Limits...
B cell antigen receptor specificity and surface density together determine B-1 versus B-2 cell development.

Lam KP, Rajewsky K - J. Exp. Med. (1999)

Bottom Line: Mice expressing the immunoglobulin (Ig) heavy (H) chain variable (V) region from a rearranged V(H)12 gene inserted into the IgH locus generate predominantly B-1 cells, whereas expression of two other V(H) region transgenes (V(H)B1-8 and V(H)glD42) leads to the almost exclusive generation of conventional, or B-2, cells.In mice coexpressing V(H)12, V(H)B1-8 and a transgenic kappa chain able to pair with both H chains, double H chain-expressing B-2 cells, and B-1 cells that have lost V(H)B1-8 are generated, whereas V(H)B1-8 single producers are undetectable.These data suggest that B-1 but not B-2 cells are selected by antigenic stimuli in whose delivery BCR specificity and surface density are of critical importance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular and Cell Biology, The National University of Singapore, Singapore 117609, Republic of Singapore. mcblamkp@imcb.nus.edu.sg

ABSTRACT
Mice expressing the immunoglobulin (Ig) heavy (H) chain variable (V) region from a rearranged V(H)12 gene inserted into the IgH locus generate predominantly B-1 cells, whereas expression of two other V(H) region transgenes (V(H)B1-8 and V(H)glD42) leads to the almost exclusive generation of conventional, or B-2, cells. To determine the developmental potential of B cells bearing two distinct B cell antigen receptors (BCRs), one favoring B-1 and the other favoring B-2 cell development, we crossed V(H)12 insertion mice with mice bearing either V(H)B1-8 or V(H)glD42. B cells coexpressing V(H)12 and one of the other V(H) genes are readily detected in the double IgH insertion mice, and are of the B-2 phenotype. In mice coexpressing V(H)12, V(H)B1-8 and a transgenic kappa chain able to pair with both H chains, double H chain-expressing B-2 cells, and B-1 cells that have lost V(H)B1-8 are generated, whereas V(H)B1-8 single producers are undetectable. These data suggest that B-1 but not B-2 cells are selected by antigenic stimuli in whose delivery BCR specificity and surface density are of critical importance.

Show MeSH
B cells coexpressing VH12, Vκ4, and VHB1-8, Vκ4 assume a conventional B cell phenotype. Phenotype of the various splenic B cell populations found in B1-8f/+, Vκ4tg; VH12f/+, Vκ4tg; and VH12f/B1-8f, Vκ4tg mice. Cells were stained with antiidiotypic Ac146 and 5C5 mAbs, and with anti-B220, anti-IgD, and anti-CD5 mAbs. Numbers indicate percentage of total splenic lymphocytes.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2195595&req=5

Figure 3: B cells coexpressing VH12, Vκ4, and VHB1-8, Vκ4 assume a conventional B cell phenotype. Phenotype of the various splenic B cell populations found in B1-8f/+, Vκ4tg; VH12f/+, Vκ4tg; and VH12f/B1-8f, Vκ4tg mice. Cells were stained with antiidiotypic Ac146 and 5C5 mAbs, and with anti-B220, anti-IgD, and anti-CD5 mAbs. Numbers indicate percentage of total splenic lymphocytes.

Mentions: The specificity of the BCR is determined by the variable regions of the H and L chains. Thus, the loss of the B-1 phenotype in cells coexpressing VH12 and VHB1-8 or VH12 and VHglD42 may be due to altered Ig L chain usage. It is conceivable that the L chains that associate with both VH12 and VHB1-8 or VH12 and VHglD42 under the condition of H chain allelic inclusion are different from those that normally associate with VH12 alone. This altered L chain usage could affect the specificity of the VH12 receptor and thus could influence the generation and/or selection of B-1 cells. To examine this possibility, we crossed Vκ4 L chain transgenic (tg) mice 8 with VH12f/+, B1-8f/+, and VH12f/B1-8f mice. The Vκ4 gene used in the generation of the transgenic mice was initially isolated from a CD5+ B lymphoma cell line that together with VH12 recognizes PtC 8. In addition, this Vκ4 L chain can also associate with the B1-8 H chain to form a BCR of innocuous specificity. Association of the Vκ4 L chain with either or both VH12 and VHB1-8 is demonstrated in Fig. 2. We had previously shown that the bone marrow pre-B cell compartment is absent in Ig transgenic mice whose H and L chains pair to form a BCR of an innocent specificity 16. This probably reflects the fact that precursor cells carrying functional Ig H and L chain transgenes rapidly differentiate into IgM+ B cells. We have used this phenomenon to examine the association of Vκ4 with both VH12 and VHB1-8. As shown in Fig. 2, B220+ CD43− pre-B cells are present in wild-type and in the various single and double IgH tg mice and represent ∼8% of the cells present. However, this population is fivefold reduced in the B1-8f/+, VH12f/+, and B1-8f/VH12f H chain tg mice that also carry the Vκ4 L chain transgene. This suggests that the Vκ4 L chain can associate efficiently with both VHB1-8 and VH12. Association of Vκ4 with VHB1-8 is also evident in the splenic B cell population of B1-8f/+, Vk4tg mice, as the cells expressing this H and L chain combination are all Ac146 Id+ (Fig. 3, top).


B cell antigen receptor specificity and surface density together determine B-1 versus B-2 cell development.

Lam KP, Rajewsky K - J. Exp. Med. (1999)

B cells coexpressing VH12, Vκ4, and VHB1-8, Vκ4 assume a conventional B cell phenotype. Phenotype of the various splenic B cell populations found in B1-8f/+, Vκ4tg; VH12f/+, Vκ4tg; and VH12f/B1-8f, Vκ4tg mice. Cells were stained with antiidiotypic Ac146 and 5C5 mAbs, and with anti-B220, anti-IgD, and anti-CD5 mAbs. Numbers indicate percentage of total splenic lymphocytes.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195595&req=5

Figure 3: B cells coexpressing VH12, Vκ4, and VHB1-8, Vκ4 assume a conventional B cell phenotype. Phenotype of the various splenic B cell populations found in B1-8f/+, Vκ4tg; VH12f/+, Vκ4tg; and VH12f/B1-8f, Vκ4tg mice. Cells were stained with antiidiotypic Ac146 and 5C5 mAbs, and with anti-B220, anti-IgD, and anti-CD5 mAbs. Numbers indicate percentage of total splenic lymphocytes.
Mentions: The specificity of the BCR is determined by the variable regions of the H and L chains. Thus, the loss of the B-1 phenotype in cells coexpressing VH12 and VHB1-8 or VH12 and VHglD42 may be due to altered Ig L chain usage. It is conceivable that the L chains that associate with both VH12 and VHB1-8 or VH12 and VHglD42 under the condition of H chain allelic inclusion are different from those that normally associate with VH12 alone. This altered L chain usage could affect the specificity of the VH12 receptor and thus could influence the generation and/or selection of B-1 cells. To examine this possibility, we crossed Vκ4 L chain transgenic (tg) mice 8 with VH12f/+, B1-8f/+, and VH12f/B1-8f mice. The Vκ4 gene used in the generation of the transgenic mice was initially isolated from a CD5+ B lymphoma cell line that together with VH12 recognizes PtC 8. In addition, this Vκ4 L chain can also associate with the B1-8 H chain to form a BCR of innocuous specificity. Association of the Vκ4 L chain with either or both VH12 and VHB1-8 is demonstrated in Fig. 2. We had previously shown that the bone marrow pre-B cell compartment is absent in Ig transgenic mice whose H and L chains pair to form a BCR of an innocent specificity 16. This probably reflects the fact that precursor cells carrying functional Ig H and L chain transgenes rapidly differentiate into IgM+ B cells. We have used this phenomenon to examine the association of Vκ4 with both VH12 and VHB1-8. As shown in Fig. 2, B220+ CD43− pre-B cells are present in wild-type and in the various single and double IgH tg mice and represent ∼8% of the cells present. However, this population is fivefold reduced in the B1-8f/+, VH12f/+, and B1-8f/VH12f H chain tg mice that also carry the Vκ4 L chain transgene. This suggests that the Vκ4 L chain can associate efficiently with both VHB1-8 and VH12. Association of Vκ4 with VHB1-8 is also evident in the splenic B cell population of B1-8f/+, Vk4tg mice, as the cells expressing this H and L chain combination are all Ac146 Id+ (Fig. 3, top).

Bottom Line: Mice expressing the immunoglobulin (Ig) heavy (H) chain variable (V) region from a rearranged V(H)12 gene inserted into the IgH locus generate predominantly B-1 cells, whereas expression of two other V(H) region transgenes (V(H)B1-8 and V(H)glD42) leads to the almost exclusive generation of conventional, or B-2, cells.In mice coexpressing V(H)12, V(H)B1-8 and a transgenic kappa chain able to pair with both H chains, double H chain-expressing B-2 cells, and B-1 cells that have lost V(H)B1-8 are generated, whereas V(H)B1-8 single producers are undetectable.These data suggest that B-1 but not B-2 cells are selected by antigenic stimuli in whose delivery BCR specificity and surface density are of critical importance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular and Cell Biology, The National University of Singapore, Singapore 117609, Republic of Singapore. mcblamkp@imcb.nus.edu.sg

ABSTRACT
Mice expressing the immunoglobulin (Ig) heavy (H) chain variable (V) region from a rearranged V(H)12 gene inserted into the IgH locus generate predominantly B-1 cells, whereas expression of two other V(H) region transgenes (V(H)B1-8 and V(H)glD42) leads to the almost exclusive generation of conventional, or B-2, cells. To determine the developmental potential of B cells bearing two distinct B cell antigen receptors (BCRs), one favoring B-1 and the other favoring B-2 cell development, we crossed V(H)12 insertion mice with mice bearing either V(H)B1-8 or V(H)glD42. B cells coexpressing V(H)12 and one of the other V(H) genes are readily detected in the double IgH insertion mice, and are of the B-2 phenotype. In mice coexpressing V(H)12, V(H)B1-8 and a transgenic kappa chain able to pair with both H chains, double H chain-expressing B-2 cells, and B-1 cells that have lost V(H)B1-8 are generated, whereas V(H)B1-8 single producers are undetectable. These data suggest that B-1 but not B-2 cells are selected by antigenic stimuli in whose delivery BCR specificity and surface density are of critical importance.

Show MeSH