Cells from the Lymphoid Progenitor: Lecture 4: Cells and Organs of the Immune System

Three main types of cells develop from the common lymphoid progenitor

B lymphocytes,T lymphocytes, and NK cells

Lymphocytes

appear very similar but different sets carry different clusters of differentiation (CD) molecules on their surface

Lymphocytes include

B cells, T cells, and innate lymphoid cells (especially NKs)

The lymphoid progenitor

differentiates into lymphocytes

T cells are divided into two large groups

CD4+ T cells and CD8+ T cells

B cells express the

B cell receptor (BCR)

T cells express the

T cell receptor (TCR)

BCRs and TCRs

are the result of somatic recombination of the BCR and TCR loci, respesctively

The recombination of BCR and TCR, generates

a population of extremely diverse B and T cells

Innate lymphoid cells (ILCs)

are lymphocytes, but play a major role in innate immunity

Natural Killer Cells (NK)

are cells involved in killing host cells that are infected or transformed (abnormal cells)

What kind of cells to NKs kill

cells that fail to express MHCI or cells that are recognized by antibodies