Aug
12
Mon
2013
Invited Talk: Discovery, engineering and applications of Blue Fish Protein with Red Flourescence @ Sathyam Hall
Aug 12 @ 10:00 am – 10:15 am

RamaswamyS. Ramaswamy, Ph.D.
CEO of c-CAMP, Dean, inStem, NCBS, Bangalore, India


Discovery, engineering and applications of Blue Fish Protein with Red Fluorescence

Swagatha Ghosh, Chi-Li Yu, Daniel Ferraro,  Sai Sudha, Wayne Schaefer, David T Gibson and S. Ramaswamy

Fluorescent proteins and their applications have revolutionized our understanding of biology significantly.  In spite of several years since the discovery of the classic GFP, proteins of this class are used as the standard flag bearers.  We have recently discovered a protein from the fish Sanders vitrius that shows interesting fluorescent properties – including a 280 nm stoke shift and infrared emission.  The crystal structure of the wild type protein shows that it is a tetramer.  We have engineered mutations to make a monomer with very similar fluorescent properties. We have used this protein for tissue imaging as well as for in cell-fluorescence successfully

Ramaswamy (1) Ramaswamy (2) Ramaswamy (3) Ramaswamy (4)

Aug
13
Tue
2013
Plenary Talk: Biosensor and Single Cell Manipulation using Nanopipettes @ Amriteshwari Hall
Aug 13 @ 10:06 am – 10:49 am

NaderNader Pourmand, Ph.D.
Director, UCSC Genome Technology Center,University of California, Santa Cruz


Biosensor and Single Cell Manipulation using Nanopipettes

Approaching sub-cellular biological problems from an engineering perspective begs for the incorporation of electronic readouts. With their high sensitivity and low invasiveness, nanotechnology-based tools hold great promise for biochemical sensing and single-cell manipulation. During my talk I will discuss the incorporation of electrical measurements into nanopipette technology and present results showing the rapid and reversible response of these subcellular sensors  to different analytes such as antigens, ions and carbohydrates. In addition, I will present the development of a single-cell manipulation platform that uses a nanopipette in a scanning ion-conductive microscopy technique. We use this newly developed technology to position the nanopipette with nanoscale precision, and to inject and/or aspirate a minute amount of material to and from individual cells or organelle without comprising cell viability. Furthermore, if time permits, I will show our strategy for a new, single-cell DNA/ RNA sequencing technology that will potentially use nanopipette technology to analyze the minute amount of aspirated cellular material.

Invited Talk: Interrogating Signaling Networks at the Single Cell Level in Primary Human Patient Samples @ Acharya Hall
Aug 13 @ 10:52 am – 11:22 am

MIchelleMichelle Hermiston, MD, Ph.D.
Assistant Professor, Department of Pediatrics University of California San Francisco, USA


Interrogating Signaling Networks at the Single Cell Level In Primary Human Patient Samples

Multiparameter phosphoflow cytometry is a highly sensitive proteomic approach that enables monitoring of biochemical perturbations at the single cell level. By combining antisera to cell surface markers and key intracellular proteins, perturbations in signaling networks, cell survival and apoptosis mediators, cell cycle regulators, and/or modulators of other cellular processes can be analyzed in a highly reproducible and sensitive manner in the basal state and in response to stimulation or drug treatment. Advantages of this approach include the ability to identify the biochemical consequences of genetic and/or epigenetic changes in small numbers of cells, to map potential interplay between various signaling networks simultaneously in a single cell, and to interrogate potential mechanisms of drug resistance or response in a primary patient sample. Application of this technology to patients with acute lymphoblastic leukemia or the autoimmune disease systemic lupus erythematosus (SLE) will be discussed.

 

 

Invited Talk: Regulation of the MHC complex and HLA solubilisation by the Flavivirus, Japanese Encephalitis Virus @ Acharya Hall
Aug 13 @ 12:13 pm – 12:40 pm

ManjunathR. Manjunath, Ph.D.
Associate Professor, Dept of Biochemistry, Indian Institute of Science, Bengaluru, India


REGULATION OF THE MHC COMPLEX AND HLA SOLUBILISATION BY THE FLAVIVIRUS, JAPANESE ENCEPHALITIS VIRUS

Viral encephalitis caused by Japanese encephalitis virus (JEV) and West Nile Virus (WNV) is a mosquito-borne disease that is prevalent in different parts of India and other parts of South East Asia. JEV is a positive single stranded RNA virus that belongs to the Flavivirus genus of the family Flaviviridae. The genome of JEV is about 11 kb long and codes for a polyprotein which is cleaved by both host and viral encoded proteases to form 3 structural and 7 non-structural proteins. It is a neurotropic virus which infects the central nervous system (CNS) and causes death predominantly in newborn children and young adults. JEV follows a zoonotic life-cycle involving mosquitoes and vertebrate, chiefly pigs and ardeid birds, as amplifying hosts. Humans are infected when bitten by an infected mosquito and are dead end hosts. Its structural, pathological, immunological and epidemiological aspects have been well studied. After entry into the host following a mosquito bite, JEV infection leads to acute peripheral neutrophil leucocytosis in the brain and leads to elevated levels of type I interferon, macrophage-derived chemotactic factor, RANTES,TNF-α and IL-8 in the serum and cerebrospinal fluid.

Major Histocompatibility Complex (MHC) molecules play a very important role in adaptive immune responses. Along with various classical MHC class I molecules, other non-classical MHC class I molecules play an important role in modulating innate immune responses. Our lab has shown the activation of cytotoxic T-cells (CTLs) during JEV infection and CTLs recognize non-self peptides presented on MHC molecules and provide protection by eliminating infected cells. However, along with proinflammatory cytokines such as TNFα, they may also cause immunopathology within the JEV infected brain. Both JEV and WNV, another related flavivirus have been shown to increase MHC class I expression. Infection of human foreskin fibroblast cells (HFF) by WNV results in upregulation of HLA expression. Data from our lab has also shown that JEV infection upregulates classical as well as nonclassical (class Ib) MHC antigen expression on the surface of primary mouse brain astrocytes and mouse embryonic fibroblasts.

There are no reports that have discussed the expression of these molecules on other cells like endothelial and astrocyte that play an important role in viral invasion in humans. We have studied the expression of human classical class I molecules HLA-A, -B, -C and the non-classical HLA molecules, HLA-E as well as HLA-F in immortalized human brain microvascular endothelial cells (HBMEC), human endothelial cell line (ECV304), human glioblastoma cell line (U87MG) and human foreskin fibroblast cells (HFF). Nonclassical MHC molecules such as mouse Qa-1b and its human homologue, HLA-E have been shown to be the ligand for the inhibitory NK receptor, NKG2A/CD94 and may bridge innate and adaptive immune responses. We show that JEV infection of HBMEC and ECV 304 cells upregulates the expression of HLA-A, and –B antigens as well as HLA-E and HLA-F. Increased expression of total HLA-E upon JEV infection was also observed in other human cell lines as well like, human amniotic epithelial cells, AV-3, FL and WISH cells. Further, we show for the first time that soluble HLA-E (sHLA-E) was released from infected ECV and HBMECs. In contrast, HFF cells showed only upregulation of cell-surface HLA-E expression while U87MG, a human glioblastoma cell line neither showed any cell-surface induction nor its solubilization. This shedding of sHLA-E was found to be dependent on matrix metalloproteinase (MMP) and an important MMP, MMP-9 was upregulated during JEV infection. Treatment with IFNγ resulted in the shedding of sHLA-E from ECV as well as U87MG but not from HFF cells. Also, sHLA-E was shed upon treatment with IFNβ and both IFNβ and TNFα, when present together caused an additive increase in the shedding of sHLA-E. HLA-E is an inhibitory ligand for CD94/NKG2A receptor of Natural Killer cells. Thus, MMP mediated solubilization of HLA-E from infected endothelial cells may have important implications in JEV pathogenesis including its ability to compromise the blood brain barrier.

Manjunath (2)