Age & Nutrition Flashcards
(23 cards)
What are the two modifiers that can affect the immune system?
Nutrition & Age
What are the examples of malnutrition and causes?
- kwashiorkor: PEM that leads to edema and bloating of belly.
- marasmus: Energy-deficiency that leads to wasting of the body.
How does PEM affect the immune system?
PEM has a greater effect on INNATE immunity than any other nutrient.
PEM decreases physical (epithelial) & Physiological barriers.
PEM decreases the function of macrophages, neutrophils, and NK cells.
Describe Iron Deficiency & Effects
- Micronutrient Deficiency
- Decreases the function of macrophages & neutrophils
- Decreaes pro-inflammatory cytokines (TNF-a & IL-6)
- Inhibits the proliferation of T cells & Thymic function
“IT” (Iron –> affect Thymic/T-cells)
Why is iron important for microbes?
- Microbes (especially bacteria) depend on iron for growth.
* High iron status promotes microbial infections.
What enzymes/protein affect iron status in a human host?
- Lactoferrin and other (fe-containing chaperones)
- Antioxidants (Haptoglobin & Hemopexin)
- Hepcidin
Describe Vitamin A Deficiency & Effects
- Micronutrient Deficiency
- Skews immune system towards Th1 response
- Reduce Th2-driven antibody response to vaccines
- Increase mortality and morbidity
How Does Obesity Affect The Immunity?
- Cause chronic low grade inflammation (lowers effects of inflammation when necessary)
- Increases pro-inflammatory cytokines (TNF-a & IL-6)
- Increases thymic aging & reduces T-cell differentiation
- Increase susceptibility to infection & wound complications
When does active IgG transportation occur?
Second Trimester (20-30 wks)
Cell-Mediated Immunity In Infants
- Very little IL-12
- Favors Th2 & Th17 Cells
- T-cell activation is impaired (MHC expression & co-stimulation)
What physiological barriers are yet to be developed in infants?
- GI tract enzymes, stomach acid
- Normal Flora
- IgA
What does breastmilk provide for infants?
- maternal IgA, IgM, and also IgG
- maternal Antibiotic-producing B cells
What are the effects of surface (MHC) & co-stimulatory molecules in infants?
- Diminished CD4 cells helping B cells –> delay in Ig synthesis, class switching
- Lack of CD8 CTL against viral infections
At what age does serum IgG, IgM, and IgA of a child reach “adult levels”?
Age 5-6
** IgA slower to rise
At what age does lymphocyte (CD4) count reach “adult levels”?
Age 6
What are three hallmarks of aging?
- Primary (causes of cellular damage)
- Antagonistic (responses to damage)
- Integrative (culprits of the phenotype; irreversible effects)
Genomic instability, Telomere Attrition, Epigenetic Alterations, and Loss of Proteostasis are examples of
Primary Hallmarks
Deregulated nutrient sensing and mitochondrial dysfunction are examples of
Antagonistic Hallmarks
Stem cell exhaustion and Altered intercellular communication are examples of
Integrative Hallmarks
How does aging affect lymphocytes?
- Decreased production of B and T cellsin BM & Thymus.
- Reduced function of mature (CD4 & CD8) lymphocytes in secondary lymphoid tissues.
What is the primary cause of T cell dysfunction in the elderly?
Thymic Involution (fewer naive T cells)
What is the major cause of humoral immunity dysfunction in the elderly?
Diminished B cell proliferation & CD4 T cell help (CD40L)–> poor response to vaccination
How does aging change innate immune cells?
- Expression of MHC II decreases
- Co-stimulation of APC decreases
- Impair the function of neutrophils
- TLR 7,8,9 (viral RNA, DNA) signaling is altered
