The impact of active HIV-1 replication on the physiological age-related decline of immature-transitional B-cells in HIV-1 infected children.
OBJECTIVE
To characterize the level of immature-transitional B-cells in blood during pediatric HIV-1 infection in relation to active or suppressed viremia. We also aimed at characterizing the level of expression of CXCR4, CXCR5 and CCR7 on immature-transitional B-cells, as these receptors are important mediators for homing of B-cells.


METHODS
Forty-eight HIV-1 vertically infected children (33 viral controllers and 15 viremic patients) and 33 age-matched healthy controls were enrolled in a cross-sectional study.


METHODS
We measured the levels of peripheral immature-transitional B-cells in all groups in relation to switched memory B-cells by flow cytometry. In parallel we evaluated CXCR4, CXCR5 and CCR7 expression on immature-transitional B-cells and measured plasma levels of CXCL12, BAFF and interleukin-7 by ELISA.


RESULTS
We observed a lack of physiological age-related decline of immature-transitional B-cells in viremic children in parallel to a decreased level of switched memory B-cells. Interestingly, immature-transitional B-cells from viremic children presented with high levels of CXCR4. On the contrary, the level of CXCL12, the natural ligand for CXCR4, was lowest in the HIV-1 infected group, as compared with controls.


CONCLUSIONS
Control of HIV-1 viremia through antiretroviral treatment appears to be crucial in decreasing the expansion and alteration of immature-transitional B-cells.
Cagigi
Alberto
A
Department of Laboratory Medicine, Division of Clinical Immunology, Karolinska University Hospital Huddinge, Stockholm, Sweden. Alberto.Cagigi@ki.se
Palma
Paolo
P
Nilsson
Anna
A
Di Cesare
Silvia
S
Pensieroso
Simone
S
Kakoulidou
Maria
M
Bernardi
Stefania
S
Rossi
Paolo
P
Chiodi
Francesca
F
D023241:Antiretroviral Therapy, Highly Active; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008297:Male; D054448:Precursor Cells, B-Lymphoid / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000276:immunology*; D014766:Viremia
D019718:Receptors, CXCR4