Difference in thymus dependency between effector and suppressor T cells for delayed footpad reaction to sheep erythrocytes in mice

Generation of Listeria monocytogenes-specific T cells mediating delayed footpad reaction and protection in neonatally thymectomized mice but not in nude mice

Neonatally thymectomized (NTx) mice, sham-operated control mice and congenitally athymic nude mice were immunized with viable Listeria monocytogenes and their spleen cells examined for the capacity to transfer both delayed footpad reaction and protection against challenge at the site of local transfer. Cells from immune NTx mice conferred significant degrees of delayed footpad reaction and protection comparable to sham mice, while cells from immune nude (nu/nu) mice did not. This ability was completely eliminated by the treatment of cells with anti-Thy1, anti-Lyt1 or anti-L3T4 antibody plus complement but not with anti-Lyt2 antibody plus complement. These results indicated that NTx mice can normally mount the immunity to L. monocytogenes by generating Lyt1+2-, L3T4+ T cells. Immune competence of NTx mice and thymus dependency of various immune responses are discussed.

The role of cytostasis in antitumor immunity: comparison between syngeneic and allogeneic systems

Different aspects of the immune response differ with respect to sensitivity of neonatal thymectomy (NTx). The effect of thymectomy on Days 1 and 7 after birth (NTx-1, NTx-7) on antitumor immune responses to both a syngeneic and an allogeneic tumor graft was examined. The tumor used was the same, Meth A fibrosarcoma of BALB/c origin, but the mice inoculated differed. The results show that the immune response to a syngeneic tumor graft is primarily cytostatic rather than cytolytic and is relatively insensitive to neonatal thymectomy, while the response to a large dose of allogeneic tumor cells includes a cytolytic mechanism of high thymus dependence.

Development of immunity against Listeria monocytogenes in athymic nude versus neonatally thymectomized mice

The thymus requirement for the development of immunological responsiveness was determined by estimation of immune responses raised to Listeria monocytogenes in athymic nude, neonatally thymectomized, and sham-operated mice at 6 weeks of age. Not only sham-operated mice, but also neonatally thymectomized mice could completely eliminate the bacteria from the spleen and liver, while athymic nude mice could not eliminate them and showed a persistent form of infection. A strong delayed footpad reaction and acquired cellular resistance could be raised in neonatally thymectomized mice just as well as in sham-operated mice, but not in athymic nude mice. The delayed footpad reaction could be induced in neonatally thymectomized mice without an accompanying ability to inhibit macrophage migration. These results suggest that T cells responsible for immunity against listerial infection require the presence of the thymus for only a very short period in their development.

Transfer of delayed hypersensitivity in the chicken

Delayed hypersensitivity (DH) can be transferred in FP and SC chickens with 1 x 10(8) spleen or peripheral blood cells from donors exhibiting moderate to strong DH reactions. Increasing the spleen cells dose from 1 to 4 x 10(8) per recipient had no marked enhancing effect on the results. Spleen cells from agammaglobulinemic donors were also shown to transfer DH reactions.