T-LYMPHOCYTE AND B-LYMPHOCYTE CHIMERISM IN MARMOSET

  • 1 January 1977
    • journal article
    • research article
    • Vol. 32  (2) , 257-263
Abstract
Marmosets are natural blood chimeras, this condition resulting from the high frequency of fraternal twinning and the consistent development of placental vascular anastomoses between the 2 embryos. Identification of chimerism by sex-chromosome analysis of cultured blood lymphocytes provided a means of determining the proportion of chimerism among T [thymus-derived] and B [bone marrow-derived] lymphocytes. Peripheral blood lymphocytes were enriched for T or B cells by filtration through a nylon column (yields > 95% T-cells) or inactivation of T lymphocytes by treatment with a goat anti-marmoset thymocyte antiserum in the presence of complement (yields > 95% B cells). Mitogenic stimulation of these separated, enriched cell populations yielded metaphase plates which could be scored for percentage male and female cells. Tests on 5 different blood chimeras showed the T and B-lymphocyte chimerism to be the same. Stimulation of blood lymphocytes with cells from another species of marmoset in a mixed lymphocyte culture test revealed the chimeric T-cell response (i.e., host and co-twin cells) to be similar to that obtained with a mitogenic lectin. The demonstration of equivalent T and B-cell chimerism in these animals suggests derivation of these cells from a common stem cell pool. The response of both T-cell populations to an antigenic stimulus in proportions similar to their percentage chimerism suggests complete immunologic tolerance exists in this species for co-twin histocompatibility antigens.