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Shawn Morton

McNair Scholar
Shawn Morton

Summary

  • Major: Microbiology & Immunology
  • Faculty Mentor: Dr. Dorothy Hudig
  • Research Topic: Reduction of Natural Killer cell ADCC by membrane bound non-supporting IgA antibody
  • New Scholar: 2023 Cohort
  • Graduating with a Baccalaureate Degree: 2025

Abstract

Viral pandemics, such as SARS-CoV-2, have caused extensive human suffering and mortality whilst efforts to mitigate such diseases have been insufficient. To improve control of infectious diseases, all mechanisms contributing to immunity must be further explored. This project will study a poorly understood mechanism of viral immunity: antibodies that bind to Natural Killer cells and direct them to kill virally infected cells, also known as antibody-dependent cellular cytotoxicity (ADCC). Enhancing this antibody-dependent cell-mediated cytotoxicity mechanism could improve the efficacy of life-saving vaccines. Ineffective antibodies for ADCC, unable to bind to NK cells, may inhibit ADCC-dependent clearance of virally infected cells. This is especially relevant in environments such as the nasal-associated lymphoid tissues (NALT), where considerable amounts of IgA, an ineffective ADCC antibody, are present. The experimental procedure consists of Daudi cells, an immortalized line of B lymphocytes expressing the CD20 surface antigen, which are radiolabeled with 51Cr. These cells are incubated in 96 well plates with the anti-CD20 IgG1 antibody GA101, which NK cells are capable of recognizing with their CD16a receptors. Then, some of the targets will receive either IgG1 LALA, a variant of GA101 modified so that NK cells can no longer recognize it, or IgA, which is an innately non-ADCC forming antibody. Our current results have shown that the sequential addition of ineffective antibody reduces ADCC significantly in both laboratories engineered NK-92 cells as well as blood NK cells. With this understanding, our next direction is to measure the ADCC inhibition following a simultaneous addition of antibodies.