Humoral immune response of Japanese eel, Anguilla japonica Temminck & Schlegel, to Pleistophora anguillarum Hoshina, 1951 (Microspora)

Abstract

A humoral response of Japanese eel, Anguilla japonica Temminck & Schlegel, to the microsporean Pleistophora anguillarum Hoshina was demonstrated using immunoblotting and an enzyme-linked immunosorbent assay (ELISA). Japanese eel immunoglobulin was purified by afifinity chromatography. The immunoglobulin was composed of 25-kDa light chains and 72-kDa heavy chains. The ELISA values of P. anguillarum antibodies in naturally infected fish sera were significantly higher than those of clinically healthy fish. Spore proteins from the microsporean were separated by electrophoresis and subjected to analysis by Western blot. Sera from naturally infected fish showed different reaction patterns to the spore proteins. While the sera randomly selected from naturally infected eels all showed a significant positive reaction to P anguillarum antigens, the mucus from only three out of the nine infected eels reacted positively in the ELISA test. Subsequent analyses indicated that there was no significant difference in the amount of mucus immunoglobufin among the tested eels. Therefore, the generally lower ELISA values of mucosal anti-/? anguillarum antibodies from the infected eels tested were evidently not caused by a lack of immunoglobulin per se, but seem to be the result of a lack of anti-7? anguillarum antibodies in the mucus and/or a lower afFmity in the anti-T? anguillarum antibodies that were present.

Humoral Immune Response of Ayu, Plecoglossus altivelis to Glugea plecoglossi (Protozoa: Microspora).

“…Studies on immune responses of teleosts to microsporidians have started recently and some authors have described about humoral immune responses to fish microsporidians (Laudan et al, 1986a(Laudan et al, , 1986bLeiro et al, 1993;Hung et al, 1996).However, most studies were focused on immunosuppression elicited by microsporidian infections (Laudan et al, 1986a(Laudan et al, , 1986b(Laudan et al, , 1987(Laudan et al, , 1989Wongtavatchaiet al, 1995) and only Leiro et al (1993) and Hung et al (1996) reported that fish can produce specific antibodies against microsporidians. The experiments conducted in this study revealed that ayu can produce antibodies against G. plecoglossi spores.…”

“…Immunodepression has been known to be caused by some microsporidian infections (Laudan et al, 1986a(Laudan et al, , 1986b(Laudan et al, , 1987(Laudan et al, , 1989Wongtavatchai et al, 1995) . In contrast, specific humoral immune responses to some microsporidians were reported by Leiro et al (1993) and Hung et al (1996). In general, immune responses to micro sporidians are poorly understood.…”

Humoral immune responses of the grouper Epinephelus akaara against the microsporidium Glugea epinephelusis

“…Soluble spore antigens were prepared using methods reported by Hung et al (1996) with some modifications. One ml aliquots of Glugea epinephelusis spores suspension (1 × 10 9 spores ml -1 PBS) were processed by 10 freeze-thaw cycles of liquid nitrogen and skived by means of a mortar.…”

“…Gels were stained for 12 h with 0.01% Coomassie Bright Blue R-250 (Rio-Rad). Western blot was performed using the method described by Irby et al (1986) and Hung et al (1996). The pooled sera of naturally infected fishes diluted (1:100) in blocked buffer, mouse anti-grouper Epinephelus spp.…”

“…Although immune responses of fish against microsporidians remain enigmatic (Laudan et al 1986, 1987, Woo 1992, Leiro et al 1993, Wongtavatchai et al 1995, Kim et al 1996, Pomport-Castillon et al 1999, specific immune responses of fish, such as humoral, mucous and cellular immune responses, have been demonstrated in some species (Leiro et al 1993, Hung et al 1996, Kim et al 1996. In the case of Glugea epinephelusis, immune responses of grouper against the infection, however, are still unknown.…”