The secondary antibody response in tissue culture. I. Observations on prolonged antibody synthesis by lymph node fragments in media of different composition

Lymph node fragments obtained from rabbits immunized 4–9 months previously were cultured in Eagle's medium supplemented with normal rabbit serum or with serine. Upon secondary stimulation with the specific antigen (rat albumin) in vitro, antibody production which lasted over 4 weeks was observed. A difference in the course of antibody synthesis was established in the two different media. In the presence of normal rabbit serum, peak titers of antibody were reached 7–13 days after secondary stimulation, while, in the presence of serine, highest titers were observed on days 13–19. Furthermore, antibody titers diminished faster in the normal rabbit serum cultures as compared to those in the serine cultures. If hydrocortisone was added to culture media containing serine, antibody production by the lymph node fragments followed a pattern similar to that for cultures containing normal rabbit serum. The possible significance of these findings is discussed.

The electrophoretic composition of guinea pig serum: effects of heat inactivation, decomplementation, and aging

The proteins of normal guinea pig serum have been characterized by several electrophoretic methods, and the effects of aging, decomplementation, and heat inactivation investigated. Storage at 4 °C for 2 weeks, decomplementation with a specific antigen–antibody precipitate, and heating at 56 °C for 30 minutes resulted in a loss of 64, 92, and 100%, respectively, of hemolytic complement activity. Moving-boundary analyses demonstrated an apparent increase of γ-globulin in the decomplemented serums. Heat inactivation caused the disappearance of the α1-globulin fraction concomitant with pronounced apparent decreases in the albumin and β-globulin fractions and a conspicuous increase in the α2-globulin area.Filter paper electrophoresis revealed an apparent increase in the α2-globulins and a decline in the γ-globulin fraction in decomplemented serums. In heated serums the concentration of the albumin and γ-globulin fractions apparently decreased and levels of the α2- and β-globulins were elevated. Twenty-one bands were observed in normal guinea pig serum by the starch gel technique. Decomplementation resulted in the loss of 1 band, and heat inactivation caused an alteration in 11. Four precipitin arcs, termed α0, β2-I, β1-IV, and β1-X, were affected in the immunoelectropherograms when complement activity was altered. Aging elicited the appearance of a new precipitin arc, β1-X, and a decrease in the mobility of β1-IV. A decrease in the mobility of the β1-IV arc was observed in decomplemented serums. Heating caused the disappearance of two precipitin lines, α0 and β1-V, an increase in the electrophoretic mobility of β1-I, and a decrease in the rate of migration of the β1-IV arc.

Antibody Synthesizing Cells: Appearance after Secondary Antigenic Stimulation in vitro

Suspensions of spleen cells from rabbits immunized with sheep erythrocytes can be stimulated to produce antibody-synthesizing cells in vitro. The cellular response is antigen specific.

THE METABOLISM OF ANTIGEN IN VIVO: II. AZOPROTEIN

Experiments were carried out to detect precipitating or non-precipitating antigenic fragments in the serum or spleen of rabbits given a single intravenous injection of arsanil azo – human gamma-globulin. The results, using a number of different methods for the detection of antibody (double diffusion, immunoelectrophoresis, inhibition of hemagglutination by serum fractions obtained by elution of paper electropherograms of the antiserum), failed to provide any evidence for the presence of antigenic fragments either in the circulation or in the spleen of the experimental animal.

THE METABOLISM OF ANTIGENS IN VIVO: I. PROTEIN ANTIGENS

Attempts were made to detect antigenic fragments in the sera or spleens of rabbits given a single intravenous injection of bovine serum albumin, human gamma-globulin, or human serum albumin. The results obtained, using a number of different methods for the detection of antibody–antigen interaction (double diffusion in gel, immunoelectrophoresis, inhibition of hemagglutination), failed to provide any evidence in favor of the presence of antigenic fragments either in the circulation or in the spleen of the experimental animal.