Research Article Volume 4 Issue 4
Department of Biological and Environmental Sciences, University of Gothenburg, Sweden
Correspondence: Michel Leclerc Henrik, 556 rue Isabelle Romée, Sandillon, (France)
Received: June 13, 2017 | Published: August 7, 2017
Citation: Leclerc M (2017) Immunocyto chemical Reactions in The Brittle-Star: Ophiocomina Nigra After Immunization. Int J Vaccines Vaccin 4(4): 00088. DOI: 10.15406/ijvv.2017.04.00088
Immunisations of Ophiocomina nigra were performed with either Bovine Serum Albumine (BSA) or Horse-Radish Peroxydase( HRP) in aquarium containing running sea water. An immunocyto chemical test was done in presence of HRP, diaminobenzidin, H2O2for both animals: Control ones, BSA ones and HRP ones. Positive reactions only occur in injected animals to HRP .So the brittle star Onigra as the sea star Asterina gibbosa Discriminates HRP from BSA : it is an antibody-like reaction. Plasmolymphocytic cells were evoked.
All echinoderms (Echinodermata),except holothurids, possess an axial organ (AO) as part of their coelomic and haemal system.Immunocytochemical positive reactions were observed in 1973 in the sea star Asterina gibbosa (Asterid, Echinoderm).1 After injections of various proteins. It seemed interesting to look for similar actions in the Ophuirid: Ophiocomina nigra (another echinoderm) which possesses also an axial organm. The sea star axial organ, an ancestral lymphoïd organ shows immune adaptative reactions2 and presents a primitive antibody.3 The question was are the Ophiocomina and Asterina gibbosa axial organs similars from the point of view of immuno competence?. So, we have repeated an experimental protocol in Ophiocomina nigra which resembles to the sea star one of 1973, at the level, exclusively, of cytologic observations.
Ophiocomina nigra were obtained from the Marine Biological Institute of Gothenburg and placed in aquarium with running sea water. 20 animals were put in three parts :
Control animals were not immunized. On the other hand BSA animals received at time t=0 10µlof BSA (1mg/ml solution) and at time t=7days after, again, 10µl of BSA (same concentration).HRP animals received 10 µl of HRP (Sigma Products) of a solution at 1mg/ml at times similar as those of BSA animals then a second injection of 10µl of HRP.3days after the last injection. All animals were sacrifiied and axial gans(A.O) were excised. Fixation of A.O in glutaraldehyde occured (2 % in cacodylate buffer). Then A.O were washed in buffer. Incubation in HRP(1mg/ml) was performed for all A.O. Washing in buffer was following.Incubation in diaminobenzidin(1mg/ml) and H2O2 (1 drop) was realized then washing in buffer occured O/N. We did dehydratation in alcohol and then embedding in paraffin. Sectioning was made at 4µ.We used Heathrow scientific LLC slides. Coloration was performed with Giemsa (1min).Observations were done with a microscope Zeiss.
Briefly we observe neither labelling in control animals, nor in BSA treated animals. In immunized animals to HRP a positive labelling(color dark-brown) occurs in hyaloplasm in ergastoplasm and sometimes in the erinuclear space It can be seen in (Figures 1 & 2). Labelling is about 5 % of the whole cell population. It Is of 0 % for BSA treated animals (Figure 3). Plasmolymphocytoplasmic and lymphocytes cells seem to exist in Ophiocomina nigra as for Asterina gibbosa1 but it must be corroborated by TEM observations.
It is shown that antigen-antibody like reactions occur in the brittle star : Ophiocomina nigra. It opens an immense field of experiments we may compare to those of Asterids (another echinoderm) : i-e research of lymphocytes (like sea star B and T lymphocytes) Research of Primitive Brittle star antibody, and brittle star genomic studies.4 In fact, It would be interesting to study the genome of O.nigra and to compare the sea star immune genes to brittle star ones. We hope that the present work will help in suggesting provocative and imaginative ideas on adaptative immunity in marine invertebrates.
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Author declares there are no conflicts of interest.
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