TAILIEUCHUNG - Ebook USMLE road map - Immunology: Part 2

(BQ) Part 2 book "USMLE road map - Immunology" presents the following contents: B cell differentiation and function, T cell differentiation and function, regulation of immune responses, immune tissue injury, protective immunity and vaccines, immune deficiency states, autotolerance and autoimmunity, transplantation. | ION I. The development of a diverse self-tolerant population of antigen-specific B cells is central to creating an adaptive immune system. DIFFERENTIATI AND FUN A. The initial events of lymphopoiesis occur in the fetal liver and bone marrow and do not require exposure to foreign antigens. 1. Hematopoietic stem cells HSC which express CD34 are pluripotent and can become any of the blood cell lineages eg erythroid lymphoid myeloid . 2. Lineage commitment is determined by the hematopoietic inductive microenvironment which includes stromal cell ligands and growth factors Chapter 12 . 3. Interleukin-7 IL-7 is an important growth factor for B and T lymphocyte development. 4. Lymphocyte lineage commitment is indicated by the formation of the lymphoid progenitor cell. 5. Commitment to the B lymphocyte lineage occurs at the progenitor B pro-B cell stage Table 9-1 . a. Most pro-B cells express CD19 as do all subsequent cells of the B cell lineage. b. Recombination activating genes 1 and 2 Rag1 Rag2 and terminal deoxynucleotidyltransferase TdT are expressed in preparation for immunoglobulin Ig locus rearrangements. c. The Ig H chain locus is rearranged by VDJ recombination but H chain polypeptides are not expressed. 6. The pro-B cell differentiates into a precursor-B pre-B cell which expresses a pre-B cell receptor BCR . a. The pre-BCR consists of a membrane p chain an invariant surrogate L chain and Iga and IgP polypeptides. b. Signaling through the pre-BCR induces allelic exclusion at the Ig H locus and rearrangement of the K locus. 7. The pre-B cell differentiates into an immature B cell expressing an authentic BCR. a. The BCR complex consists of membrane p chains K or À light chains and the Iga and IgP polypeptides. b. Immature B cells exit the bone marrow and complete their differentiation into mature B cells in the periphery. c. Most immature B cells die in the periphery unless they encounter antigen. 104 Chapter 9 B Cell Differentiation and Function 105 Table 9-1. .

• Y khoa - Dược
• Usmle road map Immunology
• B cell differentiation
• Regulation of immune responses
• Immune tissue injury
• Protective immunity and vaccines
• Immune deficiency states
• Autotolerance and autoimmunity
• Innate immunity
• Adaptive immunity
• Antigens and antibodies
• Immunoglobulin gene expression
• Antigen recognition by antibody
• Major histocompatibility complex