Altered Distribution of Peripheral Blood Memory B Cells in Humans Chronically Infected with Trypanosoma cruzi

Abstract

Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

Th2 Biased Immunity With Altered B Cell Profiles in Circulation of Patients With Sporotrichosis Caused by Sporothrix globosa

“…However, only levels of IgG2 and IgG4 were reduced in patients with SD, with comparable levels of total IgG and IgM in patients to those of HC. Similar to our results, Esteban found that T. cruzi-infected individuals had significantly lower frequencies of SM B cells with no change in the level of total IgG (41). We speculated that decreased USM B cells may be responsible for decreased IgG2 and/or IgG4 production which need further verification.…”

Regulatory IgDhi B Cells Suppress T Cell Function via IL-10 and PD-L1 during Progressive Visceral Leishmaniasis

“…Role(s) of regulatory surface receptors in the function(s) of these naïve-like B cells are not well established. CD19 + , CD27 − , IgM + , IgD + B cells increase in frequency within whole blood during clinical Chagas’ disease (13) and P. falciparum cerebral malaria (14), suggesting a causal link between IgM + /IgD + naïve-like B cells and persistence of intracellular protozoal infection. Despite these correlative findings, very little is known regarding the specific role of IgD + IL-10 producing B cells in natural infection settings, or regulatory function(s) of IgD hi expressing cells.…”

Circulating T Follicular Helper Cell Abnormalities Associated to Different Clinical Forms of Chronic Chagas Disease

“…Moreover, we were unable to obtain data on the cytokine profile and functionality of cTfh cells that could lead to a better understanding of their role in the pathogenesis of chronic Chagas heart disease. However, our detailed phenotypic characterization provides indirect evidence of a potential role of Tfh cells in the abnormal immune responses against T. cruzi (Fernández et al, 2014), establishing the basis to perform further studies to assess these processes.…”

“…Dysregulation of the cTfh cell compartment has been reported in autoimmune diseases, cancer and infections associated with abnormal B cell responses (Boswell et al, 2014;Ueno et al, 2015). However, whether Tfh cells contribute to the generation of the abnormal B cell responses observed during T. cruzi infection remains to be elucidated (Minoprio et al, 1988;Fernández et al, 2014). The aim of this work was to provide an insight in the adaptive immune response elicited by T. cruzi in humans.…”