Vural Özdemir Ph.D.
Sanjeeva Srivastava Ph.D.
Deepthy Menon, Ph.D.
Associate Professor, Centre for Nanosciences & Molecular Medicine, Health Sciences Campus, Amrita University, Kochi, India
Nanobioengineering of implant materials for improved cellular response and activity
Deepthy Menon, Divyarani V V, Chandini C Mohan, Manitha B Nair, Krishnaprasad C & Shantikumar V Nair
Abstract
Current trends in biomaterials research and development include the use of surfaces with topographical features at the nanoscale (dimensions < 100 nm), which influence biomolecular or cellular level reactions in vitro and in vivo. Progress in nanotechnology now makes it possible to precisely design and modulate the surface properties of materials used for various applications in medicine at the nanoscale. Nanoengineered surfaces, owing to their close resemblance with extracellular matrix, possess the unique capacity to directly affect protein adsorption that ultimately modulates the cellular adhesion and proliferation at the site of implantation. Taking advantage of this exceptional ability, we have nanoengineered metallic surfaces of Titanium (Ti) and its alloys (Nitinol -NiTi), as well as Stainless Steel (SS) by a simple hydrothermal method for generating non-periodic, homogeneous nanostructures. The bio- and hemocompatibility of these nanotextured metallic surfaces suggest their potential use for orthopedic, dental or vascular implants. The applicability of nanotextured Ti implants for orthopedic use was demonstrated in vivo in rat models, wherein early-stage bone formation at the tissue-implant interface without any fibrous tissue intervention was achieved. This nanoscale topography also was found to critically influence bacterial adhesion in vitro, with decreased adherence of staphylococcus aureus. The same surface nanotopography also was found to provide enhanced proliferation and functionality of vascular endothelial cells, suggesting its prospective use for developing an antithrombotic stent surface for coronary applications. Clinical SS & NiTi stents were also modified based on this strategy, which would offer a suitable solution to reduce the probability of late stent thrombosis associated with bare metallic stents. Thus, we demonstrate that nanotopography on implant surfaces has a critical influence on the fate of cells, which in turn dictates the long term success of the implant.
Acknowledgement: Authors gratefully acknowledge the financial support from Department of Biotechnology, Government of India through the Bioengineering program.
R. 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.
Vural Özdemir, MD, Ph.D., DABCP
Co-Founder, DELSA Global, Seattle, WA, USA
Crowd-Funded Micro-Grants to Link Biotechnology and “Big Data” R&D to Life Sciences Innovation in India
Vural Özdemir, MD, PhD, DABCP1,2*
- Data-Enabled Life Sciences Alliance International (DELSA Global), Seattle, WA 98101, USA;
- Faculty of Management and Medicine, McGill University, Canada;
ABSTRACT
Aims: This presentation proposes two innovative funding solutions for linking biotechnology and “Big Data” R&D in India with artisan small scale discovery science, and ultimately, with knowledge-based innovation:
- crowd-funded micro-grants, and
- citizen philanthropy
These two concepts are new, and inter-related, and can be game changing to achieve the vision of biotechnology innovation in India, and help bridge local innovation with global science.
Background and Context: Biomedical science in the 21(st) century is embedded in, and draws from, a digital commons and “Big Data” created by high-throughput Omics technologies such as genomics. Classic Edisonian metaphors of science and scientists (i.e., “the lone genius” or other narrow definitions of expertise) are ill equipped to harness the vast promises of the 21(st) century digital commons. Moreover, in medicine and life sciences, experts often under-appreciate the important contributions made by citizen scholars and lead users of innovations to design innovative products and co-create new knowledge. We believe there are a large number of users waiting to be mobilized so as to engage with Big Data as citizen scientists-only if some funding were available. Yet many of these scholars may not meet the meta-criteria used to judge expertise, such as a track record in obtaining large research grants or a traditional academic curriculum vitae. This presentation will describe a novel idea and action framework: micro-grants, each worth $1000, for genomics and Big Data. Though a relatively small amount at first glance, this far exceeds the annual income of the “bottom one billion” – the 1.4 billion people living below the extreme poverty level defined by the World Bank ($1.25/day).
We will present two types of micro-grants. Type 1 micro-grants can be awarded through established funding agencies and philanthropies that create micro-granting programs to fund a broad and highly diverse array of small artisan labs and citizen scholars to connect genomics and Big Data with new models of discovery such as open user innovation. Type 2 micro-grants can be funded by existing or new science observatories and citizen think tanks through crowd-funding mechanisms described herein. Type 2 micro-grants would also facilitate global health diplomacy by co-creating crowd-funded micro-granting programs across nation-states in regions facing political and financial instability, while sharing similar disease burdens, therapeutics, and diagnostic needs. We report the creation of ten Type 2 micro-grants for citizen science and artisan labs to be administered by the nonprofit Data-Enabled Life Sciences Alliance International (DELSA Global, Seattle: http://www.delsaglobal.org). Our hope is that these micro-grants will spur novel forms of disruptive innovation and life sciences translation by artisan scientists and citizen scholars alike.
Address Correspondence to:
Vural Özdemir, MD, PhD, DABCP
Senior Scholar and Associate Professor
Faculty of Management and Medicine, McGill University
1001 Sherbrooke Street West
Montreal, Canada H3A 1G5
Email: vural.ozdemir@alumni.utoronto.ca
