Presence of CD4, CD8 double-negative and T-cell receptor-gamma-delta-positive T cells in lymphocyte cultures propagated from coronary arteries from heart transplant patients with graft coronary disease.

Previous studies have shown that the interleukin-2-induced propagation of lymphocytes from endomyocardial biopsy specimens, an indicator of cellular rejection, is associated with the development of graft coronary disease in heart transplant patients. To further investigate the concept of cell-mediated immune responses in graft coronary disease, we have applied the methodologies of interleukin-2-induced propagation of lymphocytes from arterial tissues. In a group of 23 patients, which included 6 heart, 6 kidney, and 11 liver transplant recipients, we observed that arterial lymphocyte growth was significantly associated with obliterative vasculopathy (p less than 0.03). T-cell phenotyping analysis of coronary artery-derived lymphocyte cultures from three heart transplant patients with graft coronary disease showed significant numbers of CD4, CD8 double-negative T cells and T-cell receptor-gamma delta cells, especially when the cultures were established with relatively high doses of 400 U/ml of interleukin-2. These data suggest that the subset of CD4-CD8-, T cell receptor-gamma delta+ T cells may play a role in the pathogenesis and progression of graft coronary disease.

Trichinella spiralis: selective intestinal immune deviation in the rat.

In rats, infections with 100-2000 Trichinella spiralis muscle larvae lead to a prompt immunity that is expressed in parasite expulsion within 14 days. Rats infected with more than 2000 larvae display impaired immunity with rejection delayed by 50% (7 days) or more. Suppression is selective for expulsive immunity as the antifecundity response of rats is directly proportional to dose and is expressed sooner in heavily infected subjects. Suppression of intestinal expulsive immunity was suggested by the fact that, with low doses (2000 larvae or less), worm rejection was inhibited by cortisone, whereas cortisone inhibited antifecundity but had no discernable effect on worm rejection in high-dose infections. Evidence for local immune deviation as opposed to systemic immunosuppression was obtained in experiments using parabiotic rats. When one partner was infected with 6000 worms and the other with 200, the rat infected with 200 parasites showed earlier rejection than was seen in single controls infected with 200 worms. The prolonged survival of high-dose adults was not accompanied by a change in the site of worm residence in the gut. Immunological parameters such as serum antibody levels, the number of activated cells or specific anti-T. spiralis lymphocytes in thoracic duct lymph were all increased in a dose-dependent manner. These experiments therefore demonstrate a novel autoprotective mechanism by which adult T. spiralis selectively reduce the expression of expulsive immunity in the gut.

Failure to detect killer cell activity in rabbits.

Rabbit lymphoid cells from spleen, peripheral blood, and peritoneal cavity lacked killer (K)-cell activity against cell lines of rabbit and human origin, including virus-infected human tumor cells. This lack of activity was not affected by antibody concentration, source of antibodies, effector/target cell ratio, or length of assay. Rabbit leukocytes, however, were capable of lysing antibody-coated chicken erythrocytes. Hamster leukocytes, serving as a known source of K cells, mediated antibody-dependent cellular cytotoxicity against all targets. EA-rosette assays and mixed effector cell competition tests suggested a deficiency in rabbit K-cell activity which is not a result of an inherent lack of Fc receptor-positive cells or of some suppressor mechanism operating in the rabbit cell populations. Our data support the concept that antibody-dependent cellular cytotoxicity may not be a significant in vivo immune mechanism in certain species.

T cell-mediated cytotoxicity induced by Listeria monocytogenes. III. Phenotypic characteristics of mediator T cells.

Cytotoxic thymus-derived lymphocytes (CTL) generated in vitro by restimulating rat cells with Listeria antigen- (LMA) pulsed syngeneic accessory cells were characterized in respect to their surface membrane markers. LM-dependent CTL were devoid of detectable surface immunoglobulin (Ig) and receptors for the Fc region of rabbit IgG. Experiments with monoclonal antibodies to rat T cell markers revealed that these cytotoxic cells have the phenotypic profile W3/13+, W3/25-, MRC OX 8+. LM-dependent CTL also bind the monoclonal antibody, MRC OX 3, which recognizes an Ia-antigen-like determinant on rat cells. Although LM-dependent CTL lack the W3/25 marker, their generation depends on the cooperative interplay of W3/25+ and W3/25- T cells.

T cell-mediated cytotoxicity induced by Listeria monocytogenes. I. Activation of Listeria antigen-responsive T cells.

Soon after rats are infected with Listeria monocytogenes (LM), Listeria antigen- (LMA) responsive lymphocytes are delivered to the animal's thoracic duct. These LM-responsive lymphocytes can be restimulated in vitro by LMA to generate cells that have a potent cytolytic capability. The activation of LMA responsive lymphocytes is immunologically specific and dependent upon the activity of histocompatible accessory cells. Neither cell-free LMA nor LMA-pulsed allogeneic accessory cells can promote a significant cytotoxic response by negatively selected responder lymphocytes. LM-dependent cytolytic lymphocytes differ from natural killer (NK) cells inasmuch as their activation is not facilitated by interferon (IF). Likewise, supernatants from cultures containing specifically sensitized thymus-derived (T) lymphocytes and histocompatible LMA-pulsed accessory cells fail to augment (day 2 and day 3 supernatants actually inhibit) the activation process. The results imply that the successful activation of LM dependent cytolytic lymphocytes requires the cooperative interplay of responder T cells and specific-antigen-pulsed accessory cells.

T cell-mediated cytotoxicity induced by Listeria monocytogenes. II. Specificity of cytolytic effector cells.

Listeria monocytogenes- (LM) antigen-dependent cytotoxic lymphocytes, identified in a companion manuscript as T cells (CTL), can kill a wide variety of target cells, including syngeneic fibroblasts of both fetal and adult origin, and certain allogeneic and xenogeneic tumor cells. Cold target cell inhibition assays revealed that cells susceptible to lysis can block the cytolytic process in a dose-dependent manner, whereas lysis-resistant cells cannot. Several lines of evidence indicate that to realize their cytolytic potential, LM-dependent CTL must bind to their targets. Aggressor cells that adhere to susceptible target cell monolayers have enhanced cytolytic activity when compared with unfractionated cells or cells that do not adhere. LM-dependent CTL fail to kill when they are separated from susceptible targets by an agar barrier. Arguments against the complicity of a soluble mediator in the killing process derive from the rapid (within 3 hr) expression of cytotoxicity in circumstances where cell contact can occur, and the finding that spent medium in which LM-dependent CTL are either activated or assayed is devoid of cytolytic activity. The specificity of LM-dependent CTL suggests that these effector T cells recognize an as yet unidentified array of antigens that are expressed on a variety of rodent cells. Their cytolytic repertoire cannot be ascribed solely to the polyclonal activation of alloreactive T cells, because responder cells that have been negatively selected for a particular RT-1 haplotype can kill target cells bearing these alloantigens.

Stimulation of activated rat T cells in vitro by Listeria monocytogenes antigens.

A soluble extract of Listeria monocytogenes bound firmly and in similar amounts to a variety of rat cells. Cells that bound this material differed in their capacity to stimulate the in vitro proliferation of lymphocytes obtained from the thoracic duct of Listeria-immune donors. The capacity of cells to serve as antigen-presenting cells in this system coincided or closely overlapped the expression on these cells of an Ia antigen-like structure. Three lines of evidence indicate that T cells respond to L. monocytogenes antigen: the responder cells are members of a nylon-wool nonadherent population that lacks readily detectable surface immunoglobulin; they express determinants recognized by the W3/25 monoclonal antibody (a surface marker of rat peripheral T cells); and they are stimulated optimally by L. monocytogenes antigen when the latter is displayed on cells that share a haplotype with the responder lymphocytes.

Autochthonous, allogeneic, and exenogeneic cells as targets for vaccinia immune lymphocyte cytotoxicity.

The cytotoxicity of vaccinia-immune rabbit spleen cells against autochthonous, allogeneic, and xenogeneic vaccinia-infected target cells was studied by using the 51Cr release assay. The results showed that whereas effector cells from rabbit spleen could not lyse the xenogeneic target cells, there was no consistent difference in lysis of autochthonous and allogeneic targets. Antibody-mediated cytotoxicity showed the resistance to cell-mediated lysis in this system not to be the result to reduced virus antigen on the cell surface. The data also showed the established cell line RK13 eas markedly more sensitive to immune spleen cell lysis than short-term rabbit skin fibroblast cultures. The data suggested that it is possible to develop standardized tests to evaluate cell-mediated immunity to virus infections in a noinbred population.