Quantifying human natural killer cell-mediated direct killing of target cells

Presenter Information

Angela Ngoc TruongFollow

Presenter Type

UNO Undergraduate Student

Major/Field of Study

Biology

Other

Biology

Advisor Information

Department of Biology, Assistant Professor, PhD

Location

MBSC302 - U

Presentation Type

Oral Presentation

Start Date

24-3-2023 2:30 PM

End Date

24-3-2023 3:45 PM

Abstract

Peripheral blood mononuclear cells (PBMCs) include cells that are essential to the functions of the immune system, both in the innate and adaptive immune responses. Natural killer (NK) cells are a primary cell type responsible for executing innate responses. NK cells can recognize and kill infected or malignant cells without the need for memory functions or antigen specificity. However, NK cells can also destroy their targets using antibody-dependent cellular cytotoxicity, or ADCC (the topic of a separate presentation by fellow lab member, Cami Bisson). Direct killing requires only that target cells be recognized as “diseased” by the natural killer cells. Typically, this recognition is made based on target cells lacking expression of a normally present cell surface marker (i.e., MHC-I). Following the target cell recognition, NK cells initiate a cytotoxic response that lyses the target cell. Our lab has developed a testing system, referred to as the Natural Killer cell Simultaneous ADCC and Direct Killing Assay (NK-SADKA), that allows for the analysis of both ADCC and direct killing. The same donor samples are used for both the direct killing and ADCC portions of the assay to control for donor response variation. Within the direct killing portion of the assay (the focus of this presentation), MHC-I-deficient human leukemia cells (e.g., K562s) are labeled with a fluorescent dye to distinguish them from the unlabeled human NK effector cells. Target and effector cells are combined (5:1 effector to target ratio) and co-incubated (2 hours). Killing capacity is analyzed using a flow cytometer. Our direct killing arm of the NK-SADKA is functioning properly, as demonstrated by our data showing substantial killing following the coincubation relative to the viability of targets or effectors incubated alone. Data-to-date will be presented. Our NK-SADKA, including the direct killing arm described herein, will have impacts on clinical trial interpretations and designs, particularly when those trials are using interventions (e.g., immunotherapies) intended to alter NK cell killing capacities.

Additional Information (Optional)

Could you place me after a presentation titled, "Quantifying human natural killer cell-mediated antibody-dependent cellular cytotoxicity" by Cami Bisson? Also I have yet to finish, but would I send in the powerpoint that I would hope to use?

Scheduling

1-2:15 p.m., 2:30 -3:45 p.m.

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COinS
 
Mar 24th, 2:30 PM Mar 24th, 3:45 PM

Quantifying human natural killer cell-mediated direct killing of target cells

MBSC302 - U

Peripheral blood mononuclear cells (PBMCs) include cells that are essential to the functions of the immune system, both in the innate and adaptive immune responses. Natural killer (NK) cells are a primary cell type responsible for executing innate responses. NK cells can recognize and kill infected or malignant cells without the need for memory functions or antigen specificity. However, NK cells can also destroy their targets using antibody-dependent cellular cytotoxicity, or ADCC (the topic of a separate presentation by fellow lab member, Cami Bisson). Direct killing requires only that target cells be recognized as “diseased” by the natural killer cells. Typically, this recognition is made based on target cells lacking expression of a normally present cell surface marker (i.e., MHC-I). Following the target cell recognition, NK cells initiate a cytotoxic response that lyses the target cell. Our lab has developed a testing system, referred to as the Natural Killer cell Simultaneous ADCC and Direct Killing Assay (NK-SADKA), that allows for the analysis of both ADCC and direct killing. The same donor samples are used for both the direct killing and ADCC portions of the assay to control for donor response variation. Within the direct killing portion of the assay (the focus of this presentation), MHC-I-deficient human leukemia cells (e.g., K562s) are labeled with a fluorescent dye to distinguish them from the unlabeled human NK effector cells. Target and effector cells are combined (5:1 effector to target ratio) and co-incubated (2 hours). Killing capacity is analyzed using a flow cytometer. Our direct killing arm of the NK-SADKA is functioning properly, as demonstrated by our data showing substantial killing following the coincubation relative to the viability of targets or effectors incubated alone. Data-to-date will be presented. Our NK-SADKA, including the direct killing arm described herein, will have impacts on clinical trial interpretations and designs, particularly when those trials are using interventions (e.g., immunotherapies) intended to alter NK cell killing capacities.