Anthony Whyte

Immunology of the tonsils

Abstract The tonsils are lymphoepithelial structures that provide a protective immunological ring at the openings of both digestive and respiratory tracts. Here, as discussed by Marta Perry and Anthony Whyte, the unique nature of the various human tonsils reveals that they are capable of a variety of complex immunological functions.

Infiltrating γδ T-cells and selectin endothelial ligands in the cutaneous phytohaemagglutinin-induced inflammatory reaction

The 24 h phytohaemagglutinin-induced skin inflammatory site (intradermal and subcutaneous) was studied in inbred MHC-homozygous (SLAb/b) pigs and it was found, by immunohistology, that the predominant lymphocytes in the infiltrate are CD2-CD4-CD8-sIg-T-cells, the Null/gamma delta T-cell family, identified using the monoclonal antibodies (mAbs) MAC320 and MAC319 (which recognises a subset of MAC320+ cells). A large percentage of the infiltrating cells expressed the gamma delta T-cell receptor phenotype identified by binding of the mAb 86D. Fewer CD2+, CD8+ and CD4+ cells were present and surface immunoglobulin positive (sIg+) cells were virtually absent in the infiltrate. Areas of lymphocytic infiltration were associated with endothelial activation as determined by expression of the E-selectin and a ligand for the L-selectin.

Transfer of T-cell-mediated, antigen-specific delayed type hypersensitivity reactions to naive recipient inbred pigs.

Using inbred major histocompatibility complex-homozygous SLAb/b pigs, delayed-type hypersensitivity (DTH) reactions against either intradermal tuberculin (PPD) or topical 2,4-dinitro-1-fluorobenzene (DNFB) were transferred specifically by the intravenous injection of approximately 6 x 10(8) blood lymphocytes kg-1 bodyweight from donors sensitised, respectively, either with BCG or with DNFB into three-week-old piglets from an inbred litter. This antigen-specific, passively acquired sensitivity was revealed by three measures of DTH reactivity: first, macroscopic inflammation, which developed at the rate and intensity expected for actively acquired sensitivity to DNFB or PPD in older pigs; secondly, similarly enhanced local specific uptake of intravenously injected 51Cr-labelled normal lymphocytes (more than 35-fold for each); and, thirdly, histological evidence of markedly increased local infiltration of CD45+ lymphocytes and polymorphs, endothelial activation and the expression of adhesion molecules.