Search PubMed⌕ Search

Biomedical subjects

D B Wilson

Publications and source records attributed to D B Wilson.

At least 361 records · Page 20Linked to original sources
PubMed1971

Quantitative studies on the mixed lymphocyte interaction in rats. VI. Reactivity of lymphocytes from conventional and germfree rats to allogeneic and xenogeneic cell surface antigens.

The proliferative reactivity of lymphocytes from rat donors maintained under germfree or conventional conditions was examined in mixed lymphocyte cultures stimulated with allogeneic and xenogeneic cell surface antigens. The results show (a) that lymphocytes from conventionally maintained rats are less reactive to human, hamster, guinea pig, and mouse cell surface antigens than to the major H alloantigens, and (b) that lymphocytes from germfree rats display no demonstrable reactivity to xenogeneic cells, but are quantitatively normal in their response to allogenic cells. The conclusion drawn from these observations is that the circulating lymphocyte pool of an individual consists of a greater proportion of cells reactive to H alloantigens of other members of the same species than to the xenogeneic cellular antigens of members of other species and that this large number of cells is not generated by a mechanism involving immunization to cross-reactive environmental antigens.

Animals↗
PubMed1971

Studies on the life history of lymphocytes. I. The life-span of cells responsive in the mixed lymphocyte interaction.

The life history, within the rat, of lymphocytes responsive to histocompatibility isoantigens in the mixed lymphocyte interaction was examined by the use of in vivo labeling with tritiated thymidine and radioautography. Lymphocytes in the peripheral blood and H-ARC (mitotic figures in the MLI) were compared with respect to the frequency of labeled cells and the median grain count. The following conclusions were drawn from this study: (a) Although some can be considered long-lived, the majority of H-ARC are the products of recent divisions in the body. (b) Adult thymectomy does not eliminate the production of long-lived lymphocytes, some of which are H-ARC. Hence, in addition to direct origin in the thymus, H-ARC, as well as other lymphocytes of the long-lived lymphocyte population, may derive from already existing thymus-derived cells in the circulation and thymus-dependent areas of the secondary lymphoid tissues. (c) Sublethal X-irradiation (600 R) in combination with adult thymectomy does not eliminate the capacity to produce some long-lived lymphocytes, however, few if any are H-ARC. (d) H-ARC and other long-lived lymphocytes appear to go through a series of rapid multiple divisions before they enter the circulation. Thereafter, long-lived lymphocytes appear to undergo intermittent single divisions which decrease both the frequency and median grain count of labeled cells gradually with time. On the other hand, labeled H-ARC maintain a more stable grain count despite a rapid decrease in frequency with time. This is taken to indicate that H-ARC are less likely to undergo occasional single divisions during their life-span, but may undergo periodic rapid sequential divisions. A speculative model is developed from these data on the life history of H-ARC which may be of predictive value in future studies and which can be tested against known facts.

Animals↗
PubMed1971

Quantitative studies on the mixed lymphocyte interaction in rats. V. Tempo and specificity of the proliferative response and the number of reactive cells from immunized donors.

These studies were designed to determine what influence prior immunization with homologous H isoantigens might have on the subsequent proliferative activity of lymphocytes from these animals in the mixed lymphocyte interaction. The results demonstrate the following: (a) Subcutaneous immunization with splenic cells from donors differing at the major H locus accelerates the tempo of the proliferative response to F(1) cells bearing these same antigens in the MLI, whereas antigen given systemically reduces the proliferative response. (b) The altered proliferative behavior is specific for the immunizing antigens. (c) The period after immunization during which the MLI displays an altered tempo is a short one, lasting not longer than 3 wk. (d) Whether they are derived from previously immunized or from normal donors, the proportion of lymphocytes responsive in the MLI is the same, even though the response profiles are different. These results suggest that in comparison to immune responses to other types of antigens, immunologic reactivity to the major H isoantigens already involves a large number of antigen-reactive cells in normal animals and that the proportion of these cells is not increased as a result of immunization. Rather, lymphocytes from immunized animals respond more rapidly to the presence of these antigens.

Animals↗