Adjuvant Effect of Endotoxin on Primary Antibody Formation in Irradiated Rats

Abstract

Adult rats were irradiated (750 R) and were given sheep red blood cells (SRBC), with or without 100 µg E. coli·26 endotoxin, between 1 to 29 days after irradiation. Serum haemolysin titers, plaque forming cell (PFC) counts and relative spleen weights were determined 5 days after SRBC administration. During the 1st week after irradiation endotoxin treatment induced a mild decrease in PFC. From the 10th day on endotoxin resulted in a comparatively earlier regeneration of the antibody forming capacity. By the end of the 1st month the antibody response to SRBC returned to normal levels in the endotoxin + SRBC treated group, while irradiated animals remained impaired. Anti-SRBC PFC and anti-E. coli·26 antibody producing cells showed close parallelism. These results suggest that the antigenic property of endotoxin may play a role in its adjuvant action.

Nomenclature and Significance of Innate/Natural Immune Mechanisms and of Species Specific Resistance

“…RD-LPS adjuvant also increased innate immunity in the vaccinated animals that lasts up to 1-3 weeks. Therefore, it will provide protection prior to the induction of adaptive immunity [45,49,50].…”

“…This is related to the immunoadjuvant effect of LPS/RD-LPS [47]. Ionizing radiation does not affect the stimulation of the lymphoid system by LPS [50,51]. A vaccine was produced against human influenza virus [49].…”

Stimulation of Nonspecific Resistance by Radiation-Detoxified Endotoxin

“…It has been demonstrated that lOO,150,and 200 kGy) can regenerate the immune functions in sublethally irradiated rats. The relative spleen weight, the PFC (direct and indirect) count, and the serum hemolysin level are elevated 21 days after irradiation (Elekes et al, 1978). In the regeneration of the immune system, both T and B lymphocytes are necessary.…”