ABSTRACT
Jaagsiekte sheep retrovirus (JSRV) is the aetiological agent of ovine pulmonary adenocarcinoma (OPA). No JSRV-specific immunological responses have been detected in clinical cases of OPA or in experimentally infected lambs. The aim of the present study was to induce immune responses in sheep against JSRV proteins using several immunisation strategies. The vaccines were administered subcutaneously and intradermally, or intranasally, in adjuvant. Antibodies were measured by ELISA and immunoblotting, and T cell responses by lymphoproliferation assay. Antibodies specific for JSRV-capsid protein were induced by inoculation of recombinant proteins in adjuvant, and transient JSRV-specific T cell responses by intranasal inoculation with inactivated virus. These results will help in the design of a protective vaccine against JSRV infection and the development of OPA.
Subject(s)
Jaagsiekte sheep retrovirus/immunology , Pulmonary Adenomatosis, Ovine/prevention & control , Vaccination/methods , Adjuvants, Immunologic , Administration, Intranasal , Animals , Antibodies, Viral/blood , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Freund's Adjuvant/administration & dosage , Injections, Intradermal , Injections, Subcutaneous , Lipids/administration & dosage , Lymphocyte Activation , Sheep , T-Lymphocytes/immunology , Vaccines, Subunit/administration & dosage , Vaccines, Subunit/genetics , Vaccines, Subunit/immunology , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology , Viral Proteins/administration & dosage , Viral Proteins/genetics , Viral Proteins/immunologyABSTRACT
Jaagsiekte sheep retrovirus (JSRV) is the aetiological agent of ovine pulmonary adenocarcinoma (OPA). To monitor changes in cellular immune function during JSRV infection, lymphoproliferation in response to various mitogens was measured in the blood of conventionally housed and specific-pathogen-free lambs experimentally infected with JSRV until the development of OPA and compared with uninfected control lambs. In addition, blood samples collected from adult field cases in the terminal stages of OPA and control adult sheep were compared. No difference in the proliferative response to phytohaemagglutinin and pokeweed mitogen between the animal groups was detected. In contrast, reduced responses to concanavalin A stimulation were demonstrated in the JSRV-inoculated lambs, prior to the onset of clinical disease, and also in the terminally ill adult sheep. Peripheral blood leukocytes were monitored to identify phenotypic frequency alterations. The CD4 lymphocytopaenia and neutrophilia reported previously in adult OPA cases were demonstrated but similar phenotypic changes were not identified during experimental infection.
Subject(s)
Jaagsiekte sheep retrovirus , Pulmonary Adenomatosis, Ovine/immunology , Sheep/immunology , Animals , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/immunology , Cell Division/drug effects , Immunity, Cellular , Jaagsiekte sheep retrovirus/immunology , Leukocytes, Mononuclear/immunology , Lymphopenia/pathology , Neutropenia/pathology , Phytohemagglutinins/pharmacology , Pokeweed Mitogens/pharmacologyABSTRACT
Lectins from monocotyledonous plants such as Narcissus pseudonarcissus (NPA) possess insecticidal properties and have the potential to increase pest resistance in transgenic crops. Therefore it is of interest to investigate the mitogenic properties of such lectins. Mononuclear cells purified from human umbilical cord and adult peripheral blood samples were stimulated with NPA and compared to phytohaemagglutinin as an example of a lectin from a dicotyledonous plant. Here we report that NPA is slightly mitogenic for adult human lymphocytes but mitogenicity is increased more than sevenfold for lymphocytes from umbilical cord blood. Similarly, NPA was found to be mitogenic for peripheral blood mononuclear cells (PBMC) from lambs and not adult sheep, supporting the age-related mitogenicity and indicating that further examination of the younger human population is warranted.
