Biology subjects

Iyer, S.

Publications and source records attributed to Iyer, S..

3 recordsLinked to original sources

bioRxiv2018

Molecularly distinct models of zebrafish Myc-induced B cell leukemia

Zebrafish models of T cell acute lymphoblastic leukemia (T-ALL) have been studied for over a decade, but curiously, robust zebrafish B cell ALL (B-ALL) models had not been described. Recently, our laboratories reported two seemingly closely-related models of zebrafish B-ALL. In these genetic lines, the primary difference is expression of either murine or human transgenic c-MYC, each controlled by the zebrafish rag2 promoter. Here, we compare ALL gene expression in both models. Surprisingly, we find that B-ALL arise in different B cell lineages, with ighm+ vs. ighz+ B-ALL driven by murine Myc vs. human MYC, respectively. Moreover, these B-ALL types exhibit signatures of distinct molecular pathways, further unexpected dissimilarity. Thus, despite sharing analogous genetic makeup, the ALL types in each model are markedly different, proving subtle genetic changes can profoundly impact model organism phenotypes. Investigating the mechanistic differences between mouse and human c-MYC in these contexts may reveal key functional aspects governing MYC-driven oncogenesis in human malignancies.

cancer biology↗

bioRxiv2018

Reversible temporally-specific inhibition of muscle using a light-activated chloride channel

Achieving reversible, temporally specific inhibition of motor neurons has the potential to revolutionize treatment of disorders marked by muscle hyperactivity. Current treatment strategies are inadequate - surgical interventions are irreversible and pharmaceutical interventions have off-target effects. Optogenetic strategies for inhibiting muscle activity have theoretical promise; however, trafficking and expression problems have prevented translatable optogenetic suppression of muscle activity. Here, we exploit recent innovations in opsin engineering to demonstrate virally mediated, temporally specific optogenetic inhibition of motor neurons and muscle activity in vivo. We show that intra-muscular injection of adeno-associated virus serotype 6 can drive expression of the inhibitory channelrhodopsin mutant iC++ in both immunodeficient and wild-type mice. Illumination of the sciatic nerve in wild-type mice resulted in 64.8% inhibition of evoked twitch force. Optical excitation during tetanic stimulation in wild-type mice resulted in 59.1% inhibition at 10 Hz and 55.4% at 25 Hz. The extent of optogenetic inhibition was titratable, and ranged from 0% to 78.4% as illumination intensity was changed from 1 mW to 20 mW/mm2. These results could have therapeutic applicability to disorders such as spasticity, hypertonia and urinary incontinence, and provide a new tool to neuroscientists and muscle physiologists wishing to reversibly inhibit motor neuron activity in vivo.

neuroscience↗

bioRxiv2016

Immunological Patterns from Four Melioidosis Cases: Constant and Variable Protein Antigens

Burkholderia pseudomallei is the causative agent of the melioidosis and is endemic to Southeast Asia and northern Australia. There is no available vaccine and accurate diagnosis is difficult, time-consuming and labor intensive. Early diagnosis is an important part of successful treatment and current serological tests are inadequate and based upon multiple antigens. Identifying specific immunogenic proteins which are highly seroreactive may yield potential diagnostic targets for detecting antibodies and antigens specific to melioidosis. We have used 2D gel electrophoresis and Western blotting analysis to analyze protein antigenicity of whole cell lysates extracted from four B. pseudomallei strains and the sera from the specific infected humans. We found a total of 135 immunogenic proteins, 62 of which we were able to identify to a specific gene by mass-spectrometry. Results from the Western blotting of each strains proteins and the corresponding patient serum reveal between 30 - 40% serum x strain specific immunogenic proteins. In most cases, these differences exist despite the fact that the genes encoding these proteins were present among all four B. pseudomallei strains. Eight particular proteins were immunogenic in all four strain x serum combinations and could represent novel diagnostic and vaccine subunit targets.

immunology↗