B cell activation and human immunodeficiency virus infection. V. Phenotypic and functional alterations in CD5+ and CD5- B cell subsets.
B cell dysregulation is a hallmark of human immunodeficiency virus infection. Since B lymphocytes comprise two distinct subpopulations, CD5+ and CD5- cells, we addressed their individual phenotypic and functional behavior. Seropositive patients with both limited and advanced disease progression had an increased percentage of peripheral blood CD5+ B cells, compared to seronegative controls (20.1 +/- 2.1 and 22.7 +/- 5.7, respectively, vs 17.0 +/- 3.4 in controls); however, due to the lymphopenia and reduced number of circulating B cells in infected individuals, the absolute number of CD19+CD5+ lymphocytes was actually reduced. Although HIV-specific antibodies were synthesized spontaneously in vitro only by CD5- B cells, a 10-fold lower degree of spontaneous, non-HIV-specific activation was also displayed by unstimulated CD5+ B cells. These findings indicate that B cell dysregulation during HIV infection involves both the CD5- and the CD5+ B cell compartments; moreover, in view of the putative role of CD5+ B cells in autoimmune phenomena and IL-10 production, these data reinforce the possibility that B cell dysfunction might be causally involved in AIDS pathogenesis.
Indraccolo
S
S
Institute of Oncology, University of Padova, Italy.
Mion
M
M
Zamarchi
R
R
Veronesi
A
A
Veronese
M L
ML
Panozzo
M
M
Betterle
C
C
Barelli
A
A
Borri
A
A
Amadori
A
A
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D018956:CD5 Antigens; D015483:HIV Antibodies / Q000276:immunology; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D016130:Immunophenotyping; D008213:Lymphocyte Activation
D015703:Antigens, CD; D018956:CD5 Antigens; D015483:HIV Antibodies; D007074:Immunoglobulin G