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R Korngold

Publications and source records attributed to R Korngold.

At least 55 records · Page 3Linked to original sources
PubMed1994

Graft-versus-myeloid leukemia responses following syngeneic and allogeneic bone marrow transplantation.

A model for investigating graft-versus-leukemia (GVL) activity following syngeneic and MHC-compatible allogeneic BMT has been developed in C57BL/6 (B6) mice with use of the c-myc retrovirus-transformed MMB3.19 myeloid leukemia line. The MMB3.19 line was derived from a B6 mouse and expresses monocyte/macrophage markers, including Mac-1, Mac-2, F4/80, and LFA-1, in addition to H-2 class I and class II molecules. A challenge dosage of 10(5) of these leukemia cells was found to be completely lethal when injected into irradiated (850 cGy) B6 recipients, 1 day after the transplantation of syngeneic donor T cell-depleted-bone marrow. The addition of T lymphocytes to the donor inoculum prolonged recipient survival, and both CD4+ and CD8+ subsets were found to be capable of mediating this GVL activity. For the MHC-compatible allogeneic model, the C3H.SW-->B6 (850 cGy) strain combination was utilized, in which CD8+ T cells are known to cause graft-versus-host disease directed to minor histocompatibility antigens expressed by the recipient. In this case, both CD(4+)- and CD(8+)-enriched T cells were found to be capable of mediating GVL activity to MMB3.19 challenge, particularly if donor mice were presensitized with leukemia cells. Of most significance, only the donor CD4+ T cells mediated a GVL effect without the apparent induction of graft-versus-host disease.

Animals↗
PubMed1994

A rationally designed CD4 analogue inhibits experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE) is an acute inflammatory autoimmune disease of the central nervous system that can be elicited in rodents and is the major animal model for the study of multiple sclerosis (MS). The pathogenesis of both EAE and MS directly involves the CD4+ helper T-cell subset. Anti-CD4 monoclonal antibodies inhibit the development of EAE in rodents, and are currently being used in human clinical trials for MS. We report here that similar therapeutic effects can be achieved in mice using a small (rationally designed) synthetic analogue of the CD4 protein surface. It greatly inhibits both clinical incidence and severity of EAE with a single injection, but does so without depletion of the CD4+ subset and without the inherent immunogenicity of antibody. Furthermore, this analogue is capable of exerting its effects on disease even after the onset of symptoms.

Amino Acid Sequence↗
PubMed1994

T cell subsets involved in lethal graft-versus-host disease directed to immunodominant minor histocompatibility antigens.

T cell responses to multiple minor histocompatibility antigens are governed by the complex phenomenon of immunodominance, as demonstrated clearly in the generation of CTL in the C57BL/6By (B6) anti-BALB.B strain combination. Immunodominance has also been found in lethal graft-versus-host disease (GVHD) responses directed to BALB.B minor histocompatibility antigens, after transplantation of B6 T cells and T cell-depleted bone marrow to irradiated (825 cGy) recipients of either the BALB.B or CXB recombinant inbred strains. However, previous results indicated that the hierarchy of immunodominance in GVHD differed from that predicted from the in vitro CTL studies. Lethal GVHD was observed in BALB.B, CXBE, CXBI, and CXBJ recipients, but not in CXBG and CXBK recipients, the latter 2 strains expressing immunodominant antigens for CTL generation. A major hypothesis to account for these discordant observations is that GVHD reflected the activity of CD4+, but not CD8+, T cell subsets, in contrast to only the in vitro cytolytic potential of CD8+ T cells. Therefore, the current study was undertaken to assess the GVHD potential of both T cell subsets in the B6-->BALB.B, CXBE, CXBI, and CXBJ strain combinations and to analyze the early GVHD responses in the B6-->CXBG and CXBK strains. The results indicate that lethal GVHD responses in the B6-->BALB.B combination can be mediated by either CD4+ T cells or CD4-dependent CD8+ T cells; a similar observation was made with the B6-->CXBI strain combination. Lethal GVHD in the B6-->CXBE strain combination is mediated only by CD4-dependent CD8+ T cells, whereas GVHD in the B6-->CXBJ combination involves either CD4+ T cells alone or CD4-independent CD8+ T cells. In the B6-->CXBG and CXBK recipients, which do not develop lethal GVHD, the early phases of a GVHD response was detected with involvement of both CD4+ and CD8+ T cells. These results indicate that CD8+ T cells are active at some level in all of the strain combinations tested, that CD4+ T cells do not account for the GVHD immunodominant response in the CXBE recipients, and that the failure to obtain extensive clinical disease in the CXBG and CXBK strains is not due to a lack of a graft-versus-host response.

Animals↗
PubMed1994

Effect of human natural killer cells on the metastatic growth of human melanoma xenografts in mice with severe combined immunodeficiency.

An in vivo model for human melanoma was established with the growth of CR3 and DE5 human melanoma tumor cells following i.v. injection into C.B.-17 severe combined immunodeficient mice depleted of murine natural killer (NK) cells. The ability of human NK cells to mediate antitumor activity in vivo was investigated by evaluating the number of lung nodules and survival of mice given injections of human NK cells i.v. early after injection of CR3 tumor cells. Under these conditions, human NK cells effectively reduced lung nodule counts and prolonged survival when coinjected with interleukin 2 (IL-2). Multiple injections of IL-2 given during the first 16 h post-NK injection did not further enhance the tumor reduction. Significantly increased antitumor activity against CR3 tumor cells in vivo was observed in mice receiving NK cells coinjected with IL-2 and interleukin 12 (IL-12) in comparison to NK cells and IL-2 only. However, coinjection of IL-12 with human NK cells alone did not reduce the tumor burden. These results demonstrate the antitumor activity of human NK cells against human melanoma in severe combined immunodeficient mice and its augmentation by IL-2, alone or in combination with IL-12, suggesting that this model can be used to further investigate the interaction between human NK cells and human tumors.

Animals↗
PubMed1994

Role of mast cells in early epithelial target cell injury in experimental acute graft-versus-host disease.

The skin is a major target organ for graft-versus-host disease (GVHD), the principal complication of allogeneic bone marrow transplantation. The purpose of the present study was to test whether mast cell degranulation might be related to early target cell injury in the development of acute GVHD. We employed two irradiated murine strain combinations, one in which disease was mediated by CD4+ effector T cells (B10.D2-->DBA/2), and the other by CD8+ effector T cells (B10.BR-->CBA). As compared to controls, both models exhibited mast cell degranulation of differing extents and patterns, as well as dyskeratosis in the epidermis before the influx of effector lymphocytes. These results suggested that factors produced and released by degranulated dermal mast cells might contribute to early target cell injury. Accordingly, the possible role of tumor necrosis factor (TNF)-alpha, a cytokine recently discovered in mast cell granules, was investigated by the injection of anti-TNF-alpha antibody during the course of disease mediated by either CD4+ or CD8+ T cells. Although overall survival of recipients undergoing CD4+ T-cell-mediated GVHD was only slightly improved and the extent of mast cell degranulation was not affected by anti-TNF-alpha antibody treatment, the skin exhibited a significant diminution in the number of dyskeratotic cells/linear mm at 3-4 weeks post-transplantation. In contrast, anti-TNF-alpha antibody failed to enhance survival or reduce the number of dyskeratotic cells in the skin during CD8+ T-cell-mediated disease. Finally, to determine whether CD8+ T-cell-mediated GVHD was at all dependent upon mast cell involvement, the C3H.SW-->B6WWv strain combination was utilized, in which recipients were genetically deficient in mast cells. Onset of GVHD was significantly delayed in B6WWv mice and was clearly correlated to the appearance and increase of de novo mast cells at later time points.

Animals↗
PubMed1993

Interferon-gamma-inducible endothelial cell class II major histocompatibility complex expression correlates with strain- and site-specific susceptibility to experimental allergic encephalomyelitis.

The interaction between encephalitogenic lymphocytes and the cerebral microvascular lining is considered to be an important initial step in the recruitment of immune cells into the central nervous system (CNS) under pathological conditions such as multiple sclerosis (MS) and its investigative analog, experimental allergic encephalomyelitis (EAE). This study was conducted in order to examine whether differences in microvascular endothelial cell expression of several molecules involved in lymphovascular interactions correlate with the strain and organ-specific development of EAE. Cerebral and epididymal microvascular endothelial cells (EC) were isolated from SJL and B10.S mice, which, despite MHC-compatibility (H-2S), differ in their ability to develop EAE. The subcultured cells were then analyzed by flow cytometry for their ability to express class I MHC, class II MHC and ICAM-1 molecules in response to treatment with murine recombinant interferon-gamma (IFN-gamma). Over a range of doses and times, cerebral EC cultures derived from EAE-susceptible SJL mice expressed two-fold higher levels and higher cell surface densities of class II molecules than cerebral EC cultures derived from EAE-resistant B10.S mice, whereas class I and ICAM-1 molecules were comparably upregulated on both SJL and B10.S cerebral EC. In contrast, both SJL and B10.S epididymal EC cultures expressed lower but comparable levels of class II molecules in response to IFN-gamma. Class I and ICAM-1 molecules, however, were upregulated to at least the same degree as that observed on cerebral EC derived from both strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Biology of graft-vs.-host disease.

Graft-vs.-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation, which is an important approach for the treatment of various diseases. In experimental animal models, lethal GVHD can be induced in major histocompatibility complex (MHC)-matched strain combinations that differ in their expression of multiple minor histocompatibility antigens. It has been shown that T cell subset populations expressing the CD8+ phenotype play an important role in the development of GVHD directed to the minor histocompatibility antigens. Moreover, highly purified preparations of these cells are capable of mediating GVHD without apparent help from mature donor-derived CD4+ T cells. CD4+ T cells can also mediate GVHD, but only in certain strain combinations. The pathogenesis of GVHD is similar, whether it is mediated by CD4+ or CD8+ T cells, with the exception that CD4+ cells may be responsible for more gastrointestinal injury. The ability of T cells to respond to minor histocompatibility antigens is further complicated by the phenomenon of immunodominance, which causes T cells to focus on a limited number of antigens out of the larger available pool. Immunodominance does occur in GVHD, but it seems to involve a different pattern of responses than those observed for the generation of cytotoxic T lymphocytes in vitro. Understanding these immunologic interactions is an important step toward the ultimate goal of developing a new approach for bone marrow transplantation, one that will avoid GVHD while retaining enough immunity to counter leukemic relapse and opportunistic infections.

Animals↗
PubMed1993

Monoclonal anti-gamma interferon antibodies enhance experimental allergic encephalomyelitis.

Interferon-gamma (IFN-gamma) is a cytokine with multiple activities on a variety of cells. Under various circumstances, IFN-gamma can exhibit either pro-inflammatory or inhibitory actions. Treatment of SJL/J mice with a monoclonal antibody (Mab) to IFN-gamma during the afferent limb of the immune response to myelin protein produced an enhancement of acute experimental allergic encephalomyelitis (EAE), with increased morbidity, mortality and earlier onset of disease. Systemic administration of IFN-gamma did not improve or worsen clinical outcome, but delayed disease onset. Passive transfer of immune lymph node cells co-activated with MBP and anti-IFN-gamma Mab resulted in more sever disease than that induced by MBP stimulated cells or MBP and IFN-gamma co-stimulated cells. However, in vitro proliferation of an MBP specific T cell line was not influenced by IFN-gamma nor anti-IFN-gamma treatment. Mab to IFN-gamma inhibited suppressor function, in a non-specific assay. These in vivo and in vitro results suggest that systemic IFN-gamma serves as a physiological regulator of a suppressor mechanism in EAE. The abrogation of this regulatory mechanism by anti-IFN-gamma administration contributes to a more severe form of experimental allergic encephalomyelitis.

Animals↗
PubMed1992

Pertussis toxin-induced lymphocytosis is associated with alterations in thymocyte subpopulations.

Pertussis toxin (Ptx), an important adjuvant for inducing certain organ-specific autoimmune diseases in mice, exerts multiple effects upon the immune system. In addition to its adjuvant effects, which include enhancement of delayed-type hypersensitivity and increased antibody production. Ptx elicits a marked lymphocytosis with a concomitant decrease in thymic weight. In vitro studies indicate that Ptx acts directly on thymocytes and that both susceptible and resistant populations exist. It is believed that these susceptible cells are released into the circulation and account, in part, for the T cell component of the lymphocytosis. We have used flow cytometry to analyze the CD4, CD8, and Thy-1 phenotypes of thymic and peripheral T cells from Ptx-treated mice. In the thymus, there is a dramatic decrease in the number of CD4+CD8+ (double positive) cells at all doses tested (0.25, 0.50, and 1.0 microgram) by day 4 after Ptx treatment. The double negative and single positive populations remain relatively constant. Analysis of Thy-1 expression reveals a significant reduction in Thy-1hi thymocytes, with little change in the Thy-1lo population. Thus Ptx primarily affects and depletes, in a dose-dependent fashion, thymic T cells with an immature phenotype. These results mimic those of corticosteroids, although neither prior adrenalectomy nor treatment with the antiglucocorticoid RU486 are able to prevent the effects of Ptx. In the periphery of Ptx-treated animals, the relative increase in the number of CD4+ T cells is more than that of CD8+ T cells. Double positive and Thy-1hi cells cannot be detected in appreciable numbers. These results are consistent with the concept that Ptx may drive immature thymocytes through accelerated maturation for release into the periphery as single positive, predominantly CD4+, Thy-1lo cells. Increased numbers of such cells may in part account for the immunopotentiating effects of Ptx, particularly as they relate to the induction of organ-specific autoimmune disease. Treatment with purified Ptx beta-oligomer fails to elicit any of the responses described above, indicating that the holotoxin is required for such activities.

Animals↗
PubMed1992

Autoimmune inflammation of astrocyte transplants.

Astrocytes have been shown to be capable of serving as antigen-presenting cells and as targets for encephalitogenic cytotoxic T lymphocytes. The role of astrocytes in central nervous system (CNS) autoimmune inflammation is unclear. To study this further, we transplanted astrocyte aggregates into the anterior eye chamber of the mouse. The astrocytic nature of these transplants was confirmed by immunohistochemical detection of glial fibrillary acidic protein and the inability to detect oligodendrocyte or microglial markers. When mice bearing transplants were induced to develop experimental allergic encephalomyelitis by either passive or active protocols, the astrocyte transplants developed a perivascular inflammatory response similar to that seen in the host CNS during the course of the encephalomyelitis. The data suggest that astrocytes could serve as targets for the autoimmune attack of experimental allergic encephalomyelitis and support the possibility that the pathogenesis of this disease may involve an autoimmune reaction against a site other than the myelin sheath.

Animals↗
PubMed1992

T cell subsets required for in vivo and in vitro responses to single and multiple minor histocompatibility antigens.

The requirement for helper T cells in the in vivo and in vitro T cell response to a diverse panel of minor histocompatibility antigens in mice was investigated. Target H antigens included: (a) multiple antigens distinguishing H-2-matched, inbred strains, and (b) single H antigens, including H-4, H-3, and the male-specific (H-Y) antigen. The involvement of helper T cells in skin allograft rejection and CTL priming was evaluated by pretreating graft recipients with anti-CD4 antibody. Anti-CD4 treatment had no effect on rejection of H-3- and H-4-incompatible skin grafts, but slowed rejection of male and BALB.B skin grafts. Comparable pretreatment with anti-CD4 antibody in vivo eliminated the priming of H-4-specific CTL, multiple B10.BR anti-CBA/J CTL, and all but a minor C57BL/6 anti-BALB.B CTL population. However, CTL specific for the two classes of H antigens, single and multiple minor H antigens, differed in their in vitro requirements for CD4+ helper T cells: (a) multiple antigen-specific CTL required CD4+ helper T cells for optimal expansion, and (b) CTL specific for single H antigens expanded in the absence of helper T cells. The CTL specific for all tested H antigens were CD8+ T cells. These results suggest that CD4+ helper T cells are not always required for effective skin allograft rejection or CTL expansion in vitro; the requirement for helper T cells is apparently dependent upon the identity of the stimulatory minor H antigen(s). This variable dependency contrasts with the evident requirement for helper T cells in the in vivo priming of CTL specific for minor H antigens.

Animals↗
PubMed1992

Lethal graft-versus-host disease in mice directed to multiple minor histocompatibility antigens: features of CD8+ and CD4+ T cell responses.

Lethal graft-versus-host disease (GVHD) can be induced in MHC-matched strain combinations which differ in their expression of multiple minor histocompatibility (H) antigens. It has been shown that CD8+ T cells play an important role in the development of disease directed to the minor H antigens, and that initial indications were that highly purified preparations of these cells were capable of mediating GVHD, without apparent 'help' from mature donor-derived CD4+ T cells. To further strengthen this hypothesis, the current study was undertaken with the B10.BR----CBA strain combination in which irradiated recipient mice were additionally treated with an anti-CD4 monoclonal antibody, as a single or repeated injection, to minimize the presence of either residual host CD4+ cells or recently generated donor-derived CD4+ cells at later stages of disease development. The results indicate that these treatments do not affect the GVHD outcome and that the CD8+ cells are indeed capable of inducing disease independent of CD4+ 'help'. The addition of donor CD4+ T cells in the inoculum, however, does enhance the potential of these CD8+ cells, and is observed with both low and high dosages of CD4+ cells. CD4+ T cells, on their own, have also been observed to cause GVHD directed to minor H antigens in certain strain combinations, and their response has been further characterized in this study. Results indicate that CD4+ cells capable of mediating GVHD in the B10.D2----DBA/2 strain combination can do so over a wide range of recipient irradiation exposures. The transfer of high dosages of CD4+ cells only shortens survival times of the recipients and does not afford any apparent protection phenomenon as previously observed in CD4+ cell mediated anti-class II MHC GVHD. The study also indicates that neither CD4+ nor CD8+ cells responsible for GVHD directed to minor H antigens seem capable of targeting host stem cell elements.

Animals↗
PubMed1991

Growth and metastasis of fresh human melanoma tissue in mice with severe combined immunodeficiency.

Cryopreserved cell suspensions of freshly excised melanoma metastases from nine patients were injected s.c. into C.B-17 severe combined immunodeficiency (SCID) mice. All 9 tumors grew as s.c. masses and six of nine were successfully transplanted into other SCID mice. Transplant inocula as low as 5 x 10(5) cells resulted in 100% tumor incidence. Moreover, seven of nine tumors metastasized, five from the original s.c. implants and two from transplanted s.c. tumors. Metastases were detected mainly in the lungs but also were found in abdominal viscera (liver, spleen, and pancreas) and thoracic lymph nodes. Flow cytometric analysis showed that expression of a panel of melanoma antigens, melanoma-associated proteoglycan, ganglioside GD3, and ganglioside GD2, was maintained with SCID passage. The original tumor inocula contained a variable percentage of tumor-associated lymphocytes (1-76%). Flow cytometry analysis indicated that these were mainly CD3+ T-cells. However, there was no correlation between the percentage of tumor-associated lymphocytes and the time required for development of a palpable tumor after s.c. injection or the ability to metastasize. These results demonstrate the growth and spontaneous metastasis of fresh human melanoma in SCID mice and suggest that this model could be important for therapeutic and basic biological studies.

Animals↗
PubMed1991

Cytotoxic folliculitis in GvHD. Evidence of follicular stem cell injury and recovery.

Recent observations indicate that stem cells of the murine hair follicle exist exclusively as a subpopulation of relatively undifferentiated outer root sheath cells located in the bulge region at the mid-portion of the follicle. Because it has been hypothesized that stem cells of interfollicular epidermis may represent targets of cytotoxic responses in acute graft-versus-host disease (AGVHD), we studied murine AGVHD and observed sequential skin biopsies for the presence and evolutionary pattern of follicular injury. Highly purified subsets of donor T cells were used to produce AGVHD to multiple minor histocompatibility (H) antigens in two strain combinations of mice matched for the major histocompatibility complex (MHC). In the C3H.SW- greater than B6 strain combination, only CD8+ effector cells produced histologic evidence in skin of AGVHD, which peaked three weeks post-transplant. In the B10.D2- greater than DBA/2 strain combination, CD4+ effector cells, and to a lesser extent, CD8+ cells, mediated disease, which peaked during the fourth week post-transplant. Analysis of skin from both strain/effector cell combinations revealed follicular infiltrates preferentially involving follicular stem cell (FSC) regions (bulge) of anagen follicles between the second and third weeks post-transplant. These infiltrates often preceded infiltration of adjacent interfollicular epidermis and were associated with follicular involution to telogen (resting) phase. By the fourth week post-transplant, greater than 50% of follicles were in telogen phase and residual inflammation was minimal. This provided a unique opportunity to observe follicular recovery from telogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Graft-versus-host disease in experimental allogeneic bone marrow transplantation.

Considerable progress has been made in defining the relative contributions of CD4+ and CD8+ cells to GVHD. Studies in mice have shown that, in isolation, each T cell subset is able to induce lethal GVHD in irradiated hosts. For hosts differing at the MHC (H-2), CD4+ cells cause GVHD directed to H-2 class II antigens whereas CD8+ cells produce GVHD to H-2 class I antigens. With H-2-matched hosts expressing multiple minor H antigens, induction of lethal GVHD is largely under the control of CD8+ cells. Which particular minor H antigens provide the targets for GVHD in mice is still unclear. Clarifying this question is complicated by the finding that the target antigens for GVHD do not necessarily correlate with the targets for cytotoxicity measured in vitro; moreover, immunodominance occurs when T cells are exposed to multiple minor H antigens in vivo. In terms of clinical application, there is a need to devise animal models for improving the success of HLA-matched bone marrow transplantation. Selectively depleting the marrow inoculum of CD8+ cells and preimmunizing the donor against viral pathogens are two procedures which are currently under study.

Animals↗
PubMed1991

Characterization of target injury of murine acute graft-versus-host disease directed to multiple minor histocompatibility antigens elicited by either CD4+ or CD8+ effector cells.

The precise identity of effector mononuclear cells capable of eliciting acute graft-versus-host disease (AGVHD) is controversial. In this study, highly purified subsets of donor T cells were used to produce AGVHD to multiple minor histocompatibility (H) antigens in two strain combinations of mice matched for the major histocompatibility complex (MHC). In the C3H.SW- greater than B6 strain combination, only CD8+ effector cells produced histologic evidence of AGVHD in skin and liver, which peaked 3 weeks after transplant. In the B10.D2- greater than DBA/2 strain combination, CD4+ effector cells, and to a lesser extent, CD8+ cells, mediated disease in skin, liver, and intestine, which peaked during the fourth week after transplant. Analysis of skin and liver from both combinations showed target cell injury that was phenotypically similar and resembled that previously described in human disease in other studies. In addition, prominent epithelial injury also was detected in oropharyngeal mucosa, esophagus, hepatobiliary ducts, and seminal vesicle in both transplant settings. These findings indicate that functionally different subsets of donor T cells may be capable of initiating common pathways of cellular injury in selected target sites in AGVHD, and have potential implications for strategies that seek to ablate disease development by manipulation of donor marrow before transplantation.

Acute Disease↗
PubMed1991

Pathophysiology of graft-versus-host disease directed to minor histocompatibility antigens.

Our investigations related to GVHD over the last few years have established the role of CD8+ and CD4+ T cell subsets in the etiology of the disease across different genetic barriers and has raised several important questions about the nature of in vivo functions and mechanisms of pathogenesis of these subsets. Immunodominance in the GVHD response of T cells to multiple minor H antigens seems to play a major role in vivo, and differs from that observed in vitro. Understanding this phenomenon is a high priority if we are to be able to cope with human minor H antigens clinically. Finally, utilizing our working knowledge of T cell subsets and GVHD, we need to know whether selective depletion of donor inoculum and donor pre-sensitization could be advantageous in the clinical situation.

Animals↗