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Habjanec L.,Institute of Immunology Inc. | Halassy B.,Institute of Immunology Inc. | Tomasic J.,Institute of Immunology Inc.
International Immunopharmacology | Year: 2010

Structurally related peptidoglycan monomer (PGM) and muramyl dipeptide (MDP) differ in several aspects of biological activity but have in common immunostimulating properties. Comparative study of the effects of these adjuvants on humoral IgG immune response specific for protein antigen ovalbumin (OVA) was carried out in two inbred mouse strains, CBA and NIH/OlaHsd, and their ability to modulate the bias of immune response towards Th1/Th2 was evaluated. MDP had better adjuvant activity at some points than PGM, whereas both adjuvants stimulated Th2-biased immune response specific for OVA. In comparison to Complete Freund's adjuvant (CFA), as a golden standard of adjuvant action, both PGM and MDP exhibited considerably lower activity. Addition of PGM to Incomplete Freund's adjuvant (IFA) on humoral immune response was studied also, and the effect of such adjuvant formulation was compared to the effect of CFA. While CFA induced the switch towards Th1-biased immune response, the addition of PGM into IFA did have no impact on modulating the immune response towards more pronounced Th2-type of immune response, defined by IFA itself. © 2010 Elsevier B.V. All rights reserved.

Stimac A.,Institute of Immunology Inc. | Segota S.,Ruder Boskovic Institute | Dutour Sikiric M.,Ruder Boskovic Institute | Ribic R.,University of Zagreb | And 5 more authors.
Biochimica et Biophysica Acta - Biomembranes | Year: 2012

The aim of the present study was to encapsulate mannosylated 1-aminoadamantane and mannosylated adamantyltripeptides, namely [(2R)-N-(adamant-1-yl)-3-(α,β-d-mannopyranosyloxy) -2-methylpropanamide and (2R)-N-[3-(α-d-mannopyranosyloxy)-2- methylpropanoyl]-d,l-(adamant-2-yl)glycyl-l-alanyl-d-isoglutamine] in liposomes. The characterization of liposomes, size and surface morphology was performed using dynamic light scattering (DLS) and atomic force microscopy (AFM). The results have revealed that the encapsulation of examined compounds changes the size and surface of liposomes. After the concanavalin A (ConA) was added to the liposome preparation, increase in liposome size and their aggregation has been observed. The enlargement of liposomes was ascribed to the specific binding of the ConA to the mannose present on the surface of the prepared liposomes. Thus, it has been shown that the adamantyl moiety from mannosylated 1-aminoadamantane and mannosylated adamantyltripeptides can be used as an anchor in the lipid bilayer for carbohydrate moiety exposed on the liposome surface. © 2012 Elsevier B.V. All rights reserved.

Santak M.,Institute of Immunology Inc.
Periodicum Biologorum | Year: 2012

Influenza viruses have been with mankind for at least 300 years, with epidemics occurring every few years and pandemics every few decades. They replicate extremely rapidly in the host therefore demanding a fast and effective antiviral response. Despite the availability of seasonal trivalent vaccines and antivirals, which are effective for most recipients, influenza remains serious disease. The reason for that is a grand capacity of the influenza virus to adapt to new environmental conditions and evolutionary pressure. Vaccination remains the main protective measure against influenza for general population. The first vaccine was administered in the 1940s and ever since the influenza vaccine has provided tremendous relief against influenza infections. However, time has revealed the ultimate limit of the vaccine and the call for its reinvention has now come. The purpose of this review is to give a brief but comprehensive overview of the currently used prophylactic and therapeutic approaches against influenza and the new most promising developments in this field.

Forcic D.,Institute of Immunology Inc. | Kosutic-Gulija T.,Institute of Immunology Inc. | Santak M.,Institute of Immunology Inc. | Jug R.,Institute of Immunology Inc. | And 3 more authors.
Vaccine | Year: 2010

The two most commonly used methods for the determination of a virus potency are plaque assay and 50% cell culture infective dose (CCID50) assay, both based on cytopathic effect observation. We compared the potency estimates obtained by plaque and CCID50 assays for nine mumps virus strains that produce different cytopathic effects in Vero cells. The ratios of CCID50 and plaque assay quantification results differed for different strains and were in a range of 0.66-10, indicating that quantification results for some mumps virus strains are almost identical regardless of whether CCID50 or plaque method is used, while the potency estimates of other strains strongly depend on the choice of the assay. © 2009 Elsevier Ltd. All rights reserved.

Forcic D.,Institute of Immunology Inc. | Brgles M.,Institute of Immunology Inc. | Ivancic-Jelecki J.,Institute of Immunology Inc. | Santak M.,Institute of Immunology Inc. | And 5 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2011

The production of economically acceptable viral vaccines of high quality requires simple and efficient methods for purification and concentration of viral particles. Ion-exchange chromatography (IEC) has become one of commonly used methods for large-scale downstream purification of viruses. Viruses possess different biological and/or biochemical properties and therefore IEC conditions must be established specifically for each virus. Live attenuated rubella virus vaccines have been manufactured and successfully used widely to protect people from rubella and congenital rubella syndrome for almost 40. years. The aim of this study was to search for an efficient method for concentration and purification of rubella virus using IEC. The selected operating conditions using quaternary amine monolithic supports enabled highly efficient binding, purification and concentration of rubella virus from complex biological suspension without additional procedures. Eluted viral particles maintained their infectivity and viral recovery was almost 100%. At the same time, viral preparation was successfully depleted from host cell protein and DNA. This work indicates the possibility of using monoliths to improve the rubella virus yields in productions where high virus titers during cultivation can hardly be achieved. © 2011 Elsevier B.V.

University of Tokyo, Institute Of Immunology Co. and Aichi Medical University | Date: 2014-09-03

It is an object of the present invention to provide a monoclonal antibody, which is suitable for the quantitative analysis of asparagine synthetase in a cell. The present invention provides a monoclonal antibody which specifically recognizes asparagine synthetase that is present in a cell.

University of Tokyo, Aichi Medical University and Institute Of Immunology Co. | Date: 2012-10-03

It is an object of the present invention to provide a monoclonal antibody, which is suitable for the quantitative analysis of asparagine synthetase in a cell. The present invention provides a monoclonal antibody which specifically recognizes asparagine synthetase that is present in a cell.

PubMed | Institute of Immunology Inc., Tel Aviv University and University of Zagreb
Type: Journal Article | Journal: Vaccine | Year: 2016

Despite continuing research efforts, determinants of mumps virus virulence are still largely unknown. One of consequences of this is difficulty in striking a balance between efficacy and safety of live attenuated mumps vaccines. Among mumps vaccine strains associated with occurrence of postvaccinal aseptic meningitis is L-Zagreb, developed by further attenuation of vaccine strain L-3. Starting from an archived L-Zagreb sample with suboptimal neuroattenuation score, we isolated different viral variants and compared their genetic and phenotypic properties, in investigation of neurovirulence markers.Six different L-Zagreb variants were isolated by plaque purification. Their neurovirulent status was determined by rat-based neurovirulence test; population structure was determined by deep sequencing.We isolated one well neuroattenuated viral variant, two marginally neuroattenuated, and three insufficiently neuroattenuated. No genetic markers of neurovirulence could be identified. None of variants had detectable amounts of defective interfering particles. Two characteristics set insufficiently neuroattenuated variants apart from less-neurovirulent ones: elevated variability level in regions 1293-3314, 5363-7773 and 9382-11657, and/or elevated number of mutations present in frequencies 1%. The most neurovirulent variants possessed both of these features.Distinctive heterogeneity profiles were obtained for insufficiently neuroattenuated L-Zagreb variants. No markers that would discriminate between marginally and well neuroattenuated variants were identified. The findings of this study may serve as a guideline during development of an improved L3/L-Zagreb vaccine strain.

PubMed | Institute of Immunology Inc. and University of Zagreb
Type: | Journal: Journal of pharmaceutical and biomedical analysis | Year: 2016

Physicochemical methods are the primary tests used to ensure that batches of meningococcal polysaccharide (PS) antigens are manufactured consistently to those shown to be safe and effective in clinical trials. Although modern physicochemical methods of analysis providing structural information about the antigens have been developed and used, simpler assays, which can be readily validated, are still in use for polysaccharide batch release. The simple and cheap method for Neisseria meningitidis serogroup W or Y polysaccharide (MenW or MenY PS) content quantification has been developed. This colorimetric method is based on the galactose or glucose quantification in MenW or MenY PS hydrolysate, respectively. Intra- and inter-assay precision and accuracy of the novel method have been demonstrated, in comparison to the same properties of the current regulatory approved method for the same purpose - sialic acid quantification. We provided the calculation of the possible future regulatory requirement for the galactose or glucose content in MenW or MenY PS, respectively, and revealed in detail the stoichiometric calculation behind it.

PubMed | Institute of Immunology Inc. and University of Zagreb
Type: Journal Article | Journal: Cytotechnology | Year: 2016

L-Glutamine (L-Gln) instability in liquid media is a well-known fact. Also, negative effect of ammonia, one of the L-Gln degradation products, on viability of many cell cultures and on replication of different viruses has been described. However, negative effects of ammonia have been reported in doses excessively exceeding those that could be generated in regularly used liquid culture media due to spontaneous L-Gln breakdown (below 2mM). Traditional virus vaccine production processes have been established and registered involving L-Gln containing media use. Eventual culture media replacement in the regular production process belongs to the major regulative changes that require substantial financial expenses. The aim of this study was to evaluate the effect of storage of Minimum Essential Media with Hanks salts on their relevant biological functions during virus vaccine production process in relation to L-Gln decrease. Our results show a cell type dependent effect of spontaneous L-Gln degradation during medium storage. They also suggest that for cell cultures used in measles, mumps, and rubella virus production the media retain their functionality in respect to cell viability or virus growth over a certain time window despite L-Gln degradation.

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