Induction of resistance or enhancement to a transplantable murine plasmacytoma by transfer of non-immune leucocytes

Abstract

Newborn mice have a lower spontaneous resistance to the growth of a syngeneic plasmacytoma (MOPC-460) as compared to adult mice. The transfer of different leucocyte populations from non-immunized adult donors to newborn mice influence in a dual way the resistance to MOPC-460 growth, depending on the number of cells transferred. The transfer of a low number of neutrophils, thymus or spleen cells enhances the MOPC-460 takes. Higher numbers of neutrophils, thymus or bone marrow cells induce an effective protenction. By contrast, macrophages over a dose of 1 X 10(4) constantly produce a reduction of tumour growth.

Immunostimulation of the Lymphodependent Phase of Neoplastic Growth

“…This acceleration has actually been observed by Giovarelli et al (64) and may explain the potentiation of chemical oncogenesis sometimes seen in partially immunocrippled or young animals (65). With increasing numbers of lymphocytes, i.e., the normal situation, the stimulation should give way to increasing inhibition and the incidence curve should again decline to the baseline and, perhaps, beyond (64). Therefore, the difference in oncogenic susceptibility might be difficult to detect between a nude mouse with little lymphocytic infiltrate and a normally reactive animal in which stimulation and inhibition of a primary untransplanted lesion might be nearly at the balance point.…”

“…Under these conditions tumor growth will be poor (48,63); however, a small increase in the number of lymphocytes would produce accelerated tumor growth. This acceleration has actually been observed by Giovarelli et al (64) and may explain the potentiation of chemical oncogenesis sometimes seen in partially immunocrippled or young animals (65). With increasing numbers of lymphocytes, i.e., the normal situation, the stimulation should give way to increasing inhibition and the incidence curve should again decline to the baseline and, perhaps, beyond (64).…”

Inhibition by Lymph Node Cells and Promotion by Fetal Hepatocytes of Murine Tumours without or with Chemotherapy

“…The effective cell dose corresponds also to the one used in experiments in which newborn mice were protected against a plasmocytoma by injection of non-immune cells [8],…”

“…A comparable phenome non. however, might find its expression in the Winn assay in which normal cells injected together with tu mour cells reduce the growth capacity of the latter [7], In newborn mice, growth of a plasmocytoma could be influenced in a dual way by non-immune cells [8], Low numbers of neutrophils, thymus or spleen cells enhanced tumour takes, while higher numbers of these cells and macrophages induced an effective protection. However, since newborn mice are immunologically immature, the injection of cells from adult donors might confer a certain degree of immunological re activity to these hosts in the same way as an inoculum of normal thymocytes provides immunologically un responsive athymic "nude' mice with the faculty to reject tumour xenografts [9].…”

“…However, since newborn mice are immunologically immature, the injection of cells from adult donors might confer a certain degree of immunological re activity to these hosts in the same way as an inoculum of normal thymocytes provides immunologically un responsive athymic "nude' mice with the faculty to reject tumour xenografts [9]. Thus, the results [8] are not strictly comparable to our work in which evidence is brought forward that transplanted normal syngeneic lymphoid cells may affect the growth of previously implanted tumour tissue in adult animals in vivo. Con versely, normal fetal liver cells are shown to promote tumour development in adult murine recipients.…”