Immunoregulatory cells in aging mice. I. Concanavalin A-induced and naturally occurring suppressor cells

The status of concanavalin A (Con A)-triggered suppressor cells in aging mice was assessed in relation to untreated cells. Spleen cells of (C3H/ebJ X C57BL/6J)F1 and (BALB/cJ X C57BL/6J)F1 aging (20-41 months' old) and young (2-3 months' old) mice were triggered with Con A and examined for their capacity to suppress lymphocyte proliferative responses elicited by mitogens (Con A and phytohemagglutinin), by mixed lymphocyte reactions or by human gamma-globulin. Con A-triggered cells of the aging mice were found to be less efficient suppressors than those of the young, yet the aging mouse spleen cells exerted a more potent suppressive effect than the young, a priori, without pretreatment. Hence, the immune system in aging is characterized by a change in suppressor cell types; the Con A-triggered suppressors diminish and the naturally occurring, untreated ones become abundant.

Immune reactivity during ageing. III. Removal of peanut-agglutinin binding cells from ageing mouse spleen cells leads to increased reactivity to mitogens

Spleen cells from ageing (24--30-month-old) mice, manifesting low response to concanavalin A (Con A) and phytohemagglutinin (PHA), were separated by peanut agglutinin (PNA) into agglutinable (PNA+) and unagglutinable (PNA-) fractions. The PNA+ cells were found to suppress the response of young (2--3-month-old) mouse spleen cells to the mitogens Con A and PHA. On the other hand, PNA- cells of the ageing mice expressed a response to these mitogens, at levels higher than those of the unseparated cells. Re-mixing of the PNA- and PNA+ cells of the ageing mouse spleens at various proportions indicated that the PNA- cells are indeed suppressible by the PNA+ cells. Anti Thy-1.2 treatment to the PNA+ fraction suggested that this suppression was not exerted by T cells. It thus appears that at least part of the reduced lymphoid cell function in ageing is related to an effect of suppressor cells, interfering with the expression of available reactive cells.

Acquired cyclic esotropia in an adult

A 67-year-old women developed periodic alternate-day esotropia, documented with videotape, 16-mm film, and quantitative eye-movement recordings, after retinal detachment surgery. The eye movements suggested that central reprocessing and adaptation to a peripheral defect was in part responsible for this adult form of acquired cyclic esotropia.

Decidual extracts suppress antibody response in vitro

Extracts of decidual tissue produced in pseudopregnant rats were found to suppress in vitro antibody response to alpha-2,4-dinitrophenyl-polylysine. The peak levels of both the total antibody response and the 2-mercaptoethanol-resistant fraction were reduced. Extracts prepared in a similar manner from uteri of normal untreated or pseudopregnant rats did not exert such an effect.