The cellular response of lambs to Brucella ovis before and after birth.

The immunological response of lambs to Brucella ovis before and after birth was investigated. The establishment of indwelling cannulas in the efferent prescapular lymphatic ducts of foetal lambs allowed continual monitoring of the immune response of a single lymph node. Foetal lambs in the last trimester of pregnancy were shown to mount a strong cell-mediated immune response to B.

Response of leucocyte populations in the illeal Peyer's patch of fetal lambs treated with ferritin per os.

A combination of immunohistochemical techniques, a panel of monoclonal antibodies, and computer-assisted morphometric analysis was used to examine the response of the ileal Peyer's patch of fetal lambs 7 days after treatment with ferritin per os. Consistent with previous studies in fetal lambs that have reported the ileal Peyer's patch to be indifferent to antigen, the present study did not find any significant changes in the size of the predominantly B-cell dome/follicle compartment or the predominantly T-cell interfollicular area, nor were differences identified in the distribution of IgM-positive (+), CD4+, and CD8+ cells in these two compartments. However, both compartments showed a significant increase (p < 0.

Immunoelectron microscopy of cell populations in regional and central lymph of sheep.

The immunoreactivity and the ultrastructural localization of monoclonal anti-sheep lymphocyte antibodies conjugated with colloidal gold particles were examined in free-floating cells of sheep central lymph from the thoracic duct, postnodal lymph draining either the popliteal nodes or the mesenteric nodes, and prenodal lymph draining the pregnant uterus. The monoclonal antibodies used in this study were SBU-T1 (CD5), SBU-T4 (CD4), SBU-T8 (CD8), SBU-II (anti DR antibody), and E53 which are reported to be sheep homologues of human T1, T4, T8, HLA-DR, and pan B cell antibodies, respectively. Colloidal gold particles were evenly distributed or segmentally aggregated on the surfaces of lymphocytes and macrophages incubated with monoclonal antibodies and in vesicles in the cytoplasm of anti DR antibody labeled macrophages.

Transfer of carbonic anhydrase-positive particles from the follicle-associated epithelium to lymphocytes of Peyer's patches in foetal sheep and lambs.

Carbonic anhydrase cytochemistry of the ileal Peyer's patch in foetal and neonatal lambs has indicated secretion from the follicle-associated epithelium to the follicles. Reaction for carbonic anhydrase in the follicle-associated epithelium was found in the luminal plasma membrane, in cytoplasmic vesicles, and in vacuoles containing 50-nm membrane-bounded particles that seemed to be shed to the intercellular space. The lateral plasma membrane was negative for carbonic anhydrase, indicating that formation of carbonic anhydrase-positive particles was restricted to vacuoles.

The immune response of the sheep popliteal lymph node to a purified phenoloxidase from larval cuticle of the sheep ectoparasite, Lucilia cuprina.

The popliteal lymph node of the sheep can mount a strong immune response to a phenoloxidase, enzyme A, purified from larval cuticle of a major sheep ectoparasite, the sheep blowfly, Lucilia cuprina. Continuous sampling from a cannulated efferent lymphatic allowed monitoring of changes in both cellular output (total cells and large blast cells) and specific antibody production (by ELISA) following primary and secondary challenge with antigen. Anti-enzyme A antibodies in lymph selectively precipitated enzyme A but not a second cuticular phenoloxidase, enzyme B, a finding that will prove useful in immunolocalization of the enzymes and in elucidating their origins.