Hypersensitivity in newborn guinea pigs

The role of humoral antibodies in rejection of skin homografts in rabbits. II. Passive transfer of transplantation immunity by sensitized lymph node cells within diffusion chambers

Passive transfer of transplantation immunity by means of sensitized lymphoid cells enclosed within diffusion chambers has been accomplished in non-radiated and radiated rabbits. This result, together with other data available in the literature, suggests that humoral antibodies play an important role in rejection of skin homografts in the rabbit.

Strain- and age-associated differences in lymphocyte phenotypes and immune responsiveness in C4-deficient and Albany strains of guinea-pigs

Spleen lymphocytes from C4-deficient (C4D) and Albany strains of guinea-pigs, 1-7 days, 3-6 and 12-16 months old, genetically related to inbred strains 13 and 2 respectively, were analysed in terms of their expression of cell surface markers, allogenic and T- and B-cell mitogenic responses, and interleukin-1 (IL-1) and IL-2 production. There were strain- and age-associated differences in phenotypic expression and immune responsiveness levels. In both strains a significant shift in immunocompetence apparently occurs postnatally before 3-6 months of age, with no further significant changes noticed in animals 12-16 months old. Phenotypic changes in cell surface markers did not always correlate with functional capability of lymphoid cells. H159+ (pan T) and H155+ (CD4) lymphocyte number and levels of T-cell responsiveness (mitogenic and allogenic responses, and IL-2 production) were higher in C4D neonates compared with age-matched Albany guinea-pigs or with young animals of the same strain. On the other hand, 31D2+ (B) lymphocytes in a significantly higher proportion in Albany neonates compared with similarly aged C4D, did not correlate at this age or at any other time with their proliferative response to lipopolysaccharide (LPS) or dextran sulphate (DS), two B-cell-specific mitogens.

Delayed type skin response to myelin basic protein in chronic relapsing experimental allergic encephalomyelitis

The skin response to myelin basic protein (MBP) was studied in chronic relapsing experimental allergic encephalomyelitis (EAE) using strain 13 guinea pigs. The delayed type skin response showed a monophasic curve; it gradually increased after immunization, reached maximum levels around 80 days post-immunization, and decreased thereafter. Relapses were more frequent while it was at high levels although it did not correlate directly in individuals with the clinical stage. The skin response was also high in MBP-immunized animals which had recovered from acute EAE. Our results suggest that delayed type hypersensitivity to MBP is involved but is not sufficient by itself to cause relapsing EAE.

Impaired delayed hypersensitivity in germ-free guinea-pigs

The delayed-type hypersensitivity response of germ-free guinea-pigs was found to be defective. Whereas almost all conventionally reared guinea-pigs became hypersensitive to an allergenic hapten (picryl chloride), most germ-free guinea-pigs did not. When injected with a fully antigenic substance, bovine γ-globulin (BGG), none of the germ-free animals acquired BGG-specific delayed hypersensitivity. Further, none of the germ-free guinea-pigs developed spontaneous iso-hypersensitivity for a beta globulin as do conventional guinea-pigs. In addition, germ-free guinea-pigs given Freund's complete adjuvant did not develop the characteristic induration or erythema normally seen at injection sites and most animals died within 21 days.

Germ-free guinea-pigs given competent lymphoid cells from highly sensitized conventional guinea-pigs were unable to translate adoptive hypersensitivity into delayed dermal reactions.

A permeability factor in aged guinea-pig sera, injected into the skin of germ-free and conventional animals to determine whether the skin of germ-free guinea-pigs was able to support reactions, initiated immediate dermal reactions of equal intensity in both sets of animals.