Related Experiment Videos
Sequences related to immunoglobulin kappa chain messenger RNA in T cells
Abstract:
We investigated by molecular hybridization whether T cells contain RNA sequences homologous to RNA which codes for immunoglobulin kappa-chain (k-chain). A radioactive probe of complementary DNA (cDNA) was prepared by transcription of purified k-chain mRNA from mouse myeloma MOPC-41 with reverse transcriptase (RNA-dependent-DNA nucleotidyltransferase) from avian myeloblastosis virus. The cDNA probably corresponded only to the constant region and 3'-terminus of k-chain mRNA. Kappa-chain cDNA was found to hybridize efficiently with RNA from both thymus cells and an established culture of thymoma cells. The thymus and thymoma cells contained 99.8% and 100% theta-positive cells, respectively. Quantitatively the average thymus T cell (thymus derived lymphocyte) contained about one half as much k-chain mRNA as the average spleen B cell ("bursa" dependent lymphocyte), whereas the thymoma cells contained only 1/33 as much. Control hybridizations of k-chain cDNA with myeloma and liver RNA support the conclusion that T cells in the thymus and in the thymoma cell line synthesize k-chain mRNA-like molecules. The thermal stability of hybrids of k-chain cDNA with RNA from spleen, thymus, thymoma, and another k-chain producing myeloma tumor was lower than that with MOPC-41 RNA. This finding may be due to the existence of several slightly different ck genes in the mouse as suggested by various control experiments.
Insights
T cells, specifically thymus-derived lymphocytes, contain RNA sequences similar to immunoglobulin kappa-chain mRNA. This suggests T cells may synthesize kappa-chain mRNA-like molecules, though in lower quantities than B cells.
Area of Science:
- Immunology
- Molecular Biology
- Genetics
Background:
- T cells and B cells are key lymphocytes in the immune system.
- Immunoglobulin kappa-chain (k-chain) is a component of antibodies produced by B cells.
- The presence of k-chain mRNA in T cells has not been extensively studied.
Purpose of the Study:
- To investigate whether T cells possess RNA sequences homologous to immunoglobulin kappa-chain (k-chain) mRNA.
- To quantify the amount of k-chain mRNA-like molecules in T cells compared to B cells.
Main Methods:
- Molecular hybridization using a radioactive complementary DNA (cDNA) probe.
- Preparation of k-chain cDNA from mouse myeloma cell line MOPC-41.
- Hybridization of k-chain cDNA with RNA extracted from thymus cells, thymoma cells, spleen cells, and liver cells.
Main Results:
- T cells (thymus and thymoma) showed efficient hybridization with k-chain cDNA, indicating the presence of homologous RNA sequences.
- Thymus T cells contained approximately half the amount of k-chain mRNA as spleen B cells.
- Thymoma cells contained significantly less k-chain mRNA (1/33) compared to spleen B cells.
- Lower thermal stability of hybrids with T cell RNA suggests potential variations in k-chain genes.
Conclusions:
- T cells in the thymus and thymoma cell lines synthesize k-chain mRNA-like molecules.
- The expression of k-chain mRNA in T cells is lower than in B cells.
- Findings suggest the potential existence of multiple, slightly different kappa-chain genes in mice.