title: Age influences recovery of systemic and mucosal immune responses following acute depletion of CD4 T cells.
abstract: We have examined the influence of recipient age on the recovery of the CD4 T cell compartment following in vivo treatment with anti-CD4. Mice were treated with anti-CD4 beginning in utero (adolescent), at 8 weeks (young adult), or at 52 weeks (old adult). Following acute CD4 depletion, adolescent mice recovered CD4 T cells rapidly (99% of age-matched controls at 5 weeks after anti-CD4 treatment). Young adult mice recovered more slowly (48% of control at 5 weeks), while old adult mice recovered less than 50% of control CD4 T cell numbers at 12 weeks after depletion. At 12 weeks after anti-CD4 treatment, adolescent mice made an enhanced anti-SRBC antibody response and young adult mice mounted a response comparable to their age-matched controls. In comparison, old adult mice mounted on anti-SRBC response that was only 57% that of their age-matched controls. By 1 week after cessation of anti-CD4 treatment, adolescent mice mounted normal systemic and intestinal responses to challenge with the thymic-dependent antigen cholera toxin (CT). In contrast, young adult mice recovered < 50% of age-matched control CT responsiveness by 5 weeks post-CD4 depletion. By 5 weeks post-CD4 depletion, young adult mice exhibited normal tolerance following enteric tolerization with ovalbumin. These findings underscore the importance of recipient age in designing or interpreting studies employing T cell depletion.
authors.affiliation: Department of Internal Medicine, University of Iowa College of Medicine, Iowa City.
authors.forename: A L
authors.initials: AL
authors.lastname: Fleming
authors.forename: E H
authors.initials: EH
authors.lastname: Field
authors.forename: N
authors.initials: N
authors.lastname: Tolaymat
authors.forename: J S
authors.initials: JS
authors.lastname: Cowdery
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D000917:Antibody Formation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D007108:Immune Tolerance; D007111:Immunity, Cellular; D007413:Intestinal Mucosa / Q000276:immunology; D007583:Jejunum / Q000276:immunology; D008212:Lymphocyte Depletion; D051379:Mice; D008810:Mice, Inbred C57BL; D012397:Rosette Formation