key: cord-0985073-8ymdumhq
authors: Cepica, A.; Derbyshire, J. B.
title: The tissue distribution of spontaneous cell-mediated cytotoxicity effector lymphocytes in swine
date: 1986-05-31
journal: Journal of Comparative Pathology
DOI: 10.1016/0021-9975(86)90056-3
sha: 8bb23c5f4e8c86fda201dd19064d7e48705d69bb
doc_id: 985073
cord_uid: 8ymdumhq

Abstract Peripheral blood lymphocytes, intraepithelial lymphocytes from the small intestine and lymphocytes from the thymus, spleen, mesenteric lymph nodes and Peyer's patches from 5 young adult pigs were used as effector cells in a spontaneous cell-mediated cytotoxicity chromium release assay against PK-15 cells persistently infected with transmissible gastroenteritis virus as targets. Both peripheral blood and intraepithelial lymphocytes caused marked specific chromium release, while the lymphocytes from the remaining tissues were inactive in spontaneous cell-mediated cytotoxicity.

In previous papers, we have described spontaneous cell-mediated cytotoxicity (SCMC) against target cells infected with transmissible gastroenteritis virus (TGEV) by peripheral blood lymphocytes (PBL) and small intestinal intraepithelial lymphocytes (IEL) from young adult pigs (Cepica and Derbyshire, 1983; 1984a) . Spontaneous cell-mediated cytotoxicity against cells infected with Aujeszky's disease virus has also been described (Martin and Wardley, 1984) . These authors found that lung lavage cells, as well as PBL, were capable of causing cytolysis. Spontaneous cell-mediated cytotoxicity against a human myeloid leukemia (K-562) cell line ha.s been studied more extensively. This reaction was demonstrated with porcine PBL by Koren, Amos and Kim ( 1978) and subsequently confirmed by Charley, Petit, Laude and La Bonnardiere ( 1983), Norley and Wardley ( 1983) and by Martin and Wardley ( 1984) . Kim, Huh, Koren and Amos (1980) found that effector cells against K-562 targets were lacking in porcine spleen, thymus, mesenteric lymph nodes, bone marrow and tonsil, but these lymphoid tissues have not been examined for SCMC effector activity against virus-infected target cells. In the present study, we examined suspensions of porcine lymphocytes from thymus, spleen, mesenteric lymph nodes and Peyer's patches, as well as PBL and IEL, for SCMC effector activity against TGEV-infected target cells. Effector cells were obtained from five outbred Yorkshire pigs, approximately 6 months old, which lacked TGEV neutralizing antibodies. Suspensions of PBL and IEL were prepared as previously described (Cepica and Derbyshire, 1983; 1984a) . Spleen, thymus, mesenteric lymph nodes and Peyer's patches were gently minced and passed through a fine mesh screen and the cells were collected in Hanks' balanced salt solution (HBSS). After they were washed twice in HBSS, the cells were resuspended to appropriate concentrations in complete RPMI-I 640 medium (Cepica and Derbyshire, 1984a) . The viability of the isolated cells was shown to be greater than 90 per cent by trypan blue exclusion. Spontaneous cell-mediated cytotoxicity chromium (51Cr) releasa assays were performed as described by Cepica and Derbyshire ( 1983) with PKP15 cells persistently infected with TGEV as targets, at an effector:target cell ratio' of 50 to 1. Appropriate controls were included as before, and all determinations were made in triplicate except for the controls for spontaneous and total 5*Cr release, which were done in sextuplicate. The amounts of 5'Cr A. CEPICA AND J. B. DERBYSHIRE released were determined as counts per minute (cpm) in an automatic gamma counting system. The results of the SCMC assays were expressed as percentage specific 51Cr release, computed as 100 X [ ( mean cpm effector + target cells) --(mean cpm target cells only) t (mean total releasable cpm) -(mean cpm target cells only)].

The results of the SCMC 51Cr release assays on the various lymphocyte populations are shown in Table 1 . Peripheral blood lymphocytes and IEL were the only cells that mediated significant specific "Cr release. While consistently of SCMC were mediated by IEL than by PBL, the differences between mean values of percentage specific "'Cr release (PBL mean = 44.4f 14.5 s.D.; IEL mean = 50.0 f 13.8 s.D.) were not significant at the 5 per cent level by the l-test. The lymphoid cells derived from the thymus, spleen, mesenteric lymph nodes and Peyer's patches were devoid of cytolytic activity, except for the production of marginal amounts of cytolysis by splenic lymphocytes from pig numbers 3 and 4 (Table 1 ). This finding is in agreement with the report by Kim et al. (1980) of Guelph, in partial fulfillment of the requirements for the Ph.D. degree. We wish to acknowledge also the technical assistance of Miss Janis Milliken.

Cytotoxic activities of gut mucosal lymphoid cells in guinea pigs

 Cepica, A. and Derbyshire, J. B. (1983