The Lymphocyte Transformation Response of Fetal Hemolymphatic Tissue to Mitogens and Antigens

Species comparison of anatomical and functional immune system development

“…Mitogen-responsive T-cells can be demonstrated in spleen and peripheral blood by 16-18 weeks gestation (Kay et al, 1970). Similar results were reported by Mumford et al (1978), who observed responses to Con A with thymus cells at 13-14 weeks of gestation, and with spleen cells at approximately 18 weeks of gestation; whereas August et al (1971) observed that fetal thymocytes responded to mitogenic stimulation at 12 weeks of gestation and splenic T-cells responded between 14-16 weeks of gestation. Reactivity of fetal lymphocytes in the MLR has been variably reported as beginning during weeks 10-14 (Ohama and Kaji, 1974;Loke, 1978;Royo et al, 1987), followed by functional effector reactivity in cell-mediated lympholysis (CML) assays subsequently, proceeding in variable fashion depending on the lymphoid tissue tested (Granberg and Hirvonen, 1980;Murgita and Wigzell, 1981).…”

Development of Mitogen Responding T Cells and Natural Killer Cells in the Human Fetus

“…Stites and coworkers applied chromosome analysis to confirm that the responsive cells were fetal cells and not transplacentally derived maternal lymphocytes. In the spleen PHA responsive lymphocytes appear 3-4 weeks later (Stites et al 1974, Mumford et al 1978) when the small lymphocytes infiltrate the organ in periarteriolar sheets, i.e., in thymus-dependent areas (August et al 1971). In the spleen PHA responsive lymphocytes appear 3-4 weeks later (Stites et al 1974, Mumford et al 1978) when the small lymphocytes infiltrate the organ in periarteriolar sheets, i.e., in thymus-dependent areas (August et al 1971).…”

“…The onset of PHA responsiveness by thymocytes appears at the time when the thymus has differentiated histologically into cortex and medulla (August et al 1971). In the spleen PHA responsive lymphocytes appear 3-4 weeks later (Stites et al 1974, Mumford et al 1978 when the small lymphocytes infiltrate the organ in periarteriolar sheets, i.e., in thymus-dependent areas (August et al 1971). At about the same time PHA responsive lymphocytes are also detectable in the peripheral blood (Stites et al 1974, Mumford et al 1978.…”

“…The first responses to Con A have been observed with thymus cells at 13-14 weeks of gestation (Mumford et al 1978, Leino et al 1980). In the spleen, the first Con A responsive cells were observed by us at 18 weeks of gestation (Leino et al 1980), whereas a slight response already at 14 weeks was reported by Mumford et al (1978). Cells from the fetal liver and bone marrow show only marginal and occasional responses to Con A (Leino et al 1980).…”

Ontogeny of the mucosal immune response

“…There is virtually no information on mucosal lymphocytes. Thymocytes from 10-week-old fetuses respond to phytohemagglutinin and splenic responsiveness occurs about 3-4 weeks later [1,14,27]. Premature infants as young as 30 weeks gestation can be sensitised to dinitrochlorobenzene (DNCB) and positive skin tests can be elicited [28].…”