Cell Differentiation and Development

Cell Development and Maturation

• Stem cell pool: Hematopoietic stem cell (HSC)
• First progenitor: Common Myeloid Progenitor (CMP) for neutrophils and monocytes, and Common Lymphoid Progenitor (CLP) for B and T cells
• Second progenitor: Granulocyte-Monocyte Progenitor (GMP) for neutrophils and monocytes, and Eosinophil-Basophil Progenitor (EBP) for eosinophils and basophils

Neutrophils

• Development site: Bone marrow
• Stem cell pool: Hematopoietic stem cell (HSC)
• First progenitor: Common Myeloid Progenitor (CMP)
• Second progenitor: Granulocyte-Monocyte Progenitor (GMP)
• Production: 0.9 and 1.0 x 10^9 cells/kg per day
• Transit: 6 days from myeloblast to myelocyte
• Maturation: 3.5 days from myelocyte to mature neutrophil
• Life span: 2 to 5 days
• Function: Phagocytosis and anti-apoptotic signals
• Characteristics: Multilobed nucleus, pink to lavender color, granules that react with both acid and basic stains

Eosinophils

• Development site: Bone marrow
• Stem cell pool: Hematopoietic stem cell (HSC)
• First progenitor: Common Myeloid Progenitor (CMP)
• Second progenitor: Eosinophil-Basophil Progenitor (EBP)
• Maturation time: 3.5 days
• Life span: 60 hours
• Function: Anti-parasitic and anti-inflammatory responses
• Characteristics: Bilobed nucleus, refractile, orange-red secondary granules

Basophils

• Development site: Bone marrow
• Stem cell pool: Hematopoietic stem cell (HSC)
• First progenitor: Common Myeloid Progenitor (CMP)
• Second progenitor: Eosinophil-Basophil Progenitor (EBP)
• Maturation time: 3.5 days
• Life span: 60 hours
• Function: Inflammation and allergic responses
• Characteristics: Lobulated nucleus, acidophilic granules that stain with basic stains

Monocytes and Macrophages

• Development site: Bone marrow and spleen
• Stem cell pool: Hematopoietic stem cell (HSC)
• First progenitor: Common Myeloid Progenitor (CMP)
• Second progenitor: Granulocyte-Monocyte Progenitor (GMP)
• Production: No storage pool of mature monocytes
• Maturation: 2 mitotic divisions in 60 hours = 4 monocytes, or 4 mitotic divisions in 60 hours = 16 monocytes in the presence of infection
• Life span: No storage pool of mature monocytes
• Function: Phagocytosis and antigen presentation
• Characteristics: Indented, horseshoe-shaped or folded nucleus, blue-gray cytoplasm with fine azure granules

Lymphocytes

• Development site: Bone marrow and thymus
• Stem cell pool: Hematopoietic stem cell (HSC)
• First progenitor: Common Lymphoid Progenitor (CLP)
• Second progenitor: B Lymphocyte Progenitor or T Lymphocyte Progenitor
• Function: Adaptive immunity
• Characteristics: Mononuclear cells, not segmented, round, oval, indented, or folded nucleus

Natural Killer Cells

• Development site: Bone marrow and thymus

• Stem cell pool: Hematopoietic stem cell (HSC)

• First progenitor: Common Lymphoid Progenitor (CLP)

• Second progenitor: NK Cell Progenitor

• Function: Innate immunity, killing tumor cells and virus-infected cells

• Characteristics: CD56+CD16+CD3- cells, large granular lymphocytes### G Cell Function

• G cells release preformed cytokines through degranulation, inducing the differentiation of TH2 cells.

• Secretory vesicles in G cells contain specific granules that migrate to the plasma membrane and fuse to empty their contents into the extracellular space.

• This process releases specific proteins into the mucosal surfaces.

Immunosuppressive Functions

• G cells play a role in angiogenesis through the expression of growth factors like VEGF and its receptors.
• They suppress the immune response by degrading antigens and removing proteins from macrophages and dendritic cells.

Immunologic Functions

• G cells act as "gate keepers" due to their location in the mucosal surfaces and their role in barrier function.
• They activate both T lymphocytes and B lymphocytes to initiate the adaptive immune response.
• G cells present antigen fragments on their surfaces, acting as antigen-presenting cells.

Cytolysis

• Cytolysis occurs when extracellular antigens are degraded by G cells, leading to the initiation of the adaptive immune response.

This quiz explores the process of cell differentiation and development, including the formation of neutrophils, macrophages, osteoblasts, and other cell types.