Acceleration of intradermal catabolism of guinea pig IgG1 and IgG2 antibodies by challenge with antigen.

The intradermal catabolism of antibodies injected in guinea pigs to provoke skin reactions was studied using 125I-labeled guinea pig IgG1 and IgG2 anti-ovalbumin antibodies. Disappearance of both the IgG1 and IgG2 antibodies from injected sites was accelerated by intravenous injection of the antigen. The antigen-antibody complexes produced in vitro were also catabolized more rapidly than free antibodies, when estimated using 125I-labeled antibodies. On the other hand, the catabolism of normal IgG2 was not influenced by local anaphylactic reaction elicited by IgG1 antiovalbumin antibody coexisting at the sites. Therefore, the enhanced catabolism of antibodies on challenge was not caused by increased vascular permeability due to anaphylactic reactions, but by more rapid elimination of immune complexes formed at the sites. The Fc parts of IgG1 and IgG2 antibodies played an essential role in the enhancement of catabolism since the catabolism of the F(ab')2 fragments was not accelerated by complex formation with ovalbumin, but rather reduced.     

Drug-induced antinuclear antibodies in the guinea pig

Antinuclear antibodies (ANA) development was studied in male guinea pigs in response to chronic treatment with procainamide, hydralazine, acetanilide or caffeine. Acetanilide and caffeine have not previously been associated with ANA induction. Fifty-one weanling Hartley guinea pigs were divided into five groups which received either procainamide, hydralazine, acetanilide, caffeine or saline sc for 55 weeks; drug dosage was 10 mg/kg initially and was increased incrementally to 40 mg/kg by 10 months except for hydralazine, which was increased to 20 mg/kg. Two weeks before initiation of treatment, 1 mg of the appropriate drug in 0.4 ml of buffered Freund's complete adjuvant (FCA-PBS) was administered intradermally. Controls received FCA-PBS only. Sera ANA were assayed at 6, 10 and 13 months. After 13 months of treatment, those sera which were ANA positive were assayed for anti-deoxyribunucleoprotein antibodies and were titered for ANA. Chi-square analyses were performed on results of the 10- and 13-month ANA screening results. ANA induction was significant at P = 0.05 only for the group receiving procainamide at both 10 and 13 months of treatment. When the cumulative results of all ANA screens were analyzed, ANA induction was significant for procainamide, acetanilide and caffeine. The test system did not prove to be promising for unambiguous identification of drugs with ANA-inducing potential, but may be useful for studies of mechanisms of ANA induction by chemicals.     

Usefulness of IgG4 subclass antibodies for diagnosis of human clonorchiasis

The present study analyzed serum IgG subclass antibody reaction to major antigenic bands of Clonorchis sinensis to investigate improvement of its serodiagnosis. Of the four subclass antibodies, IgG1 and IgG2 antibodies were produced but not specific, IgG3 antibody was least produced, and IgG4 antibody was prominent and specific. The serum IgG antibody reaction to any of 43-50, 34-37, 26-28, and 8 kDa bands was found in 65.5% of 168 egg positive cases while IgG4 antibody reaction was found in 22.0% of them. The positive rates of IgG and IgG4 antibodies were directly correlated with the intensity of infection. All of the sera from heavily infected cases over EPG 5,000 showed positive reaction for specific IgG and IgG4 antibodies. The specific serum IgG4 antibody disappeared within 6 months after treatment. The bands of 35 kDa and 67 kDa cross-reacted with IgG antibodies but not with IgG4 antibodies in sera of other trematode infections. The present findings suggest that serum IgG4 antibody reaction to 8 kDa band is specific but not sensitive. Any method to increase its sensitivity is required for improved serodiagnosis.     

A more sensitive enzyme immunoassay of anti-insulin IgG in guinea pig serum with less non-specific binding of normal guinea pig IgG

An enzyme immunoassay of anti-insulin IgG in guinea pig serum was improved in sensitivity by reducing the non-specific binding of normal guinea pig IgG and enhancing the specific binding of anti-insulin IgG. Silicone rubber pieces or polystyrene balls were coated with normal rabbit IgG, followed by coupling of insulin using glutaraldehyde. The insulin-normal rabbit IgG-coated silicone rubber pieces or polystyrene balls were incubated with normal rabbit IgG and then with diluted guinea pig anti-insulin serum in the presence of normal rabbit IgG at a lower temperature (20 degrees C). Finally, the solid phases were incubated with rabbit (anti-guinea pig IgG) Fab'-horseradish peroxidase conjugate to measure the amount of guinea pig IgG bound. The detection limit of anti-insulin IgG in guinea pig serum was improved 10 to 100-fold compared to that of enzyme immunoassay performed by incubating insulin-bovine serum albumin-coated solid phases with diluted guinea pig anti-insulin serum at 37 degrees C and then with rabbit (anti-guinea pig IgG) Fab' conjugated to beta-D-galactosidase from Escherichia coli, according to a previous report (Kato, K., et al. (1978) J. Biochem. 84, 93-102).     

Development of a guinea pig colony free of complement-fixing antibodies to parainfluenza virus.

Complement-fixing antibodies to parainfluenza 3 virus were found in Hartley strain [Cds: (HA)] guinea pigs from the authors' production colony. The prevalence and distribution of these antibodies were determined by testing guinea pigs of five age categories: 4 weeks, 8 weeks, 12 weeks, 6 months to 1 year, and over 1 year of age. Forty-seven percent (28 of 60) were positive to parainfluenza 3 antigen. Positive reactors were found in all age groups except those 8 weeks old. The 12-week-old group had the highest titers; the group over 1 year of age had the highest percentage of positives (92%). When 8-week-old guinea pigs were isolated, 55% were positive at some time between 8 and 34 weeks of age. The titers characteristically rose rapidly and then dropped slowly to low or undetectable levels. Four pairs of breeders over 6 months of age (most of whom were positive for parainfluenza 3 virus antibodies and, therefore, presumed to be immune to the virus) were isolated and allowed to breed. Their offspring were found to be free of complement-fixing antibodies to parainfluenza 3 virus.     

A newly described activity of guinea pig IgG1 antibodies: transfer of cutaneous basophil reactions.

Hapten-specific delayed time course skin reactions containing predominant accumulations of basophils and eosinophils were elicited in newborn guinea pigs after i.v. transfer of small amounts of oxazolone immune serum. The immune serum was fractionated by column chromatography procedures, and the fractions were examined for their ability in transferring this form of cutaneous basophil hypersensitivity (CBH). Only the 7S IgG-containing peak from Sephadex G-200 columns, and only the IgG1-containing fractions from DEAE columns, transferred CBH. An affinity column of bound oxazolone removed the activity from immune serum, and it could be recovered from the column by eluting with soluble oxazolone. About 35 microgram of purified IgG1 anti-oxazolone antibody could systemically transfer CBH reactivity. An immunoadsorbant column of anti-IgG1 removed this activity, but a column of anti-IgG2 did not. None of the procedures were able to separate activity in transferring CBH from passive cutaneous anaphylactic (PCA) activity classically associated with guinea pig IgG1 antibody. IgG1 from 8-day immune and 31-day hyperimmune donors were both effective. The average association constant of 8-day antibody was 8 X 10(-4) M-1. Transfer of cutaneous basophil reactions can be mediated by low affinity serum 7S IgG1 antibody.     

Membrane receptor mobility changes by sendai virus

Treatment with Sendai virus does affect the lateral mobility of cell surface components on cultured human cells (KB) and cultured mouse cells (3T3). Diffusion coefficients and mobile fractions of a fluorescent lipid analog, tetramethyl rhodamine-succinyl concanavalin A (ConA) and tetramethyl rhodamine-anti human β₂ microglobulin antibodies on the cell surface were measured by fluorescence photobleaching recovery (FPR). Diffusion coefficients of receptors for ConA and for antibodies to β₂ microglobulin (presumably histocompatibility antigens) were increased 2- to 3-fold by exposure to the ultraviolet inactivated virus at virus doses from 250 to 2 500 HAU/ml, regardless of whether the particular cells measured had been fused. No mobility enhancement was induced with trypsinized Sendai virus, nor by influenza virus, indicating a probable requirement for the Sendai virus F protein. Virus treatment reduced the diffusion coefficient of a lipid analog in 3T3 cells. The results are compatible with the hypothesis that the Sendai virus disrupts a mobility restraint system, perhaps cytoskeleton-membrane connections.     

Further studies on the biologic properties of guinea pig IgG1 antibodies. II. In vivo activation of C3 by anti-glomerular basement membrane antibodies.

Normal rats were injected with guinea pig anti-rat glomerular basement membrane antibodies of the IgG1 or IgG2 class or with their F (ab') 2 fragments, in order to study which antibody site triggers the alternate complement pathway in vivo. Both IgG classes were able to induce a heavy proteinuria and led to C3 deposition in the glomeruli in a pattern similar to their own distribution along the glomerular basement membrane, as shown by the immunofluorescence technique. The Fab(ab')2 fragment of IgG2 did not produce C3 binding or proteinuria. The F(ab')2 fragment of IgG1 was difficult to obtain devoid of Fc determinants. A F(ab')2 fragment of IgG1 still bearing Fc determinants led to C3 binding and proteinuria, whereas the true F(ab')2 fragment of IgG1 had none of these effects in two out of three animals.