Mc. Fornari et al., GROWTH-HORMONE INHIBITS NORMAL B-CELL DIFFERENTIATION AND NEUTROPHILSCHEMOTAXIS IN-VITRO, International journal of immunopharmacology, 16(8), 1994, pp. 667-673
In acromegalic patients we have previously described a low ability of
B-lymphocytes to differentiate into plasma cells under PWM stimulation
, and a decreased chemotaxis of polymorphonuclear leukocytes (PMN) tow
ards N-formylmethionylphenilalanine (FMP). In this study we examined t
he effect of exogenous GH over these immune functions in normal cells.
PMN were purified by dextran sedimentation, incubated with recombinan
t human GH (0 to 20 ng/ml) and subjected to stimulation with FMP. PBMC
were cultured with or without PWM, in the presence of GH (between 0 a
nd 100 ng/ml). Plasma cells were determined as hemolysis plaque formin
g cells and also by immunofluorescence. GH, in a dose-dependent way, d
ecreased directed migration of PMN (5 ng/ml: 1.787 +/- 148 mu m; 10 ng
/ml: 1.581 +/- 221 mu m; 20 ng/ml: 1.569 +/- 149 mu m, all as mean +/-
S.E.M.), when compared to similar values of untreated PMN (0 ng/ml 2.
085 +/- 139 mu m). GH treatment did not modify spontaneous migration.
Net migration showed the same pattern as directed migration. GH decrea
sed dose-dependently the PWM-driven differentiation of B-lymphocytes i
nto plasma cells to 60% of the basal level. Although not significantly
, GH tended to increase spontaneous B-cell differentiation. These resu
lts could account for the already described defect in B-cell different
iation and PWN chemotaxis in acromegaly, emphasizing the relationship
between the endocrine and immune systems.