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M W Fanger

Publications and source records attributed to M W Fanger.

At least 127 records · Page 7Linked to original sources
PubMed1976

Complement receptor lymphocytes in the rabbit. II. The effect of immunization on the complement receptor lymphocyte population in the craining lymph node.

In an attempt to determine the effect of immunization on the size and nature of the complement receptor lymphocyte (CRL) and surface immunoglobulin (SIg)-bearing lymphocyte (B cell) populations, rabbits were injected with 1 mg alum-precipitated keyhole limpet hemocyanin and the cells of the draining popliteal lymph nodes were examined at various intervals for these populations. Comparison to unimmunized control lymph nodes revealed that immunization resulted in an approximate doubling of the percentages of both CRL and B cell populations by the peak of the response, while the cell number increased about 7-to 8-fold. Kinetic analysis of the response indicated that the percentages of CRL and B cells increased essentially in parallel beginning within 40 h after immunization. Simultaneous assay of complement receptor (CR) and SIg disclosed that CRL remained a B cell subpopulation throughout the response. To determine whether cell division could account for the increases in total cell number and per cent CRL and B cells, immunized rabbits were given 3H-thymidine in vivo, and the fraction of labeled (dividing) cells was determined by autoradiography. Results of such experiments were consistent with the possibility that the early increase in cell number and the increase in CRL and B cell percentages were a result of trapping and/or homing of lymphocytes migrating from the peripheral blood. A significant amount of lymphocyte division occurred during later stages of the response.

Animals↗
PubMed1976

Complement receptor lymphocytes in the rabbit I. an SIg-negative subpopulation in the appendix.

Complement receptor lymphocytes (CRL) were detected in various rabbit lymphoid tissues by the ability of these CRL to form rosettes with sheep red blood cells coated sequentially with rabbit antiserum directed against sheep red blood cell stroma and horse serum as a nonhemolytic source of complement (EAC). The rosette assay was shown to be specific for complement receptor (CR) activity and the EAC capable of detecting both C3b and C3d specific receptors. With lymphocyte preparations containing less than 5% phagocytic cells, the average per cent CRL in the various tissues studied was as follows: thymus 1%, popliteal lymph node 18%, spleen 30%, appendix 35%, and peripheral blood 45%. Double assays in which the lymphocytes were prestained with an FITC-labeled Fab fragment of a goat anti-rabbit Fab antibody before rosetting indicated that CRL were a subpopulation of surface immunoglobulin (SIg)-bearing lymphocytes in popliteal lymph node, spleen, and peripheral blood. In the appendix, however, in addition to finding SIg+ CR+ and SIg+ CR- populations, an SIg- CR+ population was consistently found. Double assays employing FITC-labeled goat antibodies specific for mu, alpha, and gamma determinants were also performed to determine if there was any relationship between the class of Ig displayed and presence of CR. It appeared that an approximately equivalent percentage of both IgM- and IgG-bearing cells also displayed CR. Experiments in which appendix cells were treated with Pronase to remove SIg and CR and the cells cultured in vitro to allow regeneration of surface markers confirmed the existence of SIg+CR+, SIg+CR-, and SIg-CR+ lymphocyte subpopulations. Whether the SIg-CR+, population represents a developing B cell population which will eventually also express SIg or whether it belongs to the T or "null" cell populations is unclear at present.

Animals↗
PubMed1975

Studies on the human T lymphocyte population. III. Synthesis and release of the lymphocyte receptor for sheep red blood cells by stimulated human T lymphoblasts.

The IgG fraction of a goat antibody specific for human T lymphocytes (ATG) and that of a rabbit antibody directed (anti-Ts) were used to study the synthesis, display, and release of the receptor for SRBC (Ts) by normal human peripheral lymphocytes. A large percentage of lymphoblasts obtained by stimulation of lymphocytes with PHA or PWM formed multilayered rosettes with SRBC. The vast majority of these rosetting lymphoblasts were T lymphocyte derived, whereas few B lymphoblasts formed rosettes. Significant increases were found in the quantity of Ts on the lymphoblast membrane and in the supernatants from PHA-stimulated cultures, especially late in transformation. Furthermore, lymphocytes cultured with PHA and 3H-leucine synthesized and released radiolabeled Ts.

Animals↗
PubMed1972

The oligosaccharide units of rabbit immunoglobulin G. Multiple carbohydrate attachment sites.

The carbohydrate structure of rabbit immunoglobulin G isolated from pooled sera was investigated. Amino sugar analysis of fragments of the molecule allowed three oligosaccharides to be located at separate sites on the H-chain. The corresponding glycopeptides were isolated. The average composition of the C1-oligosaccharide was 2 glucosamine, 1 mannose and 2 galactose residues. It appeared to be present in approx. 15% of the H-chains; the carbohydrate was coupled through the amide group of asparagine in a peptide containing asparagine, glycine and threonine within the Fd fragment of the molecule. The average composition of the C2-oligosaccharide was 1 galactosamine, 1 galactose and either 1 or 2 sialic acid residues. It was present on approx. 40% of the H-chains and was attached glycosidically to the OH group of threonine in a peptide Ser-Lys-Pro-Thr-Cys-Pro-Pro-Glu-Leu in the hinge region of the molecule. The average composition of the C3-oligosaccharide was 5 glucosamine, 2 galactose, 5 mannose, 1 fucose and 1 sialic acid residue. It appeared to be present in all the H-chains and was linked through the amide group of asparagine in a peptide Gln-Gln-Phe-Asn-Ser-Thr-Ile-Arg within the Fc fragment of the molecule.

Amino Acid Sequence↗
PubMed1972

The oligosaccharide units of rabbit immunoglobulin G. Asymmetric attachment of C2-oligosaccharide.

Two populations of immunoglobulin G (IgG) molecules were isolated from pooled rabbit serum. The first was almost devoid of galactosamine and was obtained in a yield of 7% of the total IgG; the second contained on average a single residue of galactosamine per molecule and was obtained in a yield of 30% of the total IgG. The galactosamine, which is present solely in the C2-oligosaccharide, appeared to be present on one H-chain and not the other in the four-chain structure. Evidence was obtained by the isolation of a glycopeptide linked through a disulphide bridge to a second peptide of the same sequence; the oligosaccharide attached to the first peptide was absent from the complementary peptide. Further evidence was obtained by degradation and analysis of the 5S IgG fragment, which comprises an intact half-molecule coupled through a disulphide bridge to the Fc fragment derived from the opposing half molecule (Goodman, 1965); only the intact H-chain carried the C2-oligosaccharide.

Amino Acid Sequence↗