African Journal of Immunology Research

African Journal of Immunology Research ISSN 2756-3375 Vol. 9 (8), pp. 001-012, August, 2022. © International Scholars Journals

Full Length Research Paper

B cell immunophenotyping reveals decreased frequency of CD11c⁺ B cells expressing FcRL5⁺ subset in naturally malaria-exposed Fulani adults 

Charles Arama^1*, Bourèma Kouriba¹, Issa Nébié², Moussa Djimdé¹, Henda Doucouré¹, Seydou Arama¹, Bakary Koné¹, Salif Yirampo¹, Amatigue Zeguimé¹, Karim Bengaly¹, Amidou Diarra², Mohamadou Siribié², Sodiomon B Sirima², Ann-Kristin Östlund Farrants³, Silvia Portugal⁴ and Marita Troye-Blomberg³ 

^*1Malaria Research and Training Centre PO Box, 1805 Point G Bamako Mali.

¹Malaria Research and Training Centre, Department of Epidemiology of Parasitic Diseases, International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Mali.

²Groupe de Recherche Action en Santé, BP 10248 Ouagadougou 06, Burkina Faso,

³Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.

⁴Department of Infectious Diseases, Parasitology Heidelberg University Hospital, Germany.

Accepted 27th June, 2022 

Abstract

The Fulani populations are more resistant to malaria than genetically distinct populations of the Mossi ethnic group. The Fulani mount an enhanced and broadly reactive immunoglobulin M (IgM). However, which B-cell subsets that are contributing to this enhanced IgM response is not known. In naturally malaria-exposed Fulani (n=30) and Mossi (n=30) adults in Burkina Faso, B cells immunophenotypes were assessed using monoclonal antibodies and flow cytometry. Frequencies of IgM⁺ naïve B cells (“40.96 ± 1.72” vs “53.84 ± 1.84”; p=0.0001), IgM⁺ activated memory Bcells (MBC) (“17.79 ± 1.09” vs “21.71 ± 1.64”; p=0.04), IgM⁺ atypical MBC (“15.73 ± 1.81” vs “34.64 ± 2.57”; p=0.00002) and IgM⁺ CD11c⁺ FCRL5⁺ subsets (“6.73 ± 1.23” vs “19.22 ± 2.40”; p=0.00013) were significantly higher in the Fulani than in the Mossi. The frequency of CD11c⁺ B-cell subset expressing FcRL5 (“34.08 ± 1.70” vs “23.96 ± 1.15”; p=0.0001) was significantly lower in the Fulani than in the Mossi. Levels of IgM⁺ atypical MBC were positively correlated with those of IgM⁺ CD11c B cells expressing FCRL5⁺.CD11c⁺ B cells expressing FcRL5⁺ subset markedly highlights differences in the Fulani versus the Mossi adults. B cells carrying the FcRL5 negatively affect the acquisition of protective immunity to malaria.  

Keywords: CD11c B cells, atypical memory B cells, Fulani, malaria, P. falciparum, susceptibility, immunity.