Induction and detection of cell-mediated reactions with different Blastomyces dermatitidis antigenic preparations.
Blastomyces dermatitidis yeast-phase antigens (killed cell, KWY; lysate, Lys; and filtrate, Fil) from canine isolate T-58 were compared with respect to the induction and detection of cellular immune responses in mice. The antigens exhibited good sensitivity and specificity when used to detect a delayed-type hypersensitivity (DTH) response in mice previously immunized with T-58 or Histoplasma capsulatum antigens. Greater reactivity was observed with the KWY and Lys antigens as DTH-inducing agents (immunogens) than with the Fil antigen. The antigens were also compared with regard to the induction and detection of a lymphoproliferative reaction using splenocytes from normal and sensitized mice, and optimal reactivity was demonstrated with the KWY and Fil antigen preparations both as immunogens (absorbance values 0.22-1.60 and 0.20-0.90, respectively) and as in vitro testing antigens (absorbance values 0.60-1.60 and 0.35-1.00 respectively) (P < 0.01). Peritoneal macrophages from mice sensitized with Fil and KWY antigens showed the greatest in vitro replication inhibition (RI) of B. dermatitidis yeast cells (RI values of 53% and 50% respectively) (P < 0.05). When mitogenic or antigenic lymphocytic supernatants were compared with respect to their ability to enhance the phagocytic activity of unelicited macrophages from normal mice to kill yeast cells, the T-cell mitogens (concanavalin A and phytohaemagglutinin) optimally activated the naive macrophages (45% and 44% RI respectively) compared with the B-cell mitogen (LPS) (23% RI) (P < 0.05). Similar results were obtained with the lymphocytic supernatants from mice immunized with KWY cells when activated using KWY or Fil antigens (46% and 40% RI respectively) (P < 0.05).
Abuodeh
R O
RO
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, USA.
Winston
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V
Scalarone
G M
GM
D000818:Animals; D000946:Antigens, Fungal / Q000276:immunology*; D001758:Blastomyces / Q000254:growth & development / Q000276:immunology* / Q000302:isolation & purification; D001759:Blastomycosis / Q000662:veterinary; D004283:Dog Diseases; D004285:Dogs; D006968:Hypersensitivity, Delayed; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008813:Mice, Inbred ICR
D000946:Antigens, Fungal