Chinese strains (Type 7) of JC virus are afro-asiatic in origin but are phylogenetically distinct from the Mongolian and Indian strains (Type 2D) and the Korean and Japanese strains (Type 2A).

We have further characterized the Asian genotypes (Types 2 and 7) and subtypes of JC virus (JCV). Urine samples from 224 individuals with Han and Mongolian populations were collected in five regions in eastern China: Kunming, Chengdu, Shenyang, Chifeng, and Manzhouli. Also, 99 urine samples were collected from coastal and hill groups in Kerala, southern India, and 23 urine samples from Seoul, Korea.

Genotypes of JC virus in East, Central and Southwest Europe.

Distinctive genotypes of JC virus have been described for the major continental landmasses. Studies on European-Americans and small cohorts in Europe showed predominantly Type 1. Types 2 and 7 are found in Asia, and Types 3 and 6 in Africa.

Cytotoxic T lymphocyte escape variants, induced mutations, and synthetic peptides define a dominant H-2Kb-restricted determinant in simian virus 40 tumor antigen.

Immunization of C57BL/6 mice with syngeneic cells transformed by simian virus 40 large T antigen (SV40 T ag) induces the generation of T antigen-specific cytotoxic T lymphocytes (CTL) which are restricted by the major histocompatibility class I antigens H-2Db and H-2Kb. Previous studies have shown that the H-2Db-restricted CTL response is directed to at least three distinct epitopes (I, II/III, and V) in the SV40 T antigen which have been precisely mapped using deletion mutagenesis and overlapping synthetic peptides. Although in vivo the CTL response to SV40 T antigen is dominated by the H-2Kb class I antigen, the precise location of the H-2Kb-restricted epitope(s) was not known, and whether there was multiplicity of H-2Kb-restricted epitopes remained unclear.

Evidence for a functional interaction between the beta chain of major histocompatibility complex class II and the T cell receptor alpha chain during recognition of a bacterial superantigen.

Several studies have suggested that there is a direct interaction between the T cell receptor (TCR) and the major histocompatibility complex (MHC) molecule during T cell recognition of superantigen. To further investigate this possibility, we have analyzed T cell recognition of a bacterial superantigen, Staphylococcal enterotoxin B (SEB), presented by a series of mutant murine I-Ek molecules in which residues of either the alpha or beta chain predicted to interact with the TCR have been substituted. Individual T cell hybridomas gave distinct patterns of responsiveness to SEB presented by the I-E beta k mutants that could not be attributed to differences in the binding of SEB to the mutants.

MHC-specific recognition of a bacterial superantigen by weakly reactive T cells.

Previous studies have suggested that MHC class II polymorphism can influence the recognition of retroviral superantigen by murine T cells that have an intrinsically weak avidity for the superantigen. The aim of the present study was to determine whether bacterial superantigen recognition also is influenced by MHC polymorphism. Therefore, we screened for TCR with a low avidity for the bacterial superantigen SEB, and identified two V beta elements (V beta 14 and V beta 16) that had not been associated previously with SEB recognition.