REVIEWS
ORIGINAL ARTICLES
Rotavirus infection is among leading causes of severe diarrhea which often leads to severe dehydration, especially, in children under 5 years old. In Russia, the incidence of rotavirus infection is constantly increased, due to higher rates of actual rotavirus infection cases and improved diagnostics of the disease. Immunity to rotavirus is unstable, thus causing repeated infections intra vitam. Anti-infectious resistance in reconvalescents is explained by induction of specific IgM, IgG, and, notably, IgA antibodies. Due to absence of market drugs with direct action against rotavirus, a rational vaccination is considered the most effective way to control the disease. Currently available vaccines for prevention of rotavirus infection are based on live attenuated rotavirus strains, human and/or animal origin, which replicate in human gut. Their implementation may result into different complications. Meanwhile, usage of vaccines based on recombinant proteins is aimed to avoid risks associated with introduction of a complete virus into humans. In this paper, we studied protective activity of candidate vaccines against rotavirus.
In this work we studied protective activity of a candidate vaccine against rotavirus infection based on recombinant FliCVP6VP8 protein which includes VP6 and VP8, as well as components of Salmonella typhimurium flagellin (FliC) as an adjuvant. Different components are joined by flexible bridges. Efficiency of the candidate vaccine was studied in animal model using Balb/c mice. We have shown high level of protection which occurs when the candidate vaccine is administered twice intramuscularly. Complete protection of animals against mouse rotavirus EDC after intramuscular immunization with a candidate vaccine was associated with arising rotavirus-specific IgA and IgG antibodies in serum and intestine of immunized animals. The efficacy of candidate vaccine based on recombinant protein FliCVP6VP8 against rotavirus infection was comparable to that of commercial Rotarix® vaccine (Glaxo Smith Kline), however, with higher safety of the candidate vaccine, due to absence of live virus in its composition. Hence, the results obtained justify further pre-clinical studies of the candidate vaccine based on a recombinant protein.
The aim of the study was to investigate a relationship between cytokine-producing reserve of invasive ductal cancer cells and its microenvironment, and cytokine-producing reserve of immunocompetent blood cells (IBC), as well as with histopathological and immunohistochemical characteristics of breast cancer. Using ELISA method we investigated the spontaneous and stimulated with polyclonal activators (PA) cytokine-producing reserve of IBC and biopsy specimens from invasive ductal cancer (adenocarcinoma) in 34 women. Appropriate values were expressed by the Influence Index of polyclonal activators (IIPA) upon cytokine production (IL-2, IL-6, IL-8, IL-10, IL-17, IL-18, IL-1β, IL-1ra, TNFα, IFNγ, G-CSF, GM-CSF, VEGF-A, MCP-1). In tumor biopsies, we studied expression of VEGF-A, estrogen receptor, progesteron receptor and pro-proliferation marker Ki-67 by means of immunohistochemical method. Activation values of blood IBC in most cases, except of IL-18, IL-1β and MCP-1, were higher than appropriate effects upon cytokine production by tumor tisuues. Meanwhile, the IIPA activation index upon IL-18 (a proinflammatory and prooncogene cytokine) production by tumor cells and its microenvironment proved to be elevated, as compared to appropriate IIPA by the blood IBC. Statistical studies showed a direct correlation between IIPA and cytokine production in tumor supernates, IIPA of VEGF-A expression in tumor tissue, with pathohistological parameters and expression of estrogen and progesterone receptors and Ki-67 proliferation marker. A high positive correlation was obtained between IIPA TNFα production by the tumor tissue, and degree of tumor vascularization.
We have revealed a negative correlation between IIPA for IL-6, MCP-1 and Ki-67 marker of cell proliferation. A direct correlation was found between IIPA values for IL-1ra/IL-1β production ratios in blood cells, and IIPA for VEGF-A expression in adenocarcinoma tissues, thus indicating to probable connections between IL-1ra production by IBC and VEGF-A expression. We have discerned several intersecting, diverging, and even circle-closed correlative chains of correlation, e.g.: VEGF-A (immunohistochemical marker of IIPA expression) – IL-10 and IL-8 (IIPA for supernate products); MCP-1, IL-6, and IL-10 (IIPA for supernate products)– VEGF-A (immunohistochemical indicator of expression for IIPA). The results of this study suggest a relationship between cytokine-producing reserves of the tumor identified by appropriate PA correlations with the processes occurring in malignant tumors, as assessed by histopathological and immunohistochemical parameters. The data are indicative for some complex mechanisms mediated by cytokines which provide invasive growth of malignant tumor.
SHORT COMMUNICATIONS
The aim of this study was to evaluate correlations between cytokine concentrations and parameters of respiratory burst in blood neutrophils, in order to predict potential development of abdominal sepsis in the patients with extended purulent peritonitis (EPP). The study involved fifteen patients with EPP. Peripheral blood samples were taken on the first day post-admissiona. Abdominal sepsis was diagnosed in thirty-five patients (70%) within 5…10 days after surgical intervention. Clinical complications were absent in fifteen patients (30%). Sixty-seven healthy individuals were examined as a control group. Evaluation of the cytokine concentrations was performed by ELISA technique. The degree of respiratory burst in blood neutrophils was measured by means of chemiluminescence assay.
It is revealed that the EPP patients exhibited increased levels of serum proinflammatory cytokines and IFNγ, along with higher intensity of respiratory burst in blood neutrophils, due to activated synthesis of of both primary and secondary reactive oxygen species (ROS). The EPP patients who later developed abdominal sepsis showed reduced spontaneous synthesis of primary ROS and increased spontaneous synthesis of secondary ROS. Upon zymosan induction of neutrophils, both primary and secondary ROS levels proved to be similar in the EPP subgroups with or without subsequent sepsis. EPP patients with uncomplicated post-surgical period still exhibited a predominant regulation of respiratory burst of neutrophils by IFNγ activity. Meanwhile, the neutrophil respiratory burst was correlated with TNFα and IL-6 in those patients who further developed abdominal sepsis. A stimulatory effect of IFNγ and a presumably inhibitory action of TNFα and IL-6 upon respiratory burst of blood neutrophils in EPP patients are associated with a release of large cytokine amounts during acute immune inflammatory events, and migration of activated cells to the inflammatory focus. In particular, the changes in the cytokine levels regulating the respiratory burst of neutrophils may be an important factor which predicts development of abdominal sepsis in EPP.
Colorectal cancer (CRC) is the third most common cancer worldwide, being quite complicated, with respect to diagnostics and postoperative prognosis. Proinflammatory cytokines are shown to be involved into CRC pathogenesis. However, the changes in alpha-2-macroglobulin (α2-MG), a known regulator of cytokine production, still remain unclear. The aim of this work was to compare contents and production of a2-MG and several pro-inflammatory cytokines in blood serum and supernates from short-term blood cell cultures. The samples were taken from the patients with CRC at initial terms and after surgical removal of the tumor.
Studies of cytokines and a2-MG concentrations in serum and supernates of 24-h blood cell cultures from the patients with verified CRC (stages T2-3N0-1M0 and T4N0-1M0) have shown some sufficient differences from healthy volunteers (control group). Pre-surgery IL-6 and TNFα contents in blood of CRC patients was significantly increased agains healthy controls (respectively, 29.9±5.4 and 3.4±1.5 pg/mL) versus control group (1.0±0.3 and 0 pg/mL, respectively). Following surgical treatment, the cytokine levels were decreased by 40- 60% after the operation, however, without significant differences from initial values.
The supernates of blood cultures stimulated with polyclonal mitogens exhibited significant reduction of IFNγ levels prior to surgery (273±123 pg/ml versus 804±154 pg/mL), and elevated IL-6 levels (14412±2570 pg/mL versus 1970±457 pg/mL). The mean α2-MG concentrations before CRC surgery comprised 1.96±0.11 g/L for blood serum, 0.0304±0.0047 g/L, for non-stimulated blood cell cultures, and 0.0300±0.0052 g/L in mitogen-induced cultures. These parameters did not significantly differ from control values (2.21±0.17 g/L, 0.0328±0.0018 g/L, and 0.0314±0.0019 g/L, respectively). Similar results have been yielded with the samples obtained after surgical treatment of the CRC patients.
The obtained data indicate that surgical treatment of CRC does not lead to normalization of the serum levels and secretion of pro-inflammatory IL-6 and TNFα cytokines by the patients’ blood cells. Marginal changes in a2-MG levels in colorectal cancer seem to be not of such importance, as functional state of the molecules which may abnormally respond to changing cytokine contents. The revealed post-surgical suppression of mitogen-induced IFNγ secretion makes it necessary to suggest administration of IFNγ and IL-2 after surgical treatment of CRC.
ISSN 2313-741X (Online)