Killing by cytotoxic T cells and natural killer cells: Multiple granule serine proteases as initiators of DNA fragmentation

1993 ◽  
Vol 71 (3) ◽  
pp. 201-208 ◽  
Author(s):  
JOSEPH A. TRAPANI ◽  
MARK J. SMYTH
Keyword(s):  
T Cells ◽  
Natural Killer Cells ◽  
Natural Killer ◽  
Dna Fragmentation ◽  
Serine Proteases ◽  
Cytotoxic T Cells ◽  
Killer Cells

scholarly journals Significant Increase in Cytotoxic T Lymphocytes and Natural Killer Cells by Triphala: A Clinical Phase I Study

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Pratya Phetkate ◽  
Tanawan Kummalue ◽  
Yaowalak U-pratya ◽  
Somboon Kietinun
Keyword(s):  
T Cells ◽  
Side Effects ◽  
Natural Killer Cells ◽  
Phase I ◽  
Natural Killer ◽  
Phase I Study ◽  
Cytotoxic T Cells ◽  
Killer Cells ◽  
Clinical Phase ◽  
Hiv Aids

Background. Searching for drugs or herbal formulations to improve the immunity of HIV/AIDS positive people is an important issue for researchers in this field. Triphala, a Thai herbal formulation, is reported to have immunomodulatory effects in mice. However, it has not yet been investigated for immunostimulatory and side effects in healthy human volunteers.Objective. To evaluate the immunostimulatory and side effects of Triphala in a clinical phase I study.Materials and Methods. All volunteers took Triphala, 3 capsules per day for 2 weeks. Complete physical examination, routine laboratory analysis, and immunological studies were performed before ingestion and after initial meeting for 4 consecutive weeks.Results. We found that Triphala demonstrated significant immunostimulatory effects on cytotoxic T cells (CD3−CD8+) and natural killer cells (CD16+CD56+). Both of them increased significantly when compared with those of the control samples. However, no significant change in cytokine secretion was detected. All volunteers were healthy and showed no adverse effects throughout the duration of the study.Conclusion. Triphala has significant immunostimulatory effects on cellular immune response, especially cytotoxic T cells and natural killer cells. Increases in the absolute number of these cells may provide a novel adjuvant therapy for HIV/AIDS positive people in terms of immunological improvement.

scholarly journals Next-Generation Immunotherapies to Improve Anticancer Immunity

2021 ◽  
Vol 11 ◽  
Author(s):  
Yaoyao Shi ◽  
Katarzyna Tomczak ◽  
June Li ◽  
Joshua K. Ochieng ◽  
Younghee Lee ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Natural Killer Cells ◽  
Natural Killer ◽  
Tumor Cells ◽  
Checkpoint Inhibitors ◽  
Cytotoxic T Cells ◽  
Cell Subset ◽  
Cytotoxic T Cell ◽  
Killer Cells

Checkpoint inhibitors are widely used immunotherapies for advanced cancer. Nonetheless, checkpoint inhibitors have a relatively low response rate, work in a limited range of cancers, and have some unignorable side effects. Checkpoint inhibitors aim to reinvigorate exhausted or suppressed T cells in the tumor microenvironment (TME). However, the TME contains various other immune cell subsets that interact to determine the fate of cytotoxic T cells. Activation of cytotoxic T cells is initiated by antigen cross-presentation of dendritic cells. Dendritic cells could also release chemokines and cytokines to recruit and foster T cells. B cells, another type of antigen-presenting cell, also foster T cells and can produce tumor-specific antibodies. Neutrophils, a granulocyte cell subset in the TME, impede the proliferation and activation of T cells. The TME also consists of cytotoxic innate natural killer cells, which kill tumor cells efficiently. Natural killer cells can eradicate major histocompatibility complex I-negative tumor cells, which escape cytotoxic T cell–mediated destruction. A thorough understanding of the immune mechanism of the TME, as reviewed here, will lead to further development of more powerful therapeutic strategies. We have also reviewed the clinical outcomes of patients treated with drugs targeting these immune cells to identify strategies for improvement and possible immunotherapy combinations.

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