Objective: The frequency of immature transitional B cells is increased in blood of HIV-1-infected individuals. We investigated whether HIV-1 infection affects expression and function of chemokine receptors important for egress of immature transitional B cells from bone marrow and migration to lymphoid organs. Design: This is a cross-sectional study analysing the migratory phenotype and function of immature transitional B cells in HIV-1-infected individuals, in relation to antiretroviral treatment and age. Methods: Frequency of blood immature transitional B cells and their phenotypic characteristics, including chemokine receptors and a maturation marker, were determined by immunostainings. Migratory capacities were studied in a migration assay. Results: The increased frequency of immature transitional B cells in untreated HIV-1 infection was normalized in patients receiving antiretroviral treatment; in our cohorts, age did not have an impact on the frequency of circulating immature transitional B cells. Immature transitional B cells from nontreated patients expressed low levels of CD21 molecule. We found an elevated frequency of CXCR3 and CXCR4 expressing immature transitional B cells in treated and nontreated patients. CXCR4 receptor was unresponsive to CXCL12 ligand in in-vitro migration and internalization assays. In addition, CXCR5 expression was downregulated on immature transitional B cells from infected patients, and these cells migrated poorly in response to CXCR5 ligand. Conclusion: Circulating immature transitional B cells from HIV-1-infected patients are not fully mature, probably due to premature egress from bone marrow; these cells showed a phenotype which could impair entry into secondary lymphoid organs. Changes in migratory capacity of immature transitional B cells may affect B-cell maturation during HIV-1 infection.
- Chemokine receptor
- HIV-1 infection
- Immature transitional B cells
ASJC Scopus subject areas
- Immunology and Allergy
- Infectious Diseases
Amu, S., Fievez, V., Nozza, S., Lopalco, L., & Chiodi, F. (2016). Dysfunctions in the migratory phenotype and properties of circulating immature transitional B cells during HIV-1 infection. AIDS, 30(14), 2169 - 2177. https://doi.org/10.1097/QAD.0000000000001182