Comparison of Human Neonatal and Adult Blood Leukocyte Subset Composition Phenotypes

Savit B Prabhu,Shailaja Sopory,Saimah Raza,Reva Tripathi,Nitya Wadhwa,Anita Chaudhary,Vineeta Bal,Satyajit Rath,Uma Chandra Mouli Natchu,Nidhi Agarwal,Aruna Batra,Anna George,Parna Kanodia,Deepa Nair,Siddharth Ramji,Sugandha Arya,Shinjini Bhatnagar,Kailash Chandra Aggarwal ,Deepak Kumar Rathore ,M H Umesh ,Harish Chellani

doi:10.1371/journal.pone.0162242

Abstract

The human peripheral leukocyte subset composition depends on genotype variation and pre-natal and post-natal environmental influence diversity. We quantified this composition in adults and neonates, and compared the median values and dispersal ranges of various subsets in them. We confirmed higher frequencies of monocytes and regulatory T cells (Tregs), similar frequencies of neutrophils, and lower frequencies of CD8 T cells, NKT cells, B1 B cells and gamma-delta T cells in neonatal umbilical cord blood. Unlike previous reports, we found higher frequencies of eosinophils and B cells, higher CD4:CD8 ratios, lower frequencies of T cells and iNKT cells, and similar frequencies of CD4 T cells and NK cells in neonates. We characterized monocyte subsets and dendritic cell (DC) subsets in far greater detail than previously reported, using recently described surface markers and gating strategies and observed that neonates had lower frequencies of patrolling monocytes and lower myeloid dendritic cell (mDC):plasmacytoid DC (pDC) ratios. Our data contribute to South Asian reference values for these parameters. We found that dispersal ranges differ between different leukocyte subsets, suggesting differential determination of variation. Further, some subsets were more dispersed in adults than in neonates suggesting influences of postnatal sources of variation, while some show the opposite pattern suggesting influences of developmental process variation. Together, these data and analyses provide interesting biological possibilities for future exploration.

Highlights

Human populations show considerable inter-individual diversity in immune phenotype and function[1,2]
The calculated cell concentrations per μL blood for all leukocyte subsets for adult blood (AB) and cord blood (CB) are provided for reference (Table 4 and Table 5)
We have characterized human adult and neonatal cord blood leukocyte phenotype in detail in terms of a number of cellular sub-lineages

Summary

Introduction

Human populations show considerable inter-individual diversity in immune phenotype and function[1,2]. Diversity in the phenotypes of leukocyte proportions and concentrations in blood is thought to have variable contributions from genetic[4,5], environmental[6,7,8] and epigenetic[9,10,11] factors. There is evidence that socio-geographic differences have consequence in immune phenotype and function[12,13,14,15]. Such differences across countries could possibly be attributed to differences in genetic structure, microbial-antigenic loads or nutritional status[16] of the population. Genetic studies using twins and genome-wide association studies have identified some of the genetic loci associated with various immune phenotypes, albeit with some conflicting results [4,6,18]

Methods

Results

Conclusion