| First Author | el Demellawy M | Year | 1992 |
| Journal | Mech Ageing Dev | Volume | 62 |
| Issue | 3 | Pages | 307-18 |
| PubMed ID | 1349934 | Mgi Jnum | J:59 |
| Mgi Id | MGI:48599 | Doi | 10.1016/0047-6374(92)90115-t |
| Citation | el Demellawy M, et al. (1992) Age-associated decrease in proportion and antigen expression of CD8+/CD4+ thymocytes in BALB/c mice. Mech Ageing Dev 62(3):307-18 |
| abstractText | We studied the distribution of Thy-1.2+, CD8+ and CD4+ thymocytes in 3-, 6.5-, 12- and 18-month-old inbred BALB/c mice by staining cells with specific monoclonal antibodies (mAb) using indirect membrane immunofluorescence. The percentages of Thy-1.2+, CD8+, and CD4+ thymocytes did not vary with age until 12 months, but they exhibited at 18 months a highly significant decline. Staining thymocytes with mAb CD8 and CD4 alone or in a mixture allowed us to show that the age-related decline in proportions of CD8+ and CD4+ thymic cells is associated with the double positive (CD8+/CD4+, immature) subset. Most importantly, we observed a progressive age-related decrease in ratio of bright/dull Thy-1.2+, CD8+ and CD4+ thymocytes. The CD8+ and CD4+ thymocytes that did not adhere to peanut agglutinin (PNA-, which is supposed to represent the mature single positive subset) did not show any age-related change in the proportion of bright and dull cells. Therefore, we concluded that the double positive (CD8+/CD4+, immature, PNA+) thymocytes display reduced expression of CD8 and CD4 antigens with aging. The implications of these findings to the fundamental mechanisms of immunosenescence are discussed. |
