Protection from experimental autoimmune thyroiditis conferred by a monoclonal antibody to T cell receptor from a cytotoxic hybridoma specific for thyroglobulin.

A clonotypic mAb, AG7, has been prepared from splenocytes of CBA/J mice immunized with a cytotoxic T cell hybridoma, HTC2, specific for a pathogenic epitope of the thyroglobulin molecule in association with class I MHC Ag. AG7 binds to HTC2 cells but not to the other T cell hybridomas tested. Moreover, when used in functional studies, AG7 blocks the HTC2 capacity of specific target lysis.

Bordetella pertussis adenylate cyclase. Purification, characterization, and radioimmunoassay.

The extracellular adenylate cyclase of Bordetella pertussis was purified either as a free enzyme or as a complex with calmodulin. The purified enzyme has a specific activity of 1600 mumol of cAMP min-1 X mg-1 and exists under two molecular forms of 45 and 43 kDa which are apparently structurally related. Calmodulin increased considerably the resistance of adenylate cyclase to inactivation by trypsin.

Differentiation antigens of human hemopoietic cells: patterns of reactivity of two monoclonal antibodies.

Two mouse anti-human monoclonal antibodies (S3.13 and S5.7) raised against cells of acute myelogenous leukemia were found to react with antigens expressed on the surface of subsets of monocytes and lymphocytes.

Structural correlates to the rabbit immunoglobulin heavy chain a100 allotype.

Three a100/a100 homozygous rabbits immunized with Micrococcus lysodeikticus produced large amounts of anti-polysaccharide antibodies of restricted heterogeneity. These antibodies were purified by either immunoabsorption or ion exchange chromatography. The almost complete sequence of one heavy chain spanning residues 1-123, with the exception of 10 residues (66-67 and 79-86), was determined.

Control of isotype expression by helper T-cell clones and suppressor cells.

We report here experiments demonstrating the profound influence of T lymphocytes on isotype expression by B lymphocytes. It was shown that in a secondary in vitro response, T helper cells from primed spleen predominantly induced an IgG1 plaque-forming cell (PFC) response, while T helper cells from primed lymph node induced IgG1, IgG2a and IgG2b PFC responses. Under the same experimental conditions, T helper cell clones were able to induce IgG1, IgG2a and IgG2b responses; therefore, T helper cells are not involved in controlling preferential isotype expression.

Isotype regulation of antibody production: T-cell hybrids can be selectively induced to produce IgG1 and IgG2 subclass-specific suppressive immunoglobulin-binding factors.

T2D4, a T-cell hybrid, spontaneously secretes suppressive immunoglobulin factor(s); when incubated with purified monoclonal mouse immunoglobulins, this hybrid produces high levels of immunoglobulin-binding factors specific for the subclass of the inducing immunoglobulin. Thus, we were able to induce the production of IgG1- or IgG2-specific inhibitory factors by the same T2D4 T-cell hybrid. These subclass-specific suppressive factors bind selectively to the IgG1 or IgG2 subclasses and inhibit specifically the secretion of antibodies of the corresponding subclass.

Organization of the diversity--joining region in rabbit immunoglobulin heavy chains as revealed by cleavage of a specific methionine residue in a100 allotype.

Three anti-micrococcus antibodies of restricted heterogeneity have been isolated from the antisera of homozygous a100/a100 rabbits. Heavy chains contained an unusual methionine residue at position 87 that may correlate with the a100 specificity. From this position, the sequence of a stretch of 35-50 amino acid residues was determined, permitting the definition of variable (V), diversity(D), and joining (J) segments in rabbit Ig heavy chains, with their most probable boundaries.

Allotypy of rabbit immunoglobulins: a fifth allele at the a locus.

Studies in wild rabbits (Oryctolagus cuniculus) allowed the detection of a fifth allele (a101) at the a locus of rabbit immunoglobulins. The structures responsible for the A101 allotypic specificity have been found on both IgG and IgM. Their location is on the Fab fragment, on the H chain.

A and b allotypy in Oryctolagus and Lepus species.

It had been previously shown by the description in wild rabbits Oryctolagus cuniculus of unknown allotypic specificities belonging to the a series and the b series, that the genetic polymorphism found in domestic rabbits was only a part of the genetic polymorphism of the species O. cuniculus. To the known a1, a2 and a3 allotypic specificities have been added in the last years a100 and a101 which are under the control of allelic genes at the a locus.

Cross-reaction of a minor variant of the a1 allotypic specificity with anti-a2 antibodies.

Certain samples of hare IgG can combine with cross-linked anti-a2 antisera prepared in the a3/a3 rabbit. This cross-reaction permitted the isolation, on hare IgG immunoadsorbent, of anti-a2 cross-reacting antibodies (anti-a2(Lv) antibodies). The binding of labeled rabbit a2 IgG to insolubilized anti-a2(Lv) antibodies is inhibited by a1 IgG, demonstrating a cross-reactivity with a2.

[Phylogeny of the e allotypic system of rabbit immunoglobulins: study of determinants recognized on ochotona IgG by anti-e15 antisera].

The phylogenetic studies of Cgamma allotypes already made in the Leporidae was extended to another family of lagomorphs, the Ochotonidae. The d allotypic system is only found in rabbits; thus, it appeared late in the lagomorphs evolution. The e system has two alleles (e14 and e15, present in rabbits and in another Leporidae genus (Sylvilagus).

Allotypes of the a series and their variants in rabbit immunoglobulins.

Six allotypic specificities of the a series are found on rabbit immunoglobulins: a1, a2 and a3 are found both in domestic and wild rabbits Oryctolagus cuniculus; a100, a101 and a102 seem to be present only in wild rabbits. Each of these specificities is a family of variants always present together in a given serum. These variants can be studied through the cross-reactivities detected between the patterns of the a series.

Study of A100 allotypic specificity of rabbit immunoglobulins: the cross-reactivity between A100, a1 and a3.

Evidence for the genetic determination of A100 allotypic specificity suggests that it is the product of an allele at the alpha locus. The A100 allotypic specificity was detected in a wild rabbit lacking all the known specificities of the a series. None of the 8 rabbits possessing the A100 allotypic specificity possessed two allotypic specificities of the a series.

[Classification of 29 Hodgkin's disease patients as a function of the concentration of 22 serum antigens].

A method of numerical classification has been applied to the study of the concentrations of 22 serum antigens in 29 patients with Hodgkin's disease. This group of patients can be split into at least two subgroups. The two subgroups greatly differ by the severity of the clinical symptoms of the disease.