Immune System - Antibody Development
Development of the immune system will also link to cardiovascular development notes (blood and vessel) and bone marrow development. Two organs which also relate to this system are the thymus and spleen, which have in the past been included in endocrine and gastrointestinal tract development respectively. There are now also movies showing lymphocyte (B and T cells) traffic within adult lymph nodes.
During prenatal development, maternal IgG antibodies are transferred from about week 13 (GA) across the placenta, from the maternal lacunae syncytiotrophoblast cell endosomes bind IgG through neonatal Fc receptors.
Some Recent Findings
T Lymphocyte Development
A study of cord blood from 19 early second and third trimester fetuses (GA 18-36 weeks) and 16 term newborns (GA 37-42 weeks).
- Percentage of lymphocytes in fetal white blood cells was 79.3%, reducing to 40% by term birth
- higher than that of adults.
- Mononuclear cells (cord blood mononuclear cells (CBMC)
- fetal mononuclear cells were unable to produce IL-2, IL-4 or IFN-gamma.
- spontaneously secreted IL-10, IL-6 and TNF-alpha in vitro.
- fail to respond to mitogen (PHA) or allogeneic stimulation in vitro.
- Stimulation with PHA up-regulated the production of IL-10, IL-6 and TNF-alpha substantially.
- CD3+ T cells in fetal (40.1%) and neonatal (42.4%)
- lower than that of men (59.6%) and pregnant women (53.6%).
- CD8+ T cells (9.5%)
- gamma delta - T cells (0.5%)
- NK cells (4.8%)
During prenatal development, maternal antibodies are transferred across the placenta to the fetus. Immunoglobulin G (IgG) is transferred across the syncytiotrophoblast cell layer is mediated by the Neonatal Fc receptor (FcRn). Once inside placental villi, immunoglobulins then need to enter fetal circulation by crossing the second cellular endothelial cell layer by an as yet unknown mechanism.
During postnatal development, maternal antibodies are transferred by maternal milk across the neonatal gastrointestinal tract epithelium.
The images below are from adult immune Lymph Nodes.
- Human natural killer cells (NK) - originate from CD34(+) hematopoietic progenitor cells.
Adult Lymphocyte Histology
- Lymphocyte EM Images: T and B Lymphocytes 1 TEM | T and B Lymphocytes 2 TEM | T Lymphocyte SEM | B lymphocyte 1 TEM | B lymphocyte 2 TEM | B lymphocyte 3 TEM | Plasma Cell TEM | T2 Lymphocyte 1 TEM | T2 Lymphocyte 2 TEM | lymphocyte rosettes | T lymphocyte 1 | T lymphocyte 2 | T lymphocyte 3 | T lymphocyte 4 | T lymphocyte 5 | T lymphocyte 6 | B lymphocyte | B lymphocytes TEM | Immune System Development | Blood
- Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link
Cite this page: Hill, M.A. (2021, June 16) Embryology Immune System - Antibody Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Immune_System_-_Antibody_Development
- © Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G