A large pre-B cell with a successfully rearranged heavy-chain gene can give rise to a population of small pre-B cells that is expanded by about how much?

Correct answer: 30- to 60-fold

Explanation

After a B cell successfully rearranges its heavy-chain gene and forms a pre-B-cell receptor, it undergoes a burst of proliferation. This expansion, from a large pre-B cell into numerous small pre-B cells, is critical because it creates a large cohort of cells from a single successful heavy-chain rearrangement. Each of these small pre-B cells can then independently rearrange its light-chain genes, greatly increasing the diversity of the resulting B-cell repertoire.

Other questions

Question 1

According to the affinity hypothesis for thymocyte development, what is the outcome for a thymocyte whose T-cell receptor binds to a self peptide:self MHC complex with high affinity?

Question 2

What is the approximate percentage of thymocytes that develop in the thymus but ultimately die there via apoptosis?

Question 3

What is the primary function of the protein AIRE (autoimmune regulator) in the thymus?

Question 4

What is the consequence of a genetic deficiency in the BTK gene in humans?

Question 5

What is the role of the Notch1 signaling pathway in lymphocyte development?

Question 6

What is the characteristic feature of the DN3 stage of thymocyte development?

Question 7

What is the primary mechanism that enforces allelic exclusion at the immunoglobulin heavy-chain locus in a developing B cell?

Question 8

How do B-1 B cells primarily differ from conventional follicular (B-2) B cells regarding their development and function?

Question 9

What is receptor editing in the context of B-cell development?

Question 10

During T-cell development, what is the fate of thymocytes that fail to recognize any self peptide:self MHC complexes on thymic epithelium?

Question 11

What is the key difference between T-cell α-chain and B-cell light-chain gene rearrangement regarding the cessation of the process?

Question 12

Which cell type is primarily responsible for mediating positive selection of developing thymocytes?

Question 14

What is the function of the surrogate light chains, λ5 and VpreB, in B-cell development?

Question 15

Which of the following describes the phenotype of a mature, naive B cell that has recently emerged into the periphery?

Question 16

What is the consequence of a mutation in the transcription factor Foxn1 in mice?

Question 17

Which cytokine receptor component deficiency causes X-linked Severe Combined Immunodeficiency (SCID) by blocking both T-cell and NK-cell development?

Question 18

Which transcription factor is considered essential for the commitment of a progenitor cell to the B-cell lineage, with its absence causing pro-B cells to potentially differentiate into T cells or myeloid cells?

Question 19

What is the human κ to λ light-chain ratio in the mature B-cell population, and what does this ratio correlate with?

Question 20

In the process of T-cell selection, what is agonist selection?

Question 21

What is the final step that allows mature thymocytes to emigrate from the thymus into the bloodstream?

Question 22

Which of the following cell populations is responsible for making 'natural' antibodies, which are constitutively produced IgM antibodies that are important in controlling infections prior to an adaptive response?

Question 23

In B-cell development, what happens to an immature B cell that encounters a multivalent, ubiquitous self-antigen like an MHC molecule in the bone marrow?

Question 24

What is the role of the cytokine BAFF in B-cell development?

Question 25

Positive selection of CD4 T cells is dependent on the T-cell's interaction with which type of molecule on thymic cortical epithelial cells?

Question 26

Which developmental stage of a B-lineage cell is primarily characterized by V-J rearrangement of the light-chain genes?

Question 27

What is the primary characteristic that defines γ:δ T cells that develop in waves in the fetal thymus, such as dendritic epidermal T cells (dETCs)?

Question 28

A deficiency in which protease, expressed in cortical epithelial cells, leads to severely impaired CD4 T-cell development due to its role in processing the class II invariant chain-associated peptide (CLIP)?

Question 29

Which of the following describes an anergic B cell?

Question 30

At which stage of B-cell development does rearrangement of the heavy-chain locus, specifically D to JH joining, predominantly occur?

Question 31

How does the final maturation of transitional B cells into follicular B cells in the spleen differ from the development of B-1 B cells regarding IL-7 dependence?

Question 32

Which transcription factor is upregulated in thymocytes to silence CD4 expression and maintain CD8 expression, committing the cell to the CD8 lineage?

Question 33

In mice, transitional B cells progress from a T1 to a T2 stage in the spleen. This transition is marked by the upregulation of which cell-surface molecule?

Question 34

What is the primary reason that T-cell development is severely blocked in mice with a genetic deficiency in IL-7 or its receptor?

Question 35

Which of the following events initiates the transition from a late pro-B cell to a large pre-B cell?

Question 36

What is the main role of the pre-T-cell receptor (pre-TCR) in thymocyte development?

Question 37

Which of these cell types is NOT found in the thymic medulla?

Question 38

What is the typical outcome for a mature T cell in the periphery that recognizes its specific peptide:MHC ligand on a dendritic cell in the absence of co-stimulation?

Question 39

Which characteristic distinguishes marginal zone B cells from follicular B cells?

Question 40

What is the estimated probability that a developing pro-B cell in humans will successfully generate a functional pre-B cell, considering a theoretical one-in-three success rate for in-frame V-D-J joins on each chromosome?

Question 41

The development of thymocytes into the CD4 or CD8 lineage is coordinated with receptor specificity. What happens to T cells from a TCR-transgenic mouse specific for an MHC class I-restricted antigen when they develop in a mouse that only expresses MHC class II molecules?

Question 42

What is the role of the transcription factor Bcl11b in T-cell development?

Question 43

In the process of rescuing nonproductive immunoglobulin light-chain gene rearrangements, how many successive rearrangements can theoretically occur on a single human kappa locus?

Question 44

Which statement accurately describes the characteristics of the DN2 stage of thymocyte development?

Question 45

Peripheral tolerance for B cells can involve their elimination or inactivation when they encounter self-antigens outside the bone marrow. What happens to transitional B cells that encounter a multivalent self-antigen in the spleen?

Question 46

How many double-positive thymocytes that can recognize a specific self peptide:self MHC complex are estimated to survive the dual screening of positive and negative selection to mature into single-positive T cells?

Question 47

Which of the following is NOT a characteristic of B-1 B cells when compared to follicular B-2 cells?

Question 48

What is the primary cellular location for the final maturation of transitional B cells into long-lived follicular B cells?

Question 49

The enzyme terminal deoxynucleotidyl transferase (TdT) enhances antibody diversity by adding N-nucleotides. At which junctions are these N-nucleotides predominantly found in human immunoglobulin genes?

Question 50

The development of iNKT cells differs from conventional T cells in that it requires interaction with which type of molecule on other thymocytes?