Damage in B2m genes and DNA methylation of H-2 genes are involved in loss of expression of class I MHC products on the membrane of LR.4, a cell line derivative of the T-cell lymphoma L5178Y.
We have isolated an H-2 deficient cell line (LR.4) from the T-cell lymphoma L5178Y which grew without restrictions in the peritoneal cavity of different inbred strains of mice. The use of polyclonal anti-H-2 antiserum and complement indicated that LR.4 cells did not express class I determinants on the cell membrane. Southern blots of genomic DNA of LR.4 cells showed that B2m genes were severely damaged and that class I H-2 genes were extensively methylated. Consequently, LR.4 cells failed to transcribe mRNAs for both B2m and class I H-2 genes. On the other hand, specific immunity to LR.4 was demonstrated in C57BL/6J mice since, in subsequent challenges with either LR.4 or EL4.4, LR.4 did not grow, whereas EL4.4 grew and killed the mice. In C57BL/6J mice, rejection of LR.4 was accompanied by the production of cytotoxic antibodies. The immune response induced in C57BL/6J mice was determined by non-H-2 antigenic determinants in LR.4 cells.
Nava
G
G
Departamento de Inmunologia, Universidad Nacional Autonoma de Mexico.
Ocadiz
R
R
Ortega
V
V
Alfaro
G
G
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics*; D005805:Genes, MHC Class I; D007940:Leukemia L5178 / Q000235:genetics* / Q000276:immunology*; D008745:Methylation; D051379:Mice; D008815:Mice, Inbred Strains; D009154:Mutation; D013045:Species Specificity; D014158:Transcription, Genetic
D004273:DNA, Neoplasm