The cytotoxic action of OK-432 from Streptococcus pyogenes.
Explore the source record for details and available documents.
Antineoplastic Agents↗
Biomedical subjects
J C Hiserodt
Publications and source records attributed to J C Hiserodt.
Lymphokine-activated killer (LAK) cell purging of leukemic bone marrow: range of activity against different hematopoietic neoplasms.
Natural killer cells activated in vitro by incubation with IL-2 display a broad range of cytolytic activity against neoplastic cells. These lymphokine-activated killer (LAK) cells can discriminate between neoplastic and normal bone marrow cells and may represent a useful means of purging bone marrow prior to autologous transplantation. We demonstrate that LAK cells can successfully remove four distinctly different malignant hematopoietic cell types from normal bone marrow grafts. The LAK purging technique is capable of a 2-3 log10 reduction in tumor cells in the bone marrow graft without compromising hematological recovery or survival. Our results also suggest, however, that an inhibitory effect on stem cell function by allogeneic LAK cells exists, and this form of purging may be used only if greater levels of bone marrow are transferred in an allogeneic setting. The ability to detect and eliminate malignant cells in bone marrow prior to use for autologous transplantation suggests that LAK cells, alone or in conjunction with current methods of bone marrow purging, could be useful for the in vitro treatment of bone marrow in patients who require high-dose chemotherapy and autologous bone marrow transplantation.
Animals↗
Laminin receptor expression on murine tumor cells: correlation with sensitivity to natural cell-mediated cytotoxicity.
Previous studies have identified a relationship between the presence of cell surface laminin receptors on murine tumor cells and sensitivity to killing by natural killer (NK) cells. On the basis of these observations, we suggested that laminin and laminin receptors may function to facilitate the interaction of NK-sensitive murine target cells with NK cells. Our original studies were conducted with a number of genetically unrelated tumor cell lines. In order to extend these earlier observations, studies have now been conducted in which sensitivity to NK-mediated lysis and responsiveness to laminin were compared in a number of variant populations derived from the NK-sensitive cell lines Yac-1 and RL-1 and from the NK/NC-resistant line P815. All of the lines which interacted with murine NK cells as indicated by sensitivity to killing and/or by ability to "cold-target" compete with the killing of sensitive Yac-1 cells were able to bind 125I-laminin and to respond to laminin in an aggregation assay. Of 4 NK-resistant populations identified in these studies, 3 failed to respond to laminin. These studies indicate that even among genetically related tumor cell lines there is a relationship between laminin receptor expression and interaction with NK cells.
Animals↗
Monoclonal antibody to a triggering structure expressed on rat natural killer cells and adherent lymphokine-activated killer cells.
To study the cellular structures involved in NK and lymphokine-activated killer (LAK) cell function, we have produced a panel of mAbs that modulate the cytolytic function of a population of cells with LAK activity that derive from large granular lymphocyte (LGL)/NK cells (adherent LAK [A-LAK] cells). In this report, we describe an mAb (3.2.3; IgG1k) that recognizes a triggering structure that is expressed on rat LGL/NK cells and A-LAK cells. This epitope is also expressed on polymorphonuclear leukocytes (PMN). The expression of the epitope identified by mAb 3.2.3 increased progressively on A-LAK cells after culture in the presence of rIL-2. mAb 3.2.3 enhanced the cytolytic activity of NK and A-LAK cells against FcR+ target cells, but not FcR- target cells. However, this effect was not induced by F(ab')2 fragments of 3.2.3. This antibody also induced the release of N-alpha-benzyloxycarbonyl-L-lysine thiobenzy esteresterase by A-LAK cells. These data suggest that the epitope identified by mAb 3.2.3 is on a triggering structure expressed on rat NK cells and A-LAK cells. The expression of the epitope recognized by mAb 3.2.3 on LGL/NK cells and PMN suggests that this structure may be analogous to that identified by the anti-CD16 (-FcR) mAbs. However, the molecule immunoprecipitated by mAb 3.2.3 was a 60-kD dimer composed of two 30-kD chains. These data suggest that mAb 3.2.3 recognizes a unique triggering structure. As mAb 3.2.3 is the first antibody recognizing a determinant with functional significance, selectively expressed on both rat NK cells and A-LAK cells, it will be a useful tool for the study of NK cell ontogeny and function, and the development of cells with LAK activity from the NK cell compartment.
Animals↗
Enhanced antimetastatic activity of lymphokine-activated killer cells purified and expanded by their adherence to plastic.
We have recently reported a simple and reproducible technique for the purification and rapid expansion of homogeneous populations of large granular lymphocytes expressing a natural killer cell phenotype and high levels of broad antitumor cytotoxic activity [lymphokine-activated killer (LAK) activity]. This technique exploits the observation that, in the presence of recombinant interleukin 2 (rIL-2), large granular lymphocytes/natural killer cells become adherent to plastic surfaces, actively proliferate, and acquire high levels of LAK activity. Because of their adherent properties these cells have been termed adherent LAK or A-LAK cells. The present studies investigate the antimetastatic effects of A-LAK cells in a syngeneic rat model of experimental pulmonary and hepatic metastases. For pulmonary metastases, F344 rats received i.v. injections with a natural killer-resistant mammary adenocarcinoma, MADB106, and, for hepatic metastases, animals received an intrasplenic injection of MADB106 tumor cells followed by surgical splenectomy. Three days later, the animals were treated with A-LAK cells alone, A-LAK cells plus rIL-2, or rIL-2 alone. These treatments were compared to immunotherapy using standard cultures of LAK cells (unfractionated spleen cells) and rIL-2. The results indicate that the administration of unfractionated LAK cells plus interleukin 2 (IL-2) was effective in reducing established lung or liver metastases in this rat model. However, the results also indicate that purified populations of A-LAK cells in combination with rIL-2 demonstrate dramatic and superior antimetastatic effects when compared to LAK cells cultured under standard conditions. The antimetastatic effects of standard LAK cells or A-LAK cells plus IL-2 translated into significant survival benefits compared to animals receiving no therapy or IL-2 therapy alone. Survival after therapy with A-LAK cells plus IL-2 was significantly prolonged compared to treatment with standard LAK cells. These data suggest that purified populations of LAK cells (derived from natural killer cells) may prove superior for adoptive immunotherapy in the clinical setting.
Animals↗
Generation and characterization of purified adherent lymphokine-activated killer cells in mice.
During the incubation of murine spleen, lymph node, or bone marrow cells with IL-2 (1000 U/ml) a small percentage of cells became adherent to the surface of plastic tissue culture flasks. After removal of the non-adherent lymphoid cells, plastic adherent lymphokine-activated killer (LAK) cells could be efficiently expanded in the presence of IL-2. Plastic adherent-derived A-LAK cells were characterized by high rates of proliferation and their cytotoxic activity was more than 10 fold higher than LAK cells generated in the bulk (unfractionated) spleen cell cultures. A-LAK cells could be continuously generated from the non-adherent cell population. Using multiple transfers (every 1 to 2 days) of non-adherent LAK cells into new flasks, new rounds of plastic adherent cells were generated with high expansion capability and high levels of cytotoxic activity. Morphologically, A-LAK cells were large granular lymphocyte and phenotypically expressed markers characteristic of NK cells (asialo GM1+, NK1.1+, Qa5+, Ly-6.2+, Thy-1.2+, but negative for Lyt-2.2 and L3T4). A-LAK cells generated from mice of different strains expressing low and high levels of NK cell activity were equally highly cytotoxic. However, A-LAK cells obtained from nude or beige mice had relatively lower levels of cytotoxicity. Stimulation of NK cell activity by poly I:C or inhibition by in vivo or in vitro treatment with anti-asialo GM1 serum did not affect the generation of A-LAK cells. A-LAK cells derived from spleen or bone marrow of C57BL/6 or nude mice treated with anti-asialo GM1 serum were found to be asialo GM1+ suggesting that A-LAK cell could be generated from the asialo GM1- precursor cells. Expansion of plastic adherent A-LAK cells in the presence of IL-2 could provide large numbers of highly purified cytotoxic A-LAK cells suitable for cancer immunotherapy.
Animals↗
Lymphokine-activated killer cells in rats: generation of natural killer cells and lymphokine-activated killer cells from bone marrow progenitor cells.
The coculture of rat bone marrow cells with recombinant interleukin-2 induced the generation of cells mediating natural killer (NK) activity and subsequent lymphokine-activated killer (LAK) activity depending upon the dose of IL-2 and time of culture. NK activity was detected as early as 4 to 5 days after the addition of IL-2 and could be evoked with as little as 5 to 50 U/ml. The induced NK cells had large granular lymphocyte (LGL) morphology and expressed 0X8 and asialo GM1 surface markers but did not express 0X19 or W3/25 markers. LAK activity was detected only after 5 days of culture, and required above 100 U/ml IL-2. Cells mediating LAK activity also expressed 0X8 and asialo GM1 but not 0X19. The generation of detectable NK and subsequent LAK activity was due to induction of early progenitor cells and not contaminating mature LGL/NK cells within the bone marrow population since of removal of such mature NK cells with L-leucine methyl ester (L-LME) did not affect the subsequent generation of either activity. Moreover, the removal of actively dividing cells as well as mature NK cells from the bone marrow by treatment with 5-fluorouracil (5-FU) in vivo enriched the remaining bone marrow population for both NK and LAK progenitor cells. The phenotype of the L-LME- and 5-FU-resistant NK and LAK progenitor cells within populations of bone marrow was determined by antibody plus complement depletion analysis. Although treatment of normal bone marrow with anti-asialo GM1 + C reduced the induction of NK and LAK activity in 5-day cultures, treatment of 5-FU marrow with anti-asialo GM1 + C did not affect either activity. Treatment with a pan-T cell antibody + C did not affect the development of NK or LAK activity under any conditions. Thus, the 5-FU-resistant NK/LAK progenitors were asialo GM1 negative but became asialo GM1+ after induction by IL-2. Finally, evidence that bone marrow-derived LAK cells were generated directly from the IL-2-induced NK cells was obtained by treating the IL-2-induced LGL/NK cells with L-LME.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
The importance of splenectomy for the adoptive immunotherapy of cancer.
Adoptive immunotherapy (AIT) of cancer using lymphocytes cultured in vitro in interleukin-2 (LAK cells) has gained much attention due to the high level of broad anti-tumor activity both in vitro and in vivo. A major hypothesis has suggested that if unfractionated lymphoid cells grown in IL-2 can mediate significant anti-tumor effects then purified LAK effector cells should yield even higher activity. Furthermore, devising new techniques to achieve optimal expansion of the purified LAK effector cells would further improve this form of immunotherapy. In this report we present data on a new method for purifying and expanding LAK effector cells obtained from the peripheral blood and spleen. The results indicate that as a source of LAK cells, the spleen is superior both quantitatively ani qualitatively when compared to peripheral blood and should be seriously considered as the source of cells for AIT of cancer.
Cytotoxicity, Immunologic↗
Mechanisms of target cell killing by natural killer cells.
Understanding of the lytic process of NK cells has been greatly advanced in the past decade. However, the definition of the primary event required for lysis has been elusive. The recent enthusiasm about the granule exocytosis/PFP model of membrane damage has been tempered by the multitude of factors that cytotoxic effector cells can secrete and the observation of rapid nuclear degradation before membrane damage which is not well explained by the PFP model. Logically, one would expect that this array of cytotoxic, cytostatic and immunoregulatory factors are secreted for a purpose, and should, therefore, be involved in the lysis of target cells. Further studies are necessary to define the role of each of these factors in plasma membrane and nuclear damage. Additional experiments to determine whether these two events are related will be necessary. On the basis of information currently available, one could hypothesize that after recognition of foreign cells, the NK cell is not single-minded in its delivery of lethal factors. The end result is that target cell lysis may occur because of many factors acting not only on the target cell itself but also on other components of the host immune response.
Animals↗
Natural killer cells and tumor immunity: 1987.
Explore the source record for details and available documents.
Animals↗
The expression and functional involvement of laminin-like molecules in non-MHC restricted cytotoxicity by human Leu-19+/CD3- natural killer lymphocytes.
We have recently reported a simple technique for the purification of large granular lymphocyte/NK cells with broad anti-tumor cytotoxicity (lymphokine-activated killer (LAK) activity) by the induction of their adherence to plastic surfaces by recombinant IL-2. Using this technique with nylon wool passed human peripheral blood or splenic lymphocytes we generated populations of adherent LAK (A-LAK) cells which were 80 to 95% large granular lymphocyte and up to 97% Leu-19+ cells. Using two-color fluorescence and cell sorting we now demonstrate that these same cells express a high density of surface structures which are immunochemically cross-reactive with affinity purified anti-laminin antibody. Laminin-like structures were expressed on 80 to 90% of Leu-19+/CD3- LAK cells but were not expressed on resting CD3+/CD4+/Leu19- T cells or CD3+/CD8+/Leu19- T cells. Laminin-like molecules were also expressed on resting Leu19+/CD3- large granular lymphocyte/NK cells (purified to more than 98% by cell sorting) and increased in intensity as these cells developed LAK activity in response to rIL-2. The functional involvement of laminin-like molecules in NK and LAK cytotoxicity was demonstrated by the ability of affinity purified anti-laminin F(ab')2 antibody to inhibit cytolytic activity in a dose-dependent manner (50% inhibition with 10 to 20 micrograms F(ab')2). Analysis of the mechanism of inhibition using single cell cytotoxicity assays indicated that the laminin-like structure was involved in activation of cytotoxicity and not in primary target cell adhesion. We believe that this structure may function as a novel recognition/activation structure used by cells mediating non-MHC restricted cytotoxicity.
Antibodies, Monoclonal↗
A new approach to generating antitumor effectors for adoptive immunotherapy using human adherent lymphokine-activated killer cells.
Lymphocytes from human peripheral blood incubated with interleukin-2 (IL2) develop lymphokine-activated killer (LAK) activity with the ability to kill a wide variety of tumor cells in a non-major histocompatibility complex-restricted manner. Adoptive immunotherapy with LAK cells and IL2 has been reported to lead to a regression of solid tumors in some patients with advanced malignancies. Aiming to improve the effectiveness of clinical adoptive immunotherapy, we developed a procedure for selective enrichment from human blood mononuclear cells (MNC) of IL2-activated antitumor effector cells. These cells, termed adherent LAK (A-LAK) cells because of their characteristic property of adherence to plastic, demonstrated both higher proliferative potential and greater antitumor cytotoxicity than unseparated MNC. Human A-LAK cells represented only 1 to 4% of IL2-activated MNC at 24 h but expanded from 130- to 1100-fold in 20 days. They comprised a population highly enriched in CD3-Leu19+ effector cells with antitumor activity against fresh human solid tumor cells and established cell lines. A-LAK cells retained antitumor activity for up to 14 days when cultured in the presence of IL2. They also mediated antibody-dependent cytotoxicity. Large-scale generation of A-LAK cells from the blood of patients with cancer proved feasible and should yield populations that are effective in vivo at lower doses than those required with unseparated LAK cells. This offers the potential for improving the antitumor effects, reducing the toxicity, and facilitating the administration of adoptive immunotherapy in humans. A Phase I/II clinical trial utilizing A-LAK cells and IL2 in patients with melanoma and renal cell carcinoma is now in progress.
Cell Separation↗
Lymphokine-activated killer cells in rats. IV. Developmental relationships among large agranular lymphocytes, large granular lymphocytes, and lymphokine-activated killer cells.
The developmental relationships among large agranular lymphocytes (LAL) large granular lymphocytes (LGL) and the activation of these cells into lymphokine-activated killer (LAK) cells by rIL-2 was investigated. Highly enriched populations of LAL were isolated from Fischer 344 spleen cells by a combination of nylon-wool filtration (to remove B cells and macrophages), treatment with a pan T cell antibody plus complement (to remove T cells) and incubation in L-leucine methyl ester (to remove LGL). The resultant cells were highly enriched in morphologically identifiable LAL which expressed asialo GM1 and partially expressed the OX8 surface marker. The enriched LAL did not contain detectable NK cytotoxic activity, did not express pan T cell (OX19), Ia, Ig, or laminin surface markers and contained less than 0.2% LGL. Incubation of LAL in a low dose of rIL-2 (100 U/ml) induced the generation of LGL having NK activity within 24 h of culture. Longer culture periods (48 h) resulted in a continued increase in the percentage of LGL and higher levels of NK activity. However, with this low dose of rIL-2, little or no LAK activity (i.e., reactivity against NK-resistant target cells) was generated. With a high dose of rIL-2 (500 U/ml), LAL responded by first generating LGL with NK activity (within 24 h), with subsequent generation of LAK activity by 48 h. Evidence that the development of granular lymphocytes from LAL was responsible first for NK activity and then LAK activity was demonstrated by depletion of the generated granular NK or LAK effector cells by second treatments with L-leucine methyl ester. Concomitant with the induction of LGL with NK or LAK activity, rIL-2 also caused LGL to proliferate and expand four- to five-fold in 48 h. This occurred in the presence of high or low dose rIL-2. These results indicate that LAL are the precursors of LGL/NK cells, that LAL, LGL/NK cells and LAK cells appear to represent sequential developmental or activation stages and that LAL may comprise major source of LAK progenitors in lymphoid populations having few LGL or mature active NK cells.
Animals↗
Suppression of natural killer cytolytic activity in mice undergoing pulmonary granulomatous inflammation.
CBA/J mice undergoing pulmonary granulomatous inflammation exhibited depressed NK cytolytic activity. Granulomas induced by i.v. embolization of Schistosoma mansoni eggs (hypersensitivity type) or Sephadex beads (foreign body type) both caused reduced NK activity, although hypersensitivity granulomas induced a significantly higher level of NK suppression. Kinetic analysis of hypersensitivity lesions at 4, 8, 16, and 32 days post-embolization indicated that NK activity was significantly suppressed by day 8, maximally suppressed by day 16 (at the peak of the inflammatory response) then returned to near control values by day 32 (as the granulomas resolved). Suppression of NK activity ranged from three- to 15-fold in different experiments. NK cells obtained from both spleen and peripheral blood demonstrated reduced NK activity with kinetic patterns similar to the granuloma NK cells. Suppression was not due to reduced splenic NK cells as the frequency of YAC-1 binding cells, as well as asialo GM1+ or laminin+ cells remained constant over the entire study period. Suppression of NK activity did not appear to be due to serum components or suppressor cells present in the spleen preparations. However, the suppression of NK activity could be reversed by overnight incubation of spleen cells at 25 or 37 degrees C or daily treatment of the mice with indomethacin. Suppression also appeared relatively specific for NK cells as the generation and expression of cytotoxic T lymphocyte activity was not affected.
Animals↗
Lymphokine-activated killer cells in rats: analysis of tissue and strain distribution, ontogeny, and target specificity.
The coculture of lymphoid cells from Fischer 344 rats with recombinant human interleukin 2 (rIL-2) resulted in the generation of lymphokine-activated killer (LAK) cells. Maximal LAK activity was obtained between 200 and 1000 units/ml rIL-2. Lymphoid cells from spleen, thymus, bone marrow, peripheral blood, and lymph nodes were able to generate LAK activity although the kinetics and magnitudes of the responses were appreciably different among these tissues. Thus, while spleen and blood lymphocytes responded quickly (by day 3) and gave the highest level of LAK activity in response to rIL-2, bone marrow and thymus cells responded only by 7 to 9 days in culture. LAK activity could be generated from a variety of rat strains regardless of whether there were high or low levels of endogenous splenic natural killer (NK) activity, but the early (day 3) response was lower in the strains with low levels of NK activity. Cells with LAK activity could lyse a variety of tumor targets including fresh ascites or fresh syngeneic solid tumor explants but could not lyse fresh normal cells including syngeneic fibroblasts, peripheral blood lymphocytes, bone marrow cells, thymocytes, or T,B blasts. The generation of LAK activity required a concomitant proliferative response and could be completely abrogated by mitomycin C, actinomycin D, or X-irradiation above 500 rads. These treatments, however, did not affect natural killer activity or short-term (4 h) IL-2-boosted NK activity. LAK activity could be generated from spleen cells obtained from rats as early as 10 days of age but could not be generated from unfractionated neonatal spleen, neonatal liver, or peritoneal macrophages. The ontogeny of the development of splenic LAK activity correlated closely to the development of concurrent natural killer activity. When mixed with an NK-resistant mammary adenocarcinoma (MADB106) and adoptively transferred to normal syngeneic recipients in standard Winn-type assays, LAK cells were effective at inducing complete tumor inhibition.
Animals↗
Lymphokine-activated killer cells in rats: analysis of progenitor and effector cell phenotype and relationship to natural killer cells.
The progenitor and effector cell phenotype of lymphokine-activated killer (LAK) cells generated in F344 rats by recombinant human interleukin 2 (IL-2) (rIL-2) were analyzed. Highly purified populations of peripheral blood large granular lymphocytes (LGL) exhaustively depleted of T-cells were fully capable of generating high levels of LAK activity by 3 to 5 days in culture while purified populations of resting T-cells devoid of LGL could not generate LAK activity. This pure population of LGL expressed surface markers characteristic of rat natural killer (NK) cells [i.e., OX8+, asialomonoganglioside (asialo-GM1+), laminin+, OX19-, R1-3B3-, W3/25-, Ia-, surface immunoglobulin negative (SIg-)]. Further evidence that NK cells were the progenitors of cells with LAK activity was obtained by treatment of spleen or peripheral blood lymphocytes with anti-laminin or anti-asialo-GM1 antibodies plus complement or with the lysosomotropic agent L-leucine methyl ester. These treatments effectively depleted LGL/NK cell activity and the subsequent generation of rIL-2-induced LAK activity. Analysis of the LAK effector phenotype by cell sorting demonstrated that the majority of cells with LAK activity were OX8+, asialo-GM1+, laminin+, OX6+, OX19-, R1-3B3-, W3/25-, and SIg-. Furthermore, treatment of LAK cells with L-leucine methyl ester also significantly reduced their cytolytic activity. Thus, the LAK effector cells were also LGL and expressed surface marker characteristic of activated NK cells and not those of mature T- or B-cells. The proliferative response of rat spleen or blood lymphocytes to rIL-2 appeared to be primarily associated with LGL/NK cells since depletion of NK cells by anti-asialo-GM1 or anti-laminin antibody plus complement or by L-leucine methyl ester significantly (P less than 0.001) reduced the incorporation of [3H]thymidine into DNA. In contrast, depletion of T-cells (by anti-T-cell antibody plus complement) did not significantly affect rIL-2-induced proliferation. Similarly, T-cell-depleted, highly purified populations of LGL gave substantial proliferative responses to rIL-2. These studies clearly indicate that in the rat, the major cell population activated by rIL-2 is the LGL/NK cell and these cells appear to represent the major population of cells in blood or spleen which generate broad antitumor (LAK) cytotoxicity.
Animals↗
Lymphokine-activated killer cells in rats. III. A simple method for the purification of large granular lymphocytes and their rapid expansion and conversion into lymphokine-activated killer cells.
A simple method for the purification and rapid expansion of large granular lymphocytes into cells with efficient broad antitumor cytotoxicity after stimulation by human rIL-2 is described. Nylon-wool nonadherent splenic mononuclear leukocytes from Fischer 344 rats were cultured in medium containing 1,000 U/ml rIL-2. The initial response of a small subpopulation of cells (less than 2%) to rIL-2 was their adherence to the plastic surface. This response was noted as soon as 2 h after addition of rIL-2. 2-h rIL-2-activated plastic adherent lymphocytes were 90-98% LGL, expressed surface markers characteristic of rat NK cells (OX8 [CD8]+, asialo GM1, laminin+, OX19 [CD5]-, R1-3B3 [CD5]-, W3/25 [CD4]-, OX39 [CD25]-, Ia-, and Ig-), and expressed very high levels of cytotoxicity against YAC-1 target cells. In addition to the above markers, plastic-adherent LGLs obtained at 24, 48, or 72 h progressively expressed Ia surface antigens, but were not phagocytic and contained less than 1% monocytes/macrophages by morphology. When 24- or 48-h plastic-adherent LGL/NK cells were cultured over 3-4 d in rIL-2, the cells expanded between 30- and 100-fold, reaching densities between 2-3 X 10(6) cells/ml. These rapidly expanding LGL/NK cells also generated very high levels of LAK activity (including lysis of fresh NK-resistant solid tumor cells), expressed a phenotype characteristic of activated rat NK/LAK cells, and incorporated [3H]TdR into DNA. This technique not only provides a novel method for the purification of LGL/NK cells for in vitro studies but also provides a means for the rapid expansion of highly purified cells with high levels of broad antitumor (LAK) cytotoxicity.
Animals↗
Reduced natural killer cell activity in patients with systemic sclerosis. Correlation with clinical disease type.
Natural killer (NK) cell number and function were determined in 69 systemic sclerosis (SSc) patients (41 with diffuse cutaneous SSc, 24 with limited cutaneous SSc, and 4 with scleroderma in an overlap syndrome). The results were compared with those obtained from 5 patients with Raynaud's disease and from 27 normal controls. Natural and antibody-dependent killing was reduced in the total group of SSc patients compared with controls, but these differences were primarily attributable to patients with the diffuse form of the disease who were seen early in their illness (less than 5 years after onset). NK cell numbers were not significantly reduced in patients compared with controls, although lower numbers were observed in individuals with early diffuse disease. Other clinical parameters, such as treatment with D-penicillamine or the presence of scleroderma-specific autoantibodies, did not exert an independent effect on NK cell function. These findings suggest a possible central role for NK cells in the pathogenesis of SSc.
Adult↗