B cell development 2025-26
Across
- 1. This costimulatory molecule on activated T cells binds to CD40 on B cells, providing essential signals for B cell activation, proliferation, and class switching.
- 5. This B cell-attracting chemokine guides B cells to B cell follicles in secondary lymphoid organs where they can encounter antigen and undergo activation.
- 7. - This early developmental stage is characterized by heavy chain gene rearrangement and expression of CD19 and CD10 but lacks surface immunoglobulin.
- 9. This TNF family cytokine promotes B cell survival and maturation, particularly during the transition from immature to mature B cell stages in the periphery.
- 12. This recombinase enzyme, along with RAG 2, catalyzes the V(D)J recombination process that creates diverse immunoglobulin genes in developing lymphocytes.
- 13. This state of functional unresponsiveness occurs when B cells encounter self-antigens without proper costimulatory signals, rendering them unable to mount an immune response.
- 14. This primary lymphoid organ serves as the site of B cell development from hematopoietic stem cells through the immature B cell stage.
- 17. This mechanism ensures that each B cell expresses only one functional heavy chain and one functional light chain by silencing the second allele once a productive rearrangement occurs.
- 18. This process eliminates self-reactive B cells in the bone marrow when they encounter high concentrations of self-antigens during development.
- 19. This cytokine is crucial for early B cell development, promoting survival and proliferation of pro-B and pre-B cells in the bone marrow.
- 20. These enzymes phosphorylate tyrosine residues on signaling proteins downstream of B cell receptor activation, initiating intracellular signaling cascades.
Down
- 2. This process allows activated B cells to change their heavy chain constant region while maintaining antigen specificity, producing different antibody classes like IgG or IgA.
- 3. This cytokine supports the survival and proliferation of early hematopoietic progenitors and is essential for B cell development from stem cells.
- 4. This heavy chain isotype is the first to be expressed during B cell development and forms part of the pre-B cell receptor and mature IgM antibodies.
- 6. This checkpoint ensures that developing B cells have successfully assembled functional immunoglobulin receptors before they can progress to the next developmental stage.
- 8. This Th2 cytokine promotes B cell activation, proliferation, and isotype switching to IgE, playing a key role in allergic responses.
- 10. This salvage mechanism allows immature B cells to escape deletion by continuing light chain gene rearrangement to reduce self-reactivity.
- 11. This temporary light chain substitute (composed of VpreB and λ5) pairs with heavy chains during early B cell development before actual light chains are rearranged.
- 15. - This developmental stage expresses surface IgM for the first time and undergoes tolerance testing in the bone marrow before migrating to peripheral lymphoid organs.
- 16. These specialized stromal cells present antigen to B cells in germinal centers and provide survival signals necessary for affinity maturation and memory cell formation.