The ability to form rosettes with rabbit red blood cells (RRBC) has been shown to be characteristic of T but not B cells from guinea pigs. In an attempt to devise an assay system to measure the guinea pig equivalent of human "active" T cells, we have investigated the effects of various conditions on RRBC binding by guinea pig lymphocytes, including incubation time, RRBC: lymphocyte ratio, presence or absence of guinea pig serum or fetal calf serum in the incubation medium, and pretreatment of RRBC with neuraminidase or 2-aminoethylisothiouronium bromide (AET). Without incubation and at a 100:1 ratio of RRBC to guinea pig lymphocytes, about 35% of guinea pig peripheral blood lymphocytes bound RRBC, similar to the number of "active" T cells in human peripheral blood as measured by rosette formation with sheep red blood cells. Cold incubation increased the number of rosetting cells to over 80%, presumably the total number of T cells. A relative decrease in the number of RRBC diminished rosetting only at ratios of 10:1 or less. Pretreatment of RRBC with neuraminidase slighily increased, whereas AET pretreatment drastically reduced the number of rosettes. Increasing concentrations of guinea pig serum in the medium up to 100% slightly inhibited rosetting. These results suggest the presence of two T-cell populations in guinea pig peripheral blood, equivalent to the human "active" and "total" rosette-forming T-cell subpopulations.
ASJC Scopus subject areas
- Immunology and Allergy
- Pathology and Forensic Medicine