The Immune Systems of Mice Reared in Clean and in Dirty Conventional Laboratory Farms. III. Ability of Old Mice to Be Sensitized to Undergo a Secondary Antibody Response

Antibody-Forming Potential of Lymph Nodes in Aged Mice, with Special Reference to the Influence of Adjuvant

“…Thus, our findings (7, 9, 10, 18) do not directly contradict those obtained by Makinodan et al (34)(35)(36), since the secondary antibody-forming potential of aged mice with long life expectancy may differ from that of aged mice with short longevity. Possibly, the reduced secondary IPFC response in the spleens of aged mice, as found by Makinodan et al (36) in comparison with that of young mice, is due to the absence of germinal centers. With respect to that, it is possible 'that in the absence of germinal centers the rate of growth in the number of memory cells may be sharply reduced' (36).…”

“…In contrast to the severe atrophy of the spleen of non-antigen-stimulated aged mice as well as after primary immunization (3,7), an impressive restitution of the follicular structure with the development of distinct germinal centers was observed after boostering (18). These data are not in full accordance with those of Makinodan et al (36). Using BC3F1 mice these authors found in young animals a secondary IPFC response that was 4 times higher than their primary 1PFC response.…”

“…Possibly, the reduced secondary IPFC response in the spleens of aged mice, as found by Makinodan et al (36) in comparison with that of young mice, is due to the absence of germinal centers. With respect to that, it is possible 'that in the absence of germinal centers the rate of growth in the number of memory cells may be sharply reduced' (36).…”

“…Nevertheless, the second ary IPFC response of young mice was about 6 times higher than that of old mice. On the basis of their observations that conventionally reared old mice on the one hand lack germinal centers but, on the other hand, can be sensitized to (36) that follicular antigen localization followed by the increased proliferative activity of germinal centers is not a prerequisite for the formation of memory cells. Such discrepancies are possibly due to the different experimental condi tions used.…”

“…Thus, there are short-lived and long-lived mouse strains (19), whereby the life expectancy of individual mice within a given strain is evidently dependent on several factors, such as housing conditions and sex differences (19,27,38). Whilst Makinodan et al (36) utilized long-living BC3F1 hybrid mice with a mean life span of 30 to 32 months (4), our studies were constantly done with the NMRl/Han mouse strain, which represents a comparatively short-lived strain. The mean life span of conventionally reared NMRl/Han mice amounts to 19.86 months (38).…”