scholarly journals The septin cytoskeleton regulates natural killer cell lytic granule release

2020 ◽  
Vol 219 (11) ◽  
Author(s):  
Prasad V. Phatarpekar ◽  
Brittany L. Overlee ◽  
Alexander Leehan ◽  
Katelynn M. Wilton ◽  
Hyoungjun Ham ◽  
...  

Natural killer (NK) cell–mediated killing involves the membrane fusion of preformed lytic granules. While the roles of actin and microtubules are well accepted during this process, the function of septins, another cytoskeletal component that associates with actin and microtubules, has not been investigated. Here we show that genetic depletion or pharmacologic stabilization of the septin cytoskeleton significantly inhibited NK cell cytotoxicity. Although the stabilization of septin filaments impaired conjugate formation, depletion of septin proteins had no impact on conjugate formation, lytic granule convergence, or MTOC polarization to the cytotoxic synapse (CS). Interestingly, septins copurify and accumulate near the polarized lytic granules at the CS, where they regulate lytic granule release. Mechanistically, we find that septin 7 interacts with the SNARE protein syntaxin 11 and facilitates its interaction with syntaxin binding protein 2 to promote lytic granule fusion. Altogether, our data identify a critical role for septins in regulating the release of lytic granule contents during NK cell–mediated killing.

2013 ◽  
Vol 24 (23) ◽  
pp. 3721-3735 ◽  
Author(s):  
Amit Tuli ◽  
Jerome Thiery ◽  
Ashley M. James ◽  
Xavier Michelet ◽  
Mahak Sharma ◽  
...  

Natural killer (NK) lymphocytes contain lysosome-related organelles (LROs), known as lytic granules, which upon formation of immune synapse with the target cell, polarize toward the immune synapse to deliver their contents to the target cell membrane. Here, we identify a small GTP-binding protein, ADP-ribosylation factor-like 8b (Arl8b), as a critical factor required for NK cell–mediated cytotoxicity. Our findings indicate that Arl8b drives the polarization of lytic granules and microtubule-organizing centers (MTOCs) toward the immune synapse between effector NK lymphocytes and target cells. Using a glutathione S-transferase pull-down approach, we identify kinesin family member 5B (KIF5B; the heavy chain of kinesin-1) as an interaction partner of Arl8b from NK cell lysates. Previous studies showed that interaction between kinesin-1 and Arl8b is mediated by SifA and kinesin-interacting protein (SKIP) and the tripartite complex drives the anterograde movement of lysosomes. Silencing of both KIF5B and SKIP in NK cells, similar to Arl8b, led to failure of MTOC-lytic granule polarization to the immune synapse, suggesting that Arl8b and kinesin-1 together control this critical step in NK cell cytotoxicity.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hee Young Na ◽  
Yujun Park ◽  
Soo Kyung Nam ◽  
Jiwon Koh ◽  
Yoonjin Kwak ◽  
...  

Abstract Background Natural killer (NK) cells mediate the anti-tumoral immune response as an important component of innate immunity. The aim of this study was to investigate the prognostic significance and functional implication of NK cell-associated surface receptors in gastric cancer (GC) by using multiplex immunohistochemistry (mIHC). Methods We performed an mIHC on tissue microarray slides, including 55 GC tissue samples. A total of 11 antibodies including CD57, NKG2A, CD16, HLA-E, CD3, CD20, CD45, CD68, CK, SMA, and ki-67 were used. CD45 + CD3-CD57 + cells were considered as CD57 + NK cells. Results Among CD45 + immune cells, the proportion of CD57 + NK cell was the lowest (3.8%), whereas that of CD57 + and CD57- T cells (65.5%) was the highest, followed by macrophages (25.4%), and B cells (5.3%). CD57 + NK cells constituted 20% of CD45 + CD57 + immune cells while the remaining 80% were CD57 + T cells. The expression of HLA-E in tumor cells correlated with that in tumoral T cells, B cells, and macrophages, but not CD57 + NK cells. The higher density of tumoral CD57 + NK cells and tumoral CD57 + NKG2A + NK cells was associated with inferior survival. Conclusions Although the number of CD57 + NK cells was lower than that of other immune cells, CD57 + NK cells and CD57 + NKG2A + NK cells were significantly associated with poor outcomes, suggesting that NK cell subsets play a critical role in GC progression. NK cells and their inhibitory receptor, NKG2A, may be potential targets in GC.


Blood ◽  
2020 ◽  
Vol 135 (9) ◽  
pp. 629-637
Author(s):  
Michael T. Lam ◽  
Emily M. Mace ◽  
Jordan S. Orange

Abstract Natural killer cell deficiencies (NKDs) are an emerging phenotypic subtype of primary immune deficiency. NK cells provide a defense against virally infected cells using a variety of cytotoxic mechanisms, and patients who have defective NK cell development or function can present with atypical, recurrent, or severe herpesviral infections. The current pipeline for investigating NKDs involves the acquisition and clinical assessment of patients with a suspected NKD followed by subsequent in silico, in vitro, and in vivo laboratory research. Evaluation involves initially quantifying NK cells and measuring NK cell cytotoxicity and expression of certain NK cell receptors involved in NK cell development and function. Subsequent studies using genomic methods to identify the potential causative variant are conducted along with variant impact testing to make genotype-phenotype connections. Identification of novel genes contributing to the NKD phenotype can also be facilitated by applying the expanding knowledge of NK cell biology. In this review, we discuss how NKDs that affect NK cell cytotoxicity can be approached in the clinic and laboratory for the discovery of novel gene variants.


2002 ◽  
Vol 11 (4) ◽  
pp. 219-224 ◽  
Author(s):  
Toshiaki Kogure ◽  
Naoki Mantani ◽  
Hirozo Goto ◽  
Yutaka Shimada ◽  
Jun'ichi Tamura ◽  
...  

Interleukin (IL)-15 has emerged as a key regulator of both natural killer (NK) cell differentiation and activation. The aim of the present study was to investigate the expansion of the population of cells expressing killer-cell immunoglobulin-like receptors (CD158a and CD158b) in human peripheral lymphocytes by treatment with IL-15. One million peripheral lymphocytes were cultured in RPMI1640 medium alone or in medium containing IL-2 at 100 U/ml or IL-15 at 0.1, 1.0, or 10.0 ng/ml for 48 h. After each incubation, we assessed the natural killing activity and the population of CD16+CD158a+/b+cells and CD8+CD158a+/b+cells. IL-15 increased the NK activity and expanded the populations of CD16+CD158a+/b+cells and CD8+CD158a+/b+cells. These actions were dose dependent, and the effects of IL-15 at 1.0 ng/ml were close to those of IL-2 at 100 U/ml. These findings suggest that IL-15 induces the effector functions of resting NK cells throughout the body, and thereby plays a critical role in the activation of tissue-associated immune responses.


2003 ◽  
Vol 197 (10) ◽  
pp. 1245-1253 ◽  
Author(s):  
Melissa Lodoen ◽  
Kouetsu Ogasawara ◽  
Jessica A. Hamerman ◽  
Hisashi Arase ◽  
Jeffrey P. Houchins ◽  
...  

Natural killer (NK) cells play a critical role in the innate immune response against cytomegalovirus (CMV) infections. Although CMV encodes several gene products committed to evasion of adaptive immunity, viral modulation of NK cell activity is only beginning to be appreciated. A previous study demonstrated that the mouse CMV m152-encoded gp40 glycoprotein diminished expression of ligands for the activating NK cell receptor NKG2D on the surface of virus-infected cells. Here we have defined the precise ligands that are affected and have directly implicated NKG2D in immune responses to CMV infection in vitro and in vivo. Murine CMV (MCMV) infection potently induced transcription of all five known retinoic acid early inducible 1 (RAE-1) genes (RAE-1α, RAE-1β, RAE-1δ, RAE-1ε, and RAE-1γ), but not H-60. gp40 specifically down-regulated the cell surface expression of all RAE-1 proteins, but not H-60, and diminished NK cell interferon γ production against CMV-infected cells. Consistent with previous findings, a m152 deletion mutant virus (Δm152) was less virulent in vivo than the wild-type Smith strain of MCMV. Treatment of BALB/c mice with a neutralizing anti-NKG2D antibody before infection increased titers of Δm152 virus in the spleen and liver to levels seen with wild-type virus. These experiments demonstrate that gp40 impairs NK cell recognition of virus-infected cells through disrupting the RAE-1–NKG2D interaction.


1996 ◽  
Vol 184 (6) ◽  
pp. 2243-2250 ◽  
Author(s):  
Nicholas M. Valiante ◽  
Joseph H. Phillips ◽  
Lewis L. Lanier ◽  
Peter Parham

The killer cell inhibitory receptors (KIR) of human natural killer (NK) cells recognize human leukocyte antigen class I molecules and inhibit NK cell cytotoxicity through their interaction with protein tyrosine phosphatases (PTP). Here, we report that KIR recognition of class I ligands inhibits distal signaling events and ultimately NK cell cytotoxicity by blocking the association of an adaptor protein (pp36) with phospholipase C-γ in NK cells. In addition, we demonstrate that pp36 can serve as a substrate in vitro for the KIR-associated PTP, PTP-1C (also called SHP-1), and that recognition of class I partially disrupts tyrosine phosphorylation of NK cell proteins, providing evidence for KIR-induced phosphatase activity.


2020 ◽  
Vol 21 (24) ◽  
pp. 9499
Author(s):  
Dong Oh Kim ◽  
Jae-Eun Byun ◽  
Won Sam Kim ◽  
Mi Jeong Kim ◽  
Jung Ha Choi ◽  
...  

The function of natural killer (NK) cell-derived interferon-γ (IFN-γ) expands to remove pathogens by increasing the ability of innate immune cells. Here, we identified the critical role of thioredoxin-interacting protein (TXNIP) in the production of IFN-γ in NK cells during bacterial infection. TXNIP inhibited the production of IFN-γ and the activation of transforming growth factor β-activated kinase 1 (TAK1) activity in primary mouse and human NK cells. TXNIP directly interacted with TAK1 and inhibited TAK1 activity by interfering with the complex formation between TAK1 and TAK1 binding protein 1 (TAB1). Txnip−/− (KO) NK cells enhanced the activation of macrophages by inducing IFN-γ production during Pam3CSK4 stimulation or Staphylococcus aureus (S. aureus) infection and contributed to expedite the bacterial clearance. Our findings suggest that NK cell-derived IFN-γ is critical for host defense and that TXNIP plays an important role as an inhibitor of NK cell-mediated macrophage activation by inhibiting the production of IFN-γ during bacterial infection.


2003 ◽  
Vol 5 (2) ◽  
pp. 142-152 ◽  
Author(s):  
Sandra Adams Motzer ◽  
Joyce Tsuji ◽  
Vicky Hertig ◽  
Sandra K. Johnston ◽  
James Scanlan

The purpose of this study is to describe design considerations for the use of flow cytometry (FC) com-pared to51chromium (51Cr)-release assays utilizing cryopreserved peripheral blood mononuclear cells (PBMCs) to detect natural killer (NK) cell cytotoxicity. Subjects were 10 healthy women aged 18 to 39 years. Intra-assay variability between methods differed only at the lowest effector-target ratios evaluated. Interassay variability was wide but did not differ between methods. The relationship of lytic unit-10 between methods was strongly positive. Cytotoxicity detected by51Cr release was higher than that detected by FC for all 10 subjects. Cost was comparable. How-ever, had more assays been performed, technician time would have been greater with flow cytometry. More whole blood was needed to perform the flow cytometry cytotoxicity assay than51Cr-release cytotoxicity assay. The authors found no compelling reason to adopt NK cell cytotoxicity by flow cytometry over51Cr release.


2021 ◽  
Vol 17 ◽  
Author(s):  
Idris Kirhan ◽  
Huseyin Taskiran ◽  
Ataman Gönel

Background: The effects of chemotherapeutics agents are considered to influence immune system and cells due to their myelosuppressive and immunosuppressive functions. Natural Killer Cells are one of the important components of innate immune system and have a critical role against tumor cells and infections. Objective: The study was aimed to demonstrate whether conventional chemotherapies had an effect on Natural Killer (NK) cell activity. Methods: 49 adjuvant, 19 first time metastatic chemotherapy-naïve cancer patients were recruited into the study. Pre-chemotherapy and post-chemotherapy, at 1th and 4th cycles, blood samples were obtained for NK cell activity. Results: We found no difference between baseline and post-chemotherapy NK cell activity levels. In addition, we found no difference between pre-chemotherapy and post-chemotherapy NK cell activity in both adjuvant and metastatic cancer patients separately. Conclusion: Conventional chemotherapy seems to no affect NK cell activity levels in cancer patients in both metastatic and adjuvant settings.


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