Anti-alpha-fetoprotein Research Articles

Characteristics of five monoclonal anti-alpha-fetoprotein antibodies.

Five monoclonal anti-alpha-fetoprotein (AFP) antibodies (IgG1) were isolated from six fusions. They were characterized by examining titration values, affinity constants, isotypes, and epitope binding. Employing an epitope-blocking procedure which was based on the exclusion of like antibodies, four of the five monoclonal antibodies were found to be different. Antibody individuality was further demonstrated by comparison of isoelectric focusing patterns. The existence of four distinct anti-AFP antibodies strongly suggests the presence of at least that many epitopes on the AFP molecule.

Effect of anti alphafetoprotein antibody (AAA) on the AFP producing hepatoma: [formula omitted] for the First Department of Surgery, Hokkaido University School of Medicine, N-14, W-5, Sapporo, Japan

Effect of anti alphafetoprotein antibody (AAA) on the AFP producing hepatoma: [formula omitted] for the First Department of Surgery, Hokkaido University School of Medicine, N-14, W-5, Sapporo, Japan

Characteristics of the androgenization produced in mice by neonatal exposure to alpha‐fetoprotein antibodies

Neonatal male and female mice, ages 1-5 days, were injected intracranially with either anti-alpha-fetoprotein (AFP) IgG, steroids, or various control solutions. The mice were autopsied 60-70 days later and the spleen, thymus, liver and gonads were examined by light microscopy. The antibody to AFP produced a gonadal response which was sexual specific. Histological examination of the tissue sections from female mice treated with either anti-AFP IgG or steroids revealed the presence of polyfollicular ovaries lacking in corpora lutea formation. A comparable antibody-induced specific effect on the testes could not be demonstrated; however, steroidal administration induced aspermatogenesis and delayed maturation in parallel studies. In the anti-AFP IgG-treated groups, there appeared a gross neurological lesion which was termed external hydrocephaly. The physiologic responses in the female gonad were found independent of the presence of this anatomical brain lesion, whereas those in the male gonad were found causally related. The immunological specificity of the gonadal response was demonstrated by the use of IgG devoid of anti-AFP IgG and by various IgG control solutions. Thus, exposure to anti-AFP IgG during the critical period of sexual development in the brain appears to mimic steroidal androgenization of the female mouse.

Biosynthesis of alpha-fetoprotein in cultured hepatoma cells.

Pulse and pulse-chase experiments demonstrated that a heterogeneous polypeptide with an apparent Mr = 68,000 was the first intracellular anti-alpha-fetoprotein (AFP)-precipitable polypeptide synthesized by rat Mc-A-RH-7777 hepatoma cells. The 68,000-dalton polypeptide may consist of polypeptides with apparent molecular weights ranging from 68,000 to 70,000. It was the precursor of two intracellular anti-AFP-precipitable polypeptides of 69,000 and 73,000 apparent molecular weight. The latter were secreted into the medium without further processing. The anti-AFP-precipitable polypeptides in both cells and medium incorporated [3H]glucosamine, indicating that these polypeptides are at least partially glycosylated. The 68,000-dalton polypeptide in cells was bound mostly to concanavalin A-Sepharose, whereas the 69,000-dalton polypeptide was entirely unbound. The 73,000-dalton polypeptide consisted of concanavalin A-bound and -unbound variants. Tunicamycin completely abolished the uptake of [3H]glucosamine into anti-AFT-precipitable polypeptides in both cells and medium, and the resulting polypeptide of apparent Mr = 66,000 did not bind to concanavalin A-Sepharose. Tunicamycin did not affect the synthesis or secretion of AFP by hepatoma cells.

Immunoradioautographic study of alpha-fetoprotein in hepatoma cells.

Trypsin treatment, which is frequently used in the field of immunocytochemistry to faciliate conjugated antibody penetration through the cell membrane, was applied for the immunoradiographic demonstration of alpha-fetoprotein in ascites hepatoma cells using 125I-labeled anti rat alpha-fetoprotein antibody. No significant number of silver grains were detectable in the group without trypsin treatment, while numerous silver grains were recognizable in the ascites hepatoma cells after trypsin treatment. This indicates that trypsin treatment is effective for the immunoradiographic demonstration of alpha-fetoprotein and contributes to the quantitative immunoradioautographic investigation.