Biology subjects

Harrington, W. E.

Publications and source records attributed to Harrington, W. E..

9 recordsLinked to original sources

bioRxiv2026

Inherited maternal memory T cells protect offspring from respiratory viral infection through disease tolerance

Maternal immune transfer is a powerful mechanism for early-life protection from infection, yet the full repertoire of protective factors remains unknown. We discovered that maternal memory T cells are both necessary and sufficient to protect offspring from lethal respiratory infection. This antigen-specific protection operated independently of maternal antibodies and offspring T cell responses and required IL-10 produced by maternal T cells. Transfer of protective maternal T cells reduced offspring inflammatory responses and lung tissue damage without affecting viral burdens, indicating that maternal memory T cells directly suppress pathogenic innate inflammatory responses to preserve offspring health. Critically, maternal vaccination similarly protected offspring in a T cell-dependent manner. These findings reveal maternal antigen-specific T cell transfer as a complementary immunological defense mechanism to protect offspring against pathogens that escape maternal antibodies, with broad implications for maternal vaccination strategies.

immunology↗

bioRxiv2026

Neonatal T cell maternal microchimerism is common and associates with early pregnancy SARS2 vaccination

The fetus acquires a graft of maternal cells in utero, known as maternal microchimerism (MMc), which may be enriched for T cells. However, little is known regarding the determinants of T cell trafficking into the fetus or regarding the prevalence of T cell MMc in healthy neonates. Using a closely followed cohort, we determined the association between maternal vaccination and acute infection and the detection of T cell MMc in cord blood, as measured using polymorphism-specific qPCR. We identified an association between early pregnancy SARS2 mRNA vaccination, a potent T cell stimulus, and increased detection of T cell MMc.

immunology↗

bioRxiv2026

A sensitive and specific microchimerism detection method using custom designed genotyping and companion qPCR assays

Since first reports of the presence of a small number of cells from one individual persisting in another, researchers have developed a number of methods to detect microchimerism. Molecular based detection platforms range from gel electrophoresis to quantitative PCR to Next-Gen Sequencing. Central to all approaches is the need for informative polymorphic loci to effectively distinguish microchimeric cells from the host. However, we observed in our studies of maternal microchimerism that currently published approaches can limit the number of samples available for assessment due to the inability to identify an informative marker of the donor in the recipient. This was most striking in our studies of populations of African descent in which the use of HLA-based markers, a common approach, prevented the testing of 30-50% of participants. Other potential options were cost prohibitive or lacked sufficient sensitivity. To address this challenge, we developed a novel, simple, and low-cost approach that leverages global population frequency databases for polymorphism selection, reduces cost by amplifying multiple targets in one multiplex assay to complete genotyping, and has high sensitivity and specificity using rigorously designed qPCR assays to quantify microchimerism. Herein, we outline our design process, detailed assay protocol, and assessment of maternal microchimerism using this approach in two different populations of infants from the United States and South Africa.

molecular biology↗

bioRxiv2026

Prenatal immune priming to Plasmodium falciparum is characterized by multi-lineage T-cell responses that are influenced by maternal microchimerism and predict malaria outcomes

In malaria endemic settings, the fetus may be exposed to Plasmodium falciparum (Pf) antigens leading to prenatal immune primming (PIP). The fetus also acquires a graft of maternal cells in utero, a phenomenon known as maternal microchimerism (MMc). We have previously identified that MMc at birth predicts altered malaria susceptibility in early childhood, and we hypothesized that this association may be mediated via two potential mechanisms. First, the fetus may acquire Pf-specific MMc T-cells that directly respond to postnatal parasitemia. Alternatively, MMc may indirectly influence the quantity or quality of PIP. To investigate this hypothesis, infant cord bloods from 97 Malian primigravidae were screened for MMc using qPCR. A subset of ten cord blood mononuclear cells with variable MMc levels were stimulated with purified Pf merozoite extract and activated T-cells were sorted by flow cytometry for scRNAseq analysis. Transcriptional profile was used to differentiate Pf-responsive versus bystander activated T-cells, and MMc cells were identified using the Cellector algorithm. Among Pf-responsive cells, we identified four key populations: activated CD4 T-cells, ZBTB16+ CD4 T-cells, activated V{delta}1+ {gamma}{delta} T-cells, and cytotoxic V{gamma}9V{delta}2+ {gamma}{delta} T-cells. The minority of sorted cells were of MMc origin; however, there was a strong association between the presence of MMc and the quantity and quality of PIP. MMc+ infants had significantly fewer Pf-responsive T-cells, as well as a shifted distribution of these cells with fewer ZBTB16+ CD4 and cytotoxic V{gamma}9V{delta}2+ {gamma}{delta} T-cells. Clinically, MMc was protective from incident parasitemia and febrile malaria, whereas the frequencies of ZBTB16+ CD4 and activated CD4 T-cells were associated with increased risk. Together, these data demonstrate that MMc influences malaria outcomes through regulation of offspring inflammatory responses to Pf.

immunology↗

bioRxiv2025

Infant CD4 T-cell response to SARS-CoV-2 mRNA vaccination is restricted in cytokine production and modified by vaccine manufacturer

BACKGROUNDSafe and effective vaccines are a key preventative measure to protect infants from SARS-CoV-2 infection and disease. Although mRNA vaccines induce robust antibody titers in infants, little is known about the quality of CD4 T-cell responses induced by vaccination. CD4 T-cell responses are important in orchestrating coordinated immune responses during infection and may help to limit disease severity. METHODS: To characterize the CD4 T-cell response to SARS-CoV-2 mRNA vaccination in infants, we sampled blood from 13 infants before and after primary SARS-CoV-2 mRNA vaccine series; samples from 12 historical vaccinated adults were used for comparisons. PBMC were stimulated with Spike peptide pools and the ability of CD4 T-cells to secrete Th1, Th2, and Th17 cytokines was quantified. A measure of polyfunctionality was generated using the COMPASS algorithm. RESULTS: We observed a significant increase in CD4 T-cells producing IL-2 (0.01% vs. 0.08%, p=0.04) and TNF- (0.007% vs. 0.07%, p=0.007) following vaccination in infants but a more muted induction of IFN-{gamma} production (0.01% vs 0.04%, p=0.08). This contrasted with adults, in whom vaccination induced robust production of IFN-{gamma}, IL-2, and TNF-. Th2 and Th17 responses were limited in both infants and adults. In infants, CD4 T-cell responses post-vaccination were greater in those who received mRNA-1273 versus BNT162b. In contrast to CD4 T-cell responses, Spike-specific IgG titers were similar in infants and adults. CONCLUSIONS: These data suggest that infants have restricted induction of cytokine producing CD4 T-cells following SARS-CoV-2 mRNA vaccination relative to adults.

immunology↗

bioRxiv2024

Exposure to HIV alters the composition of maternal microchimeric T cells in infants

Infants exposed to HIV but uninfected (iHEU) display altered cellular immunity and are at increased risk of infection through poorly understood mechanisms. We previously reported that iHEU have lower levels of maternal microchimerism (MMc), maternal cells transferred to the offspring in utero/during breastfeeding. We evaluated MMc levels in T cell subsets in iHEU and HIV unexposed infants (iHU) to determine whether a selective deficiency in MMc may contribute to altered cellular immunity. Across all infants, MMc levels were highest in CD8+ T cells; however, the level of MMc in the CD8 T cell subset was significantly lower in iHEU compared to iHU.

immunology↗

bioRxiv2023

A novel non-invasive method to sample immune cells in the lower female genital tract

T cells in the human female genital tract (FGT)2 are key mediators of susceptibility to and protection from infection, including HIV and other sexually transmitted infections. There is a critical need for increased understanding of the distribution and activation of T cell populations in the FGT, but current sampling methods require a healthcare provider and are expensive, limiting the ability to study these populations longitudinally. To address these challenges, we have developed a method to sample immune cells from the FGT utilizing disposable menstrual discs which are non-invasive, self-applied, and low-cost. To demonstrate reproducibility, we sampled the cervicovaginal fluid (CVF)3 of healthy, reproductive-aged individuals using menstrual discs over three sequential days. CVF was processed for cervicovaginal cells, and high parameter flow cytometry was used to characterize immune populations. We identified large numbers of live, CD45+ leukocytes, as well as distinct populations of T cells and B cells. Within the T cell compartment, activation and suppression status of T cell subsets were consistent with previous studies of the FGT utilizing current approaches, including identification of both tissue resident and migratory populations. In addition, the T cell population structure was highly conserved across days within individuals but divergent across individuals. Our approach to sample immune cells in the FGT with menstrual discs will decrease barriers to participation and empower longitudinal sampling in future research studies.

immunology↗

bioRxiv2021

Factors influencing maternal microchimerism throughout infancy and its impact on infant T cell immunity

Determinants of the acquisition and maintenance of maternal microchimerism (MMc) during infancy and the impact of MMc on infant immune responses are unknown. We examined factors which influence MMc detection and level across infancy and the effect of MMc on T cell responses to BCG vaccination in a cohort of HIV exposed, uninfected and HIV unexposed infants in South Africa. MMc was measured in whole blood from 58 infants using a panel of quantitative PCR assays at day one and 7, 15, and 36 weeks of life. Infants received BCG at birth, and selected whole blood samples from infancy were stimulated in vitro with BCG and assessed for polyfunctional CD4+ T cell responses. MMc was present in most infants across infancy with levels ranging from 0-1,193/100,000 genomic equivalents and was positively impacted by absence of maternal HIV, maternal-infant HLA compatibility, infant female sex, and exclusive breastfeeding. Initiation of maternal antiretroviral therapy prior to pregnancy partially restored MMc level in HIV exposed, uninfected infants. Birth MMc was associated with an improved polyfunctional CD4+ T cell response to BCG. These data emphasize that both maternal and infant factors influence the level of MMc, which may subsequently impact infant T cell responses. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

immunology↗

bioRxiv2020

In silico detection of SARS-CoV-2 specific B-cell epitopes and validation in ELISA for serological diagnosis of COVID-19

Rapid generation of diagnostics is paramount to understand epidemiology and to control the spread of emerging infectious diseases such as COVID-19. Computational methods to predict serodiagnostic epitopes that are specific for the pathogen could help accelerate the development of new diagnostics. A systematic survey of 27 SARS-CoV-2 proteins was conducted to assess whether existing B-cell epitope prediction methods, combined with comprehensive mining of sequence databases and structural data, could predict whether a particular protein would be suitable for serodiagnosis. Nine of the predictions were validated with recombinant SARS-CoV-2 proteins in the ELISA format using plasma and sera from patients with SARS-CoV-2 infection, and a further 11 predictions were compared to the recent literature. Results appeared to be in agreement with 12 of the predictions, in disagreement with 3, while a further 5 were deemed inconclusive. We showed that two of our top five candidates, the N-terminal fragment of the nucleoprotein and the receptor-binding domain of the spike protein, have the highest sensitivity and specificity and signal-to-noise ratio for detecting COVID-19 sera/plasma by ELISA. Mixing the two antigens together for coating ELISA plates led to a sensitivity of 94% (N=80 samples from persons with RT-PCR confirmed SARS-CoV2 infection), and a specificity of 97.2% (N=106 control samples).

bioinformatics↗