A recent resurgence of mumps in doubly vaccinated cohorts has been observed, identifying genotype G as the current predominant genotype. In this study, the neutralization efficacy of guinea pig sera ...immunized with three vaccine viruses: L-Zagreb, Urabe AM9 and JL5, was tested against seven mumps viruses: three vaccine strains and four wild-type strains (two of genotype G, one of genotype C, one of genotype D) isolated during 1998–2011. All sera neutralized all viruses although at different levels. The neutralization efficiency of sera decreases several fold by temporal order of virus isolation. Therefore, we concluded that gradual evolution of mumps viruses, rather than belonging to a certain genotype, results in an antigenic divergence from the vaccine strains that decrease the neutralization capacity of vaccine-induced antibodies. Moreover, the amino-acid sequence alignment revealed three new potentially relevant regions for escape from neutralization, i.e. 113–130, 375–403 and 440–443.
•We show that PDGF-AB and IFN-α, produce significant induction of IFN-α, -β and -γ.•The induction was dose-dependent.•It was the highest when IFN-α was combined with the lowest concentration of ...PDGF-AB.•Results presented here open new possibilities in multi-cytokine therapy.
Platelet-derived growth factor (PDGF) is a potent mediator of fibroblast proliferation and chemotaxis. Also it has been reported as a strong suppressor of interferon (IFN) expression. IFN-α has opposite effect on fibroblast function and IFN induction. Here is our early report on the effect of low concentration of PDGF-AB alone or in combination with IFN-α on IFN mRNA production in MRC5 fibroblasts. MRC5 cells incubated with IFN-α or PDGF-AB, alone or in combination, produced significant induction of IFN-α, -β and -γ mRNA in comparison with untreated cells. The induction was dose-dependent, with higher effect in cells treated with lower concentrations of PDGF-AB. Also, low concentration of PDGF-AB showed synergism with IFN-α in IFN-β and -γ induction. Results presented here open new possibilities in multi-cytokine therapy and expand previous results on PDGF activity.
Abstract Native human interferon-α (nHuIFN-α) has a stronger reductive effect on procollagen type I mRNA expression than recombinant human interferon-α (rHuIFN-α). It is partially due to the additive ...activity of interleukin-1β (IL-1β), which is present in small concentrations in nHuIFN-α. Here, we show that the reductive effect is also the result of the endogenous cytokines induced by the activity of nHuIFN-α. In the culture of MRC5 fibroblasts, we have further found that nHuIFN-α induces endogenous interferons in higher amounts than rHuIFN-α, measured with PCR. That is more pronounced when interferon-γ (IFN-γ) is measured. This result puts a new light on IFN-γ activity in the nHuIFN-α treatment because its role was neglected due to the loss of its activity during the nHuIFN-α preparation process. The findings lead to the conclusion that endogenous cytokines play a significant role in the nHuIFN-α -mediated reduction of procollagen type I mRNA and are therefore an important factor in potential therapeutic usage.
Previously we reported on the HPIV2 genotype distribution in Croatia 2011–2014. Here we expand this period up to 2017 and confirm that G1a genotype has replaced G3 genotype from the period 2011–2014. ...Our hypothesis was that the G1a-to-G3 genotype replacement is an antibody-driven event. A cross-neutralisation with anti-HPIV2 sera specific for either G1a or G3 genotype revealed the presence of genotype-specific antigenic determinants. By the profound, in silico analyses three potential B cell epitopic regions were identified in the hemagglutinin neuraminidase (regions 314–361 and 474–490) and fusion protein (region 440–484). The region identified in the fusion protein does not show any unique site between the G1a and G3 isolates, five differentially glycosylated sites in the G1a and G3 genotype isolates were identified in epitopic regions of hemagglutinin neuraminidase. All positively selected codons were found to be located either in the region 314–316 or in the region 474–490 what indicates a strong positive selection in this region and reveals that these regions are susceptible to evolutionary pressure possibly caused by antibodies what gives a strong verification to our hypothesis that neutralising antibodies are a key determinant in the inherently complex adaptive evolution of HPIV2 in the region.
Physicochemical characteristics of liposome/DNA complexes influence transfection efficiency and affect each other in a very intricate way. The result of this is discrepancies in conclusions drawn ...about the individual influence of each one.
Aiming to elucidate the influence of liposome/DNA charge ratio and size on transfection efficiency and on each other, we used liposome/DNA complexes with charge ratio (+/-) in the range of 1-50 and extruded through membranes of 400, 200, and 100 nm. Plasmid DNA encoding green fluorescent protein was used to measure transfection efficiency by flow cytometry. Sizes of liposome/DNA complexes were measured by dynamic light scattering.
Liposome size was reduced after extrusion but this was mainly driven by the charge ratio and not by the size of the membrane pores. Reduction of complex size at each charge ratio positively correlated with transfection efficiency. When the size of the complexes was approximately constant, increasing the charge ratio was found to promote transfection efficiency. Cationic lipid N-(1-(2,3-dioleoyloxy)propyl)N,N,N trimethylammonium chloride was used for modulation of positive charge and a cytotoxicity test showed that increasing its amount increases cytotoxicity.
It can be concluded that charge ratio dictates the size of the complex whereas overall size reduction and higher charge ratios promote transfection efficiency in vitro.
In the present work, we compared the antitumor effects of native human interferon-α (IFN-α) (nHuIFN-α) and recombinant human IFN-α (rHuIFN-α) on human lung adenocarcinoma A549 cells.
The antitumor ...activity was determined by measuring cell viability and apoptosis, while the abundance of mRNA, measured by polymerase chain reaction (PCR), determined the potential role of p21 and survivin in antitumor activity of nHuIFN-α.
The results show that nHuIFN-α significantly reduced A549 cell viability, compared to rHuIFN-α. The most potent effect of nHuIFN-α was also observed when apoptosis was measured. A549 cells treated with nHuIFN-α expressed a significantly higher amount of p21 mRNA, while the amount of survivin mRNA was significantly reduced.
Considering both the anti-proliferative and anti-apoptotic effects of each IFN-α, we conclude that further elucidation of the mechanisms of the antitumor activity of nHuIFN-α will help in producing more effective and less toxic therapeutic protocols and preparations.
Background Commercial preparations of native human interferon alpha (nHuIFN-α) contain several subtypes of interferon-alpha (IFN-α) and traces of other cytokines. Recently, we described its ...antifibrotic potential and showed nHuIFN-α to have a greater effect than that of recombinant human IFN-α (rHuIFN-α). We hypothesized that cooperation between different cytokines in the nHuIFN-α preparation is essential for this effect. Considerable concentrations of interleukin-1β (IL-1β) and platelet-derived growth factor AB (PDGF-AB) are present in the nHuIFN-α preparations. Methods We tested the viability and the expression of procollagen type I messenger RNA (mRNA) in MRC5 fibroblasts treated with interleukin-1 beta (IL-1β) and/or PDGF-AB, or the corresponding antibodies in combination with rHuIFN-α or nHuIFN-α. Results We showed that neither IL-1β nor PDGF-AB significantly affect the viability of MRC5 cells. Furthermore, cell viability was not affected when IL-1β or PDGF-AB were applied along with rHuIFN-α, relative to the viability of cells treated with rHuIFN-α only. In contrast, both cytokines suppressed the synthesis of procollagen type I mRNA. When coadministered with rHuIFN-α, IL-1β enhanced the suppression induced by rHuIFN-α. Conversely, PDGF-AB acted as an antagonist of rHuIFN-α and restored partially the synthesis of procollagen type I mRNA. Interestingly, the addition of IL-1β to the PDGF-AB/rHuIFN-α mix not only abolished the antagonistic activity of PDGF-AB but also decreased the synthesis of procollagen type I mRNA beyond the level achieved by IL-1β/rHuIFN-α. Therefore, IL-1β was able to reverse the activity of PDGF-AB. Conclusion Our study suggests that IL-1β is an important component of nHuIFN-α preparations, acting directly and indirectly to modulate the action of other components. This study provides insight into these complex cytokine networks, which is necessary for better and safer antifibrotic therapy.
The viral safety of plasma-derived products with respect to hepatitis C virus (HCV) is assured by selection of donors, screening of individual donations for antibodies to HCV and the incorporation of ...effective viral inactivation-removal steps into manufacturing processes. As antibody screening of single donations is not sufficient to completely eliminate HCV RNA positive plasmas from plasma pools, testing for HCV RNA by gene amplification techniques may be necessary to identify positive donations. Using modern molecular biology techniques, we developed a specific, sensitive and reproducible method for routine PCR screening for HCV RNA in plasma pools.
Interferon-alpha(IFN-alpha) inhibits fibroblast proliferation, differentiation into myofibroblasts, and extracellular matrix synthesis, which are key events during both normal wound repair and ...fibrotic lesion formation. Unlike recombinant human IFN-alpha (rHuIFN-alpha), a native human IFN-alpha (nHuIFN-alpha) consists of several IFN-alpha subtypes and traces of other cytokines produced by the Sendai virus-stimulated human leukocytes. This study compares the antifibrotic effect of nHuIFN-alpha and rHuIFN-alpha in normal human dermal fibroblasts (HDFs). Treatment of HDF culture with nHuIFNA-alpha markedly affects HDF viability, whereas different rHuIFN-alpha subtypes show various effects. Two of twelve rHuIFN-alpha subtypes (IFN-alpha B2 and IFN-alpha K) significantly reduce cell viability of HDFs compared with nontreated HDFs. However, nHuIFN-alpha significantly reduces HDF cell viability in comparison to both nontreated cells and cells treated with rHuIFN-alpha. The 50% inhibitory concentration (IC(50)) varied 10-fold between nHuIFN-alpha and rHuIFN-alpha (1,103 IU/mL and 10,762 IU/mL, respectively). The impact on procollagen type I mRNA synthesis level is comparable at low doses of IFN (100 and 500 IU/mL), whereas at the dose of 1,000 IU/mL, nHuIFN-alpha shows higher repression of collagen type I gene than does rHuIFN-alpha. Both, nHuIFN-alpha and rHuIFN-alpha antagonize the effect of exogenous transforming growth factor-beta (TGF-beta) and interleukin-4 (IL-4) as measured by the alpha-smooth muscle actin (alpha -SMA) and procollagen type I mRNA level, but the effect of nHuIFN-alpha is more pronounced. This study suggests that nHuIFN-alpha is a more potent suppressor of the HDF response to profibrotic stimuli than rHuIFN-alpha, probably because of the synergism between different IFN-alpha subtypes and antifibrotic cytokines and factors.
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