Immunosuppression of in vivo and in vitro lymphocyte responses in swine induced by Trichinella spiralis or excretory-secretory antigens of the parasite.
The in vivo and in vitro effects of Trichinella spiralis excretory-secretory (ES) antigens on porcine peripheral blood lymphocyte (PBL) responses induced with mitogens (phytohemagglutinin, PHA; concanavalin A, Con A; pokeweed mitogen, PWM) or unrelated antigen (Protein A) were studied to determine whether ES antigens depress lymphocyte responses in experimental swine trichinosis, and/or if this response was manifested after lymphocytes from infected pigs had been pretreated with ES antigens. Additionally, the range of inhibition of lymphocyte responses was tested in parasite-free pigs using different doses of ES antigens and compared with the responsiveness of control cultures from the same animals. The responses of lymphocytes from pigs inoculated with 4 x 10(3) muscle larvae (ML) were strongly depressed (P < 0.05) at post-inoculation days (PID) 7 (after stimulation with PHA), 14, 35 (Con A or PWM), and 49 (PWM). At PID 56 and 63 the lymphocytes from T. spiralis-infected pigs responded better (P < 0.05) to all three mitogens than those from non-infected controls. After 7 weeks post-inoculation, PBL which were pretreated with 10 or 250 micrograms ml-1 of ES antigens showed significantly weaker (P < 0.05, P < 0.001) responses to PWM or PHA, respectively, than those from non-infected animals. The responsiveness of lymphocytes from both groups of pigs to Protein A was not affected by the pretreatment with ES antigens in vitro. The responses of lymphocytes from the parasite-free pigs induced by PHA, PWM or Protein A were strongly depressed (P < 0.01) after in vitro pretreatment regardless of the dose of ES antigens (5, 10, 15, or 20 micrograms ml-1) applied.
Gerencer
M
M
Immuno AG, Biomedical Research Center, Vienna, Austria.
Marinculić
A
A
Rapić
D
D
Franković
M
M
Valpotić
I
I
D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007108:Immune Tolerance; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D013552:Swine; D013553:Swine Diseases / Q000276:immunology*; D017160:Trichinella spiralis / Q000276:immunology*; D014235:Trichinellosis / Q000276:immunology / Q000662:veterinary*
D000909:Antibodies, Helminth; D000947:Antigens, Helminth