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Exopolysaccharide-producing Bifidobacterium animalis subsp lactis strains and their polymers elicit different responses on immune cells from blood and gut associated lymphoid tissue
No full textThe effect of exopolysaccharide (EPS) producing bifidobacteria, and the EPS derived thereof, on the modulation of immune response was evaluated. Cells isolated from gut associated lymphoid tissue (GALT) and from peripheral blood mononuclear cells (PBMC) of naive rats were used. The proliferation and cytokine production of these immune cells in the presence of the three isogenic Bifidobacterium animalis subsp. lactis strains (A1, A1dOx and A1dOxR), as well as their purified polymers, were in vitro analysed. The cytokine pattern produced by immune cells isolated from GALT showed that most levels remained stable in the presence of the three strains or their corresponding polymers. However, in PBMC the UV-inactivated bacteria induced higher levels of the ratios IFN gamma/IL-17, TNF alpha/IL-10 and TNF alpha/TGF beta, and no variation in the ratio IFN gamma/IL-4. Thus, B. animalis subsp. lactis strains were able to activate blood monocytes as well as T lymphocytes towards a mild inflammatory Th1 response. Furthermore, only the EPS-A1dOxR was able to stimulate a response in a similar way than its EPS-producing bacterium. Our work supports the notion that some bifidobacterial EPS could play a role in mediating the dialog of these microorganisms with the immune system. In addition, this study emphasizes the effect that the origin of the immune cells has in results obtained; this could explain the great amount of contradiction found in literature about the immunomodulation capability of EPS from probiotic bacteria
Construction of recombinant adenoviral vector expressing genes of the conservative proteins M2 “ion channel” and nucleoprotein of influenza A virus
No full textInfluenza is a highly contagious disease and one of the most wide spreaded infection in the world. Influenza type A strains are of very great epidemiological significance. A high degree of genetic variability leads to constant modification in the antigenic structure of influenza virus. Therefore, current influenza vaccines require periodic updating of the composition of the strains. At present, it is important to develop a universal vaccine that could protect against different strains of influenza A virus and it is can be based on the conserved antigens of the virus. Recombinant adenoviral vectors expressing genes of conserved viral antigens may be used for a promising candidate vaccine against influenza A. Using a homologous recombination method, in this study we have developed a recombinant adenoviral serotype 5 vector that expresses the genes of the M2 ion channel and nucleoprotein (NP) of influenza A virus. The genes of the consensus sequences of the M2 protein and NP of human influenza A virus were inserted into the structure of the viral genome. The expression of the M2 and NP antigens using the recombinant adenovirus vector in a permissive line of eukaryotic cells was detected by Western blot assay. The high immunogenicity of the recombinant adenovirus vector obtained was demonstrated by intranasal immunization of laboratory mice
Effects of Lactobacillus rhamnosus LA68 on the immune system of C57BL/6 mice upon oral administration
No full textProbiotic bacteria have been used in human nutrition for centuries and are now attracting more attention. In order to examine the immunological aspects of probiotic consumption, Lactobacillus rhamnosus LA68 was orally administrated using gavage to healthy C57BL/6 mice. After one month splenocytes were isolated, and analysed by flow cytometry. The magnitude of splenocyte proliferation upon stimulation with lipopolysaccharide and peptidoglycan and cytokine levels (IFN-gamma, IL-6, IL-10 and IL-17) was assessed. Cytokine levels in the serum were also analysed. Oral application of strain LA68 leads to a significant decrease of CD3+, CD25+ and CD19+ cells, and an increase of CD11b+ and CD16/CD32+ positive cell populations in the mouse spleen. Increased sensitivity to stimulation through proliferation and IL-6 secretion was detected. Increased serum IFN-gamma and decreased IL-10 levels were found. Our results show increased responsiveness of splenocytes, activation of the Th1 type of immune response, and a shift of leucocyte populations towards monocyte/granulocyte populations
Age-associated changes in rat immune system: Lessons learned from experimental autoimmune encephalomyelitis
No full textAging is associated with the decline in immune response to infectious agents and tumors and increasing risk of autoimmunity, but the incidence of autoimmune diseases does not increase in the elderly. To elucidate the cellular and molecular mechanisms influencing clinical expression of autoimmunity in aged animals, the phenotypic and functional characteristics of mononuclear cells isolated from the spinal cords of 3-month-old (young) and 26-month-old (aged) Dark Agouti rats immunized to induce experimental autoimmune encephalomyelitis (EAE) - the model of multiple sclerosis, the most common autoimmune disease of the central nervous system, were examined. Aged rats were less susceptible to EAE induction, and the neurological and histological picture was milder in those rats which developed the clinically manifested disease. At the peak of the disease, several times fewer mononuclear cells and T lymphocytes were isolated from the spinal cords of aged rats compared with the young ones. The frequency of CD4+ cells among TCR alpha beta+ lymphocytes, as well as that of reactivated CD134(OX40)+ cells within its CD4+ T-lymphocyte subpopulation, was less in spinal cords of aged compared with young rats. Additionally, CD134 surface density on CD4+ lymphocytes was decreased in the spinal cord of aged rats. The changes in CD134 expression most likely reflected in part age-related intrinsic changes in CD4+ lymphocytes as the expression of this molecule was also impaired on in vitro stimulated naive CD4+ splenocytes from aged rats compared with young animals. In addition, greater frequency of CD8+ lymphocytes with regulatory phenotypes could also contribute to impaired CD4+ cell reactivation in aged rats. The increased apoptosis of CD4+ cells from aged rats was consistent with their impaired reactivation and it was accompanied by the greater frequency of CD4+CD11b+CD45(int/high) cells, which are supposed to be actively engaged in apoptotic cell phagocytosis and to have immunoregulatory properties. Compared with young rats, following short-term PMA and ionomycin stimulation in vitro, the frequency of IL-17+ and IFN-gamma+CD4+ T lymphocytes among the spinal cord mononuclear cells from aged rats and the cytokine expression density on a per lymphocyte basis were reduced. Additionally, the increase in the proportion of autoregulatory IL-17+IL-10+ cells on the account of proinflammatory IL-17+IFN-gamma+ cells within IL-17+ lymphocytes suggested their lower pathogenic capacity in aged rats. This most likely reflected alterations in the aged rat spinal cord cytokine milieu, which were mirrored in a diminished expression of IL-1 beta mRNA followed by an enhanced expression of IL-6 and TGF-beta mRNA. Overall, the study points to age-related changes in T lymphocytes and other cells from the spinal cord infiltrate which could contribute to the decreased susceptibility of aged rats to the induction of EAE. (C) 2014 Elsevier Inc. All rights reserved
Active actinidin retains function upon gastro-intestinal digestion and is more thermostable than the E-64-inhibited counterpart
No full textBACKGROUND: Actinidin is a cysteine protease and major allergen from kiwi fruit. When purified under specific native conditions, actinidin preparations from fresh kiwi fruit contain both an active and inactive form of this enzyme. In this study, biochemical and immunological properties upon simulated gastro-intestinal digestion, as well as thermal stability, were investigated for both active and E-64-inhibited actinidin. RESULTS: Active actinidin retained its primary structure and proteolytic activity after 2 h of simulated gastric digestion, followed by 2 h of intestinal digestion, as assessed by SDS-PAGE, zymography and mass spectroscopy. Immunological reactivity of active actinidin was also preserved, as tested by immunoelectrophoresis. The E-64 inhibited actinidin was fully degraded after 1 h of pepsin treatment. Differential scanning calorimetry showed that active actinidin has one transition maximum temperature (T-m) at 73.9 degrees C, whereas in the E-64-actinidin complex the two actinidin domains unfolded independently, with the first domain having a T-m value of only 61 degrees C. CONCLUSION: Active actinidin is capable of reaching the intestinal mucosa in a proteolytically active and immunogenic state. Inhibitor binding induces changes in the actinidin molecule that go beyond inhibition of proteolytic activity, also influencing the digestion stability and T-m values of actinidin, features important in the characterisation of food allergens. (C) 2014 Society of Chemical Industr
Novel antilisterial bacteriocin licheniocin 50.2 from Bacillus licheniformis VPS50.2 isolated from soil sample
Get PDFImmunization via conjunctiva and CALT as a route for chlamydia vaccine delivery: Immune responses to PmpC, an outer membrane protein of C. trachomatis
No full textPricing and reimbursement analysis of bacillus calmette-guerin (BCG) immunotherapy for bladder cancer
Get PDFAging oppositely affects TNF-alpha and IL-10 production by macrophages from different rat strains
No full textAltered functions of macrophages with aging contribute to impairment of both innate and adaptive immunity in the elderly. The present study aimed to examine strain specificity of age-related changes in the phenotypic and functional characteristics of macrophages from DA and AO rats, which differ in average life span. Resident peritoneal macrophages from young (10-12 weeks old) and aged (98-104 weeks old) rats were tested for: (a) the surface expression of TLR4 and CD14; (b) the basal and LPS-induced production of TNF-alpha and IL-10; and (c) the basal and LPS-induced activity of iNOS and arginase, by measuring the levels of NO and urea, respectively, in the culture supernatants. Aging elevated TLR4 macrophage surface density in rats of both strains. Conversely, the age-related decrease in the surface density of CD14 co-receptor was detected only on macrophages from aged DA rats. Accordingly, with aging in DA rats, contrary to AO rats, upon LPS-stimulation both TNF-alpha and IL-10 levels decreased in culture supernatants. However, in rats of both strains TNF-alpha stimulation index (LPS-induced over basal production) remained stable with aging, but it was significantly greater in AO rats. Furthermore, with aging, IL-10 stimulation index decreased and increased in DA and AO rats, respectively. Age-related shift in urea stimulation index complied with the changes of IL-10 stimulation index during aging. In conclusion, the study suggests that the preserved ability of macrophages from aged AO rats to synthesize not only proinflammatory TNF-alpha, but also immunoregulatory IL-10 cytokine most likely contributes to their longer average life compared with DA rats
Androgens Contribute to Age-Associated Changes in Peripheral T-Cell Homeostasis Acting in a Thymus-Independent Way
No full textObjective: Considering a causal role of androgens in thymic involution, age-related remodeling of peripheral T-cell compartments in the absence of testicular hormones was evaluated. Methods: Rats were orchidectomized (ORX) at the age of 1 month, and T-peripheral blood lymphocytes (PBLs) and splenocytes from young (75-day-old) and aged (24-month-old) rats were examined for differentiation/activation and immunoregulatory marker expression. Results: In ORX rats, following the initial rise, the counts of CD4+ and CD8+ PBLs diminished with aging. This reflected the decline in thymic export as shown by recent thymic emigrant (RTE) enumeration. Orchidectomy increased the count of both of the major T-splenocyte subsets in young rats, and they (differently from controls) remained stable with aging. The CD4+:CD8+ T-splenocyte ratio in ORX rats shifted towards CD4+ cells compared to age-matched controls. Although in the major T-cell subsets in the blood and spleen from aged ORX rats the numbers of RTEs were comparable to the corresponding values in age-matched controls, the numbers of mature naive and memory/activated cells substantially differed. Compared with age-matched controls, in aged ORX rats the numbers of CD4+ mature naive PBLs and splenocytes were reduced, whereas those of CD4+ memory/activated cells (predictive of early mortality) were increased. Additionally, in spleens from aged ORX rats, despite unaltered thymic export, CD4+CD25+FoxP3+ and natural killer T cell counts were greater than in age-matched controls. Conclusion: (i) Age-related decline in thymopoietic efficacy is not dependent on androgen presence, and (ii) androgens are involved in the maintenance of peripheral T-cell (particularly CD4+ cell) homeostasis during aging. (C) 2014 S. Karger AG, Base