Evolution of Human Memory B Cells From Childhood to Old Age

Abstract

High quality medical assistance and preventive strategies, including pursuing a healthy lifestyle, result in a progressively growing percentage of older people. The population and workforce is aging in all countries of the world. It is widely recognized that older individuals show an increased susceptibility to infections and a reduced response to vaccination suggesting that the aged immune system is less able to react and consequently protect the organism. The SARS-CoV-2 pandemic is dramatically showing us that the organism reacts to novel pathogens in an age-dependent manner. The decline of the immune system observed in aging remains unclear. We aimed to understand the role of B cells. We analyzed peripheral blood from children (4-18 years); young people (23-60 years) and elderly people (65-91 years) by flow cytometry. We also measured antibody secretion by ELISA following a T-independent stimulation. Here we show that the elderly have a significant reduction of CD27dull memory B cells, a population that bridges innate and adaptive immune functions. In older people, memory B cells are mostly high specialized antigen-selected CD27bright. Moreover, after in vitro stimulation with CpG, B cells from older individuals produced significantly fewer IgM and IgA antibodies compared to younger individuals. Aging is a complex process characterized by a functional decline in multiple physiological systems. The immune system of older people is well equipped to react to often encountered antigens but has a low ability to respond to new pathogens.

Full-Length Transcriptome: A Reliable Alternative for Single-Cell RNA-Seq Analysis in the Spleen of Teleost Without Reference Genome

“…In order to obtain a more detailed clustering and cell classification of the B cells ( Figures 8C–G ), we used the above mentioned approaches to analyze the B cell population ( Figure 7K ). As a result, the B cell population was further sub-divided into 4 clusters: 1) the cluster with high expression level of CD34 ( 51 ) and hardly expression level of CD20 ( 40 ), CD40 ( 52 , 53 ), IgM ( 54 ), CD27 ( 54 ) and IgD ( 55 ) were identified as early-pre B cell; 2) the cluster with expression of CD20 and CD40 , together with hardly expression of CD34 , IgM , CD27 and IgD were identified as pre B cell; 3) the cluster with expression of CD20 , CD40 and IgM , together with hardly expression level of CD34 , CD27 and IgD were identified as immature B cell; the cluster with the highest expression level of CD20 , CD40 , IgM , CD27 and IgD , together with hardly expression level of CD34 were identified as mature B cell, respectively ( Figures 8C, D ). To verify the reliability of the classification results, we carried out a pseudo-time analysis ( Figure 8E ).…”

“…CMRF35 is a B cell surface protein as well as an immunoregulatory molecule, which has been observed involving in the mucosal immunity of teleost ( 96 ). Then, the B cell population was further sub-divided into 4 clusters: 1) the cluster with high expression level of CD34 ( 51 ) and hardly expression level of CD20 ( 40 ), CD40 ( 52 , 53 ), IgM ( 54 ), CD27 ( 54 ) and IgD ( 55 ) were identified as early-pre B cell; 2) the cluster with high expression level of CD20 and CD40 , together with hardly expression level of CD34 , IgM , CD27 and IgD were identified as pre B cell; 3) the cluster with high expression level of CD20 , CD40 and IgM , together with hardly expression level of CD34 , CD27 and IgD were identified as immature B cell; the cluster with the highest expression level of CD20 , CD40 , IgM , CD27 and IgD , together with hardly expression level of CD34 were identified as mature B cell, respectively. The CD34 molecule is a highly glycosylated type I transmembrane glycoprotein that is selectively expressed on the surface of human and other mammalian pro B cells, and gradually weakens to disappear as the cells mature ( 51 ).…”

Implicit, Intrinsic, Extrinsic, and Host Factors Attributing the COVID-19 Pandemic. Part 3- Host Factor GDP: A Systematic Analysis

“…Several studies highlight adaptive immunity against COVID-19 re-infection associated with memory B cells, several T cell subsets, along with antibodies protects the individual and population groups 21,22 . In continuation, a recent report by Ciocca and coworkers, outlines human immune system ability to remember previously encountered pathogens is acquired by experience and it changes throughout life 23 . With the advent of whole-genome sequencing analyses, we are also capable enough to shed light on the heterogeneity of immune responses, this is all due to different functional alleles in genes.…”

B cell-derived cfDNA after primary BNT162b2 mRNA vaccination anticipates memory B cells and SARS-CoV-2 neutralizing antibodies

“…The concentration of B cell-derived cfDNA on day 14 was significantly correlated with the number of memory B cells at later time points (day 14 to day 28) in vaccinees of both age groups (above and below 40 years), and the correlation resisted a correction for age (Figures 5C and 5D). In contrast, the well-established correlation between memory B cells and the titer of neutralizing antibodies 8,32,35 was eliminated when we corrected for age (Figures S7C-S7F). These findings suggest that the relationship between B cell cfDNA and subsequent memory B cell counts is not explained simply by an age confounder.…”