. Shikov ◽  
Elena V. Flisyuk ◽  
Ekaterina D. Obluchinskaya ◽  
Olga N. Pozharitskaya

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.


2004 ◽  
Vol 72 (6) ◽  
pp. 3359-3365 ◽  
Author(s):  
Dea Garcia-Hermoso ◽  
Françoise Dromer ◽  
Guilhem Janbon

ABSTRACT Cryptococcus neoformans capsule structure modifications after prolonged in vitro growth or in vivo passaging have been reported previously. However, nothing is known about the dynamics of these modifications or about their environmental specificities. In this study, capsule structure modifications after mouse passaging and prolonged in vitro culturing were analyzed by flow cytometry using the glucuronoxylomannan-specific monoclonal antibody E1. The capsule structures of strains recovered after 0, 1, 8, and 35 days were compared by using the level of E1-specific epitope expression and its cell-to-cell heterogeneity within a given cell population. In vitro, according to these parameters, the diversity of the strains was higher on day 35 than it was initially, suggesting the absence of selection during in vitro culturing. In contrast, the diversity of the strains recovered from the brain tended to decrease over time, suggesting that selection of more adapted strains had occurred. The strains recovered on day 35 from the spleen and the lungs had different phenotypes than the strains isolated from the brain of the same mouse on the same day, thus strongly suggesting that there is organ specificity for C. neoformans strain selection. Fingerprinting of the strains recovered in vitro and in vivo over time confirmed that genotypes evolved very differently in vitro and in vivo, depending on the environment. Overall, our results suggest that organ-specific selection can occur during cryptococcosis.


2020 ◽  
Vol 117 (31) ◽  
pp. 18840-18848 ◽  
Author(s):  
Panyu Yang ◽  
Qiming Wen ◽  
Renbo Yu ◽  
Xue Han ◽  
Xing Wang Deng ◽  
...  

Light and gravity are two key environmental factors that control plant growth and architecture. However, the molecular basis of the coordination of light and gravity signaling in plants remains obscure. Here, we report that two classes of transcription factors, PHYTOCHROME INTERACTING FACTORS (PIFs) and ELONGATED HYPOCOTYL5 (HY5), can directly bind and activate the expression ofLAZY4, a positive regulator of gravitropism in both shoots and roots inArabidopsis. In hypocotyls, light promotes degradation of PIFs to reduceLAZY4expression, which inhibits the negative gravitropism of hypocotyls.LAZY4overexpression can partially rescue the negative gravitropic phenotype ofpifqin the dark without affecting amyloplast development. Our identification of the PIFs-LAZY4regulatory module suggests the presence of another role for PIF proteins in gravitropism, in addition to a previous report demonstrating that PIFs positively regulate amyloplast development to promote negative gravitropism in hypocotyls. In roots, light promotes accumulation of HY5 proteins to activate expression ofLAZY4, which promotes positive gravitropism in roots. Together, our data indicate that light exerts opposite regulation ofLAZY4expression in shoots and roots by mediating the protein levels of PIFs and HY5, respectively, to inhibit the negative gravitropism of shoots and promote positive gravitropism of roots inArabidopsis.


2006 ◽  
Vol 19 (2) ◽  
pp. 174-186 ◽  
Author(s):  
Regina Brigelius-Flohé

More than 80 years after the discovery of the essentiality of vitamin E for mammals, the molecular basis of its action is still an enigma. From the eight different forms of vitamin E, only α-tocopherol is retained in the body. This is in part due to the specific selection of RRR-α-tocopherol by the α-tocopherol transfer protein and in part by its low rate of degradation and elimination compared with the other vitamers. Since the tocopherols have comparable antioxidant properties and some tocotrienols are even more effective in scavenging radicals, the antioxidant capacity cannot be the explanation for its essentiality, at least not the only one. In the last decade, a high number of so-called novel functions of almost all forms of vitamin E have been described, including regulation of cellular signalling and gene expression. α-Tocopherol appears to be most involved in gene regulation, whereas γ-tocopherol appears to be highly effective in preventing cancer-related processes. Tocotrienols appear to be effective in amelioration of neurodegeneration. Most of the novel functions of individual forms of vitamin E have been demonstrated in vitro only and require in vivo confirmation. The distinct bioactivities of the various vitamers are discussed, considering their metabolism and the potential functions of metabolites.


Food Control ◽  
2013 ◽  
Vol 30 (1) ◽  
pp. 222-226 ◽  
Author(s):  
Declan Bolton ◽  
Alessandro Patriarchi ◽  
Áine Fox ◽  
Séamus Fanning

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