The development of specific antibody-containing cells in the spleen of rabbits during the secondary immune response against free or liposome-associated albumin antigen.

In order to study the distribution pattern of specific antibody-containing cells in the spleen of rabbits during the secondary immune response, rabbits were given two intravenous injections of either free or liposome-associated human serum albumin (HSA) within an interval of 2 months. Demonstration of specific antibody-containing cells was performed by incubation of sections of spleen with HSA-horseradish peroxidase (HRP) conjugates, followed by peroxidase cytochemistry. Specific anti-HSA antibody-containing cells were detected already within 2 days after booster and peak numbers were found 4 days after booster. The bulk of these cells localized in the coaxial lymphocyte sheaths surrounding the terminal arterioles in the spleen. Specific antibody-containing cells were also found in the follicles. Using a double immunoenzyme technique we demonstrated that a majority of the specific antibody-containing cells produced immunoglobulin G(IgG) antibodies. From the results, it is also concluded that, after a priming injection with liposome-associated HSA, liposomes do not further enhance the secondary immune response, when they are also used for the booster injection.