Immune cell landscape in symptomatic and asymptomatic SARS-CoV-2 infected adults and children in urban Dhaka, Bangladesh

Evana Akhtar; Akhirunnesa Mily; Protim Sarker; Bikash Chandra Chanda; Farjana Haque; Rakib Ullah Kuddusi; Md Ahsanul Haq; Magda Lourda; Susanna Brighenti; Rubhana Raqib

doi:10.1016/j.imbio.2023.152350

Immune cell landscape in symptomatic and asymptomatic SARS-CoV-2 infected adults and children in urban Dhaka, Bangladesh

Immunobiology. 2023 Mar;228(2):152350. doi: 10.1016/j.imbio.2023.152350. Epub 2023 Feb 18.

Affiliations

¹ Infectious Diseases Division, icddrb, Dhaka 1212, Bangladesh.
² Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, 141 52, Huddinge, Sweden.
³ Laboratory Sciences and Services Division, icddr,b, Dhaka 1212, Bangladesh.
⁴ Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, 141 52, Huddinge, Sweden; Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
⁵ Infectious Diseases Division, icddrb, Dhaka 1212, Bangladesh. Electronic address: rubhana@icddrb.org.

Abstract

Objectives: The study of cellular immunity to SARS-CoV-2 is crucial for evaluating the course of the COVID-19 disease and for improving vaccine development. We aimed to assess the phenotypic landscape of circulating lymphocytes and mononuclear cells in adults and children who were seropositive to SARS-CoV-2 in the past 6 months.

Methods: Blood samples (n = 350) were collected in a cross-sectional study in Dhaka, Bangladesh (Oct 2020-Feb 2021). Plasma antibody responses to SARS-CoV-2 were determined by an electrochemiluminescence immunoassay while lymphocyte and monocyte responses were assessed using flow cytometry including dimensionality reduction and clustering algorithms.

Results: SARS-CoV-2 seropositivity was observed in 52% of adults (18-65 years) and 56% of children (10-17 years). Seropositivity was associated with reduced CD3⁺T cells in both adults (beta(β) = -2.86; 95% Confidence Interval (CI) = -5.98, 0.27) and children (β = -8.78; 95% CI = -13.8, -3.78). The frequencies of T helper effector (CD4⁺T_EFF) and effector memory cells (CD4⁺T_EM) were increased in seropositive compared to seronegative children. In adults, seropositivity was associated with an elevated proportion of cytotoxic T central memory cells (CD8⁺T_CM). Overall, diverse manifestations of immune cell dysregulations were more prominent in seropositive children compared to adults, who previously had COVID-like symptoms. These changes involved reduced frequencies of CD4⁺T_EFF cells and CD163⁺CD64⁺ classical monocytes, but increased levels of intermediate or non-classical monocytes, as well as CD8⁺T_EM cells in symptomatic children.

Conclusion: Seropositive individuals in convalescence showed increased central and effector memory T cell phenotypes and pro-resolving/healing monocyte phenotypes compared to seronegative subjects. However, seropositive children with a previous history of COVID-like symptoms, displayed an ongoing innate inflammatory trait.

Keywords: Adults; Asymptomatic infection; Children; Immune-phenotyping; SARS-CoV-2; Seropositivity; Symptomatic infection.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antibodies, Viral
Bangladesh
COVID-19*
Cross-Sectional Studies
Humans
Leukocytes
SARS-CoV-2

Substances

Antibodies, Viral