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Biomedical subjects

D C Poskitt

Publications and source records attributed to D C Poskitt.

22 records · Page 2Linked to original sources
PubMed1978

Behaviour of sheep-immunoglobulin-bearing and non-immunoglobulin-bearing lymphocytes isolated by nylon wool columns.

The technique of separating lymphocytes on nylon wool columns has been applied to sheep lymphocytes obtained from efferent lymph. The non-immunoglobulin-bearing (sIg-) lymphocytes which pass through the column were MLR-reactive, responsive only to T cell mitogens, and migrated in vivo like T lymphocytes described in rodents. Immunoglobulin-bearing (sIg+) lymphocytes were MLR-non-reactive, responsive to lipopolysaccharide and migrated in vivo like B lymphocytes in rodents. It is considered that the majority of sIg- lymphocytes obtained in this way are T lymphocytes and the majority of sIg+ lymphocytes are B lymphocytes.

Animals↗
PubMed1977

Two distinct pools of recirculating T lymphocytes: migratory characteristics of nodal and intestinal T lymphocytes.

A pronounced asymmetry in the recirculation from blood to lymph of resting small recirculating T lymphocytes is described. When 51Cr-labeled small T-recirculating lymphocytes (TRL) from intestinal lymph were infused intravenously their relative recovery in intestinal lymph was about twice that in nodal lymph. In contrast, the relative recovery in nodal lymph of 51Cr-labeled nodal TRL was twice that in intestinal lymph. Intestinal TRL migrated in large numbers through the small intestine. Nodal TRL did not. It is proposed that the pool of recirculating small T lymphocytes consists of two major subdivisions, an intestinal pool and a nodal pool. The nodal circulation comprises small TRL which traverse PCV in all lymph nodes (LN) but not the small intestine. The intestinal circulation comprises small TRL which do not traverse PCV in LN, but which do recirculate through the small intestine from which they pass via afferent lymphatics to the mesenteric LN and subsequently via the thoracic duct into the blood. It is suggested that the intestinal circulation is present in the fetus and that its initial development is independent of extrinsic antigen.

Animals↗
PubMed1977

The appearance of non-specific antibody-forming cells in the efferent lymph draining antigen-stimulated single lymph nodes.

Immunization of single lymph nodes with various antigens led to the appearance of cells in the efferent lymph that secreted antibody specific for the antigen which induced their formation and for a number of unrelated, non-crossreacting antigens. Immunization of single lymph nodes with mitogens led to the appearance of cells secreting antibodies specific for an even greater number of antigens, including one (TNP) that in all probability is not present in the animals' natural environment. When the node was primed with one antigen, a subsequent challenge with an unrelated antigen 12 weeks later led to the appearance of greater numbers of cells containing and secreting antibody against the previously experienced antigen, than was the case in unprimed lymph nodes. These findings indicate that the immune response to antigen provokes the maturation of lymphocytes of specificities unrelated to that of the injected immunogen. Such a mechanism may be important in maintaining immunological memory. Mitogens may directly activate lymphocytes into maturation and expression as antibody-secreting cells, whereas antigens appear to act indirectly.

Animals↗