Márcia Medeiros

I am a medical doctor from the Faculty of Medicine, University of São Paulo (FMUSP), a specialist in General and Internal Medicine from the Hospital das Clínicas, FMUSP, and in Travel Medicine from the Institute of Hygiene and Tropical Medicine, University NOVA of Lisbon (IHMT-NOVA), and I have a PhD in Sciences in the area of Host-Pathogen interactions from the Institute of Biomedical Sciences, University of São Paulo. As a PhD researcher at some Portuguese institutions of the highest international scientific prestige, such as the Gulbenkian Institute of Science, the Institute of Molecular Medicine-João Lobo Antunes, Faculty of Medicine, University of Lisbon and currently, IHMT-NOVA, I have been investigating the interactions between malaria parasites (protozoa of the genus Plasmodium) and their vertebrate (man and experimental rodent models) and invertebrate (mosquitoes of the genus Anopheles) hosts, and more recently, between the microbiota of the intestinal and upper respiratory tracts and the human host.

Since October 2021, I also join the clinical staff of the IHMT-NOVA Travel Medicine Clinic.

As a PhD student, I showed the role of naturally acquired IgG antibodies against three antigens expressed by Plasmodium falciparum merozoites in the development of asymptomatic infections with low parasite density in the western Brazilian Amazon. As a PhD researcher at the Gulbenkian Institute of Science, I showed the role of regulatory T cells in the generation of a tolerogenic environment in the liver of mice, favouring the massive local accumulation of erythrocytes infected with Plasmodium chabaudi AS. As a PhD researcher at the Institute of Molecular Medicine-João Lobo Antunes, I investigated the suppressive effect of the blood stage of malarial infection on specific IFN-gamma-producing CD8T cells directed to the main protein of sporozoite surface through a parasite density-dependent mechanism and MyD88-dependent toll-like receptors (unpublished results). As a PhD researcher at the IHMT-NOVA, I have shown i) changes in the microbiota composition of the intestinal and upper respiratory tracts of infants after oral polio revaccination, hypothesized as a mechanism which supports the non-specific effects of the live-attenuated oral polio vaccine, promoting the so-called trained immunity (results submitted for publication), ii) the inhibitory effect of a synthetic formulation of the main allosteric regulator of oxygen affinity for haemoglobin (2,3-BPG) on the in vitro intraerythrocytic development of Plasmodium falciparum and formation of its offspring, and iii) the effect of this same synthetic formulation on the membrane of uninfected erythrocytes in vitro, mimicking the phenotype of aged erythrocytes and inhibiting erythrocyte invasion by Plasmodium falciparum (results submitted for publication), thus exploring the phenotype of malaria resistance conferred by pyruvate kinase deficiency, as a host-directed therapy. As a supervisor of a PhD in Tropical Diseases and Global Health (IHMT-NOVA), I have supervised a project that aims to evaluate the contribution of low-density malaria infections to the maintenance of malaria in Guinea-Bissau.

1. Morais I*, Medeiros MM*, Carvalho M*, Morello J, Teixeira SM, Maciel S, Nhantumbo J, Balau A, Rosa MTG, Nogueira F, Rodrigues JA, de Carvalho FA, Antunes AMM and Arez AP (2022) Synthetic Red Blood Cell-Specific Glycolytic Intermediate 2,3-Diphosphoglycerate (2,3-DPG) Inhibits Plasmodium falciparum Development In Vitro. Cell. Infect. Microbiol. 12:840968. https://doi.org/10.3389/fcimb.2022.840968 (*shared first authorship)
2. Miguel Lanaspa, Quique Bassat, Marcia Melo Medeiros & Camen Muñoz-Almagro. (2017). Respiratory microbiota and lower respiratory tract disease, Expert Review of Anti-infective Therapy, 15:7, 703-711, https://doi.org/10.1080/14787210.2017.1349609 (Cited 21)
3. Fotoran WL, Santangelo RM, Medeiros MM, et al. Liposomes loaded with P. falciparum merozoite-derived proteins are highly immunogenic and produce invasion-inhibiting and anti-toxin antibodies. Journal of Controlled Release: Official Journal of the Controlled Release Society. (2015) Nov; 217:121-127.; https://doi.org/10.1016/j.jconrel.2015.08.045 (Cited 10)
4. Medeiros MM, Silva HBd, Reis AS, Barboza R, Thompson J, Lima MRD, et al. (2013) Liver Accumulation of Plasmodium chabaudi-Infected Red Blood Cells and Modulation of Regulatory T Cell and Dendritic Cell Responses. PLoS ONE 8(11): e81409. https://doi.org/10.1371/journal.pone.0081409 (Cited 17)
5. Medeiros, M.M., Fotoran, W.L., dalla Martha, R.C. et al. Natural antibody response to Plasmodium falciparum merozoite antigens MSP5, MSP9 and EBA175 is associated to clinical protection in the Brazilian Amazon. BMC Infect Dis 13, 608 (2013). https://doi.org/10.1186/1471-2334-13-608 (Cited 25)