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Biomedical subjects

G W Butcher

Publications and source records attributed to G W Butcher.

108 records · Page 6Linked to original sources
PubMed1980

Isolation of six monoclonal alloantibodies against rat histocompatibility antigens: clonal competition.

We describe the isolation of six clones and some variant derivatives of rat x mouse hybrid myelomas secreting alloantibody against antigens of the rat major histocompatibility complex. Very large numbers of active hybrids were obtained but many were lost early in the post-fusion period; evidence is presented for rapid selective processes operating in uncloned complex hybrid cultures. The results suggest that the secretion of specific immunoglobulin chains is as stable a function in rat x mouse hybrid myelomas as in mouse x mouse hybrid myelomas.

Animals↗
PubMed1979

The role of subregions of the rat major histocompatibility complex in the rejection and passive enhancement of renal allografts.

The laboratory recombinant haplotype H-1acl of the Norway rat has been used in studies of the rejection and passive enhancement of kidney allografts. While the full H-1a haplotype provoked acute rejection, neither of the isolated subregions, H-1Aa and H-1Ba, did so. It was also found that alloantisera raised against either the H-1Aa or the H-1Ba antigens would enhance the grafts. It is suggested that both MHC subregions contain a histocompatibility locus (i) for kidney (as they do for skin) and that in the genetic combinations studied only incompatibility for both provokes a response sufficient for rejection. In other combinations, however, single region incompatibilities may be sufficient.

Animals↗
PubMed1976

Sensitivity of Staphylococcus aureus to unsaturated fatty acids.

Some unsaturated fatty acids were found to inhibit the growth of Staphylococcus aureus. Their effectiveness was related both to the degree of unsaturation and to the configuration of the molecule about the double bonds. Both linoleic acid and linolenic acid increased the proportion of plasmid-negative bacteria in a growing culture of bacteria containing a penicillinase plasmid. This was not due to a 'curing' effect of the fatty acids but was the result of greater sensitivity of the growth of bacteria containing penicillinase plasmid to inhibition by the unsaturated fatty acids. The presence of a plasmid conferring resistance to tetracycline, however, did not make the bacterium more sensitive to inhibition by linoleic or linolenic acids.

Drug Resistance, Microbial↗
PubMedDate not supplied

MHC class II region encoding proteins related to the multidrug resistance family of transmembrane transporters.

The T-cell immune response is directed against antigenic peptide fragments generated in intracellular compartments, the cytosol or the endocytic system. Peptides derived from cytosolic proteins, usually of biosynthetic origin, are presented efficiently to T-cell receptors by major histocompatibility complex (MHC) class I molecules, with which they assemble, probably in the endoplasmic reticulum (ER). In the absence of recognizable N-terminal signal sequences, such cytosolic peptides must be translocated across the ER membrane by a novel mechanism. Genes apparently involved in the normal assembly and transport of class I molecules may themselves be encoded in the MHC. Here we show that one of these, the rat cim gene, maps to a highly polymorphic part of the MHC class II region encoding two novel members of the family of transmembrane transporters related to multidrug resistance. Other members of this family of transporter proteins are known to be capable of transporting proteins and peptides across membranes independently of the classical secretory pathway. Such molecules are credible candidates for peptide pumps that move fragments of antigenic proteins from the cytosol into the ER.

Amino Acid Sequence↗
PubMedDate not supplied

Restoration of antigen presentation to the mutant cell line RMA-S by an MHC-linked transporter.

In mammalian cells, short peptides derived from intracellular proteins are displayed on the cell membrane associated with class I molecules of the major histocompatibility complex (MHC). The surface presentation of class I-peptide complexes presumably alerts the immune system to intracellular viral protein synthesis. Peptides derived from the cytosol must reach the cisternae of the endoplasmic reticulum where they are required for the assembly of stable class I molecules, and it has been proposed that the products of the two MHC-encoded ATP-binding cassette (ABC) transporter genes function to deliver the peptides across the membrane of the endoplasmic reticulum. This idea is supported by experiments in which transfection of a human cell line defective in class I expression with a complementary DNA of one of these genes restored cell surface expression levels. Here we show that the complete phenotype of the mouse mutant cell line RMA-S, in which lack of surface expression of stable class I molecules correlates with an inability to present viral peptides originating in the cytosol, is repaired by the cDNA of the other transporter gene. These results are consistent with the possibility that the two transporter polypeptides form a heterodimer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Electrophoretic resolution of two rat class I alloantigens expressed on (WF X F344)F1 liver cells in primary culture.

Polyvalent alloantisera, prepared by reciprocal immunization of F344 (RT1lv1 haplotypes) and WF (RT1u haplotype) rats, as well as monoclonal antibodies, were used to immunoprecipitate class I alloantigens from detergent extracts of monolayer cultures of 35S-methionine-labelled liver cells. Two-dimensional IEF/SDS-PAGE gel analysis resolved the RT1.Alv1 and RT1.Au class I antigens expressed on the liver cells in culture.

Animals↗