Properties of a minor cross-reactive idiotype associated with anti-p-azophenylarsonate antibodies of A/J mice

Experiments are described that further characterize an A/J anti-phenylarsonate (anti-Ar) antibody population, which is idiotypically cross-reactive within the strain but differs from the family of antibodies expressing the major cross-reactive idiotype (CRI). This population has been designated as expressing a "minor" cross-reactive idiotype. Chain recombination studies with hybridoma products (HP) revealed that 2 of 3 HP expressing minor idiotypic determinants contain L chains that are idiotypically closely related to L chains in anti-Ar antibodies bearing the major CRI. The results indicate the expression of the same or very similar L chains in antibodies that differ in idiotype. The minor idiotypic population in serum was investigated by separating antibodies with minor and major idiotypic determinants by use of an immunoadsorbent containing anti-idiotype directed to an HP expressing the major CRI. Studies with the nonadherent, minor idiotypic population showed that such molecules constitute about 8 to 10% of the anti-Ar antibodies in a pool of serum but that individual sera vary markedly in their content of anti-Ar antibodies bearing minor idiotypes. Preinoculation of mice with conventional anti-idiotypic antiserum before immunization with KLH-Ar was found to suppress the appearance of the minor idiotypes as well as the major CRI upon subsequent immunization. The suppression of the minor idiotypic population is presumably mediated by the small fraction of rabbit anti-id antibodies directed against such molecules.

Role and strain distribution of genes controlling light chains needed for the expression of an intrastrain cross-reactive idiotype

Several strains of mice were tested for their capacity to provide immunoglobulin L chains required for the expression of the major cross-reactive idiotype (CRIA) associated with p-azophenylarsonate-specific antibodies of strain A mice. To facilitate testing, mice were bred that were homozygous for Igh-Ce and Lyt-2a, 3a, i.e., they possessed genes controlling H chains but not L chains required for expression of the CRIA. Such male mice were mated to females of various strains and their offspring were tested; expression of CRIA indicated the presence in the female parent of genes controlling the appropriate L chains. All females bearing the Lyt-2a, 3b or Lyt-2b, 3b genotype yielded offspring, most of which were CRIA+, whereas all the offspring of females that were Lyt-2a, 3a were CRIA-. The female parents included mice of several strains that are congenic for Lyt-2a, 3a, Lyt-2b, 3b or Lyt-2a, 3b, thus demonstrating very close linkage between the Lyt loci and the expression of CRIA. In addition, doubly congenic strains of mice with the heavy chain allotype of the CRIA+ AL/N strain and the Lyt-2a, 3a genotype on a BALB/c background failed to express CRIA. The data provide further evidence for the similarity of repertoires of L chains in Lyt-3b mice of various strains. When genes were present controlling A/J H chains and L chains of C57BL/6 or BALB/c origin, the quantitative expression of CRIA was only slightly lower than that observed in A/J mice. Mice possessing genes controlling the H or L chains required for CRIA expression, but not both, did not express CRIA but synthesized Ar-specific antibodies which contained low but significant concentrations of the idiotype-associated chain.

Quantitation of the anticonvulsant cinromide (3-bromo-N-ethylcinnamamide) and its major plasma metabolites by thin-layer chromatography

A quantitative thin-layer chromatography (TLC) procedure is described for the analysis of cinromide (3-bromo-N-ethylcinnamamide) and its two major metabolites, 3-bromocinnamamide and 3-bromocinnamic acid in plasma of the dog. These compounds were recovered from acidified plasma by extraction into benzene with a recovery of 95 +/- 5%. All three compounds were quantitated directly on a TLC plate by ultraviolet absorbance densitometry at 270 nm. The linear dynamic range for the quantitation of the compounds on a TLC plate ranged between 10 and 1000 ng. The complete procedure is useful in the working range of 50 ng/ml to 100 microgram/ml of plasma with a coefficient of variability of about 10%. Specificity of the method for parent drug and each of its plasma metabolites was confirmed by high-performance liquid chromatography. The method was used to determine the pharmacokinetics of cinromide and its two major plasma metabolites in dogs following a single oral dose of the drug.

Antigen- and receptor-driven regulatory mechanisms. III. Induction of delayed type hypersensitivity to azobenzenearsonate with anti-cross-reactive idiotypic antibodies

Delayed-type hypersensitivity (DTH) to p-azobenzenearsonate (ABA) can be induced in A/J mice with intravenous injection of minute amounts of anti-cross-reactive idiotypic (CRI) antibodies, providing that the animals have been pretreated 2 d earlier with low doses of cyclophosphamide (50 mg/kg). However intravenous injection of the F(ab')2 fragments of the anti-CRI antibodies or subcutaneous administration with anti-CRI antibodies induces comparable immunity in both cyclophosphamide-pretreated and normal nontreated animals. Furthermore adoptive transfer experiments indicate that lymph node cells taken from animals sensitized with anti-CRI 4 d earlier can adoptively transfer immunity to naive recipients. Transfer of immunity is mediated by a population of thymus-dependent (T) cells, which express idiotypic structures on their surface. Treatment of effector cells with either anti-theta serum or anti-idiotypic antibodies plus complement completely abrogated their ability to transfer immunity. In addition idiotype-bearing suppressor T cells induced with ABA-coupled spleen cells inhibit the development of ABA-specific DTH induced with anti-CRI antibodies. Genetic analysis revealed that the ability of anti-CRI antibodies to induce ABA-specific DTH was linked to Igh-1 heavy-chain allotype. Anti-idiotypic antibodies to the major CRI associated with anti-ABA antibodies in A/J mice failed to induce significant immunity in BALB/c mice (H-2d, Igh-1a). Nevertheless, they were able to induce significant immunity in C.AL20 mice (H-2d, Igh-1d) which possess a heavy-chain allotype similar to that of A/J mice.

Dominance of an immune response by secondary cells: quantitation by allotype analysis

Dominance of an immune response by secondary cells was demonstrated in a cell transfer system utilizing allotype-congenic mice. Spleen cells from BALB/c mice immunized with TNP-KLH were adoptively transferred into sublethally irradiation (200 R) congenic partners of a different allotype (C.B.-17 mice). Subsequent to the cell transfer, the recipients were challenged with TNP-KLH and bled periodically. Anti-TNP antibodies were isolated and analyzed for their content of donor and host IgG allotypes. Through day 58 after the adoptive transfer, 80% or more of the IgG antibody measured was of donor allotype. By day 110, most but not all recipients made IgG antibody principally of host allotype. In contrast, control C.B-17 recipients, which received nonimmune BALB/c spleen cells but otherwise treated as above, produced IgG antibodies almost entirely of host allotype. Total anti-TNP synthesis was reduced markedly in recipients of immune BALB/c cells so that there was a decrease of about 95% in the production of anti-TNP antibodies of host allotype, as compared with controls that received nonimmune cells. The results are discussed in terms of dominance of an immune response by secondary B cells.

Dominance of an immune response by secondary cells: quantitation by allotype analysis

Dominance of an immune response by secondary cells was demonstrated in a cell transfer system utilizing allotype-congenic mice. Spleen cells from BALB/c mice immunized with TNP-KLH were adoptively transferred into sublethally irradiation (200 R) congenic partners of a different allotype (C.B.-17 mice). Subsequent to the cell transfer, the recipients were challenged with TNP-KLH and bled periodically. Anti-TNP antibodies were isolated and analyzed for their content of donor and host IgG allotypes. Through day 58 after the adoptive transfer, 80% or more of the IgG antibody measured was of donor allotype. By day 110, most but not all recipients made IgG antibody principally of host allotype. In contrast, control C.B-17 recipients, which received nonimmune BALB/c spleen cells but otherwise treated as above, produced IgG antibodies almost entirely of host allotype. Total anti-TNP synthesis was reduced markedly in recipients of immune BALB/c cells so that there was a decrease of about 95% in the production of anti-TNP antibodies of host allotype, as compared with controls that received nonimmune cells. The results are discussed in terms of dominance of an immune response by secondary B cells.

In nature of idiotypes associated with anti-p-azophenylarsonate antibodies in A/J mice

Antiphenylarsonate (anti-Ar) hybridomas were prepared according to Milstein and Köhler with the cell line 45.6TG1.7 and A/J spleen. About 20% of initial wells with anti-Ar activity expressed the major A/J cross-reactive idiotype. Many wells contained anti-Ar antibodies whose binding to Ar-coated plates was strongly inhibited by antiidiotypic (anti-id) antibody but which did not compete effectively with labelled serum antibody for anti-id. Three such hybridoma products (HP) were cloned twice in agar; a 4th was cloned once. All were IgG1K. Each of the four HP, when specifically purified from a BGG-Ar-Sepharose and then radiolabelled, was strongly bound by anti-id. Pooled purified anti-Ar antibodies and anti-Ar antiserum from 9 of 10 mice competed with each HP for anti-id. The serum of the mouse which was non-inhibitory contained normal amounts of the major cross-reactive idiotype. These results demonstrate the presence of cross-reactive anti-Ar idiotypes other than the major idiotype in the A/J strain. Such idiotypes represent a small proportion of the anti-Ar population. Serological analysis of the four HP, which may reflect the serum antibody population, suggest that these "minor" idiotypes may be quite heterogeneous. An HP which did compete with the major cross-reactive idiotype for anti-id failed to compete with three of the four HP described above. This provides support for the concept that the "minor" idiotypes are serologically distinct from the major cross-reactive idiotype.

A phosphorylcholine idiotype related to TEPC 15 in mice infected with Ascaris suum

A serum component, binding antigens having phosphorylcholine (PC) determinants were induced in several strains of mice by infection with Ascaris suum. This component was isolated and demonstrated to be an IgM (K) anti-PC antibody having idiotypic determinants in common with the IgA PC-binding myeloma protein TEPC 15. Rabbit anti-idiotypic antisera prepared with this component had idiotypic specificity for TEPC 15 and cross-idiotypic recognition of MOPC 167 and McPC 603, all IgA PC-binding myeloma proteins. The antisera also recognized determinants not present on TEPC 15. IgM and idiotype levels were quantitated by radial immunodiffusion and PC-specific antibody measured by hemagglutination (HA) with sheep erythrocytes coated with pneumococcal-C-polysaccharide. Mean IgM levels ranged from 2.5 to 8.7 mg/ml, idiotype from 0.54 to 5.3 mg/ml; and HA titers from 1:512 to 1:130,000 in different mouse strains. The high PC-specific antibody response was not duplicated by immunization with dead ascaris larvae or by infection with two other nematode species.

Non-gangrenous ischaemic colitis. A review of 17 cases

Ischaemic lesions of the colon can be divided into gangrenous and non-gangrenous groups.

In this paper 17 patients with non-gangrenous ischaemic colitis are reported; 16 of these occurred spontaneously and 1 followed an anterior resection of the rectum.

The clinical and radiological findings are described.

The lesions varied in extent and severity from a short segment of transient mucosal damage to a long permanent stricture.

An early barium-enema examination is essential for the initial diagnosis. Repeat barium enemas are necessary to ascertain the final outcome. The radiological changes are at least partially reversible and even extensive strictures may show a marked improvement over a period of months.

In this group five lesions were resected but none of the resections was performed during the acute phase. It is concluded that non-gangrenous lesions can usually be managed conservatively. The indications for surgical intervention are discussed.