Recruitment of effector lymphocytes by initiator lymphocytes. Circulating lymphocytes are trapped in the reacting lymph node.

In previous studies, we have shown that initiator T lymphocytes (ITL) sensitized in vitro recruit effector T lymphocytes in vivo. When ITL were sensitized against fibroblast antigens in vitro and injected into footpads of syngeneic recipients, they induced enlargement of the draining popliteal lymph node (PLN) and the development there of specific effector lymphocytes of recipient origin. To study the basis of this lymph node response in recruitment, we injected 51Cr-labeled spleen cells i.v. into recipients of sensitized ITL and found that the labeled circulating lymphocytes were trapped in the reacting PLN. The trapping depended on surface properties of the labeled circulating lymphocytes, as revealed by various enzymatic treatments. The trapping process was radiosensitive, both on the part of the trapped lymphocytes and the lymph node-trapping mechanism. Thus, sensitized ITL injected into the hind footpads migrate to the PLN and induce the trapping of circulating recruitable lymphocytes, which either differentiate into or regulate the differentiation of effector T lymphocytes.     

Recruitment of effector lymphocytes by initiator lymphocytes. Recruited lymphocytes are immunospecific and include graft-versus-host-reactive lymphocytes.

We have shown previously that initiator T lymphocytes (ITL), sensitized in vitro against fibroblast antigens, recruit effector T cells in vivo. After injection into hind footpads of syngeneic recipients, sensitized ITL migrated to the draining popliteal lymph nodes (PLN) and activated a trapping mechanism by which circulating lymphocytes were recruited in the PLN. This paper reports experiments designed to test the immunospecificity of these recruited T lymphocytes (RTL). We found that immunospecific RTL were depleted from other lymphoid organs during recruitment in the PLN. However, immunospecific ITL were not depleted from spleens during PLN recruitment. Thus ITL and RTL are functionally distinguishable. We show that specific GVH reactive lymphocytes were also lost from spleens and distal lymph nodes during trapping of RTL in the PLN. Thus, the trapping phase of the recruitment response is immunospecific, as are the sensitization and effector phases. The trapped RTL are antigen-specific, and include the pool of GVH-reactive-lymphocytes committed to the same alloantigen. Thus, it appears that GVH-reactive cells respond to syngeneic ITL sensitized against allogeneic fibroblasts.     

Specific sensitization of Lyt-1+2- T cells to spleen cells modified by the drug D-penicillamine or a stereoisomer

A mouse model for assessing the sensitization of T cells to the drug D-penicillamine (D-Pen) has been established. Mice were primed with D-Pen in vivo and the secondary response of specific T cells was measured in a proliferative assay in vitro. Priming was achieved by injecting either free D-Pen or, more effectively, D-Pen in complete Freund's adjuvant at the base of the tail. After 7 to 9 days, the draining lymph node cells (responder cells) were restimulated in vitro with syngeneic spleen cells that had been preincubated with D-Pen for 20 to 22 hr and washed (D-Pen-SC). The thiol (-SH) group of D-Pen was required for generating effective stimulator cells; other thiol compounds, however, or heavy metals (Hg, Au) were unable to generate cross-reacting stimulators on incubation with spleen cells. Although D-Pen-SC proved to be good stimulator cells, thymocytes and mouse erythrocytes, after having been preincubated with D-Pen, completely failed to stimulate. The proliferating responder cells were Lyt-1+2- T cells that were highly specific for D-Pen-SC and were even capable of distinguishing between the two stereoisomers D-Pen and L-Pen. The splenic T cells of recipient mice were effectively primed by injecting D-Pen-SC, but not free D-Pen, via the i.v. route. These findings indicate that D-Pen can act as a hapten for specific T cells when presented on the surface of appropriate stimulator cells. Conceivably, if D-Pen were able to generate effective stimulator cells in vivo, this could lead to T cell reactions comparable to those in the graft-vs-host reaction (GVHR). We discuss the possibility that the GVH-like adverse immunologic side-effects of D-Pen in patients may have a GVHR-like pathogenesis.     

Kinetics and morphology of chemically induced popliteal lymph node reactions compared with antigen-, mitogen-, and graft-versus-host-reaction-induced responses

Changes in the popliteal lymph node (PLN) in mice evoked by a local graft-versus-host (GVH) reaction and by a single injection of various agents into the hind footpad were compared. The drug diphenylhydantoin induced similar weight changes in time as the GVH reaction. More vigorous and protracted reactions were induced by the drug nitrofurantoin and the contact sensitizer dinitrochlorobenzene, whereas the antigens lipopolysaccharide and sheep erythrocytes caused very moderate and short-lasting weight changes. Alterations of lymph node architecture upon injection of diphenylhydantoin resembled those observed during the GVH response. Some quantitative and qualitative differences were noted for nitrofurantoin, but clearly deviant morphological alterations were seen in response to lipopolysaccharide and sheep erythrocytes. The PLN reaction to dinitrochlorobenzene had features of both the GVH reaction and the antigen-induced responses. These findings support the concept that some drugs and chemicals may induce or exacerbate lymphoproliferative disorders by GVH-like mechanisms.     

Experimental allergic encephalomyelitis: changes in growth and proliferation within the draining lymph node following injection of basic encephalitogenic protein in Freund's complete adjuvant

Changes in wet weight, dry mass, and DNA synthesis of draining lymph nodes from rats injected with encephalitogenic basic protein in Freund's complete adjuvant (FCA) were studied. Lymph nodes of rats injected with encephalitogenic basic protein in FCA show accelerated enlargement from the second up to the fourth day after injection, as compared to lymph nodes of rats injected with FCA alone, or with nonencephalitogenic basic protein in FCA. The greatest difference in lymph node weight was found on the fourth day. At this time cell division is higher in the group injected with encephalitogenic protein in FCA than in the group injected with FCA alone. However, the increased division of cells in situ cannot account, in and by itself, for the enlargement of the lymph node which was observed. It is concluded that migration of lymphocytes into the lymph node makes a substantial contribution to the hyperplasia of the lymph node.The results suggest that accelerated lymph node enlargement may be specific, at least in part, for induction of experimental allergic encephalomyelitis.     

Natural cytotoxicity of lymphocytes from lymph nodes draining breast carcinoma and its augmentation by interferon and OK432

Summary Lymphocytes isolated from axillary lymph nodes draining breast carcinoma were tested for natural killer (NK) activity against K562 in a 4-h ⁵¹Cr-release assay, and the in vitro effects of interferon (IFN) and OK432 (a streptococcal preparation) on their cytotoxicity were examined in comparison with NK activity of autologous peripheral blood lymphocytes (PBL). The levels of NK activity were lower in lymph node lymphocytes (LNL) than in PBL of the same patients. Significant levels of LNL-mediated lysis were recorded in 14 of 42 (33%) lymph node samples and in nine of 14 (64%) patients. Purification of large granular lymphocytes (LGL) from lymph node cells by discontinuous Percoll density gradient centrifugation resulted in an induction or enhancement of cytotoxic activity, with no reactivity in LGL-depleted, small T-lymphocyte populations. Positive reactions were observed with 10 of 13 (77%) LGL samples. The low reactivity of LNL was not attributable to coexistent suppressor cells for NK function, since lymph node cells failed to suppress NK activity of normal PBL. Partially purified human IFN and OK432 augmented NK activity of patients' PBL in approximately 70% and 90% of the cases, respectively, while LNL-mediated lysis was augmented in only 7% and 36% of the lymph node samples by IFN and OK432, respectively. These results indicate that K562-reactive NK cells and/or their precursors may frequently be present at subthreshold levels in the lymph nodes draining breast carcinoma, and that the augmentation of LNL-mediated cytotoxicity by OK432 might provide a local potentiation of natural immune function at the host-tumor interface rather than IFN.     

Kinetics and morphology of chemically induced popliteal lymph node reactions compared with antigen-, mitogen-, and graft-versus-host-reaction-induced responses

Changes in the popliteal lymph node (PLN) in mice evoked by a local graft-versus-host (GVH) reaction and by a single injection of various agents into the hind footpad were compared. The drug diphenylhydantoin induced similar weight changes in time as the GVH reaction. More vigorous and protracted reactions were induced by the drug nitrofurantoin and the contact sensitizer dinitrochlorobenzene, whereas the antigens lipopolysaccharide and sheep erythrocytes caused very moderate and short-lasting weight changes. Alterations of lymph node architecture upon injection of diphenylhydantoin resembled those observed during the GVH response. Some quantitative and qualitative differences were noted for nitrofurantoin, but clearly deviant morphological alterations were seen in response to lipopolysaccharide and sheep erythrocytes. The PLN reaction to dinitrochlorobenzene had features of both the GVH reaction and the antigen-induced responses. These findings support the concept that some drugs and chemicals may induce or exacerbate lymphoproliferative disorders by GVH-like mechanisms.     

Prevention of lymphadenopathy in MRL-lpr/lpr mice by blocking peripheral lymph node homing with Mel-14 in vivo

MRL-lpr/lpr mice develop massive lymphadenopathy and autoimmunity. There is evidence that both migration and local proliferation contribute to the accumulation of Ly-2-, L3T4-, 6B2+ T cells in the peripheral lymph node (PLN). Mel-14 is an antibody which binds to the lymphocyte lymph node homing receptor (gp90Mel-14) and can block migration of lymphocytes to the PLN. Treatment of mice from birth to 11 wk of age with Mel-14 and another rat IgG2a mAb, 6B2, resulted in reduction (10- to 20-fold) in lymphadenopathy. Mel-14, but not 6B2, preferentially reduced the percentages of Thy-1+, 6B2+ lymphocytes in the lymph node. Treatment with a third antibody, anti-Ly-1, had no effect on lymphadenopathy. Mel-14 treatment resulted in diversion of the Ly-2-, L3T4-, 6B2+, gp90Mel-14 cells to the spleen and consequently induced marked splenomegaly. Thymocytes from MRL-lpr/lpr and MRL-+/+ mice were analyzed by two-color flow cytometry analysis after depletion of Ly-2+ and L3T4+ T cells. There was no difference in the percent of Ly-2-, L3T4-, 6B2+, gp90Mel-14 positive thymocytes comparing these two strains. Mel-14 treatment did not alter Ig levels or autoantibody production. These studies suggest Mel-14 reduced lymphadenopathy by interfering with homing to PLN, whereas 6B2 may have interfered with marrow production of precursor cells or killed 6B2+ cells after they exited the marrow. The data are consistent with the idea that lymphadenopathy occurs in MRL-lpr/lpr mice due to increased homing gp90-Mel-14 T cells to the PLN and that gp90Mel-14 is a necessary receptor for the abnormal 6B2+ T cells.     

Adult thymectomy promotes the manifestation of autoreactive lymphocytes.

Spleen cells from adult thymectomized mice (ATX) were assayed in a syngeneic graft vs host (GVH) model based upon enlargement of the draining popliteal lymph node following syngeneic cell inoculation into the hind footpad. Spleen cells from ATX mice have been found to induce a significantly higher increase in the weight of the regional lymph node than that induced by the injection of normal spleen cells. Irradiated spleen cells from ATX donors did not cause a similar increase, suggesting either that proliferation of the transferred cells was required at some stage of the reaction or that autoreactive cells are radiosensitive. Autoreactive cells were found in the spleen of mice 2 to 3 months after the thymectomy but were never found in the lymph nodes of such animals or in the thymus of intact mice. They are not phagocytic adherent cells and are not retained on nylon wool columns, which suggests that they belong to the T-cell lineage. Autoreactivity is lost when spleen cells from ATX donors are depleted of autologous rosette-forming cells (A-RFC) by centrifugation on a Ficoll-Hypaque gradient after rosette formation. Autoreactive spleen lymphocytes might belong to the population of A-RFC previously characterized as a population of immature T cells.     

Influence of heparin and protamine on enlargement of the draining lymph node during induction of EAE

Popliteal lymph node enlargement four days after immunization with encephalitogenic guinea pig basic protein in Freund's complete adjuvant (EGPBP-FCA) was less in heparin treated and greater in protamine-treated Lewis rats than in salineinjected controls. These agents were without influence on the node enlargement occasioned by Freund's adjuvant alone or on node size in nonimmunized rats. Decreased cell trapping in the node in heparinized rats and increased trapping in protamine-treated rats immunized with EGPBP-FCA is suggested.     

Limb lymph node response to bone fracture

In previous clinical studies, dilation of afferent lymphatics and enlargement of inguinal lymph nodes (LN) were observed in lymphoscintigrams from patients with persistent posttraumatic edema of lower extremities after fractures and trauma of soft tissues. In this study, changes in rat popliteal and iliac lymph nodes draining lymph from the site of tibial fracture and adjacent soft tissue injury were investigated. The observed parameters were lymph node weight, cell number, phenotype frequency, cell cytokine expression, and reactivity to mitogens. The key observations included: a) increase in the weight and total cell number of the lymph nodes; b) increased autotransformation rate and responsiveness of lymph node cells to mitogen; c) decreased frequency of ED1 macrophages and activated OX8 cytotoxic cells in flow cytometry analysis; d) high expression of OX6 class II-positive, OX7 (stem cells), OX62 (migrating dendritic cells), ED1 (macrophages), and OX12 (B cells) on immunohistochemical sections of LNs with some few HIS48 (granulocytes); e) high expression of NOS3 and TGF beta by lymph node lymphocytes and endothelial cells. In summary, local lymph nodes reacted to internal wounds, such as bone fracture and injury to adjacent tissues, through mobilization of cells from the blood circulation, along with activation of cellular subsets. The molecular mechanism that provides the signal for this reaction remains unknown. The absence of major changes in the frequency of lymph node cell subpopulations indicates that lymph nodes are constitutively prepared for influx of antigens from damaged tissues and react only with increase in cell number and cell activation. The nature of the reaction, including lack of immunization against autoantigens, remains unclear. Further elucidation will require studies on the mechanism of cross-tolerance to self-antigens during wound healing.     

Neonatal tolerance induction in the thymus to MHC-class II-associated antigens. II. Significance of MHC antigens in anti-Mls tolerance

Specificity of anti-Mlsa tolerance induced in BALB/c (H-2d, Mlsb) neonates was investigated by a popliteal lymph node (PLN)-swelling assay for the local graft-versus-host (GVH) reaction by injecting tolerant thymus cells into the footpads of several types of F1 hybrid mice. When thymus cells were obtained from 1-week-old normal BALB/c, they evoked enlargement of PLNs of (BALB/c X DBA/2)F1 (H-2d, Mlsb/a) [CDF1] recipients and of other hybrid recipients, heterozygous in Mlsa,c,d alleles, irrespective of the major histocompatibility complex (MHC) haplotypes. The same thymus cells did not cause the response in MHC-heterozygous F1 hybrids when the hybrids were homozygous in Mlsb, identical with BALB/c mice. Therefore, the PLN response to Mls antigens, known to be closely associated with MHC-class II antigens, was not directed to the class II antigens themselves. This enabled us to examine the effects of MHC on tolerance induction to the Mls antigens. When BALB/c neonates were injected with CDF1 bone marrow cells, complete tolerance to Mlsa-H-2d antigens of CDF1 cells was induced in the thymus, while responsiveness to Mlsa antigens in the context of H-2k and H-2b antigens, was not affected. This indicates MHC-restriction of neonatal tolerance to Mls antigens. Furthermore, when Mls and H-2-heterozygous (BALB/c X AKR)F1 (H-2d/k, Mlsb/a) bone marrow cells served as the tolerogen, thymus cells of BALB/c neonates were also tolerized to Mlsa-H-2k antigens as well as to Mlsa-H-2d antigens, which suggests the involvement of MHC, probably class II antigens of tolerance-inducing cells.     

Loss of IL-4 secretion from human type 1a diabetic pancreatic draining lymph node NKT cells

Altered frequency and function of peripheral invariant NKT (iNKT) cells have been implicated in the regulation of murine and human type 1a diabetes. To examine regulatory cells from the site of drainage of autoinflammatory tissue and autoantigenic T cell priming in diabetes, we directly cloned iNKT cells from human pancreatic draining lymph nodes (PLN). From 451 T cell clones from control and diabetic PLN, we derived 55 iNKT cells by two methods and analyzed function by cytokine secretion. iNKT cell clones isolated from control PLN secreted IL-4 and IFN-gamma upon TCR stimulation. For type 1a diabetic subjects, PLN iNKT cell clones from three samples secreted IFN-gamma and no IL-4. In a rare recent onset diabetic sample with islet-infiltrating CD4+ T cells, the phenotype of PLN iNKT cell clones was mixed. From normal and diabetic PLN, one-third of CD1d tetramer+-sorted T cell clones were reactive with CD1d transfectants or proliferated/secreted cytokine in response to alpha-galactosylceramide-pulsed PBMCs; tetramer-staining T cell clones from diabetic PLN did not secrete IL-4. This is the first report directly examining iNKT cells from lymph nodes draining the site of autoimmunological attack in humans; iNKT cells were altered in cytokine secretion as previously reported for circulating iNKT cells in human type 1a diabetes.     

Tumour-associated proliferative responses in vitro of regional lymph nodes draining solid cancers in man

Summary The proliferative responses in vitro of tumourdraining lymph node lymphocytes were evaluated against autologous colon and lung carcinoma cells. The reactivity of lymphocytes appeared to be directed against tumour-associated rather than tumour-specific antigens. The lymphocyte reactivity detected was not due to an autologous mixed lymphocyte reaction. Recombinant interleukin-2 augmented the responses detected but not their tumour specificity. Phenotypic characterisation indicated the presence of T suppressor/cytotoxic (TS/C) cells as well as natural killer (NK) cells. Only the latter, however, were active in functional cytotoxicity assays. The inability to generate both tumour-specific proliferation of tumour-draining lymph node lymphocytes and tumour-specific cytotoxic killer cells may be due to the presence of suppressor cells in the regional lymph nodes; preliminary data suggest the presence of such cells.Part of this project was supported by a grant from Cancer Research Campaign     

Graft-versus-host response,measured by splenomegaly assay,by populations of allosensitized mouse lymphocytes

The graft-vs-host (G-v-H) reactivity of sensitized or nonsensitized mouse lymphoid cell populations was measured using a splenomegaly assay. Sensitized populations were obtained either from the local lymph nodes of alloimmunized animals or from the spleens of heavily irradiated mice previously infused iv with allogeneic lymphocytes (educated cells). Immunization of animals resulted in increased G-v-H responses of the cells in their local lymph nodes. This effect was more pronounced when the immunizing cells differed only at non-H-2 transplantation antigens than when H-2-disparate strain combinations were tested. There was no evidence of a changed doseresponse profile of lymphocytes obtained from immunized mice. The G-v-H reactivity of educated cell populations was complex. The slopes of the dose-response lines obtained for lymph node cells or thymic cells educated in an H-2-disparate strain were generally lower than those obtained for nonsensitized cells. This difference was particularly evident when testing educated thymocytes. By studying the G-v-H indices obtained in A/Sn × C57B1 hybrids after inoculation of nonsensitized C57B1 lymph node cells or specifically educated C57BL lymph node cells, it was observed that the latter cells were approximately 30 times more reactive when small cell inocula were compared. On the contrary, education of lymphocytes in H-2-compatible allogeneic hosts did not result in any increment of their G-v-H reactivity. The results indicate that different methods of sensitizing lymphocyte populations against alloantigens may lead to activation of different subclasses of T-cells which differ in their mode of antigen reactivity.     

Calcein: a novel marker for lymphocytes which enter lymph nodes.

Previous studies have identified unique cell surface antigens which are associated with the specific binding of lymphocytes to high endothelial venules (HEV). Evidence is presented in this paper which demonstrates that uptake of the fluorescent dye calcein by lymphocytes represents an additional marker for the lymph node homing subpopulation of lymphocytes. Calcein exhibits a characteristic ability to label lymphocytes differentially into two distinct populations, based on fluorescence intensity, that does not occur with three other structurally related, fluorescein-based dyes. In vivo lymphocyte migration studies revealed that cells displaying the "dull" fluorescence phenotype, although entering all lymphoid organs examined, preferentially homed to the lymph nodes, particularly the popliteal lymph node (PLN). By contrast, lymphocytes displaying the "bright" phenotype were essentially excluded from entering lymphoid organs, where entry is HEV dependent, but were observed entering spleen, where entry is HEV independent. Furthermore, a high proportion (76.5%) of lymphocytes displaying the dull fluorescence phenotype expressed the PLN homing receptor MEL-14. Based on these observations it is suggested that calcein uptake may be a marker for general membrane properties, such as fluidity and plasticity, essential for the passage of lymphocytes through HEV.     

Priming of peripheral lymph node B cells with TNP-Ficoll: role of lymphokines in B cell differentiation.

We have previously shown that peripheral lymph node (PLN) B lymphocytes of adult DBA/2J mice failed to make an antibody response to type 2 antigen TNP-Ficoll, but exhibited a good antibody response to type 1 antigen TNP-Brucella abortus. In the present study we wanted to find out whether the unresponsiveness of PLN B cells to TNP-Ficoll is due to defects in the early activation and proliferation stage or in the final differentiation stage of B cells. Therefore, we have used a two-step protocol of in vivo immunization of mice with TNP-Ficoll and the subsequent in vitro challenge with TNP-Brucella abortus and studied the anti-TNP plaque-forming cell (PFC) responses. The results indicate a three- to sixfold increase of PFC responses in PLN cell cultures derived from TNP-Ficoll-primed animals compared to saline control mice. This increased antibody response was TNP-specific as 93% of the PFC's were inhibited by TNP-lysine. Limiting dilution experiments confirm that the increase in anti-TNP PFC response from the TNP-Ficoll-primed animals was indeed due to an increase in TNP-specific precursor B cells. Further, the addition of rIL-5 or rIL-6 induced anti-TNP PFC in the TNP-Ficoll-primed and in control PLN cell cultures in the presence of antigen. However, in primed PLN cells lymphokines alone were sufficient to restore anti-TNP PFC response. In conclusion, our results show that in PLN, the TNP-Ficoll can induce proliferation of hapten-specific B cells but not final differentiation. These primed PLN B cells mature into antibody-secreting cells upon stimulation with TNP-BA or lymphokines.     

In Situ Analysis of Lymphocyte Migration to Lymph Nodes

Blood-borne lymphocytes migrate continuously to peripheral lymph nodes (PLN) and other organized lymphoid tissues where they are most likely to encounter their cognate antigen. Lymphocyte homing to PLN is a highly regulated process that occurs exclusively in specialized high endothelial venules (HEV) in the nodal paracortex. Recently, it has become possible to explore this vital aspect of peripheral immune surveillance by intravital microscopy of the subiliac lymph node microcirculation in anesthetized mice. This paper reviews technical and experimental aspects of the new model and summarizes recent advances in our understanding of the molecular mechanisms of lymphocyte homing to PLN which were derived from its use. Both lymphocytes and granulocytes initiate rolling interactions via L-selectin binding to the peripheral node addressin (PNAd) in PLN HEV. Subsequently, a G protein-coupled chemoattractant stimulus activates LEA-1 on rolling lymphocytes, but not on granulocytes. Thus. granulocytes continue to roll through the PLN, whereas LEA-I activation allows lymphocytes to arrest and emigrate into the extravascular compartment. We have also identified a second homing pathway that allows L-selectin low/(activated/memory) lymphocytes to home to PLN. P-selectin on circulating activated platelets can mediate simultaneous platelet adhesion to PNAd in HEV and to P-selectin glycoprotein ligand (PSGL)-l on lymphocytes. Through this mechanism, platelets can form a cellular bridge which can effectively substitute for the loss of L-selectin on memory cell subsets.     

T and B lymphocyte migration into syngeneic tumors.

The migration of splenic T and B lymphocytes into syngeneic tumors undergoing immunologic rejection was investigates. Spleen cells were obtained from normal BALC/c mice or BALB/c mice bearing tumors induced by murine sarcoma virus (MSV). Either whole spleen cells or immunoabsorbent purified T and B cells were radiolabeled with sodium chromate-51 and injected i.v. into normal or MSV inducted-tumor bearing syngeneic recipients. Twenty-four hours later the recipient mice were sacrificed and radioactivity was assessed for tumor, contralateral normal muscle, the lymph nodes draining the tumor and contralateral draining lymph nodes, peripheral lymph nodes, spleen, and liver. Both T and B lymphocytes from either normal or MSV tumor-bearing animals show greatly increased migration into the tumor when compared with normal muscle. Migration of T cells from both normal and MSV tumor bearers was 30 times that of migration to normal muscle. B cells from tumor-bearing mice, on the other hand, localized in the tumor itself only 50% as frequently as did B cells from normal animals. In addition, T cells from MSV tumor bearers were found in the highest proportion in the lymph node draining the tumor site. We conclude that T and B lymphocytes from either normal or tumor-bearing mice migrate to a syngeneic tumor undergoing immunologic rejection. In contrast, the migration of both T and B cells from tumor-bearing animals was decreased to the peripheral lymph nodes at the time of maximum tumor growth.     

Analysis of the intralesional adriamycin-induced regression of primary and metastatic growth of line-10 guinea-pig hepatoma

Summary A single intralesional injection of 2.4 mg adriamycin/kg into 7-day-old intradermal strain-2 guinea-pig hepatoma, line-10, caused regression of the tumor and prevented the growth of regional lymph node metastasis. Cured animals were resistant to challenge with the same tumor. Intratumoral injection of 20 mg DTIC/kg was not effective in causing tumor regression or preventing growth of regional lymph node metastasis. Comparative histological examinations performed on the tumor site and the draining lymph node showed that both chemotherapeutic drugs caused extensive necrosis at the injection site and that within 7 days only adriamycin eradicated tumor cells from the draining lymph nodes.The number of host lymphocytes and monocytes in the adriamycin-treated tumor sites was less than that seen in the saline- or DTIC-injected animals at all time intervals examined. Minimal peripheral effects, as measured by total and differential analysis of the blood, were noted in drug-treated normal and tumor-bearing animals. In addition, the concentration of drug used did not interfere with the development of immunity.The results suggest that the effect(s) of intralesional adriamycin treatment is probably caused by a combination of cytotoxic and cytostatic actions of the drug and the development of tumor-specific immunity. Abbreviations used: DTIC, 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboximide; BCNU, 1,3-bis-(2-chloroethyl)-1-nitrosourea; SDA, superficial distal axillary lymph node