Characterization of Pseudomonas aeruginosa ghost and evaluation of its immune proficiency in Nile tilapia (Oreochromis niloticus)
AQUACULTURE INTERNATIONAL
Authors: Ghazy, Haneen A.; El-Nahas, Abeer F.; Mahmoud, Shawky A.; Fahmy, Hanan A.; El-Domany, Ramadan A.; Mahmoud, Hoda E.; Omar, Amira A.
Abstract
Pseudomonas aeruginosais known to be multidrug-resistant organisms so its infection is challenging. This study aimed to use the sponge-like reduced protocol in preparation ofP. aeruginosaghosts (PAGs) as a vaccine alternative and evaluate its competency in stimulating the immune response in Nile tilapia. Characterization of PAGs was done using the light, fluorescent and transmission electron microscope. 240 fish have been divided into four groups (60 fish each; three groups were injected with a high, medium, or low dose of PAGs, and a control group. Total and differential leukocyte count, phagocytic activity, lysozyme activity, and gene expression of some immune-related genes were done after the first and booster ghost dose injection. All fish groups were challenged intraperitoneally withP. aeruginosa(1 x 10(7) CFU ml(-1)); the mean percent mortality was calculated. Significant immunization potency of the large dose of PAGs was prominent. It is associated with a significant increased number of WBCs, heterophile, lymphocytes, and monocytes. Also the phagocytic activity and indexes were significantly increased by the high and moderate dose of PAGs. Additionally, significant upregulation of immune-related gene (MHC-II)and inflammatory-related gene (IL8) and maintained expression level ofTLR7were recorded.We conclude that chemically preparedP. aeruginosaghosts maintained both the 3D structure and surface molecules of live bacteria and also are capable of inducing specific immune responses in Nile Tilapia, and reduced mortalities in challenged fish.Our results indicate the advantage of this procedure for production of bacterial ghost, which can be used in wide a range of hosts.
Neutrophil Extracellular Traps Induced by IL8 Promote Diffuse Large B-cell Lymphoma Progression via the TLR9 Signaling
CLINICAL CANCER RESEARCH
Authors: Nie, Man; Yang, Linbin; Bi, Xiwen; Wang, Yu; Sun, Peng; Yang, Hang; Liu, Panpan; Li, Zhiming; Xia, Yi; Jiang, Wenqi
Abstract
Purpose: More than 30% of patients with diffuse large B-cell lymphoma (DLBCL) experience treatment failure after first-line therapy. Neutrophil extracellular traps (NETs), a pathogen-trapping structure in tumor microenvironment, can promote the transition of autoimmunity to lymphomagenesis. Here, we investigate whether NETs play a novel role in DLBCL progression and its underlying mechanism. Experimental Design: NETs in DLBCL tumor samples and plasma were detected by immunofluorescence and ELISA, respectively. The correlation between NETs and clinical features were analyzed. The effects of NETs on cellular proliferation and migration and mechanisms were explored, and the mechanism of NET formation was also studied by a series of in vitro and in vivo assays. Results: Higher levels of NETs in plasma and tumor tissues were associated with dismal outcome in patients with DLBCL. Furthermore, we identified NETs increased cell proliferation and migration in vitro and tumor growth and lymph node dissemination in vivo. Mechanistically, DLBCL-derived IL8 interacted with its receptor (CXCR2) on neutrophils, resulting in the formation of NETs via Src, p38, and ERK signaling. Newly formed NETs directly upregulated the Toll-like receptor 9 (TLR9) pathways in DLBCL and subsequently activated NFkB, STAT3, and p38 pathways to promote tumor progression. More importantly, disruption of NETs, blocking IL8-CXCR2 axis or inhibiting TLR9 could retard tumor progression in preclinical models. Conclusions: Our data reveal a tumor-NETs aggressive interaction in DLBCL and indicate that NETs is a useful prognostic biomarker and targeting this novel cross-talk represents a new therapeutic opportunity in this challenging disease.