Natural Killer (NK) Cell Expression of CD2 as a Predictor of Serial Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

Abstract

NK cell ADCC supports monoclonal antibody anti-tumor therapies. We investigated serial ADCC and whether it could be predicted by NK phenotypes, including expression of CD16A, CD2 and perforin. CD16A, the NK receptor for antibodies, has AA158 valine or phenylalanine variants with different affinities for IgG. CD2, a costimulatory protein, associates with CD16A and can augment CD16A-signaling. Pore-forming perforin is essential for rapid NK-mediated killing. NK cells were monitored for their ADCC serial killing frequency (KF). KF is the average number of target cells killed per cell by a cytotoxic cell population. KF comparisons were made at 1:4 CD16pos NK effector:target ratios. ADCC was toward Daudi cells labeled with 51Cr and obinutuzumab anti-CD20 antibody. CD16A genotypes were determined by DNA sequencing. CD2, CD16A, and perforin expression was monitored by flow cytometry. Serial killing KFs varied two-fold among 24 donors and were independent of CD16A genotypes and perforin levels. However, high percentages of CD2pos of the CD16Apos NK cells and high levels of CD16A were associated with high KFs. ROC analysis indicated that the %CD2pos of CD16Apos NK cells can predict KFs. In conclusion, the extent of serial ADCC varies significantly among donors and appears predictable by the CD2posCD16Apos NK phenotype.

Identification of the predominant human NK cell effector subset mediating ADCC against HIV‐infected targets coated with BNAbs or plasma from PLWH

“…In contrast, NK lysis through the indirect pathway of killing utilizes the Fc-γ-RIII (CD16) activating receptor to mediate ADCC in the presence of antibodies specific for viral surface proteins on target cells [16,26,27]. Additional signals from NK adapter proteins, such as 2B4 [23,[28][29][30][31][32] and CD2 [33,34], may further increase ADCC activity by serving as costimulatory signals in synergy with CD16. Cytokines, such as IL-2, IL-12, IL-15, IL-21, and type-I interferons (IFN-α, -β) provided by accessory cells further augment NK lysis of virally infected target cells through both the direct and indirect pathways of cytotoxicity [35][36][37].…”

“…A subset of these NKG2C pos NK cells become deficient in the Fc-γ signaling chain over time which allows them to mediate stronger ADCC signaling following utilization of the CD3ζ signaling chain [57][58][59]. NKG2C pos NK cells from CMV sero-positive individuals also possess increased levels of the CD2 coreceptor for mediating strong ADCC in conjunction with CD16 [33,34,60,61]. Together, these phenotypic results help to explain the strong ADCC activity of NKG2C pos NK cells against CMV infected target cells coated with CMV-specific antibodies [62,63].…”

Natural Killer Cell-Associated Radiogenomics Subtyping of Hepatocellular Carcinoma Based on CD2 Expression and Enhanced CT-Derived Radiomics Signatures

“…CD2, a transmembrane molecule belonging to the immunoglobulin superfamily [40], has been found to play a critical role in regulating and enhancing the cytotoxicity of NK cells [41]. CD2 has been shown to participate in antibodydependent cell-mediated cytotoxicity by "adaptive" NK cells [41,42]. The present study found that high CD2 expression signi cantly activated NK cell related pathways and biological processes in three independent HCC datasets, and also was validated in a TCIA-TCGA-LIHC subset of HCC patients.…”