Multivariate profiling of African green monkey and rhesus macaque T lymphocytes

Wail M Hassan,Mackenzie E Johnson,Nader N Mahdi,Gabriella A Pinter,Istvan G Lauko,Gregory F Burton

doi:10.1038/s41598-019-41209-x

Abstract

The complexity of immune responses limits the usefulness of univariate methods in answering complex immunology questions. To demonstrate the utility of a multivariate approach, we employ such approach to compare T cells of African green monkeys (AGMs) and rhesus macaques (RMs). Among the most prominent distinguishing features we found were lower CD3 and higher CD28 surface expression in AGMs compared to RMs. After in vitro stimulation, a larger proportion of AGM T cells secreted cytokines, especially those producing more than one cytokine (i.e. multifunctional cells). To find out whether multifunctional responses associate with protection in other species, we compared T cells of cynomolgus macaques (CMs) infected with wild-type Simian Immunodeficiency Virus (SIV) to those of CMs infected (vaccinated) with a replication-defective virus. Wild-type SIV infection in macaques leads to simian Acquired Immunodeficiency Syndrome (AIDS), which does not happen in animals previously vaccinated with a replication-defective virus. Interestingly, after in vitro stimulation, multifunctional cells were more abundant among T cells of vaccinated CMs. Our results propose T-cell multifunctionality as a potentially useful marker of immunity, although additional verification is needed. Finally, we hope our multivariate model and its associated validation methods will inform future studies in the field of immunology.

Highlights

The current study aims to demonstrate the utility of multivariate data analysis in studying complex immunological variables
A couple of questions emerged: (1) are these differences merely species-specific variations that has no generalizable applications in other species? (2) do these differences bear any resemblance to the features that separate pathogenic from non-pathogenic Simian Immunodeficiency Virus (SIV) infections in susceptible host species? To address these questions, we present a comparison between wild-type and replication-deficient SIV infection in cynomolgus macaques (CMs)
The current study is mainly focused on CD4+ T cells, but before exclusively focusing on these cells, we wanted to examine their abundance relative to the rest of T-cell subsets in both African green monkeys (AGMs) and rhesus macaques (RMs)

Summary

Introduction

The current study aims to demonstrate the utility of multivariate data analysis in studying complex immunological variables. Univariate studies have shown admirable success in building our knowledge of the immune system as we know it today Using this knowledge, it was possible to define simple patterns of protective immunity, such as immunity against hepatitis B virus[1] and exotoxins of Clostridium tetani and Corynebacterium diphtheriae[2]. Graphical display of subjects based on the new, condensed variables — more formally known as principal components (PCs) — enables visual inspection of the data. We developed an immune-profiling scheme composed of multivariate analyses (e.g. PCA and MDS) and additional confirmatory tests [e.g. Bartlett’s test of sphericity, Kaiser-Meyer-Olkin measure of sampling adequacy (KMO) and Monte Carlo simulation] that we hope will inform future studies.

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Conclusion