Endogenous CD4+ CD25+ regulatory T cells play no apparent role in the acute humoral response to intact Streptococcus pneumoniae.
Immunoglobulin G (IgG) antiprotein and antipolysaccharide responses to intact Streptococcus pneumoniae are CD4+-T-cell dependent and therefore might be under the negative control of CD4+ CD25+ regulatory T cells. Injection of anti-interleukin 2 receptor alpha (anti-IL-2Ralpha) MAb to deplete regulatory T cells, injection of agonistic MAb against glucocorticoid-induced tumor necrosis factor receptor family-related protein to inhibit regulatory-T-cell function, and adoptive transfer of regulatory-T-cell-depleted CD4+ T cells into athymic nude mice each had no effect on either the primary or secondary protein- or polysaccharide-specific IgG response to intact S. pneumoniae. Surprisingly, anti-IL-2Ralpha MAb also had no effect on the IgG response to intact S. pneumoniae in MyD88-/- mice or to a soluble protein-polysaccharide conjugate injected into wild-type mice in the absence of adjuvant. Collectively, these data are the first to suggest that, in contrast to their role in limiting chronic cell-mediated immunity, regulatory T cells may play no significant role in an acute humoral immune response to an intact extracellular bacterial pathogen.
Lee
Katherine S
KS
Department of Pathology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814, USA.
Sen
Goutam
G
Snapper
Clifford M
CM
D048868:Adaptor Proteins, Signal Transducing; D019264:Adoptive Transfer; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000943:Antigens, Differentiation / Q000502:physiology; D001426:Bacterial Proteins / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D005260:Female; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification; D051379:Mice; D008807:Mice, Inbred BALB C; D053594:Myeloid Differentiation Factor 88; D011971:Receptors, Immunologic / Q000502:physiology; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D013296:Streptococcus pneumoniae / Q000276:immunology*
D048868:Adaptor Proteins, Signal Transducing; D000907:Antibodies, Bacterial; D000943:Antigens, Differentiation; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; C051592:pneumococcal surface protein A