title: B cells play a regulatory role in mice infected with the L3 of Brugia pahangi.
abstract: Mice infected with the L3 of the filarial nematode Brugia pahangi make a strong T(h)2 response characterized by elevated levels of antigen-specific IL-4, IL-5 and IL-10. Here we show that B cells from these animals are the major proliferating population in vitro with depletion of B cells or infection of muMT mice, resulting in reduced levels of antigen-specific proliferation. B cells also act as antigen-presenting cells (APC) to CD4(+) cells as demonstrated by the switch in cytokine profiles upon B cell depletion. The efficiency of B cells in antigen presentation is attenuated by IL-10 which down-regulates the expression of B7-1 and B7-2 on the surface of B cells both in vitro and in vivo. Thus, IL-10 may modulate CD4 responses in L3-infected mice by suppressing the expression of B7 ligands on B cells. In support of this hypothesis, blockade of the IL-10R in vivo results in increased proliferation of CD4(+) cells. We propose that B cells participate in a negative feedback loop: IL-10 elicited by infection with L3 and produced by B cells (and CD4(+) cells) down-regulates the expression of B7 molecules on the B cell surface, attenuating their efficiency as APC to CD4(+) T cells and restricting their expansion.
authors.affiliation: Parasitology Group, Institute of Comparative Medicine, University of Glasgow, Garscube Estate, Bearsden Road, Glasgow, G61 1QH UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Gillan
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Lawrence
authors.forename: Eileen
authors.initials: E
authors.lastname: Devaney
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen / Q000276:immunology; D051940:B7-2 Antigen; D017179:Brugia pahangi / Q000276:immunology*; D049109:Cell Proliferation; D005368:Filariasis / Q000276:immunology*; D005434:Flow Cytometry; D016753:Interleukin-10 / Q000378:metabolism; D007814:Larva / Q000276:immunology; D008024:Ligands; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D018123:Receptors, Interleukin / Q000037:antagonists & inhibitors; D053701:Receptors, Interleukin-10; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D008024:Ligands; D008562:Membrane Glycoproteins; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10; D016753:Interleukin-10