Search PubMed⌕ Search

Biomedical subjects

E B Reilly

Publications and source records attributed to E B Reilly.

34 records · Page 2Linked to original sources

Quantitative of anti-NP (4-hydroxy-3-nitrophenyl)-acetyl idiotype expression on spleen and thymus cells.

Direct binding of 125I-labeled rabbit anti-NPb idiotype antibodies (RaId) was used to quantitate the expression by immune spleen and thymus cells of NPbId, the characteristic Id of the lambda 1-containing antibodies made by C57BL/6 (B6) mice to the (4-hydroxy-3-nitrophenyl)acetyl (NP) group. Direct binding of RaId by B and T cell preparations reached a maximum of 12 ng RaId per 10(8) cells at 7 days after immunization. Spleen T cell preparations maintained similar levels of binding after positive selection for Thy-1.2+ cells and overnight culture. RaId binding was also demonstrated for immune B6 thymus cells and for spleen and thymus cells of immune SJL mice, which have the appropriate heavy chain allotype for NPbId expression but have only barely detectable serum Id. However, the NPbId of T and B cell preparations were indistinguishable by (a) the susceptibility of RaId binding by the cells to inhibition by hapten or by antibodies to the variable regions of lambda light chains (anti-V lambda) and by (b) the ability of anti-V lambda and of monoclonal antibodies to the constant region of lambda 1 chains (anti-C lambda 1) to immunoprecipitate antigen (NP10-bovine serum albumin)-binding proteins from detergent extracts of isotopically labeled cells. The results strongly imply that virtually all of the NPbId of T cell preparations is due to conventional NPbId antibody that is tightly bound to T cells. The results do not, however, exclude the possibility that the T cell preparations contain a trace amount (less than or equal to 1 ng/10(8) cells) of unusual NPbId-like molecules that lack lambda chains.

Animals↗

Synthesis of lambda light chain subtypes by stimulated and unstimulated mouse B cells.

Inbred mouse make 3 lambda chain subtypes. The lambda 1 and lambda 3 chains have similar variable (V) regions (in both the same V gene segment [V lambda 1] is used), whereas lambda 2 and lambda 3 have similar constant (C) regions. Despite the lambda 1 and lambda 3 V region similarity, lambda 1 occurs much more frequently than lambda 3 (and lambda 2) in the serum immunoglobulins and antibody responses of most inbred strains of mice. To explore the basis for the lambda 1 predominance, we compared the rates of synthesis of the 3 subtypes and the frequencies of the B cells that synthesize them, focussing on "resting" (i.e., unstimulated) and on polyclonally stimulated B cells from spleens of unimmunized BALB/c mice. In resting cells the relative rates of synthesis and the relative frequencies of the respective B cells were in accord, indicating that the rate of lambda chain synthesis is approximately the same per resting B cell, regardless of the lambda subtype it produces. However, in the polyclonally stimulated cells, lambda 1 was made 7 times faster than lambda 2 and 10 times faster than lambda 3; normalizing these rates by the frequencies of the respective stimulated cells suggests that in stimulated B cells lambda 1 chains are made 5 times faster per cell than lambda 2 or lambda 3, while the latter are made at about the same rate per cell. In view of the marked structural homology between lambda 2 and lambda 3 genes in segments other than the V-gene segment, we suggest that the pronounced differences among polyclonally stimulated B cells in expression of the genes for the various lambda subtypes may be due to the presence of less potent enhancer-like sequences in the lambda 2 and lambda 3 genes than in the lambda 1 gene.

Animals↗

Medical testing.

Explore the source record for details and available documents.

Clinical Laboratory Techniques↗

Synthesis of lambda 1, lambda 2, and lambda 3 light chains by mouse spleen B cells.

To determine whether the infrequency of immunoglobulins with lambda 3 light chains is due to a corresponding scarcity of lambda 3 B cells, the production of the various lambda chain subtypes (lambda 1, lambda 2, and lambda 3) by normal spleen cells was compared. The results showed that lambda 1, lambda 2, and lambda 3 chains are produced in a ratio of about 1.0: 0.7 : 0.3, respectively. The argument is made that lambda 1, lambda 2, and lambda 3 B cells exist in the same ratio. Results obtained with neonatal and nude mouse spleen cells suggest that these small differences are not due to stimulatory effects of environmental antigens or regulatory T cells. The much greater disparity in the abundance of lambda subtypes in various antibody responses and serum Ig suggests that lambda 1 B cells may be more likely than lambda 2 or lambda 3 B cells to differentiate into antibody-secreting plasma cells.

Animals↗

A functional gamma gene formed from known gamma-gene segments is not necessary for antigen-specific responses of murine cytotoxic T lymphocytes.

Structural similarities between surface immunoglobulins (s Ig) on B cells and antigen-specific receptors on T cells suggest that a T cell, like a B cell, should express only two immunoglobulin-like genes, one for each subunit of the disulphide-linked, heterodimeric, antigen-specific (alpha beta) T-cell receptor. However, cytotoxic T lymphocytes (Tc cells) and immature thymocytes also contain RNA transcripts of a third immunoglobulin-like gene, called gamma (refs 1-4). A polypeptide corresponding to the gamma gene has not yet been identified and the function of this gene remains an enigma. Judging from its nucleotide sequence, the rearranged gamma gene is expected to encode an integral membrane polypeptide chain, and gamma complementary DNAs from two cloned Tc cell lines have previously been found to have different sequences around the V-J (variable region-joining region) junction, suggesting that, in these cells, the gamma-gene product is a clonally diverse surface structure that may form part of an as yet unidentified, antigen-specific receptor. To analyse further the extent of diversity of the gamma-gene product, we have determined the partial sequences of 11 gamma cDNA clones from three other cloned Tc cell lines, and report here that the sequences are indeed clonally diverse, but in all instances they are out-of-phase in the region of the V-J junction. This finding and the pattern of gamma-gene rearrangements in these cell lines indicate that a polypeptide product of the previously reported gamma gene, V2J2-C2, is not expressed in them and is, therefore, not necessary for the antigen-specific cytotoxic and proliferative responses of these mature T cells.

Animals↗