ABSTRACT
Leucine enkephalin (Leu-enk) was coupled to both T and B cell antibodies in order to investigate the possibility of enhanced immunogenicity via targeted immunization. The two antibodies used were Hm x Mo CD3 and Gt x Mo Ig, respectively. The data indicate that while both antibody carriers enhanced the immunogenicity of Leu-enk, the use of the Hm x Mo CD3 antibody resulted in a greater number of mice with positive Leu-enk specific serum titers. 12 Leu-enk cell lines were produced and one, LE4H8, was chosen for characterization.
Subject(s)
Antibodies, Anti-Idiotypic/metabolism , CD3 Complex/immunology , Enkephalin, Leucine/immunology , Enkephalin, Leucine/metabolism , Amino Acid Sequence , Animals , Antibodies, Anti-Idiotypic/blood , Antibodies, Anti-Idiotypic/immunology , Antibody Affinity , B-Lymphocytes/drug effects , B-Lymphocytes/immunology , CD3 Complex/metabolism , Epitopes/analysis , Female , Kinetics , Mice , Mice, Inbred A , Mice, Inbred BALB C , Mice, Nude , Molecular Sequence Data , Stimulation, Chemical , T-Lymphocytes, Helper-Inducer/drug effects , T-Lymphocytes, Helper-Inducer/immunologyABSTRACT
Big Pod Ceanothus (Ceanothus megacarpus) is an obligate seeder after fire; Laurel Sumac (Rhus laurina) is primarily a resprouter after fire. Both species commonly occur together in mixed stands and are dominant members of the coastal chaparral of southern California. We compared the mean survival of post-fire seedlings of each species during the first summer drought after fire and found C. megacarpus to have a mean survival of 54% while R. laurina had a mean survival of only 0.1%. Rooting dephs were similar between species but predawn water potentials and leaf temperatures were higher for R. laurina seedlings. Leaf temperatures for R. laurina reached a mean value of 46.8° C on hot, summer days, about 5° C higher than seedlings of C. megacarpus. By the end of the first growing season, 92% of all C. megacarpus seedlings had suffered herbivory compared to only 17% of all R. laurina seedlings. Herbivory did not appear to be the immediate cause of seedling mortality. Transect data indicated that full recovery of prefire species composition and density at our study site was likely but the mode of recovery was different for the species examined. R. laurina recovered primarily by sprouting, C. megacarpus totally by seedling establishment and a third species, Adenostoma fasciculatum (chamise), by a combination of sprouting and seedling establishment. We attribute the higher mortality of R. laurina seedlings to the greater sensitivity of its tissue to water stress. It may be that differential survival of shrub seedlings and differential modes of reestablishment after fire play an important role in maintaining species diversity in the chaparral communities of coastal, southern California.
ABSTRACT
Plasma levels of alpha 1-PI(T) and alpha 1-PI(E), two closely related murine alpha 1-protease inhibitors, having affinities for trypsin and elastase, respectively, were compared to changes in specific liver mRNA levels after induction of the acute-phase reaction by subcutaneous injection of turpentine. In earlier, qualitative experiments an increase in plasma levels of alpha 1-PI(E), but not alpha 1-PI(T), during the acute-phase reaction had been shown. It is now shown that stimulation of plasma alpha 1-PI(E) levels reaches a maximum of 35-50% above baseline 12 h after induction of the acute-phase response using either a functional or immunological assay to measure protease inhibitor activity. Consistent with earlier observations, little or no change in plasma levels of alpha 1-PI(T) is seen. Determination of mRNA levels in the mouse liver specific for alpha 1-PI(E) and alpha 1-PI(T) was accomplished using a cell-free translation system followed by immunoprecipitation of the 35S-labeled protease inhibitors. The apparent Mr's of alpha 1-PI(E) and alpha 1-PI(T) synthesized in vitro are 42K and 46K, respectively. Apparent Mr's of the native proteins in plasma are 55K and 65K. Unexpectedly, mRNA levels for both alpha 1-PI(E) and alpha 1-PI(T) were found to increase after induction of the acute-phase reaction. Maximal stimulation for both mRNAs was approximately 300% and occurred 9 h after turpentine administration. Under these conditions, levels of translatable albumin mRNA in the mouse liver decreased to 40% of baseline in 6-9 h.
