Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec 12:13:1052374.
doi: 10.3389/fimmu.2022.1052374. eCollection 2022.

Longevity of memory B cells and antibodies, as well as the polarization of effector memory helper T cells, are associated with disease severity in patients with COVID-19 in Bangladesh

Marjahan Akhtar  1 , Salima Raiyan Basher  1 , Nuder Nower Nizam  1 , Mohammad Kamruzzaman  1 , Fatema Khaton  1 , Hasan Al Banna  1 , M Hasanul Kaisar  1 , Polash Chandra Karmakar  1 , Al Hakim  1   2 , Afroza Akter  1 , Tasnuva Ahmed  1 , Imam Tauheed  1 , Shaumik Islam  1 , Faisal Ahmmed  1 , Shakil Mahamud  1 , Mohammad Abul Hasnat  3 , Mostafa Aziz Sumon  3 , Asif Rashed  4 , Shuvro Ghosh  4 , Stephen B Calderwood  5 , Jason B Harris  5   6 , Richelle C Charles  5   6   7 , Regina C LaRocque  5   6 , Edward T Ryan  5   6   7 , Sayera Banu  1 , Tahmina Shirin  8 , Fahima Chowdhury  1 , Taufiqur Rahman Bhuiyan  1 , Firdausi Qadri  1
Affiliations

Longevity of memory B cells and antibodies, as well as the polarization of effector memory helper T cells, are associated with disease severity in patients with COVID-19 in Bangladesh

Marjahan Akhtar et al. Front Immunol. .

Abstract

The longevity of immune responses induced by different degrees of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection provides information important to understanding protection against coronavirus disease 2019 (COVID-19). Here, we report the persistence of SARS-CoV-2 spike receptor-binding domain (RBD) specific antibodies and memory B cells recognizing this antigen in sequential samples from patients in Bangladesh with asymptomatic, mild, moderate and severe COVID-19 out to six months following infection. Since the development of long-lived memory B cells, as well as antibody production, is likely to be dependent on T helper (Th) cells, we also investigated the phenotypic changes of Th cells in COVID-19 patients over time following infection. Our results show that patients with moderate to severe COVID-19 mounted significant levels of IgG antibodies out to six months following infection, while patients with asymptomatic or mild disease had significant levels of IgG antibodies out to 3 months following infection, but these then fell more rapidly at 6 months than in patients with higher disease severity. Patients from all severity groups developed circulating memory B cells (MBCs) specific to SARS-CoV-2 spike RBD by 3 months following infection, and these persisted until the last timepoint measured at 6 months. A T helper cell response with an effector memory phenotype was observed following infection in all symptomatic patients, while patients with asymptomatic infection had no significant increases in effector Th1, Th2 and Th17 effector memory cell responses. Our results suggest that the strength and magnitude of antibody and memory B cells induced following SARS-CoV-2 infection depend on the severity of the disease. Polarization of the Th cell response, with an increase in Th effector memory cells, occurs in symptomatic patients by day 7 following infection, with increases seen in Th1, Th2, Th17 and follicular helper T cell subsets.

Keywords: COVID-19; antibodies; asymptomatic; memory B cells; symptomatic.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Antibody responses in COVID-19 patients with different disease severity, compared to healthy controls. RBD specific IgG was analyzed in serum samples collected from healthy adults (n=21) as well as patients with (A) asymptomatic (n = 25), (B) mild (n = 25), (C) moderate (n = 25), and (D) severe (n = 25) COVID-19 on day 1, 7, 28, 90 and 180. Each symbol represents one individual, and bars indicate geometric mean values. Statistical analysis was performed between healthy controls and different time points in patients using the Mann-Whitney U test. Compared to healthy controls, all patients had significantly higher (P < 0.0001) IgG antibodies at all time points. (E) Line graphs showing the geometric mean values of antibody concentration in patients with differing disease severity. Statistical analysis was performed between asymptomatic vs. other groups (*) and mild vs. other groups (#) on each day using the Mann-Whitney U test. (F) line graphs showing the geometric mean values of antibody concentrations on day 90 (asymptomatic, n = 7; mild, n = 4; moderate, n = 4; severe, n = 6) and 180 (asymptomatic, n = 8; mild, n = 9; moderate, n = 10; severe, n = 6) in a patient group after receiving a COVID-19 vaccine one month after infection. Dotted line indicates the cut-off (500 ng/ml) limit of seropositivity. #/* P <0.05, ##/** P <0.01, ###/*** P <0.001, ns, not significant; P >0.05.
Figure 2
Figure 2
Memory B cell responses in COVID-19 patients with differing disease severity, compared to healthy controls. (A) Representative image of total and RBD-specific IgG+ MBC spots. Frequency of RBD specific IgG+ MBC within the total IgG+ MBCs from healthy adults (n = 10), as well as patients with (B) asymptomatic (n = 10-11), (C) mild (n = 8-11), (D) moderate (n = 9-13), and (E) severe (n = 8-11) COVID-19 on day 1, 28, 90 and 180. Each symbol represents one individual, and bars indicate mean values. Statistical analysis was performed between healthy controls and different time points in patients using the Mann-Whitney U test. (F) Line graphs showing mean values of the frequency of RBD specific IgG+ MBC within the total IgG+ MBCs in patients with differing severity of infection. No significant difference in the frequency of MBCs were found between the groups with differing severity of infection. Total and antigen-specific MBC spots were calculated as IgG spots/106 cells. Frequencies of MBCs against RBD are expressed as the percentages of specific MBCs per total IgG MBCs. * P <0.05, ** P <0.01, *** P <0.001, ns, not significant; P >0.05.
Figure 3
Figure 3
Kinetics of peripheral blood CD4+ memory Th cells, effector memory Th cells, and effector Th1, Th2, Th17 and Tfh cells in COVID-19 patients and healthy controls. (A) Representative images of the gating strategy of Th cells analyzed using flow cytometry. Frequencies of (B) memory Th (CD4+CD45RO+) (C) effector memory TEM (CD4+CD45RO+CCR7-), (D) effector memory Th1 (CD4+CD45RO+CCR7-CXCR3+CCR6-), (E) effector memory Th2 (CD4+CD45RO+CCR7-CXCR3-CCR6-), (F) effector memory Th17 (CD4+CD45RO+CCR7-CXCR3-CCR6+), and (G) effector memory Tfh (CD4+CD45RO+CCR7-CXCR5+) populations within CD4+ cells in PBMCs isolated from healthy adults (n = 10) and patients with COVID-19 on days 1 (n = 24), 7 (n = 45), and 28 (n = 26). Each symbol represents the percentage of cells for one individual, and bars indicate median values. Statistical analysis was performed between healthy controls and different time points in patients using Mann-Whitney U test. *P < 0.05, **P < 0.01, ***P < 0.001.
Figure 4
Figure 4
Frequencies of peripheral blood CD4+ memory Th cells, effector memory Th cells, and effector Th1, Th2, Th17 and Tfh cells in patients with differing disease severity of COVID-19, compared to healthy controls. Frequencies of (A) memory Th (CD4+CD45RO+), (B) effector memory TEM (CD4+CD45RO+CCR7-), (C) effector memory Th1 (CD4+CD45RO+CCR7-CXCR3+CCR6-), (D) effector memory Th2 (CD4+CD45RO+CCR7-CXCR3-CCR6-), (E) effector memory Th17 (CD4+CD45RO+CCR7-CXCR3-CCR6+), and (F) effector memory Tfh (CD4+CD45RO+CCR7-CXCR5+) populations within CD4+ cells in PBMCs isolated from healthy adults (n = 10) and patients with asymptomatic, mild, moderate and severe COVID-19 on day 7 (n = 10-11 per group). Each symbol represents the percentage of cells for one individual, and bars indicate median values. Statistical analysis was performed between healthy controls and patients using Mann-Whitney U test. *P < 0.05, **P < 0.01, ***P < .001.
Figure 5
Figure 5
Frequencies of activated and exhausted Th cells in patients with differing severity of COVID-19 infection compared to healthy controls. (A) Representative images of different stages of Th cell activation analyzed using flow cytometry. Frequencies of ICOS+PD-1+ late activated memory (B), Th1 (C). Th2 (D). Th17. and (E) Tfh, as well as frequencies of ICOS-PD-1+ exhausted memory (F), Th1 (G), Th2 (H), Th17, and (I) Tfh populations within CD4+ cells in PBMCs isolated from healthy adults (n =1 0) and patients with asymptomatic, mild, moderate and severe COVID-19 on day 1 (n = 6-7 per group), 7 (n = 10-12 per group) and 30 (n = 8-10 per group). Bars indicate mean+SEM values. Asterisks (*) represent significant differences between healthy controls vs. asymptomatic, mild, moderate and severe patients and hash (#) represent significant differences between asymptomatic patients vs. mild, moderate and severe patients on different days. Statistical analysis was performed between healthy controls and patients using Mann-Whitney U test. *P < 0.05, **P < 0.01, ***P < 0.001.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. worldometer . COVID-19 CORONAVIRUS PANDEMIC (2022). Available at: https://www.worldometers.info/coronavirus/ (Accessed 06 Nov 2022).
    1. GARDAWORLD . Bangladesh: First cases of COVID-19 confirmed march 8 (2020). Available at: https://www.garda.com/crisis24/news-alerts/320606/bangladesh-first-cases... (Accessed 18 October 2020).
    1. Nazneen A, Sultana R, Rahman M, Rahman M, Qadri F, Rimi NA, et al. . Prevalence of COVID-19 in Bangladesh, April to October 2020-a cross-sectional study. IJID Regions (Online) (2021) 1:92–9. doi: 10.1016/j.ijregi.2021.10.003 - DOI - PMC - PubMed
    1. Bhuiyan TR, Akhtar M, Akter A, Khaton F, Rahman SIA, Ferdous J, et al. . Seroprevalence of SARS-CoV-2 antibodies in Bangladesh related to novel coronavirus infection. IJID Regions (Online) (2022) 2:198–203. doi: 10.1016/j.ijregi.2022.01.013 - DOI - PMC - PubMed
    1. Robbiani DF, Gaebler C, Muecksch F, Lorenzi JCC, Wang Z, Cho A, et al. . Convergent antibody responses to SARS-CoV-2 in convalescent individuals. Nature (2020) 584(7821):437–42. doi: 10.1038/s41586-020-2456-9 - DOI - PMC - PubMed

Publication types