Comparisons of T cell receptor (TCR) V beta repertoires of lamina propria and peripheral blood lymphocytes with respect to frequency and oligoclonality.

The TCR repertoires of CD4+ and CD8+ lamina propria and peripheral blood lymphocytes (PBL) were compared with respect to V beta frequencies and oligoclonality. Disease-free colon specimens and paired peripheral blood samples were obtained from eight adult patients undergoing surgical resections for colorectal carcinoma. Mononuclear cell were isolated from the lamina propria and peripheral blood and separated into CD4+ and CD8+ cells by immunomagnetic adsorbtion. Analysis of V beta frequencies by qPCR revealed that PBL and lamina propria lymphocytes (LPL) from the same individual have very different repertoires, especially within the CD8+ population. Furthermore, CD8+, but not CD4+, LPL display extensive oligoclonality, similar to that which has previously been reported for CD8+ PBL. However, the oligoclonal receptors observed in CD8+ LPL are, in general, distinct from those observed in CD8+ PBL, and differ for each individual. These observations indicate that the TCR repertoires of LPL are as diverse as PBL, and suggest that LPL and PBL are normally exposed to different sets of antigens. In addition, these observations provide a baseline for examining the effects of various disease states and environmental insults on the LPL repertoire.