The effect of exosomes released from apheresis platelet concentrates under the impact of gamma irradiation and storage time upon platelet aggregation and hemostasis.

BACKGROUND: Blood components should be gamma-irradiated (γ-IR) in order to prevent transfusion-associated graft-versus-host disease. The aim of this study is to determine the effect of γ-IR and storage time on the exosomes released from apheresis platelet concentrates (aPC) and to investigate their impact on the maximum platelet aggregation (MPA) and hemostasis. MATERIALS AND METHODS: Eight units of aPC were included in this study. These were divided into four equal portions. Two portions were irradiated before storage while the other two were not. Thus, irradiated and non-irradiated aPC samples for storage Days 0 (D0) and 5 (D5) were obtained. Exosomes were isolated from these samples using a commercial kit and were evaluated to ascertain their parent cells by flow cytometry. For the following steps, exosomes were pooled according to their features. Pooled exosomes were then used for aggregometry and thromboelastography. RESULTS: Platelet-derived exosome (PD-EX) levels decreased in D5 compared to D0 in NI-aPC, whereas granulocyte-derived exosome (GD-EX) levels increased. Exosome pools had no effect on MPA compared to saline groups. Exosome pools decreased the time to initial fibrin formation (R), whereas they increased the rate of clot formation (α-angle) and coagulation index (CI) compared to saline groups. DISCUSSION: Storage time and γ-IR each have almost the opposite effects on PD-EX and GD-EX. Exosomes have no impact on MPA, but enhance the clot strength. The impact of exosomes on aPC quality and effectiveness can be ignored or considered as a positive effect.

Effect of storage period of red blood cell suspensions on helper T-cell subpopulations.

BACKGROUND: The aim of this study was to investigate the immunological alterations that occur during the storage of erythrocyte suspensions which may lead to transfusion-related immunomodulation following allogeneic blood transfusion. MATERIALS AND METHODS: One part of the erythrocyte suspensions obtained from donors was leucoreduced while the other part was not. The leucoreduced (LR) and non-leucoreduced (NL) erythrocyte suspensions were then further divided into three equal amounts which were stored for 0, 21 or 42 days prior to measurements, by enzyme-linked immunosorbent assays, of cytokine levels in their supernatants. T-helper (Th) lymphocyte subgroups and gene expression were analysed in the NL erythrocyte suspensions by flow cytometry and real-time polymerase chain reaction, respectively. Results were compared to those of storage day 0. RESULTS: By day 21, the number of Th2 cells had increased significantly and the numbers of Th1, Th22 and Treg cells had decreased significantly in the NL erythrocyte suspensions. On day 42 the numbers of Th2 and Treg cells in the NL suspensions were significantly increased while the number of Th1 cells was significantly decreased. The levels of transcription factors (TBX21, GATA3, and SPI.1) were significantly decreased on days 21 and 42, and AHR, FOXP3 and RORC2 levels were significantly increased on day 42 in NL erythrocyte suspensions. The decrease in interleukin-22 and increase in transforming growth factor-ß levels found in NL erythrocyte suspensions on day 21 were statistically significant. Elevated levels of interleukin-17A were found in both LR and NL erythrocyte suspensions on day 42. DISCUSSION: Our results suggest that allogeneic leucocytes and cytokines may play significant roles in the development of transfusion-related immunomodulation.

IL-10 and IL-6 gene polymorphisms as potential host susceptibility factors in Brucellosis.

Several genes encoding for different cytokines may play crucial roles in host susceptibility to Brucellosis, since the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphism. The association of the cytokine gene polymorphisms with the development of Brucellosis was investigated in this study. DNA samples were obtained from a Turkish population of 40 patients with Brucellosis, and 50 healthy control subjects. All genotyping (IL-6, IL10, IFN-gamma, TGF-beta and TNF-alpha) experiments were performed using sequence-specific primers PCR (PCR-SSP). When compared to the healthy controls, the frequencies of high/intermediate producing genotypes of IL-10 and high producing genotype of IL-6 were significantly more common in the patient group. These results suggest that IL-10 and IL-6 gene polymorphisms may affect susceptibility to Brucellosis and increase risk of developing the disease. In order to confirm the biological significance of our results, further studies should be performed in larger population groups.

Interleukin-10 (IL-10) gene polymorphism as a potential host susceptibility factor in tuberculosis.

Several genes encoding for different cytokines may play crucial roles in host susceptibility to tuberculosis (TB), since the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphism. The association of the cytokine gene polymorphisms with the development of TB was investigated in this study. DNA samples were obtained from a Turkish population of 81 patients with the different clinical forms of TB, and 50 healthy control subjects. All genotyping (IL-6, IL-10, IFN-gamma, TGF-beta and TNF-alpha) experiments were performed using sequence-specific primers PCR (PCR-SSP). Analysis of allele frequencies showed that IL-10 -1082 G allele frequency was significantly more common in TB patients than healthy controls (37.7% vs 23.0%, p: 0.014). No statistically significant differences were observed between the different clinical forms of the disease. These results suggest that the polymorphisms in IL-10 gene may affect susceptibility to TB and increase risk of developing the disease. To confirm the biological significance of our results, further studies should be performed on other population groups.

Regulation of T cells and cytokines by the interleukin-10 (IL-10)-family cytokines IL-19, IL-20, IL-22, IL-24 and IL-26.

The family of IL-10-related cytokines includes several human members, IL-19, IL-20, IL-22, IL-24 and IL-26, and a series of herpesviral and poxviral paralogs. Some of these cytokines share common receptor subunits. In this study, we investigated the effects of these cytokines on naive T cell differentiation, antigen-specific T cell suppression, survival ad expression of surface markers in comparison to IL-10 and cytomegalovirus (CMV)-IL-10. Human CD45RA(+) T cells were stimulated in the presence of IL-10-family cytokines in sequential 12-day cycles. After three to four cycles of stimulation, IL-10 and CMV-IL-10 led to increased IFN-gamma and IL-10 but decreased IL-4 and IL-13. Interestingly, long-term exposure of T cells to IL-19, IL-20 and IL-22 down-regulated IFN-gamma but up-regulated IL-4 and IL-13 in T cells and supported the polarization of naive T cells to Th2-like cells. In contrast, neutralization of endogenous IL-22 activity by IL-22-binding protein decreased IL-4, IL-13 and IFN-gamma synthesis. The antigen-specific suppressor activity of IL-10 and CMV-IL-10 was not observed for any of the other IL-10-family cytokines. These data demonstrate that IL-19, IL-20 and IL-22 may participate in T cell-mediated diseases by distinct regulation of T cell cytokine profiles.