Selection Leads to Maturity by Le Chen

Selection Leads to Maturity by Le Chen https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t Topic 4- B Cell Development. Selection of Paper: A B-cell receptor-specific selection step governs immature to mature B cell differentiation. en-us 2022-06-19 23:29:10 UTC 2025-11-07 18:50:22 UTC hello@padlet.com Creator extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225128741 Student Name: Le Chen
Student Number: 1002640939
Infographic Assignment #4 ]]> 2022-06-19 23:31:11 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225128741 Introduction extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225129325 2022-06-19 23:32:37 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225129325 Background: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225129591 It is pointed out by existing studies that most peripheral immature conventional B cells bearing fraction E will not be able to make it to maturity¹. Whether the cell loss is caused by a stochastic step, or a selective step remains unknown. ]]> 2022-06-19 23:33:10 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225129591 Rationale & Hypothesis: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225129779 The experiment is conducted in order to find out if the cell loss is governed by a stochastic or selective process through comparing the differences in BCR repertoire between immature and mature B cells² in mice model. If the BCR repertoires show significant differences, the process will be proven to be selective. The authors made the hypothesis that the step determining the survival of immature B cell is selective. ]]> 2022-06-19 23:33:39 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225129779 Importance: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225130157 The study is of great importance because it shows that positive selection plays a huge role in BCR repertoire, and it lays the foundation for the evidence showing the receptor-ligand interactions in the survival of lymphocytes². ]]> 2022-06-19 23:34:25 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225130157 Materials & Methods extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225130555 2022-06-19 23:35:21 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225130555 Model organism: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225131074 Transgenic mice.

Image By Maggie Bartlett, NHGRI. - http://www.genome.gov/pressDisplay.cfm?photoID=5006, Public Domain, https://commons.wikimedia.org/w/index.php?curid=19805359]]> 2022-06-19 23:36:38 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225131074 Steps: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225143205 2022-06-20 00:00:42 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225143205 FACS Analysis: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225143968 A step used to purify cell populations based on flow cytometry³.]]> 2022-06-20 00:02:17 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225143968 PCR Amplification: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225144272 A step to ensure that target DNA is sufficient to be analyzed⁴.]]> 2022-06-20 00:02:54 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225144272 Cloning and Sequencing: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225144481 A step in which PCR products were cloned and sequenced². ]]> 2022-06-20 00:03:27 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225144481 Sequence Analysis: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225144710 A step to understand structure and properties⁵.]]> 2022-06-20 00:03:58 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225144710 Statistical Analysis: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225145267 A step to quantitatively test hypothesis².]]> 2022-06-20 00:05:05 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225145267 Overview of Findings extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225145962 2022-06-20 00:06:32 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2225145962 Figure 2 extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123050 Figure from: 1. Levine, M. H. et al. A B-cell receptor-specific selection step governs immature to mature B cell differentiation. Proceedings of the National Academy of Sciences 97, 2743–2748 (2000). Retrieved June 19, 2022, from https://www.pnas.org/doi/full/10.1073/pnas.050552997]]> 2022-06-20 22:35:29 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123050 Figure 3 extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123334 Figure from: 1. Levine, M. H. et al. A B-cell receptor-specific selection step governs immature to mature B cell differentiation. Proceedings of the National Academy of Sciences 97, 2743–2748 (2000). Retrieved June 19, 2022, from https://www.pnas.org/doi/full/10.1073/pnas.050552997]]> 2022-06-20 22:36:17 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123334 First Transgenic Line: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123732 As a significant difference was observed between the frequencies between immature and mature B cells by figure 2, data from the first line is consistent with BCR-specific selection².]]> 2022-06-20 22:37:19 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123732 Second Transgenic Line: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123960 As demonstrated by figure 3, there were differences between the repertoire between immature and mature B cells, data from the second line also proves the hypothesis the process is done selectively.]]> 2022-06-20 22:37:51 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226123960 Control Group: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226124116 As shown in Figure 3, there is no major difference in the repertoire between immature and mature B cells in the control group, suggesting that the process of interest could not be a stochastic one. ]]> 2022-06-20 22:38:14 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226124116 Discussion/Conclusion: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226124787 2022-06-20 22:39:26 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226124787 Major Conclusion: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226144979 The hypothesis stating that the step determining the survival of immature B cells is selective was proved to be true by this set of experiments. Another major finding is that the selection is positive².]]> 2022-06-20 23:20:20 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226144979 Comparing with recent studies: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226145232 Major findings from this study was proven to be consistent with existing studies which examined the importance of continued BCR expression in survival of mature B cells⁶. What was lacking in previous studies is the research on the specificity of the BCR. Role of BCR was further explained in this study.]]> 2022-06-20 23:20:50 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226145232 Sources of error: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226145479 A major source of error comes from the chain-pairing effects. Due to the nature that immature B cells are all high in IgM levels, biases will not be able to affect the subsequent repertoire shift². Thus, whether the selection is negative or positive remains unsolvable. ]]> 2022-06-20 23:21:23 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226145479 Impacts & Implication of findings: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226145675 A significant implication of the experimental findings is that there might be a pre-selection between the environmental antigens and the B cell repertoire. Another implication is that survival of B cells from positive selections can lead to the formation of memory cells due to a ligand-receptor interaction⁷.]]> 2022-06-20 23:21:49 UTC https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226145675 Reference: extradimensionaloracle https://padlet.com/extradimensionaloracle/z8lxfh0sq85g134t/wish/2226146276 1. MP;, A. D. M. F. S. E. L. V. M. C. (n.d.). Peripheral B cell maturation. II. heat-stable antigen(hi) splenic B cells are an immature developmental intermediate in the production of long-lived marrow-derived B cells. Journal of immunology (Baltimore, Md. : 1950). from https://pubmed.ncbi.nlm.nih.gov/8409411/ (Accessed: 19th June 2022)

2. Levine, M. H. et al. A B-cell receptor-specific selection step governs immature to mature B cell differentiation. Proceedings of the National Academy of Sciences 97, 2743–2748 (2000). Retrieved June 19, 2022, from https://www.pnas.org/doi/full/10.1073/pnas.050552997

3. Liao, X., Makris, M. & Luo, X. M. Fluorescence-activated cell sorting for purification of plasmacytoid dendritic cells from the mouse bone marrow. Journal of visualized experiments : JoVE (2016). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5226086/. (Accessed: 19th June 2022)

4. Polymerase chain reaction (PCR) (article). Khan Academy Available at: https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/biotechnology/a/polymerase-chain-reaction-pcr. (Accessed: 19th June 2022)

5. Sequence analysis. Sequence Analysis - an overview | ScienceDirect Topics Available at: https://www.sciencedirect.com/topics/medicine-and-dentistry/sequence-analysis. (Accessed: 19th June 2022)

6. K;, L. K. P. K. R. R. In vivo ablation of surface immunoglobulin on mature B cells by inducible gene targeting results in rapid cell death. Cell Available at: https://pubmed.ncbi.nlm.nih.gov/9323135/. (Accessed: 20th June 2022)

7. MS;, N. Antigen receptor signaling gives lymphocytes a long life. Cell Available at: https://pubmed.ncbi.nlm.nih.gov/9323124/. (Accessed: 20th June 2022)

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