Thirty-two calves were studied to determine the effects of level of nutrition (400 and 1000 g (air-dry matter) milk substitute per d) and age at weaning (5, 9 and 13 weeks) on humoral immune responses measured in serum and bronchoalveolar washings (BAW). All calves were immunized with Keyhole limpet haemocyanin (KLH) at 3 weeks of age, and with horse erythrocytes (HRBC) 1 d after weaning. Feedi...

Human cases of infection due to a novel swine-origin variant of influenza A virus subtype H3N2 (H3N2v) have recently been identified in the United States. Pre-existing humoral and cellular immunity has been recognized as one of the key factors in limiting the infection burden of an emerging influenza virus strain, contributing to restrict its circulation and to mitigate clinical presentation. A...

T follicular helper (TFH) cell responses are essential for generation of protective humoral immunity during influenza infection. Aging has a profound impact on CD4(+) T cell function and humoral immunity, yet the impact of aging on antigen specific TFH responses remains unclear. Influenza specific TFH cells are generated in similar numbers in young and aged animals during infection, but TFH cel...

Studies were performed to investigate the effects of FireMaster FF-1, a chemical fire retardant consisting of a mixture of polybrominated biphenyls (PBB), on immune functions in mice and rats. Animals received 22 daily treatments of 0.03, 0.3, 3.0, or 30 mg PBB/kg body weight in a period covering 30 days. PBB exposure severely depressed cell mediated immunity in both mice and rats at the higher...

A currently popular hypothesis states that the expression of carotenoid-dependent sexual ornaments and immune function may be correlated because both traits are positively affected by carotenoids. However, such a correlation may arise for another reason: it is well known that immune function is dependent on nutritional condition. A recent study has suggested that the expression of ornaments may...

Helicobacter bacteria colonize in the stomach and induce strong, specific local and systemic humoral and cell-mediated immunity. Helicobacter binds to the host epithelial cells, directly triggering the recruitment of neutrophils. Local inflammatory processes in the gastric mucosa are followed by extensive immune cell infiltration, resulting in chronic active gastritis characterized by a marked ...

Humanized mice historically have not been good models of human humoral immunity induced by either infection or immunization. However, newer versions of humanized mice generated in severely immunodeficient mice with a targeted disruption of the IL2Rγc gene have recently been reported to produce antigen-specific class-switched human antibodies, with some demonstrating neutralizing activities. Her...