Liver gamma delta T cells. TCR junctions reveal differences in heat shock protein-60-reactive cells in liver and spleen.

The liver of mice contains elevated percentages of gamma delta T cells when compared with peripheral lymphoid organs. We have now analyzed these cells clonally, by generating a random collection of liver gamma delta T cell hybridomas and sequencing the productively rearranged TCR-gamma and -delta genes in each hybridoma clone. Examining C57BL/10 mice of various ages, we have found that over half of their normal gamma delta T cells are one of two types, V delta 4+ or V delta 6.3+. gamma delta T cell hybridomas generated from mouse liver contain clones that are "spontaneously" reactive, and respond to purified protein derivative from mycobacteria and to a 17-amino acid peptide from mycobacterial heat shock protein-60 (HSP-60). Like similar cells found in newborn thymus or adult spleen, all of the cells showing this HSP-60 reactivity pattern were found to express V gamma 1-J gamma 4-C gamma 4, most in conjunction with V delta 6-J delta 1-C delta, particularly with V delta 6.3. However, the gamma and delta junctional sequences of the V gamma 1/V delta 6+ cells isolated from adult liver differed from those found in adult spleen; being less diverse, their receptors instead resemble those of similar cells from newborn thymus. These data suggest that HSP-60-reactive gamma delta cells in adult murine liver and spleen are independent of each other and may be resident in their respective sites.