scholarly journals Excess histone levels mediate cytotoxicity via multiple mechanisms

Cell Cycle ◽  
2010 ◽  
Vol 9 (20) ◽  
pp. 4236-4244 ◽  
Author(s):  
Rakesh Kumar Singh ◽  
Dun Liang ◽  
Ugander Reddy Gajjalaiahvari ◽  
Marie-Helene Miquel Kabbaj ◽  
Johanna Paik ◽  
...  
Keyword(s):  
1982 ◽  
Vol 156 (6) ◽  
pp. 1854-1859 ◽  
Author(s):  
S L Wee ◽  
L K Chen ◽  
G Strassmann ◽  
F H Bach

We report here a class of helper cell-independent cytotoxic T cell (HITc) clones in man that can proliferate in response to antigenic stimulation as well as mediate cytotoxicity. HITc appear to be rare among clones derived from primary in vitro allosensitized culture, but constitute the majority of clones derived from cells sensitized to autologous Epstein-Barr virus-transformed lymphoblastoid cell lines. The implications of the derivation and function of HITc clones are discussed.


2004 ◽  
Vol 78 ◽  
pp. 153-154
Author(s):  
C L. Hsieh ◽  
H Obara ◽  
O M. Martinez ◽  
S M. Krams

Parasitology ◽  
1994 ◽  
Vol 109 (4) ◽  
pp. 479-485 ◽  
Author(s):  
C. M. Adema ◽  
E. C. Van Deutekom-Mulder ◽  
W. P. W. Van Der Knaap ◽  
T. Sminia

SUMMARYMacrophage-like defence cells (haemocytes) of the pond snailLymnaea stagnalismediate cytotoxicity through reactive oxygen intermediates (ROIs). This activity is NADPH-oxidase dependent, as in mammalian phagocytes during the respiratory burst. In this study, mother sporocysts of schistosomes, the compatibleTrichobilharzia ocellataand the incompatibleSchistosoma mansonievokein vitroROI activities (detected by luminol dependent chemiluminescence, LDCL) fromL. stagnalishaemocytes.S. mansoniis encapsulated by haemocytes and eliminated, whereasT. ocellataescapes encapsulation and survives. Both schistosomes were equally susceptible toin vitrooxidative damage from exposure to hydrogen peroxide and to ROIs generated by a xanthine/xanthine oxidase system. Protocatechuic acid, a specific antagonist of NADPH-oxidase, delayed the killing ofT. ocellataandS. mansonisporocysts by haemocytes of resistant snails (Biomphalaria glabrata and L. stagnalis, respectively). We conclude that ROIs take part in haemocyte-mediated cytotoxicity. However, neither a snail's capability to generate ROIs, nor a schistosome's susceptibility to ROIs, determine snail/schistosome incompatibility. Snail/schistosome compatibility is rather determined by the parasite's ability modulate haemocyte behaviour such that effective encapsulation and the generation of lethal concentrations of ROIs are prevented.


1999 ◽  
Vol 67 (7) ◽  
pp. 3207-3214 ◽  
Author(s):  
James C. Comolli ◽  
Leslie L. Waite ◽  
Keith E. Mostov ◽  
Joanne N. Engel

ABSTRACT The interaction of Pseudomonas aeruginosa type IV pili and the glycosphingolipid asialo-GM1 (aGM1) can mediate bacterial adherence to epithelial cells, but the steps subsequent to this adherence have not been elucidated. To investigate the result of the interaction of pili and aGM1, we used polarized epithelial monolayers of Madin-Darby canine kidney (MDCK) cells in culture, which contained little detectable aGM1 on their apical surface but were able to incorporate exogenous aGM1. Compared to an untreated monolayer,P. aeruginosa PA103 displayed an eightfold increase in association with and fivefold more cytotoxicity toward MDCK cells pretreated with aGM1. Cytotoxicity of either carrier-treated or aGM1-treated monolayers required the type III secreted protein ExoU. Asialo-GM1 pretreatment of MDCK monolayers likewise augmented bacterial internalization of an isogenic invasive strain approximately fourfold. These increases were not seen in monolayers treated with GM1, the sialyated form of the glycolipid, and were inhibited by treatment with an antibody to aGM1. Also, the aGM1-mediated adhesion, cytotoxicity, and internalization required intact type IV pili since nonpiliated PA103 mutants were unaffected by aGM1 pretreatment of MDCK cells. These results demonstrate that epithelial cell injury and bacterial internalization can proceed from the same adhesin-receptor interaction, and they indicate that P. aeruginosa exoproducts solely determine the steps subsequent to adhesion.


2020 ◽  
Vol 11 ◽  
Author(s):  
Yueyun Pan ◽  
Yinda Yu ◽  
Xiaojian Wang ◽  
Ting Zhang

Tumor-associated macrophages (TAMs) represent one of the main tumor-infiltrating immune cell types and are generally categorized into either of two functionally contrasting subtypes, namely classical activated M1 macrophages and alternatively activated M2 macrophages. The former typically exerts anti-tumor functions, including directly mediate cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC) to kill tumor cells; the latter can promote the occurrence and metastasis of tumor cells, inhibit T cell-mediated anti-tumor immune response, promote tumor angiogenesis, and lead to tumor progression. Both M1 and M2 macrophages have high degree of plasticity and thus can be converted into each other upon tumor microenvironment changes or therapeutic interventions. As the relationship between TAMs and malignant tumors becoming clearer, TAMs have become a promising target for developing new cancer treatment. In this review, we summarize the origin and types of TAMs, TAMs interaction with tumors and tumor microenvironment, and up-to-date treatment strategies targeting TAMs.


1973 ◽  
Vol 138 (6) ◽  
pp. 1521-1532 ◽  
Author(s):  
Claude Carnaud ◽  
David Ilfeld ◽  
Itzhak Brook ◽  
Nathan Trainin

Unprimed mouse spleen cells cultured in vitro on syngeneic tumor cell monolayers have been previously shown to become specifically sensitized and to mediate cytotoxicity against the same type of tumor cells. This complete in vitro system of cell-mediated response has been presently used to test the effect of a thymic humoral factor (THF) upon the differentiation process leading to the generation of specifically committed lymphocytes. Culture media were supplemented with 2% THF during either the sensitization or effector phase, or both phases of the reaction. Whereas the addition of THF during both phases or during sensitization only resulted in a significant increase in the cytotoxicity index, THF added during the effector phase was ineffective. The behavior of unsensitized spleen cells and of spleen cells sensitized against nonrelated transplantation antigens remained unmodified by THF. After showing that the entire reaction is mediated by lymphocytes of thymic origin, THF was directly tested on T or B spleen cells. It was found that only T cells reacted to THF by an increased cytotoxic capacity, while B cells remained inactive after addition of THF. It was therefore concluded that THF activates a postthymic population of lymphoid cells, transforming them into fully competent lymphocytes.


2007 ◽  
Vol 22 (2) ◽  
pp. 144-153 ◽  
Author(s):  
M. Papazahariadou ◽  
G.I. Athanasiadis ◽  
E. Papadopoulos ◽  
I. Symeonidou ◽  
M. Hatzistilianou ◽  
...  

Host resistance against pathogens depends on a complex interplay of innate and adaptive immune mechanisms. Acting as an early line of defence, the immune system includes activation of neutrophils, tissue macrophages, monocytes, dendritic cells, eosinophils and natural killer (NK) cells. NK cells are lymphoid cells that can be activated without previous stimulation and are therefore like macrophages in the first line of defence against tumor cells and a diverse range of pathogens. NK cells mediate significant activity and produce high levels of proinflammatory cytokines in response to infection. Their cytotoxicity production is induced principally by monocyte-, macrophage- and dendritic cell-derived cytokines, but their activation is also believed to be cytokine-mediated. Recognition of infection by NK cells is accomplished by numerous activating and inhibitory receptors on the NK cells’ surface that selectively trigger the cytolytic activity in a major histocompability complex-independent manner. NK cells have trypanocidal activity of fibroblast cells and mediate direct destruction of extracellular epimastigote and trypomastigote forms of T. cruzi and T. lewisi in vitro; moreover, they kill plasmodia-infected erythrocytes directly through cell-cell interaction. This review provides a more detailed analysis of how NK cells recognize and respond to parasites and how they mediate cytotoxicity against tumor cells. Also the unique role of NK cells in innate immunity to infection and the relationship between parasites and carcinogenesis are discussed.


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