What do we know about the role of regulatory B cells (Breg) during the course of infection of two major parasitic diseases, malaria and leishmaniasis?

Abstract

Parasitic diseases, such as malaria and leishmaniasis, are relevant public health problems worldwide. For both diseases, the alarming number of clinical cases and deaths reported annually has justified the incentives directed to better understanding of host's factors associated with susceptibility to infection or protection. In this context, over recent years, some studies have given special attention to B lymphocytes with a regulator phenotype, known as Breg cells. Essentially important in the maintenance of immunological tolerance, especially in autoimmune disease models such as rheumatoid arthritis and experimentally induced autoimmune encephalomyelitis, the function of these lymphocytes has so far been poorly explored during the course of diseases caused by parasites. As the activation of Breg cells has been proposed as a possible therapeutic or vaccine strategy against several diseases, here we reviewed studies focused on understanding the relation of parasite and Breg cells in malaria and leishmaniasis, and the possible implications of these strategies in the course of both infections.

Arginase activity of Leishmania isolated from patients with cutaneous leishmaniasis

“…Leishmaniasis is one of the major neglected tropical diseases (NTD) that mainly affects the population of low‐income countries . The disease is categorized as cutaneous (CL), mucocutaneous (MCL) and visceral leishmaniasis (VL), which is caused by over 20 species of the Leishmania (L) parasites . Cutaneous leishmaniasis (CL) with an estimated incidence of 1.5‐2 million cases annually is the most prevalent form of leishmaniasis .…”

Potential Role for Regulatory B Cells as a Major Source of Interleukin-10 in Spleen from Plasmodium chabaudi-Infected Mice

“…Breg cells suppress immunopathology in autoimmune diseases (39,40) and dampen anti-tumor immunity and host defense in cancer and bacterial and viral infections (41)(42)(43). The function of Breg cells in parasitic diseases is complex and seems to depend on parasite species and their pathogenic mechanisms (44). So far, studies investigating the immunomodulatory role of B cells in Plasmodium infection are rare (44).…”

“…The function of Breg cells in parasitic diseases is complex and seems to depend on parasite species and their pathogenic mechanisms (44). So far, studies investigating the immunomodulatory role of B cells in Plasmodium infection are rare (44). It was noticed a long time ago that B cells were required for the switch from Th1to Th2-regulated immune responses in malaria (45), but only recently was the importance of B cell-mediated immunoregulation in malaria confirmed.…”

B Regulatory Cells: Players in Pregnancy and Early Life

“…Viruses, bacteria, helminths [ 109 ], and parasites [ 110 ] can imbue B cells with regulatory functions. Rapidly after infection, Salmonella and Listeria induce the apparition of IL-10-producing cells in a TLR/MyD88-dependent fashion in mice.…”