Formation of lymph follicles and germinal centers in draining lymph nodes after local injection of phytohemagglutinin and lipopolysaccharide in mice.

Histological observations on rat popliteal lymph nodes after blockage of their afferent lymphatics.

“…In a previous study, we presented evidence suggesting that the lymph follicles provide sites for germinal center development (HosHI et al, 1984a). Our observations further indicated that the lymph follicle itself is a reactive structure which develops in the superficial cortex in response to certain substances carried into the node via the afferent lymphatics; these may include some antigens and non-antigenic agents.…”

Patterns of age‐dependent changes in the numbers of lymph follicles and germinal centres in somatic and mesenteric lymph nodes in growing C57Bl/6 mice

“…These antigens then stimulate germinal centre development in the existing primary follicles, on the one hand, and induce the formation of new lymph follicles, on the other, resulting in a continuous increase in the number of follicles until a plateau is reached at around 56 d of age. In connection with this observation, we previously found that when administered subcutaneously, both killed and living Escherichia coli, as well as their derivatives, such as lipopolysaccharide (Boivin type) and lipid A, were very efficient in inducing the development of new lymph follicles with or without germinal centres outside pre-existing follicles in the draining lymph nodes (Hoshi et al 1984Aijima et al 1994). Once the number of follicles per node reaches a plateau, the ileocaecal node may maintain this level until it comes into contact with new types of effective antigens.…”

“…(Primary) lymph follicles develop ' spontaneously ' within the peripheral lymphoid organs during their ontogeny, and this event is thought to be antigen-independent, whereas the development of germinal centres within lymph follicles is an antigendependent phenomenon. It is known that, if properly stimulated by exogenous antigens, lymph nodes produce new lymph follicles (with or without germinal centres) outside the existing ones, resulting in an increase in the number of follicles per node (Sjo$ vall & Sjo$ vall, 1930 ;Conway, 1937 ;Hoshi et al 1984Hoshi et al , 1986Hoshi et al , 1989Horie et al 1999). The lymph nodes have been classified into 2 groups : the somatic lymph nodes, which drain the skin and underlying musculature, and the visceral lymph nodes, which drain mainly the thoracic, abdominal and pelvic organs (Tilney, 1971).…”

Reconstruction of lymph follicles in the mouse popliteal lymph node after X-irradiation damage.

“…A previous study from this laboratory indicates that the primary follicle itself is a reactive structure whose develop- The number of lymph follicles per whole popliteal lymph node in ddY mice at different intervals after 1,000 R of lower half body X-irradiation ment is induced by the factor(s) carried in the lymph node via the afferent lymphatic vessels (Hoshi et al 1984). Providing that sublethal to lethal doses of X-irradiation completely destroy the majority of lymph follicles in the node, only few follicles that escape complete destruction may reappear in the node unless new lymph follicles are formed.…”