Passive Transfer Of IgG Research Articles

Dimethyl sulphoxide reduces anti-receptor antibody titres in experimental myasthenia gravis.

The basic abnormality in myasthenia gravis (MG) is a reduction of acetylcholine receptors (AChRs) at neuromuscular junctions, due to an autoimmune attack directed against the receptors. Several lines of evidence support the idea that humoral immune mechanisms play an important part in this process: anti-AChR antibodies are present in the sera of more than 80% of myasthenic patients; the pathogenicity of the antibodies has been demonstrated by passive transfer of IgG from myasthenic patients to mice which reproduces the typical features of MG in the recipient animals; finally, procedures that reduce levels of anti-AChR antibody, such as plasmapheresis, produce improvement in the clinical symptoms of MG. Present treatments of MG depend largely on the prolonged use of immunosuppressive drugs, which have significant drawbacks, for they usually produce only a slow fall in antibody titres, and have toxic side effects. An agent that could produce a rapid and sustained fall of autoantibody titre might have wide application in the treatment of MG and other autoimmune diseases. In the course of testing immunosuppressive drugs for their effect in treating experimental autoimmune MG (EAMG), we discovered that the vehicle used to dissolve some of these agents, dimethyl sulphoxide (DMSO), itself produced a rapid and sustained fall of anti-AChR antibody titre. We now report similar results for a controlled trial of DMSO treatment in rats with EAMG.

Kinetics and Specificity of Transfer of Immunoglobulin G and Serum Albumin across Rabbit Yolk Sac in Utero

Abstract The kinetics and specificity of yolk sac transfer of IgG and of serum albumin in vivo, from mother to fetus in the rabbit, were studied by uterine intraluminal administration of 125I-IgG and 125I-serum albumin (125I-RSA). Methodologic and biologic factors were investigated to assess their effects on the quality of experimental transfer data. The observed range in the data could not be ascribed to problems related to temperature or time of experimental manipulation nor to a failure to extract completely labeled protein from fetal tissue. Metabolic degradation of the labeled proteins was also ruled out as a cause for the observed variation in the data. Factors markedly influencing transfer data and requiring correction include: a) the failure to achieve a uniform distribution of administered protein among the fetuses in a horn, when material was injected through the fallopian tube and cervical canal of the uterine horn, and b) differences in the amounts of endogenous protein in the uterine horns of different rabbits and in the horns of a given rabbit. The influence of the first two was minimized by modifying the surgical techniques so that we could study transfer of the separate fetuses. The problems due to the second factor were corrected by use of a “dilution factor.” The transfer reaction of IgG and of serum albumin was shown to follow zero order kinetics. Competition experiments indicated that independent recognition sites on the fetal yolk sac membrane are involved in the transport of each protein. When the observed transfer data were corrected for dilution by endogenous uterine IgG and serum albumin, a preference for the transfer of 125I-RSA over 125I-IgG was seen in most cases. There is no evidence for a mandatory requirement for a carbohydrate moiety for transfer of protein in this model. A generalized hypothesis is presented for the materno-fetal (or neonate) passive transfer of IgG, based on ontogenetic and morphologic similarities of the membranes involved in the transfer.