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J L Gowans

Publications and source records attributed to J L Gowans.

36 records · Page 2Linked to original sources
PubMed1972

The specific selection of recirculating lymphocytes by antigen in normal and preimmunized rats.

Thoracic duct lymphocytes (TDL) from normal rats will restore a primary antibody response to sheep erythrocytes (SRBC) in irradiated recipients and cause a graft-versus-host reaction in F(1) hybrid rats; lymphocytes from rats immunized with either tetanus toxoid or dinitrophenylated bovine gamma globulin (DNP BGG) will generate specific antibody after cell transfer and challenge. The ability of TDL to mediate each of these responses is severely depressed by giving a single intravenous dose of the specific antigen shortly before cannulation of the thoracic duct, although the lymphocyte donors themselves respond normally. The injection of antigen does not decrease the output of lymphocytes in the thoracic duct and the effect is specific for the antigen injected. The findings are most readily accounted for by assuming that small subpopulations of specific lymphocytes are selected from the recirculating pool by antigen which has localized in lymphoid tissue. The observation that passive antibody abolishes selection by SRBC supports this interpretation. The strong selection exerted by a subcutaneous injection of SRBC in Freund's complete adjuvant, which induces delayed hypersensitivity but little early antibody, suggests that a common cell type may be involved in the induction of both delayed hypersensitivity and antibody formation. The anti-DNP antibody response generated by TDL from rats immunized with DNP BGG was abolished by a selecting injection of the homologous conjugate. The response was depressed to a smaller degree by injections of either BGG or dinitrophenylated human serum albumin, suggesting that carrier-specific (T) and hapten-specific (B) lymphocytes could be separately selected from the recirculating pool. The regional selection of recirculating lymphocytes by antigen may explain a number of phenomena in which the prior injection of antigen has been found to inhibit a subsequent immune response.

Animals↗
PubMed1972

Identification of marrow-derived and thymus-derived small lymphocytes in the lymphoid tissue and thoracic duct lymph of normal rats.

These experiments show that small lymphocytes from the thoracic duct of rats are normally a mixture of thymus-derived and marrow-derived cells, and define the traffic areas in lymphoid tissues through which the two populations recirculate. Thoracic duct lymphocytes were labeled in vitro with uridine-(3)H and their histological distribution in the lymphoid tissues of normal recipients was demonstrated by radioautography. Labeled lymphocytes occupied two adjacent areas distinguished by a marked difference in the intensity of labeling; heavily labeled cells were found in thymus-dependent traffic areas of lymphocyte recirculation, while lightly labeled cells localized in the thymus-independent follicular areas around germinal centers. A corresponding heterogeneity of uridine uptake among small lymphocytes from normal donors was demonstrated by sedimentation at 1 g; slowly sedimenting cells incorporated little uridine and localized in follicular areas after transfusion while rapidly sedimenting cells incorporated more uridine and localized in thymus-dependent areas after transfusion. Experimentally prepared marrow-derived small lymphocytes behaved in sedimentation studies and after transfusion like a pure population of the lightly labeled small lymphocytes in normal lymph. Artificially reconstituted mixtures of marrow-derived and thymus-derived lymphocytes were qualitatively indistinguishable from normal lymphocyte populations.

Animals↗
PubMed1971

Antigen modulation of the immune response. The effect of delayed challenge on the affinity of anti-dinitrophenylated bovine gamma globulin antibody produced in adoptive recipients.

Secondary immune responsiveness to dinitrophenylated bovine gamma globulin (DNP-BGG) was transferred to heavily irradiated rats by means of small lymphocytes from the thoracic duct of immunized syngeneic donors. Affinity of the antibody produced by the adoptive recipients when challenged immediately was the same as that seen in immunized controls and cell donors, suggesting that the performance of lymphocytes in the thoracic duct of immunized rats provide an accurate measure of the immunologic history of memory cells both in the intact animal and the lymphocyte-depleted donor. The relevance of this to cell cooperation in the production of antibody to hapten-protein complexes is discussed. Direct evidence on antigen modulation of the immune response was also obtained. When immune thoracic duct lymphocytes were transferred to adoptive recipients and challenged either immediately or after a delay of 6 wk, it was found that, although the amount of antibody decreased with this delay in challenge, the affinity remained constant. Thus it would seem that in control rats, the increase in the affinity of antibody with time after immunization is, in fact, due to the selection of new populations of cells by the progressively waning concentration of antigen.

Animals↗
PubMed1971

The sensitization of rats by allografts transplanted to alymphatic pedicles of skin.

Pedicles of skin which lacked a lymphatic drainage were raised on the backs of rats in order to study the importance of afferent lymphatics in sensitization by skin allografts. Although allografts transplanted to the alymphatic pedicles enjoyed a prolonged survival, they contracted progressively from about 3 wk after transplantation and were reduced eventually to small scars. In contrast, autografts survived unchanged in size for the life-span of the pedicles which carried them. The slow contracture of the allografts was associated with sensitization of the host because test allografts applied orthotopically were destroyed with a second-set tempo. No regeneration of lymphatics from the long-standing pedicles could be demonstrated, and it was concluded that sensitization had occurred eventually through the blood, presumably by the process of peripheral sensitization. Allografts on skin pedicles could be destroyed rapidly by active or adoptive immunization, so it is probable that the level of sensitization to which they themselves gave rise was a low one. Although it is not disputed that afferent lymphatics are essential for the rapid destruction of skin allografts, it is clear that the absence of a lymphatic supply does not permanently exempt them from immunological attack in the rat.

Animals↗
PubMed1966

The carriage of immunological memory by small lymphocytes in the rat.

Lymphocytes were obtained from the thoracic duct of rats 1(1/2) to 15 months after primary immunization with a single dose of bacteriophage phiX 174. An intravenous injection of these lymphocytes conferred on heavily X-irradiated rats the ability to form antibody in a secondary-type manner after a first injection of phiX. Negligible responses were obtained after cell transfer if the recipients were not challenged with antigen. Thoracic duct cells from some immunized donors were incubated in vitro for 24 hr before transfer in order to destroy selectively the large, dividing lymphocytes. The responsiveness conferred on X-irradiated recipients by such "incubated" inocula was then compared with that given by equal numbers of "fresh" thoracic duct cells. In all such comparisons the recipients of the "incubated" cells gave higher and more rapid antibody responses. It was concluded that the cells in thoracic duct lymph which carried immunological memory were small lymphocytes.

Allergy and Immunology↗
PubMedDate not supplied

The natural history of the cells producing IgA in the gut.

The IgA-secreting cells in the lamina propria of the small intestine are derived from large lymphocytes which enter the blood by way of the thoracic duct and then migrate into the gut where they complete their differentiation into plasma cells. Three aspects of this cellular traffic have been examined in rats. 1. The cells in thoracic duct lymph which give rise to IgA-secreting cells in the lamina propria are among those which carry surface IgA. Blast cells lacking surface immunoglobulin migrate mainly into the Peyer's patches and do not contribute to the IgA response. 2. Studies on a secondary antibody response to cholera toxoid, in which the challenge was given into a Thiry-Vella loop, showed that the antibody-containing blast cells in thoracic duct lymph were derived from Peyer's patches. The mesenteric nodes contributed little, if anything, to the cellular response in the lymph. 3. The idea that secretory component is a signal for the emigration of large lymphocytes from the blood into the lamina propria lacks experimental support. Secretory component does not bind to the IgA on the surface of thoracic duct cells. On the other hand, antigen in the gut may play an important part in immobilizing large lymphocytes in the lamina propria once they have migrated.

Animals↗
PubMedDate not supplied

Subpopulations of B lymphocytes and the carriage of immunological memory.

Thoracic duct lymphocytes from rats primed with DNP-BGG confer on irradiated, syngeneic recipients the ability to mount a large, IgG anti-DNP response after challenge with the immunizing conjugate. An analysis of this adoptive response lead to the following conclusions. the B memory cells which generate the IgG response carry IgG on their surface and are present in a subpopulation amounting to less than l0% of all B cells in thoracic duct lymph. The view that memory cells carry exclusively IgD is untenable. The majority of B lymphocytes in thoracic duct lymph are recirculating cells which carry surface IgM...

Animals↗
PubMedDate not supplied

Lymphocytes.

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Animals↗