P2 purinergic receptor modulation of cytokine production

Cytokines serve important functions in controlling host immunity. Cells involved in the synthesis of these polypeptide mediators have evolved highly regulated processes to ensure that production is carefully balanced. In inflammatory and immune disorders, however, mis-regulation of the production and/or activity of cytokines is recognized as a major contributor to the disease process, and therapeutics that target individual cytokines are providing very effective treatment options in the clinic. Leukocytes are the principle producers of a number of key cytokines, and these cells also express numerous members of the purinergic P2 receptor family. Studies in several cellular systems have provided evidence that P2 receptor modulation can affect cytokine production, and mechanistic features of this regulation have emerged. This review highlights three separate examples corresponding to (1) P2Y6 receptor mediated impact on interleukin (IL)-8 production, (2) P2Y11 receptor-mediated affects on IL-12/23 output, and (3) P2X7 receptor mediated IL-1β posttranslational processing. These examples demonstrate important roles of purinergic receptors in the modulation of cytokine production. Extension of these cellular observations to in vivo situations may lead to new therapeutic strategies for treating cytokine-mediated diseases

In vitro polyploidisation of Helleborus species

Helleborus species are members of the family of the Ranunculaceae. These popular perennials are all diploids (2n = 2x = 32). This study investigates polyploidy induction by different antimitotic agents. Colchicine, oryzalin and trifluralin were tested in vitro on shoots of Helleborus niger, H. orientalis and H. 9 nigercors. Furthermore the effect of the antimitotic agents on the viability and the multiplication rate of cultured plantlets were analyzed. Flow cytometry demonstrated that polyploidisation was genotype dependent: using H. niger, tetraploids were obtained using either oryzalin (3 mu M) or trifluralin (3 or 10 lM), whereas for H. 9 nigercors only trifluralin (3 or 10 mu M) induced polyploidisation. For H. orientalis neither treatment was effective to produce tetraploids or mixoploids. For these three species, colchicine (100 mu M) was ineffective. The polyploidisation events in H. niger and H. 9 nigercors were confirmed by chromosome counts of mounted nuclei derived from root tips (2n = 4x = 64)

Co-Evolutionary Dynamics of the Bacteria Vibrio sp. CV1 and Phages V1G, V1P1, and V1P2: Implications for Phage Therapy

Bacterial infections are the second largest cause of mortality in shrimp hatcheries. Among them, bacteria from the genus Vibrio constitute a major threat. As the use of antibiotics may be ineffective and banned from the food sector, alternatives are required. Historically, phage therapy, which is the use of bacteriophages, is thought to be a promising option to fight against bacterial infections. However, as for antibiotics, resistance can be rapidly developed. Since the emergence of resistance is highly undesirable, a formal characterization of the dynamics of its acquisition is mandatory. Here, we explored the co-evolutionary dynamics of resistance between the bacteria Vibrio sp. CV1 and the phages V1G, V1P1, and V1P2. Singlephage treatments as well as a cocktail composed of the three phages were considered. We found that in the presence of a single phage, bacteria rapidly evolved resistance, and the phages decreased their infectivity, suggesting thatmonotherapy may be an inefficient treatment to fight against Vibrio infections in shrimp hatcheries. On the contrary, the use of a phage cocktail considerably delayed the evolution of resistance and sustained phage infectivity for periods in which shrimp larvae are most susceptible to bacterial infections, suggesting the simultaneous use of multiple phages as a serious strategy for the control of vibriosis. These findings are very promising in terms of their consequences to different industrial and medical scenarios where bacterial infections are present