Influence of Serum from Atopic Children on T Lymphocytes

Abstract

The relative and absolute number of peripheral T cells was found to be depressed in atopic children. Sera from atopic children had slightly less stimulatory effects on lymphocyte DNA synthesis induced by PHA, Con A and PPD, than sera from nonatopic children. This finding indicates an occurrence of inhibitory factor(s) in atopic serum. Sera from some severely ill atopic patients almost completely abolished mitogen-induced lymphocyte DNA synthesis. Inhibition by atopic serum appeared to be an early event in lymphocyte mitogenesis and not due to CRP, IgE or factors binding to mitogens. Lymphocytes from atopic children were no more sensitive to suppressive influences of atopic serum factors than were lymphocytes from adult blood donors. Normal serum enhanced mitogen-induced DNA synthesis more in lymphocytes from adult blood donors than in those from atopic children. The results indicate that, although the T cell defect in atopy may be partly caused by serum factors, occurring during clinical allergic disease, the main reason for the defect is probably an altered reactivity of the T lymphocytes in atopic individuals.

Increased Sensitivity of Lymphocytes from Atopic Individuals to Histamine‐Induced Suppression

“…A suppressor-cell deficiency might thus preferentially result in incrtascd formation of IgE antibodies, with subsequent development of clinical allergy. This hypothesis would be consistent with our previous findings of T-cell defects in atopy (19,20) and also with the results reported in this paper that lymphocytes exposed to histamine develop a pattern of reactivity to T-cell mitogens which is similar to that found in lymphocytes from atopic individuals (19). The difference in response to histamine which was found between lymphocytes from children and adults may help to explain why atopic disease is more common in childhood than in adult life.…”

“…The role of histamine in the elidtation of It would also seem possible that histamine may atopic reactions is weil known. However, the account for the altered T-cell number and possible influence ot histamine on the indue-mitogen reactivity found in atopic individuals tion of the hyperproduction of IgE, which (8,19,20). usually underlies the atopic state, has hitherto…”

Stimulatory and Inhibitory Effects of Cyclic AMP on Lymphocytes from Atopic Children

“…The difference between our results and those of some, other studies cited above may be explained as due to age-dependent differences in lymphocyte sensitivity to cAMP. Evidence of age-relat ed differences in lymphocyte sensitivity to normal, yet undefined serum factors has been obtained in our earlier studies [Strannegârd and Strannegârd, 1977a].…”

Viability of Cultured Peripheral Blood Mononuclear Cells from Atopic Individuals

“…The numbers and mitogen responsiveness of T cells in atopy are decreased [1] and there also ap pears to be a shift in the balance between different subset of T cells at least in cases of severe atopy [2][3][4][5][6][7], Furthermore, the atopic lymphocytes are character ized by an altered response to cyclic AMP-inducing agent manifested as an apparently decreased response to the inducing agents [10] and as a greater sensitivity to the proliferation-inhibiting effect of such agents [8,9]. Some results suggest that atopic lymphocytes have a reduced sensitivity to the proliferation-enhancing effects of normal serum factors [11].…”