Group formation of female pigtail macaques (Macaca nemestrina).

Human epidemiological studies have suggested that social variables can modulate the effects of stress on the immune system, and this concept has been gaining increasing attention with positive results emerging from empirical studies using nonhuman primates over the last two decades. Results from a previous study in rhesus monkeys suggested that receiving grooming positively affected recovery of T-helper and T-suppressor cells following the initial stress associated with group formation, and this co-varied with high dominance rank. Thus, the present study was undertaken in order to determine: (1) if the stress effect of formation could be replicated in another species and (2) if social behaviors or dominance rank, given that formation is a stressor, might independently correlate with physiological recovery from the stressor.

Absence of CSF-1 in macrophage-deficient op/op mice has differential effects on macrophage colony stimulating activity (M-CSA) released by various organs and cells.

The absence of detectable levels of CSF-1 in op/op mice results in a marked deficiency of macrophage colony-stimulating activity (M-CSA) in both the unstimulated and postendotoxin sera of these animals. These deficiences are not secondary to the presence of an inhibitor of macrophage formation. In contrast, various organs, particularly the organs of endotoxin-treated op/op mice, released amounts of M-CSA comparable to those of normal mice.

CSF-1 deficiency in the op/op mouse has differential effects on macrophage populations and differentiation stages.

Osteopetrosis and the absence of colony-stimulating factor 1 (CSF-1) in op/op mice are associated with decreased cellularity of the bone marrow (to one tenth of the normal), a very significant reduction in the number of cells recovered from peritoneal, pleural, and alveolar lavages, moderate leukopenia, and a slight decrease in the number of cells per spleen and thymus. Furthermore, op/op mice possess deficiencies in the number of macrophages in various organs. These cells are apparently absent in the bone marrow, severely reduced (5%-15% of the normal number) in peritoneal and pleural cavities and in the lungs.

Removal from natal social group to peer housing affects cortisol levels and absolute numbers of T cell subsets in juvenile rhesus monkeys.

Psychosocial stress associated with the removal of six naive juvenile rhesus monkeys from their natal social group to peer housing resulted in increased basal cortisol secretion and significant decrements in the absolute numbers of the T lymphocyte subsets in the peripheral blood. Six subjects matched for age and social rank remained in the group of 80 animals serving as controls. Baseline immune and cortisol measurements were obtained before the six test subjects were removed from the group and housed together in an outdoor circular enclosure.

Social separation and reunion affects immune system in juvenile rhesus monkeys.

Removal of juvenile rhesus monkeys from their natal social group to indoor individual caging resulted in increased basal cortisol secretion and significant decrements in the frequency of lymphoid subpopulations. Fourteen juvenile rhesus monkeys, which had never been removed from the group, were studied. Baseline immune and cortisol measurements were obtained before seven of the subjects were removed from social housing to standard individual cages.