The early life immune system is characterized by unique developmental milestones. Functionally diverse immune cells arise from distinct waves of hematopoietic stem cells, a phenomenon referred to as 'layered' immunity. This stratified development of immune cells extends to lineages of both innate and adaptive cells. The defined time window for the development of these immune cells lends itself to the influence of specific exposures typical of the early life period. The perinatal immune system develops in a relatively sterile fetal environment but emerges into one filled with a multitude of antigenic encounters. A major burden of this comes in the form of the microbiota that is being newly established at mucosal surfaces of the newborn. Accumulating evidence suggests that early life microbial exposures, including those arising in utero, can imprint long-lasting changes in the offspring's immune system and determine disease risk throughout life. In this review, I highlight unique features of early life immunity and explore the role of intestinal bacteria in educating the developing immune system.
A developmental switch in thymic lymphocyte maturation potential occurs at the level of hematopoietic stem cells.
Neutrophil pool sizes and granulocyte colony-stimulating factor production in human mid-trimester fetuses
Early human T cell development: analysis of the human thymus at the time of initial entry of hematopoietic stem cells into the fetal thymic microenvironment
The human embryo, but not its yolk sac, generates lympho-myeloid stem cells: mapping multipotent hematopoietic cell fate in intraembryonic mesoderm
Effect of exclusive breast-feeding and early solid food avoidance on the incidence of atopic dermatitis in high-risk infants at 1 year of age
Development of innate CD4+ alpha-chain variable gene segment 24 (Valpha24) natural killer T cells in the early human fetal thymus is regulated by IL-7
Monocyte toll-like receptor 4 expression and LPS-induced cytokine production increase during gestational aging
Immaturity of infection control in preterm and term newborns is associated with impaired toll-like receptor signaling
Poor immunogenicity of BCG in helminth infected population is associated with increased in vitro TGF-beta production
Day-care attendance, position in sibship, and early childhood wheezing: a population-based birth cohort study
Activated human neonatal CD8+ T cells are subject to immunomodulation by direct TLR2 or TLR5 stimulation
Exclusive breastfeeding and incident atopic dermatitis in childhood: a systematic review and meta-analysis of prospective cohort studies
Chronic intestinal helminth infections are associated with immune hyporesponsiveness and induction of a regulatory network.
B cell subsets in healthy children: reference values for evaluation of B cell maturation process in peripheral blood
Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns.
Relationships among environmental exposures, cord blood cytokine responses, allergy, and wheeze at 1 year of age in an inner-city birth cohort (Urban Environment and Childhood Asthma study)
Blood And Marrow Transplantation
The use of hematopoietic stem cell transplantation or blood and marrow transplantation (bmt) is on the increase worldwide. BMT is used to replace damaged or destroyed bone marrow with healthy bone marrow stem cells. Here is the latest research on bone and marrow transplantation.