AUTHOR=Piao Xianyu , Ma Yu , Liu Shuai , Hou Nan , Chen Qijun 

TITLE=A Novel Thioredoxin-Like Protein of Babesia microti Involved in Parasite Pathogenicity

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.826818

DOI=10.3389/fcimb.2022.826818

ISSN=2235-2988

ABSTRACT=<p>Babesiosis poses a serious threat to immunocompromised individuals and the major etiological species of <italic>Babesia</italic> for human babesiosis is <italic>Babesia microti</italic>. Merozoites are a critical stage in the life cycle of <italic>Babesia microti</italic>. Several merozoite proteins have been demonstrated to play important roles in this process; however, most of the merozoite proteins of <italic>B. microti</italic> remain unknown. In the present study, we identified a novel merozoite protein of <italic>B. microti</italic> with similar structure to the thioredoxin (Trx)-like domain of the Trx family, which was named as <italic>B. microti</italic> Trx-like protein (<italic>Bm</italic>TLP). Western blot assays demonstrated that this protein was expressed by <italic>B. microti</italic> during the erythrocytic infection process, and its expression peaked on day 7 post-infection <italic>in vivo</italic>. Immunofluorescence assay further showed that this protein is mainly expressed in <italic>B. microti</italic> merozoites. <italic>Bm</italic>TLP hold both heparin- and erythrocyte-binding properties, which are critical functions of invasion-related proteins. Immunization with recombinant <italic>Bm</italic>TLP imparted significant protection against <italic>B. microti</italic> infection in mice. Taken together, these results suggest that the novel merozoite protein, <italic>Bm</italic>TLP, is an important pathogenic molecule of <italic>B. microti</italic> and may be a possible target for the design of babesiosis control strategy.</p>