Research Project 1: Establishing a platform to detect polyreactive antibodies in saliva and breastmilk
- Thematic field of study: Establishing a platform to detect polyreactive antibodies in saliva and breastmilk
- Supervisor(s):Prof Clive Gray, Dr Helen Payne, Dr Novel Chegou, Dr Lily Verhagen
- Contact details: cgray@sun.ac.za Professor Clive Gray
Summary of hosting Lab
| The Gray lab at Stellenbosh University works on Immune Regulation in Maternal and Child Health in the context of Reproductive Immunology. Prof Gray investigates the characteristics and functional capacity of T cells and other cell types in HIV exposed, uninfected newborn infants. This has great relevance for understanding abnormalities in immune regulatory networks and will provide clues to understanding susceptibility to HIV infection and in devising new treatments that can reduce the morbidities found in this vulnerable infant population. His team studies the human placenta and the impact of maternal HIV infection on cells at the feto-maternal interface. He has recently established the Reproductive Immunology Research Consortium in Africa at Stellenbosch University (SU). |
Project Description
| Our earlier research has highlighted the significance of low levels of immunoglobulin A (IgA), an antibody that is abundantly present in saliva, as a risk factor for respiratory tract infections in children. Both IgA and IgG antibodies are detectable in mucosal samples. Recent findings show a pool of respiratory mucosal broadly neutralizing IgA and IgG antibodies that naturally bind to multiple targets and act as the initial defense against new pathogens. Polyreactive mucosal antibodies play an important role in the susceptibility to and transmission of respiratory viruses. However, it remains unknown whether these antibodies are present in early life and if mothers transfer them to their infants through breastmilk. In this project, we will therefore develop an assay capable of detecting polyreactive antibodies in both infant saliva and maternal breastmilk and examine the relationship with maternal and infant characteristics, including HIV exposure. This assay will utilize a Luminex Multiplex Immuno Assay, a robust tool for quantifying antibodies in low-volume samples. The assay employs fluorescently labeled microspheres coated with five structurally and biologically distinct antigens, binding the same subset of broadly reactive antibodies.. |
Publications
| Koenen, M. H., van Montfrans, J. M., Sanders, E. A. M., Bogaert, D. & Verhagen, L. M. Immunoglobulin A deficiency in children, an undervalued clinical issue. Clin. Immunol. 209, 108293 (2019). Koenen, M. et al. A novel method to standardise serum IgA measurements shows an increased prevalence of IgA deficiency in young children with recurrent respiratory tract infections. Clin. Transl. Immunol. 10, e1344 (2021).. Koenen, M. H. et al. Articles Mycoplasma pneumoniae carriage in children with recurrent respiratory tract infections is associated with a less diverse and altered microbiota. eBioMedicine 98, 104868 (2023).. Gallo, O., Locatello, L. G., Mazzoni, A., Novelli, L. & Annunziato, F. The central role of the nasal microenvironment in the transmission, modulation, and clinical progression of SARS-CoV-2 infection. Mucosal Immunol. 14, 305–316 (2021). Verhagen, L. Respiratory tract infections: importance of the mucosal immune system. Eur. Soc. Paediatr. Infect. Dis. Conf. 2022. Plenary Symp. Present. Available from https//www.youtube.com/watch?v=eJXrNpQB1nU.. |
Major Lab techniques
| Sample processing, Luminex Multiplex Immuno Assay setup, Fluorescent microsphere handling, Collaborative research, Documentation and reporting, Data analysis |
Research Project 2: CMV infection and protective immunity at the maternal-fetal interface in human
- Thematic field of study: CMV infection and protective immunity at the maternal-fetal interface in human
- Supervisor(s):Dr. Doty Ojwach, Dr. Helen Payne and Professor Clive Gray
- Contact details: cgray@sun.ac.za Professor Clive Gray
Summary of hosting Lab
| The Gray lab at Stellenbosh University works on Immune Regulation in Maternal and Child Health in the context of Reproductive Immunology. Prof Gray investigates the characteristics and functional capacity of T cells and other cell types in HIV exposed, uninfected newborn infants. This has great relevance for understanding abnormalities in immune regulatory networks and will provide clues to understanding susceptibility to HIV infection and in devising new treatments that can reduce the morbidities found in this vulnerable infant population. His team studies the human placenta and the impact of maternal HIV infection on cells at the feto-maternal interface. He has recently established the Reproductive Immunology Research Consortium in Africa at Stellenbosch University (SU). |
Project Description
| Cytomegalovirus (CMV) reactivation frequently occurs during gestation especially in HIV-1 infected women including those on suppressive ART. In some African clinics, CMV infection is universal with >90% of pregnant women with serostatus compatible with non-primary CMV infection. CMV has been reported to enhance placental cell susceptibility to replication of HIV-1, and may facilitate in utero HIV transmission. We hypothesize that maternal HIV and CMV co-infection disrupts immune homeostatic balance at the foetal-maternal interface (FMI) leading to dysregulation in infant immunity. In vitro, CMV traditionally infect a limited range of cells such as skin fibroblasts, whereas in vivo, these viruses exhibit a broader cell tropism and CMV dissemination is believed to occur primarily through cell-associated virus, rather than free virus particles. We wish in this project to examine possible protective immunity at the maternal-fetal interface (MFI) by examining for T cell immunity in the decidua membranes of placentas at delivery. We predict that high levels of T cell responsiveness to CMV peptides/epitopes at the MFI will negatively associate with the presence of CMV in the placenta, and vice versa. This project aims has 2 objectives: 1. To identify CMV-specific T cells in the decidua 2. To measure CMV infection in the placenta by identifying anti-pp65 and anti-IE proteins in specific placental cells, employing techniques such as immunohistochemistry, multiplex immunofluorescence and qPCR. By employing established protocols, this project will lay the foundation for gaining mechanistic insights into the relationship between immune events at the FMI, ultimately contributing to our understanding of the relationship between maternal-foetal interactions and compromised neonatal immunity. |
Publications
| TAlfi O, Cohen M, Bar-On S, Hashimshony T, Levitt L, Raz Y, Blecher Y, Chaudhry MZ, Cicin-Sain L, Ben-El R, Oiknine-Djian E, Lahav T, Vorontsov O, Cohen A, Zakay-RonesZ, Daniel L, Berger M, Mandel-Gutfreund Y, Panet A, Wolf DG. Decidual-tissue-resident memory T cells protect against nonprimary human cytomegalovirus infection at the maternal-fetal interface. Cell Rep. 2024 Jan 23;43(2):113698. doi: 10.1016/j.celrep.2024.113698. Epub ahead of print. PMID: 38265934. Kim Y, Kim YM, Kim DR, Kim HG, Sung JH, Choi SJ, Oh SY, Kim YJ, Chang YS, Kim D, Kim JS, Moon IJ, Roh CR. The Multifaceted Clinical Characteristics of Congenital Cytomegalovirus Infection: From Pregnancy to Long-Term Outcomes. J Korean Med Sci. 2023 Aug 14;38(32):e249. doi: 10.3346/jkms.2023.38.e249. PMID: 37582499; PMCID: PMC10427218. Degrelle SA, Buchrieser J, Dupressoir A, Porrot F, Loeuillet L, Schwartz O, Fournier T. IFITM1 inhibits trophoblast invasion and is induced in placentas associated with IFN- mediated pregnancy diseases. iScience. 2023 Jun 15;26(7):107147. doi: 10.1016/j.isci.2023.107147. PMID: 37434700; PMCID: PMC10331461. Girsch JH, Mejia Plazas MC, Olivier A, Farah M, Littlefield D, Behl S, Punia S, Sakemura R, Hemsath JR, Norgan A, Enninga EAL, Johnson EL, Chakraborty R. Host- Viral Interactions at the Maternal-Fetal Interface. What We Know and What We Need to Know. Frontiers (Boulder). 2022 Mar;2:833106. doi: 10.3389/fviro.2022.833106. Epub 2022 Mar 24. PMID: 36742289; PMCID: PMC9894500. Forner G, Saldan A, Mengoli C, Pizzi S, Fedrigo M, Gussetti N, Visentin S, Angelini A, Cosmi E, Barzon L, Abate DA. Four-Year Follow-Up of the Maternal Immunological, Virological and Clinical Settings of a 36-Year-Old Woman Experiencing Primary Cytomegalovirus Infection Leading to Intrauterine Infection. Viruses. 2022 Dec 30;15(1):112. doi: 10.3390/v15010112. PMID: 36680152; PMCID: PMC9865737. |
Major Lab techniques
| Cell culture, Histology (cell and tissue staining), Immune cell quantification in tissue, dissection and sectioning of placenta, ELISA and qPCR. |
Research Project 3: Altered cardiometabolic and mitochondrial function in people living with HIV
- Thematic field of study: Altered cardiometabolic and mitochondrial function in people living with HIV
- Supervisor(s):Prof Hans Strijdom, Dr Taahirah Boltman, Dr Jeffery Adoga
- Contact details: cgray@sun.ac.za Professor Clive Gray
Summary of hosting Lab
| Hans Strijdom and his research group has been studying HIV‐associated cardiometabolic and vascular disease since 2014. With generous funding from the EU FP7 programme (ERAfrica), the NRF and NIH, Strijdom and his group have over the last 10 years generated substantial data on altered endothelial, vascular and cardiac function in in vitro and in vivo models, and later in human studies. The now concluded EndoAfrica study focused on vascular and endothelial changes in people living with HIV (PLWH), and currently, the MITO‐SAKen study is investigating whether altered mitochondrial function may be a putative underlying mechanism in HIV‐ associated cardiometabolic disease. Strijdom has established wide‐ranging collaborations within the University and South Africa, as well as in Europe, the USA and Kenya. |
Project Description
| Antiretroviral therapy (ART) has resulted in a reduction in global HIV/AIDS‐related mortality. These advances are, however, accompanied by an increased risk of HIV‐associated cardiometabolic diseases (CMD). More than half of people living with HIV (PLWH) are from Southern and Eastern Africa. Furthermore, PLWH in sub‐Saharan Africa (SSA) have a high prevalence of CMD risk factors, although the epidemiologic data on CMD among PLWH in SSA are limited. Mitochondrial dysfunction is characterized by impaired oxidative phosphorylation, oxidative stress, cellular senescence and apoptosis. Both HIV infection and ART can induce mitochondrial dysfunction. PLWH in SSA have high co‐infection rates with tuberculosis, which has been associated with mitochondrial damage; chronic inflammation is prevalent in SSA populations, as a result of exposure to infectious diseases, air pollution and lifestyle factors, and may further exacerbate mitochondrial dysfunction. Given the collision of communicable and non‐communicable diseases in SSA, and epidemiological CMD trends, more studies on mechanisms such as mitochondrial dysfunction are required. We hypothesize that ART‐experienced PLWH with CMD in SSA will show greater mitochondrial dysfunction as measured by mitochondrial respiratory function(Aim 1) and by mitochondrial gene expression (Aim 2) compared to PLWH without CMD and controls without HIV. The following two specific aims will test the hypothesis in participants aged 18‐75 years (N=300), recruited in South Africa and Kenya: Aim 1: Compare mitochondrial respiratory function in participants with and without HIV, and determine whether mitochondrial dysfunction is more pronounced in PLWH with CMD. Mitochondrial respiratory function (mitochondrial membrane potential, oxidative phosphorylation, and adenosine triphosphate (ATP) and reactive oxygen species (ROS) production) is measured in peripheral blood mononuclear cells (PBMCs) via high‐resolution respirometry (HRR); O2k‐FluoRespirometer). CMD will be defined by the presence of ≥3 of the following cardiometabolic risk factors: obesity, hypertension, hyperglycemia, low high‐density lipoprotein cholesterol or hypertriglyceridemia. Aim 2: Compare mRNA expression of genes linked with mitochondrial function and dynamics in participants with and without HIV, and determine whether gene expression is different in PLWH with CMD. PBMC‐extracted RNA samples will be subjected to real‐time quantitative reverse transcription polymerase chain reaction (qRT‐PCR) analysis. The mRNA expression of the following genes will be measured: PCG‐1α (mitochondrial biogenesis), CS (marker of intact mitochondria), VDAC (mitochondrial membrane transport), MFN (mitochondrial fusion), coQ10 (electron transport), OPA‐1 (mitochondrial fusion, oxidative phosphorylation), and FIS1 (mitochondrial fission). The South African cohort will be followed‐up at 18 months.. |
Publications
| TStrijdom H, De Boever P, Walzl G, Essop MF, Nawrot TS, Webster I, Westcott C, Mashele N, Everson F, Malherbe ST, Stanley K, Kessler HH, Stelzl E, Goswami N. Cardiovascular risk and endothelial function in people living with HIV/AIDS: design of the multi‐site, longitudinal EndoAfrica study in the Western Cape Province of South Africa. BMC Infect Dis. 2017;17(1):41. Everson FP, Genis A, Ogundipe TR, De Boever P, Goswami N, Lochner A, Blackhurst D, Strijdom H. Treatment with a fixed dose combination antiretroviral therapy drug containing tenofovir, emtricitabine and efavirenz is associated with cardioprotection in high calorie diet‐induced obese rats. PLoS ONE. 2018; 13(12): e0208537. Marincowitz C, Genis A, Goswami N, De Boever P, Nawrot TS, Strijdom H. Vascular Endothelial Dysfunction in the wake of HIV and ART. FEBS J. 2019; 286(7): 1256‐1270. Williams C, Kamau FM, Everson F, Kgokane B, De Boever P, Goswami N, Webster I, Strijdom H. HIV and antiretroviral therapy are independently associated with cardiometabolic variables and cardiac electrical activity in adults from the Western Cape region of South Africa. J Clin Med. 2021; 10(18): 4112.. Solanke T, Kamau, F, Esterhuizen, T, Maartens, G, Khoo, S, Joska, JA, Kellermann T, Strijdom H, Decloedt E. Concentrations of efavirenz, tenofovir, and emtricitabine in obesity: a cross‐ sectional study. J. Acquir. Immune. Defic. Syndr. 2022; 91(1): 101‐108. |
Major Lab techniques
| Epidemiological study activities, clinical vascular measures (ultrasound, carotid intima‐media thickness and retinal microvascular imaging), human blood and urine sample processing, mitochondrial high‐resolution respirometry, Luminex multiplex assays, qRT‐PCR, flow cytometry, etc.. |
Links to other University Program
https://www.sun.ac.za/english/faculty/healthsciences/Molecular_Biology_Human_Genetics/Pages/MSc.aspx
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