Emergence of a subpopulation of lymphocytes bearing theta antigen and complement receptor during tumor growth.

Spleens from BALB/c mice transplanted with mammary tumors display a significant increase in the percentage of lymphocytes bearing complement receptors (CRL) while the percentage of cells bearing surface immunoglobulins (SIg) remains unchanged in comparison with that in spleens from normal animals. Upon separation on nylon columns, the increase in CRL in the spleens from tumor-bearing mice was limited to the non-adherent cell population. Simultaneous maker analysis disclosed that these CRL lacked detectable SIg.

In vitro immune responses to viral and tumor antigens in murine breast cancer.

Inhibition of migration of peritoneal exudate cells proved to be a useful measurement of cell-mediated immunity which correlated in several respects with blastogenic transformation reactions. Lectins (phytohemagglutinin and concanavalin A) inhibited the migration of peritoneal exudate cells from normal and tumor-bearing mice, whereas tumor antigen caused inhibition of migration of cells from tumor-bearing animals only. The disparity in immunogenic capacity previously observed with lymphocyte transformation studies was also manifested in migration inhibition, i.

Macrophage migration inhibition and lymphocyte stimulation with mammary tumor virus associated antigens in Balb/c mice.

Lymphocytes of MTV-negative Balb/c mice are sensitive to one or more antigens of MTV as determined by blastogenic transformation and migration inhibition assays. The lymphocytes from MTV-positive Balb/cfC3H mice are nonresponsive in these assays but become responsive after the mice have been implanted with MTV-positive tumors. The latter findings imply that there may be either a state of tolerance to MTV antigens which is broken by the tumor transplant or that the responses are directed towards antigens to which the host is not tolerant.

Increase in the proportion of cells with the C'3 receptor in BALB/c mice bearing mammary tumors.

Transplantation of mammary tumors originally induced by dimethylbenzanthracene caused splenomegaly and an increase in the total population of spleen cells paralleling the increase in tumor size. At least part of the hypercellularity was due to in situ proliferation as evidenced by the increased number of blast forms and mitotic figures. The cells were characterized with respect to parameters generally associated with B-cells; surface immunoglobulins as detected by immunofluorescence and C'3 receptors as determined by rosette formation with sheep red blood cells (SRBC) coated with rabbit anti-SRBC and mouse complement.

Urinary bladder carcinogenesis in the dog: preliminary studies on cellular immunity.

The immunologic status of dogs undergoing bladder carcinogenesis with 4-amino-biphenyl and normal littermate controls is being evaluated. Studies using blastogenic transformation, nonimmune cytotoxic reactions, and rosette formation have revealed that dogs possess lymphocytes that have some properties similar to those of B and T cells of other species. Since tumors are now just appearing and hence are not yet available for specific immunologic determinations, the assessments had to be limited for the present to other types of antigens and mitogens (yeast, red blood cells and plant lectins).