Severe Suppression of the B‐cell System has No Impact on the Maturation of Natural Killer Cells in Mice

Abstract

Mice were treated with a heterologous anti-IgM serum to obtain B-cell-deprived mice. Spleen cells from normal and B-cell-deprived mice were tested in three different cytolytic systems: natural killer cells (NK); antibody-dependent cell-mediated cytolysis (ADCC) against an NK-sensitive tumour, P815; and ADCC against chicken erythrocytes. The impact of administration of an interferon-inducing NK enhancing agent, Tilorone, was also investigated. Whereas the cell population from B-cell-deprived mice was significantly suppressed in antibody-producing cells, the capacity to function in NK or ADCC was largely unimpaired both before and after administration of Tilorone. Our results would imply that mature B cells play no significant role in either the maturation of the NK cells or the expression of their cytolytic ability. Furthermore, effector cells for both NK and ADCC against antibody-coated tumour target cells were found to be distinct from those functioning in ADCC against chicken erythrocytes.

Natural killing of tumor cells by human peripheral blood cells. Suppression of killing in vitro by tumor-promoting phorbol diesters.

“…NK cells lack the features of mature T cells, B cells, or macrophages (1, 2, 4), though a portion of human NK cells binds weakly to sheep erythrocytes, suggesting an association with T cells (5). Most NK cells in human peripheral blood bear Fc receptors, but natural killing is not primarily dependent on antibody nor on the Fc receptor (6)(7)(8).…”

Plasmodium falciparum parasites induce interferon production in human peripheral blood ‘null’ cells in vitro

“…The cytotoxic activity of the fractionated cells was determined using a 4 h 51Cr-release assay with K562 erythroleukaemia cells as labelled targets and varying effector/target ratios with two-fold dilutions (Gidlund et al 1979 The cytotoxic activity of the various fractions was expressed as lytic units which were calculated by multiplying the inverted extrapolated effector/target cell ratio that gave 30% specific lysis with 100 (Kalden et al 1977). pH 2 treatment and sensitivity to inactivation by anti-IFN-a as shown in Table 2.…”

Natural Antitumor Resistance in Immune-Deficient Mice

“…Firstly, as indicated in the previous section, a high incidence o f 'sponta neous' lymphomas appears in nude mice treated with anti-p.-antibodies. in spite of high levels of NK activity in those animals, which are either not affected [10] or even increased [4] by the anti-ju-treatment. It is also possible that the pinworm model of lymphoma induc tion in nude mice [2,3] is also accompanied by high NK levels.…”

“…One may con clude that the age-dependent resistance to polyoma oncogenesis which appears in nude mice can be abrogated by anti-ju and CY treat ment, suggesting a main but not exclusive B cell component. Anti-/x treatment has been shown either as not affecting [10] or actually augmenting NK activity [4] in mice. Our own findings showed no major difference in NK or NC [36] activity in spleens of anti-ju-treated animals, whether nu/nu.…”