Ebook USMLE road map - Immunology: Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook USMLE road map - Immunology: Part 2
Ebook USMLE road map - Immunology: Part 2
• "iB CELL DIFFERENXlATIOI^j^\ AND FUNCTIONy/^I.rhe development of a diverse, self-tolerant population of anti gen-specific B cells is central to crea Ebook USMLE road map - Immunology: Part 2ating an adaptive immune system.A. The initial events of lymphopoiesis occur in the fetal liver and bone marrow and do not require exposure to foreign antigens.1Hematopoietic stem cells (HSC), which express CD34, arc pluripotent and can liecome any <>l the blood cell lineages (eg. erythroid, lymphoi Ebook USMLE road map - Immunology: Part 2d, myeloid).2Lineage commitment is determined by the hematopoietic inductive microen-vừonment, which includes stromal cell ligands and growth factorsEbook USMLE road map - Immunology: Part 2
(Chapter 12).3ĩnterlcukin-7 (II-7) is an important growth factor lor B and T lymphocyte development.4Lymphocyte lineage commitment is indicated by the• "iB CELL DIFFERENXlATIOI^j^\ AND FUNCTIONy/^I.rhe development of a diverse, self-tolerant population of anti gen-specific B cells is central to crea Ebook USMLE road map - Immunology: Part 2ro-B cells express CD 19 as do all subsequent cells of the B cell lin-b.Recombination activating genes 1 and 2 (Ragl, Rag2) and terminal de-oxynudcotidyltransferase (TdT) are expressed in preparation lor immunoglobulin (lg) locus rearrangements.c.rhe 1g H chain locus is rearranged by VDJ recombinati Ebook USMLE road map - Immunology: Part 2on, but H chain polypeptides arc not expressed.6The pro-B cell differentiates into a prccursor-B (pre-B) cell, which expresses a pre-B cell receptor (Ebook USMLE road map - Immunology: Part 2
BCR).a.rhe pre-BCR consists of a membrane n chain, an invariant surrogate L chain, and Igtx and IgJI polypeptides.b.Signaling through rhe prc-BCR indu• "iB CELL DIFFERENXlATIOI^j^\ AND FUNCTIONy/^I.rhe development of a diverse, self-tolerant population of anti gen-specific B cells is central to crea Ebook USMLE road map - Immunology: Part 2c BCR.a.The BCR complex consists of membrane p chains, K or Ầ light chains, and the Iga and lg(I polypeptides.b.Immature B cells exit the bone marrow and complete their differentiation into mature B cells in the periphery.e. Most immature B cells die in rhe periphery unless they encounter antigen.10 Ebook USMLE road map - Immunology: Part 24Chapter 9: B Cell Differentiation and Function105Table 9-1. Stages of antigen-independent B cell differentiation/3HSC. hematopoietic stem cells; Ig.Ebook USMLE road map - Immunology: Part 2
immunoglobulin; Rag I, Rag2. recombination activating genes I and 2; Tdt. terminal deoxynucleotidyltransferase; Btk, Bruton’s tyrosine kinase.8Mature • "iB CELL DIFFERENXlATIOI^j^\ AND FUNCTIONy/^I.rhe development of a diverse, self-tolerant population of anti gen-specific B cells is central to crea Ebook USMLE road map - Immunology: Part 2dominantly in the peritoneal and pleural cavities.b.B-1 B cells produce natural antibodies thought to be induced by microbial Hora.c.B-l B cells have a limited BCR repertoire.-1.Most B-l B cells produce low-affinity IgM antibodies specific for polysaccharide antigens.-2The BCRs ol B-l B cells contai Ebook USMLE road map - Immunology: Part 2n relatively conserved V regions.B. Selection occurs at several differentiation checkpoints and determines the peripheral B cell repertoire.1PositiveEbook USMLE road map - Immunology: Part 2
selection rescues bone marrow B cells from apoptosis (“death by neglect”) (Table 9-2).a.Positive selection occurs at the prc-B and immature B cell sta• "iB CELL DIFFERENXlATIOI^j^\ AND FUNCTIONy/^I.rhe development of a diverse, self-tolerant population of anti gen-specific B cells is central to crea Ebook USMLE road map - Immunology: Part 2differentiation into mature B cells.d.Positive selection through the BCR probably involves low affinity binding to self-ligands.• "iB CELL DIFFERENXlATIOI^j^\ AND FUNCTIONy/^I.rhe development of a diverse, self-tolerant population of anti gen-specific B cells is central to creaGọi ngay
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