Transplantation Immunity and Tolerance

Delayed Hypersensitivity in Mice to Dextran

“…Perhaps a Felton-type of immune paralysis was interfering with development of immediate but not delayed hypersensitivity, since injection of only small quantities of certain polysaccharides render mice unable to make specific humoral antibodies (31). To test this possibility, as well as to gain some data on minimal quantities of dextran required for sensitiza tion, we vaccinated mice with various small quantities of the antigen in w/o emulsion.…”

“…In view of native dextran's apparent excellence as an antigen, one might suggest that mice injected with milligram quantities of it did not develop any humoral antibody to it because these quantities might be large enough to induce Felton-type immunologic pa ralysis (31). But this seems improbable because dextran unlike pneumoccocus polysaccharides can be catabolized in the mouse (30), and because none of the mice which we vaccinated with exceedingly small quantities of dextran to try to circumvent this possible problem developed any immediate hypersensitivity.…”

Complexity of the State of Immunological Tolerance

“…In our considerations on the mechanism of immunological tolerance we have suggested four hypothetical possibilities (Hasek et al 1961) (Table I): active and passive, positive and negative mechanisms. In support of the passive mechanism are mainly the results from experiments on abolition of immunological tolerance by the adoptive transfer of immunity in tole-rant animals.…”

Mouse cytolytic T lymphocytes induced by xenogeneic rat stimulator cells exhibit specificity for H-2 complex alloantigens.

“…Hasek et al (14,15), in their studies of tolerance after inter-species embryonic parabiosis, observed that occasionally the capacity to recognize antigenic differences within the species was suppressed. It was initially thought that the loss of response to alloantigens after a xenogeneic parabiosis was due to some nonspecific and unphysiological effect on the immune system.…”