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Biomedical subjects

L S Rodkey

Publications and source records attributed to L S Rodkey.

At least 55 records · Page 3Linked to original sources
PubMed1979

Clonal dominance of low-affinity antibodies in rabbit hyperimmune anti-streptococcal group A-variant polysaccharide antisera.

Intraveneous hyperimmunization of selectively bred rabbits with streptococcal group A-variant vaccines elicits antibody responses of restricted heterogeneity at high antibody levels. In these antisera, IgG with dissociation constants Kd = 10(-6) M constitutes 90% and IgG with Kp = 10(-9) M accounts for only 10% of the group A-variant polysaccharide-specific antibodies. The low affinity antibody fraction represents the dominant clonotypes. Preparative isoelectric focusing in granulated (Ultrodex G-75) gels was used to successfully purify single-band material belonging to dominant spectrotypes. Affinity studies with these antibody fractions with the highest reported degree of purity yielded Kd = 10(-6) M values, thus confirming that clonal dominance is exclusively associated with low-affinity antibodies. Since it is known from previous work (M. Cramer and D. G. Braun, Scand. J. Immunol. 1975. 4:63) and from the rabbit antisera used here that clonal dominance of this sort is long-lived, this work fails to support the argument of immune maturation. The data more logically relate to antibodies that emerge with different subspecificities -- recognized in the antigen as a function of time in immunization procedures -- rather than to an inherent property of the immune system.

Animals↗
PubMed1979

Rabbit allotype a locus subspecificities of homogeneous anti-streptococcal antibodies.

Rabbits were immunized with group A-variant (Av) streptococcal vaccine to elicit antisera containing antibodies of "restricted heterogeneity" specific for Av polysaccharide. Antibodies that migrated as single bands in polyacrylamide gel isoelectric focusing were isolated on agarose block electrophoresis and preparative isoelectric focusing. These homogeneous antibodies were analyzed for content of the a locus markers by inhibition of allotype-anti-allotype radioimmunoassays. Both single-band preparations and preparations containing 2--5 bands were deficient in content of the a locus markers. These analyses were strongly influenced by the different anti-allotype antisera used. Single-band preparations, deficient in a 2 or a 3 markers, were further used to produce anti-allotype antisera, and these sera were assayed for reaction with pooled a2 or a3 molecules. The results, in contrast to the a1 allotype, failed to demonstrate common determinants on either a 2 or a 3 molecules indicating that each a allotype consists of a set of different Ig molecules. The data suggest different evolutionary pathways of the a 1, as opposed to the a 2 and a 3 molecules.

Alleles↗
PubMed1978

Morphologic evaluation of IgM cells of the canine small intestine by fluorescence microscopy.

Biopsies of small intestine from 7 dogs were examined by fluorescence microscopy to determine the number of IgM-containing cells in the lamina propria. Biopsies were taken from duodenum, jejunum, and ileium. (Cell counts were made by 2 persons to demonstrate reproducibility.) There were 452.24 +/- 60.09 cells per mm2 in the duodenum 572.68 +/- 62.13 cells per mm2 in the jejunum, and 107.47 +/- 59.57 cells per mm2 in the ileum. All sections were cut at 6 micrometer. The ileum had fewer cells than either duodenum or jejunum (P = 0.000038 and 0.00001, respectively), whereas duodenum and jejunum did not differ significantly in numbers of cells (P = 0.17528). Quantifying autofluorescent cells in the same sites showed no significant differences among the 3 tissues (P = 0.24697). The autofluorescent cells differed in intensity and morphology from the IgM cells. These two observations tend to support the contention that the autofluorescent cells did not bias the IgM cell counts at the 3 sites. Total autofluorescence (cells, collagen, and vessels) was higher in the ileum than in either the jejunum or the duodenum (P = 0.04967 and 0.03050, respectively). However, all 3 categories counted (IgM cells, autofluorescent cells, and autofluorescent structures) had significant dog-tissue interactions. This will necessitate determining normals for each age-sex-breed category of dog studied.

Animals↗
PubMed1977

Quantitation of cytoplasmic tubulin by radioimmunoassay.

A radioimmunoassay has been developed for the quantitation of crytoplasmic tubulin. It measures tubulin between 20 and 1500 nanograms and does so independently of decay in colchicine-binding activity. In addition, the state of tubulin as subunit or polymer does not alter the measurement.

Animals↗
PubMed1976

A method for preparing IgG F(ab')2 fragments using small amounts of serum.

An alternative method devised to isolate functionally active antibody F(ab')2 fragments required fewer manipulations and used less serum than do methods generally used. The method involved pepsin digestion of the whole globulin fraction precipitated from as little as 3 ml of serum. Chromatographic separation of the digest on Sephadex G-150 yielded two distinct peaks: Peak I consisted of lipoprotein and showed no immunoglobulin determinants; Peak II, as established by immunodiffusion analysis, contained immunoglobulin F(ab')2 fragments. Radioimmunoassays performed on Peak II protein to determine the presence of allotypic markers revealed less than 10% contamination by non-immunoglobulin protein; coprecipitation tests, used to characterize Peak II further, also showed less than 10% contamination by non-immunoglobulin protein. Recovery of total serum IgG F(ab')2 was 90% or greater using this technique, compared with a potential 20-25% recovery using standard isolation procedures.

Animals↗
PubMed1976

Studies of idiotypic antibodies: reactions of isologous and autologous anti-idiotypic antibodies with the same antibody preparations.

Outbred rabbits were immunized with keyhole limpet hemocyanin diazotized to p-aminophenyl-N-trimethylammonium chloride (TMA). Anti-TMA antibodies were specifically purified and the F(ab')2 fragments were isolated after pepsin digestion. Glutaraldehyde-polymerized anti-TMA F(ab')2 fragments were reinjected back into the same animal that synthesized the antibodies to elicit an autologous anti-idiotypic (AAI) antiserum and were also injected into an allotypically matched recipient to elicit isologous anti-idiotypic (IAI) antiserum. AAI and IAI antisera reactive with the same F(ab')2 preparation were compared by assaying the populations of anti-TMA molecules reactive with each antiserum. The assays showed that the AAI antiserum reacted with smaller populations of molecules than did the IAI antiserum. The population of molecules recognized by the AAI antiserum was contained within the larger population recognized by the IAI antiserum. Hapten inhibition studies showed that the differences in the populations of molecules recognized by each antiserum were not related to the hapten-binding properties of the idiotypic antibodies: in one case both AAI and IAI reactions were equally inhibited by hapten; in another, the AAI reaction was inhibited more than was the IAI; in another, the IAI reaction was inhibited more.

Animals↗
PubMed1975

Antigenic comparison of swine influenza virus isolates.

Cross hemagglutination inhibition (HI) and neuraminidase inhibition (NI) tests demonstrated strong antigenic relationship between A/Swine/Wisconsin/1/73 (SW/73) and A/Swine/Shope/15/31 (SW/31) influenza viruses. An eigthyone fold purification of virus was achieved by adsorption and elution followed by differential ultracentrifugation and sedimentation through linear sucrose gradient. Radioimmunoassay using purified 125I labeled viral antigens revealed antigenic variation between the two virus isolates. Neuraminidase of both viruses had pH optima between 6.5 and 7.0, and SW/31 enzyme was relatively more heat stable than SW/73.

Antigens, Viral↗
PubMed1974

Studies of idiotypic antibodies. Production and characterization of autoantiidiotypic antisera.

Rabbits were immunized with a hapten-protein conjugate and sera were collected for 189 days. The antihapten antibodies were purified by affinity chromatography, then the same animal that synthesized the antibody was reinjected with polymerized F(ab')(2) fragments of antihapten antibodies. Sera were collected after autoimmunization and tested by an indirect radioimmunoassay technique for reaction with [(125)I]F(ab')(2) fragments of the original antihapten antibody. Results showed that each individual responded to its own F(ab')(2) and the antisera were specific for antihapten antibodies of that individual. Quantitative allotype assays established the immunoglobulin nature of the labeled test antigen. Inhibition assays showed that the reaction was specifically inhibitable with hapten. The relationship of this system with other idiotypic systems and the possible autoimmune implications of autoantiidiotypic antibodies are discussed.

Animals↗