Anti-CD8 monoclonal antibody-mediated depletion alters the phenotype and behavior of surviving CD8+ T cells

Abstract

It is common practice for researchers to use antibodies to remove a specific cell type to infer its function. However, it is difficult to completely eliminate a cell type and there is often limited or no information as to how the cells which survive depletion are affected. This is particularly important for CD8+ T cells for two reasons. First, they are more resistant to mAb-mediated depletion than other lymphocytes. Second, targeting either the CD8α or CD8β chain could induce differential effects. We show here that two commonly used mAbs, against either the CD8α or CD8β subunit, can differentially affect cellular metabolism. Further, in vivo treatment leaves behind a population of CD8+ T cells with different phenotypic and functional attributes relative to each other or control CD8+ T cells. The impact of anti-CD8 antibodies on CD8+ T cell phenotype and function indicates the need to carefully consider the use of these, and possibly other “depleting” antibodies, as they could significantly complicate the interpretation of results or change the outcome of an experiment. These observations could impact how immunotherapy and modulation of CD8+ T cell activation is pursued.

Memory CD8+ T cells exhibit tissue imprinting and non‐stable exposure‐dependent reactivation characteristics following blood‐stage Plasmodium berghei ANKA infections

“…This will include analysing pro‐inflammatory cytokine production by the intracerebral memory CD8 + T‐cell subsets, as Trm cells are characterized by rapid and high levels of IFN‐γ production (reviewed [44, 45]). Notably, although our observation that in vivo administered anti‐CD8 mAb bound to but did not deplete memory OT‐I cells was surprising, our results are consistent with a recent report indicating that anti‐CD8mAb clone 53·7.62 binds to and functionally inactivates CD8 + T cells (including causing downregulation of the CD8 receptor), but does not promote extensive depletion [59]. Importantly, we and others have used the anti‐CD8 mAb clone 53‐7·62 extensively in murine models of malaria to inhibit CD8 + T cell‐mediated pathology [36, 38, 60]…”

Dynamically linking influenza virus infection kinetics, lung injury, inflammation, and disease severity

“…Given that viral loads were lower at early time points and that the anti-CD8α antibody is known to cause concentration-dependent changes in CD8 E differentiation, activation, and efficacy ( Cross et al, 2019 ) in addition to resulting in death of the cells that would initiate activation of and removal by other immune cells, we did not expect our model to match the data without modulation of parameter values. However, we did expect that no changes to the model formulation would be required.…”

Dynamically Linking Influenza Virus Infection Kinetics, Lung Injury, Inflammation, and Disease Severity

“…To further test our model formulation and identify how viral load kinetics are altered with dynamically changing CD8 + T cells, we infected groups of mice with 75 TCID 50 and depleted these cells Given that viral loads were lower at early time points and that the anti-CD8α antibody is known to cause concentration-dependent changes in CD8 E differentiation, activation, and efficacy [86] in addition to resulting in death of the cells that would initiate activation of and removal by other immune cells, we did not expect our model to match the data without modulation of parameter values. However, we did expect that no changes to the model formulation would be required.…”