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At least 19 recordsLinked to original sources
PubMed1975

Preparation of monospecific antiserums against porcine immunoglobulins, using agarose-linked immunosorbents.

Immunoglobulins IgG, IgA, and IgM were isolated from porcine serum and milk, and antiserums against the 3 immunoglobulin classes were prepared. Monospecificity of the antiserums for the gamma-, alpha-, and mu-chains was obtained by absorbing them in agarose-linked immunosorbent columns. These immunosorbents were prepared by linking IgG or IgA-IgM to CNBr-activated agarose. Contaminating anti-alpha2-macroglobulin antibodies in the anti-IgA and anti-IgM serums were removed with agarose-linked fetal globulins.

Absorption↗
PubMed1978

Human lymphoid cells of the intestinal mucosa showing specificity for both immunoglobulin light and heavy chains.

The presence of single human lymphoid cells expressing on the one hand both kappa and lambda light chain and on the other hand either both mu and alpha or both mu and gamma heavy chains, was observed in the intestinal mucosa. The variability of the frequency of such cells, both from one subject to another, or in the same sample, is a characteristic of this population.

Humans↗
PubMed1976

Isolation and preliminary characterization of two varieties of low molecular weight immunoglobulin in the bullfrog, Rana catesbeiana.

Two varieties of low m.w. immunoglobulins have been isolated from the serum of Rana catesbeiana frogs. They are highly cross-reactive, although each also contains unique antigenic determinants. Since both low m.w. immunoglobulins were identified in the serum of 22 individual frogs, it was concluded that they are isotypic variants. The light chains of R. catesbeiana and mammalian high and low m.w. immunoglobulins are similar in electrophoretic mobility on polyacrylamide gels containing sodium dodecyl sulfate. The heavy chains of fropg high m.w. immunoglobulins have the mobility of mammalian mu-chains; the heavy chains of both variants of frog low m.w. immunoglobulins migrate between mammalian mu- and gamma-chains in approximately the position of mammalian alpha-chains. An unusual structural feature of the R. catesbeiana high ald low m.w. immunoglobulins is that the unreduced proteins are partially dissociated in sodium dodecyl sulfate.

Animals↗
PubMed1977

Alpha-beta thalassaemia.

In a Greek Cypriot family in which genes for both alpha and beta thalassaemias were expressed, haematological and biosynthetic investigations indicated that one family member was homozygous for beta thalassaemia and had alpha-thalassaemia1 trait. The concurrent inheritance of an alpha-thalassaemia gene in the beta-thalassaemia homozygote seemed to have modified his degree of chain imbalance and to have reduced the clinical severity of the disease.

Adult↗
PubMed1976

[28 cases of malabsorption syndromes with villopathy].

A personal series of 28 cases of malabsorption with villopathy (22 Gee, 1 Whipple, 1 alpha-chain, 1 hypogammaglobulinaemia, 3 not yet diagnosed) is presented. The response to a gluten-free diet is the essential clue to diagnosis. Where sensitivity is not found, diagnosis becomes difficult and requires careful immunological, histopathological and parasitological investigation, which is not always conclusive. The main features of the series are indicated, along with the criteria employed in the diagnosis of some unusual forms.

Adolescent↗
PubMed1977

Selective proteolysis of the J chain component in human polymeric immunoglobulin.

To clarify the losses that have been observed in the J chain portion of human IgM and IgA, were carried out studies on the enzymatic susceptibility of the J polypeptide. When Waldenström macroglobulins and myeloma IgA polymers were subjected to limited proteolysis with various endopeptidases, only subtilisin was found to attack the J chain component. The pattern of cleavage was a function of the polymer species. The J chain in IgM was highly susceptible to digestion, quantitative cleavage being achieved at very low enzyme to IgM ratios and without significant changes in the remaining pentamer structure. Analyses of the digestion products showed that the initial cleavage occurred at an exposed region midway in the J sequence and was followed by extensive degradation of the carboxy-terminal segment. These findings indicated that the observed loss of the IgM J component can be explained by the inadvertent introduction of subtilisin in vitro or by the attack of in vivo enzymes with a specificity similar to subtilisin. In contrast, the IgA J chain was found to be much more resistant to subtilisin proteolysis; its cleavage required higher enzyme concentrations and was accompanied by significant degradation of the alpha-chains. Thus, it appears unlikely that the IgA J polypeptide is degraded by either in vitro or in vivo enzymes unless its accessibility is first enhanced by changes in the IgA Fc structure.

Amino Acid Sequence↗
PubMed1978

Evidence of acquired immune deficiencies in Mediterranean lymphoma. A possible aetiological link.

Patients with Mediterranean lymphoma (M.L.) had a significant reduction in humoral immunity (IgG and IgM) as well as impaired cellular immunity (50% were anergic to three antigens--P.P.D., mumps, and dinitrochlorobenzene). Any hypothesis for the pathogenesis of M.L. has to account for the peculiar geographic distribution of the disease, the age and sex incidence, the plasma-cell nature of the tumours, the associated heavy plasmacytic proliferation with relatively intact intestinal mucosa, involvement of the proximal small intestine, and alpha-chain production in a large proportion of patients. All areas in which M.L. is common are currently involved in the seventh cholera pandemic. Vibrio cholerae toxin inhibits both immediate and delayed immune reaction in vitro through its effect on cyclic adenosine monophosphate. V. cholerae antigens stimulate the proliferation of IgA-producing immunocytes in the mucosa without deeply penetrating the mucosa. The proximal small bowel is usually affected by the disease but there is little epithelial damage. The population in endemic areas is continuously exposed to V. cholerae antigens and toxins. It is suggested that such exposure, under certain genetic or other circumstances, may produce a state of immunosuppression in the gut thus accelerating, predisposing to, or producing lymphoplasmacytic neoplasia.

Antigens, Bacterial↗
PubMed1975

Immunogenic properties of modified antigen E. III. Effect of repeated injections of modified antigen on immunocompetent cells specific for native antigen.

It has been shown that ragweed antigen E loses its major antigenic determinants after denaturation in 8 M urea, but urea-denatured (UD) antigen and an alpha-polypeptide chain isolated from the denatured molecules are capable of priming mouse T cells specific for native antigen. Weekly injections of 10mug UD antigen or alpha-chain into antigen E-primed animals depressed the ongoing IgE antibody response, whereas injections of the same dose of antigen E failed to depress the antibody response. It was found by adoptive transfer experiments that helper activity of antigen E-primed splenic T cells was depressed by the treatment of the donors with either modified antigen or native antigen E. The same treatment of antigen E-primed animals depressed the DNA synthetic response of their splenic T cells to antigen E. The treatment of antigen E-primed animals with UD antigen resulted in a decrease of antigen E-specific IgE-B cells and IgG-B cells in their spleen, whereas the treatment with native antigen expanded the B cell populations. In view of the results obtained in the mouse, cellular basis for the immunologic effects of hyposensitization treatment is discussed.

Animals↗
PubMed2026

Distinct HLA Associations for Antibody Multireactivity With Citrulline-Containing Type II Collagen Epitopes Versus More Limited Antibody Reactivity With Citrulline-Containing IgG Epitopes in Rheumatoid Arthritis.

OBJECTIVE: Anticitrullinated protein antibodies (ACPAs) in rheumatoid arthritis (RA) can be promiscuous, with cross-reactive binding to many antigens containing short motifs, or private with little cross-reactivity. Also, ACPA reactivity patterns differ among patients with RA, including for motif-containing epitopes in important self-antigens like collagen and IgG (bound by RA-associated rheumatoid factors [RFs]), with limited understanding of the underlying mechanism. The objective of this study was to determine if HLA alleles associate with ACPA reactivity patterns. METHODS: For 100 ACPA+RF+ participants with RA, serum IgG binding was quantified by enzyme-linked immunosorbent assay to 10 citrulline-containing peptides derived from Type II collagen and IgG1 (nine with motifs), and HLA loci were genotyped. Also, antibody and serum multireactivity were evaluated. HLA alleles present differentially in RA participants with high versus low IgG binding to specific peptides, as well as with multireactivity versus limited reactivity were identified by Fisher's exact test. RESULTS: Serum IgG multireactivity for citrulline-glycine motif-containing collagen peptides was high, at least partially due to promiscuous antibodies. HLA-DQA1*01:02 was present in more participants with anticitrullinated collagen antibodies and multireactive sera. In contrast, serum multireactivity was low for IgG1-derived peptides due at least in part to more private antibodies. Shared epitope-containing HLA-DRB1*04:01 was present more frequently in participants with RA-associated RFs irrespective of the citrulline-serine motif and less frequently in participants with anticitrullinated collagen antibodies. Several HLA alleles associated with specific antibody reactivities. CONCLUSION: Different HLA alleles may contribute to the different reactivity patterns of promiscuous anticitrullinated collagen antibodies and more private RA-associated RFs.

Humans↗
PubMed1978

Serologic and structural comparisons of rabbit IgA allotypes.

Serologic and structural comparisons of the rabbit IgA-g allotypes revealed that 1) the IgA-g allotypes have multiple allotypic determinant sites, 2) the g74, g76 and g77 allotypic specificities have several allotypic determinants in common whereas g75 molecules do not appear to have allotypic determinants in common with g74, g76 and g77 molecules, 3) the partial amino acid sequence of alpha chain from g75 and g76 Fc2alpha fragments differ by at least one amino acid residue, and 4) the g74 alpha-chains may have the "extra" intradomain disulfide bond in the Calpha2 domain whereas the g75 and g76 alpha chains lack this disulfide bond. Thus, multiple mutational events must have occurred during the evolution of g74, g75 and g77 genes.

Amino Acid Sequence↗