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M Giovarelli

Publications and source records attributed to M Giovarelli.

At least 55 records · Page 3Linked to original sources
PubMed1991

Blockade of physiologically secreted IFN-gamma inhibits human T lymphocyte and natural killer cell activation.

The role of physiologically secreted human IFN-gamma in T lymphocyte and NK cell activation has been probed with a panel of mouse mAb directed against various epitopes of the human IFN-gamma molecule, or human IFN-gamma R. Addition to the culture medium of those mAb that neutralize the antiviral activity of IFN-gamma or interact with its receptor inhibited proliferative and cytotoxic responses elicited in PBL by HLA alloantigens, anti-CD3 mAb, and IL-2, but not the proliferative response to PHA. The IFN-gamma blockade also inhibited IFN-gamma, IL-2, and TNF-alpha release during MLC. Kinetic experiments showed that reduction of proliferative and cytotoxic responses to HLA alloantigens is maximal when IFN-gamma is blocked within the first 48 h. Exogenous rIFN-gamma restored the proliferative response only when added at the beginning. Moreover, when IFN-gamma was blocked, T lymphocytes recovered from 6-day MLC displayed a profound decrease in their expression of p55 and p75 chains of the IL-2R, as well as in the number of high-affinity IL-2 binding sites. These findings strongly suggest that IFN-gamma is required in the early phases of induction of the oligo- and polyclonal proliferative and cytotoxic responses of lymphocytes.

Antibodies, Monoclonal↗
PubMed1991

Growth and dissemination of human malignant lymphoblasts in immunosuppressed nu/nu mice.

Athymic nu/nu mice are commonly employed for the heterotransplantation of solid human tumors. Leukemias, however, have consistently proved difficult to transplant and, to enhance their take, recipient nu/nu mice have been variously immunosuppressed. In this study, the natural reactivity against human malignant T lymphoblast (PF382) of splenectomized nu/nu mice (S-nu/nu), nu/nu mice splenectomized and treated with polyinosinic-polycytidylic acid (SIC-nu/nu), and nu/nu mice splenectomized, irradiated and repeatedly injected with antiasialo GM1 antiserum (SIA-nu/nu) has been correlated with the in vivo growth of subcutaneous and intravenous PF382 cell challenges. SIC-nu/nu mice display a marked natural killer (NK) activity, quickly clear 125I-Urd-labelled PF382 cells injected intravenously and do not allow the growth of subcutaneous nor intravenous PF382 cell challenges. S-nu/nu mice display a slightly lower NK activity and slower clearance of 125I-Urd-labelled PF382 cells. Moreover, an intravenous PF382 cell challenge kills 56% of S-nu/nu mice. SIA-nu/nu mice have no NK activity, slowly clear 125I-Urd-labelled PF382 cells and always allow the growth of PF382 cells injected either subcutaneously or intravenously with a consistent pattern. Following the intravenous challenge, PF382 cells first metastasize to liver and kideny, then focal or diffuse infiltrations of the bone marrow and menings become evident. SIA-nu/nu mice thus offer an interesting experimental model for study of the pathogenesis of leukemic infiltration of the meninges, and the exploration of possible therapeutic approaches.

Animals↗
PubMed1990

Low doses of IL-4 injected perilymphatically in tumor-bearing mice inhibit the growth of poorly and apparently nonimmunogenic tumors and induce a tumor-specific immune memory.

The ability of rIL-4 to trigger host reactivity against both a chemically induced fibrosarcoma (CE-2) and a spontaneous adenocarcinoma (TS/A) of BALB/c mice was studied. Daily local s.c. administration around tumor draining lymph nodes of 10 injections of progressive amounts (0.00001 to 1000 pg/day) of rIL-4 induced appreciable inhibition of the growth of both tumors after a dose-response survival curve peaking at 0.1 pg/day. Inasmuch as rIL-4 has no direct antitumor activity, as shown by in vitro tests, host immune reactivity plays a fundamental role in this lymphokine activated tumor inhibition (LATI). LATI, in fact, is abolished when recipient mice are sublethally irradiated or treated with cyclosporin A, or when the reactivity of CD4+ lymphocytes is suppressed, whereas it is not affected by anti-asialo GM1 antibody. The morphologic data show that rIL-4 LATI rests on the recruitment of several cell reaction mechanisms, among which those that are nonspecific seem to predominate. rIL-4 LATI also leads to a state of long lasting and specific immune memory: the growth of a second contralateral tumor challenge is significantly impaired after LATI. This immune memory takes place after LATI of both the poorly immunogenic CE-2 fibrosarcoma and the TS/A adenocarcinoma, previously classed as nonimmunogenic on the basis of immunization-protection tests. In the latter case, adoptive transfer experiments show that Thy-1+ lymphocytes and, in particular, the CD4 cell-depleted T lymphocyte subpopulation, are responsible for the immune memory. Finally, the ability of rIL-4 to trigger LATI is greater than that of the most effective doses of rIL-2, rIL-1 beta, and IFN-gamma, whereas its association with rIL-1 beta induces a more effective immune memory.

Adenocarcinoma↗
PubMed1990

Perilymphatic injections of cytokines: a new tool in active cancer immunotherapy. Experimental rationale and clinical findings.

Various strategies for local immunotherapy performed by using lymphokines and lymphocytes are presented. In experimental mice models, the antitumor reaction elicited through the injection of little amounts of IL-2 and gamma-IFN at the tumor growth site is significantly enhanced by the concurrence of lymphocytes from tumor bearing mice artificially admixed to challenging tumor cells. These lymphocytes act as initiator or helper cells that elicit both a local and a systemic long lasting immune reaction by the release of additional lymphokines. The reaction activated mostly involves draining lymph nodes, where multiple reaction mechanisms are induced. The local injection of cocktails of molecularly defined lymphokines can also mimic the helper action of lymphocytes and trigger a similarly effective anti-tumor reaction. A set of pilot clinical trials with IL-2 or gamma-IFN injected perilymphatically were initiated in patients with advanced primary or recurrent localized tumors of the head and neck and the bladder. This treatment appears to elicit a local reaction by activating a few pathways of patients immunoreactivity, whose efficiency may well be high, as shown by the tumor inhibition often observed.

Amino Acid Sequence↗
PubMed1990

Infiltrating leukocyte populations and T-lymphocyte subsets in head and neck squamous cell carcinomas from patients receiving perilymphatic injections of recombinant interleukin 2. A pathologic and immunophenotypic study.

Nine patients with squamous cell carcinoma of the oral cavity and oropharynx underwent preoperative perilymphatic administration of recombinant interleukin 2 (rIL-2). A more marked eosinophil and lymphocyte infiltration and more extensive edema than in 13 untreated cases were observed in surgical specimens. Necrosis was present in five of nine cases, but involved no more than 10% of the neoplastic tissue; in three of nine cases, characteristic necrotic changes with intense eosinophil infiltration possibly induced by lymphokines involved the peritumoral soft tissues. Of the tumor-infiltrating lymphocytes, T-lymphocytes (mostly CD4+ cells) prevailed over B-lymphocytes. CD4+ and CD8+ cells were mainly located close to the neoplastic sheets. Moderate amounts of CD38+ and CD11c+ cells (macrophages) and few CD16+ and CD56+ lymphocytes were found in all cases. CD25+ and LAK1+ cells were significantly more numerous in treated than in untreated cases. This suggests that local administration of rIL-2 induces an increase in activated T-lymphocyte subsets infiltrating the neoplastic tissue, thus eliciting a tumor-specific T-lymphocyte reactivity.

Adult↗
PubMed1989

Lymphokine-activated tumor inhibition in mice. Ability of a nonapeptide of the human IL-1 beta to recruit anti-tumor reactivity in recipient mice.

The ability of the VQGEESNDK synthetic peptide corresponding to fragment 163-171 of human IL-1 beta to trigger lymphokine-activated tumor inhibition (LATI) of a poorly immunogenic fibrosarcoma (CE-2) of BALB/c mice was compared to that of the whole IL-1 beta. Neither molecule inhibits in vitro proliferation of CE-2 cells. Administration at the tumor challenge site for 10 days of daily injections of 50 micrograms of peptide 163-171 induce a consistent, although limited, inhibition of tumor growth, whereas similar injections of 1 pg of IL-1 beta induced a more marked LATI. However, strong LATI was elicited when these injections were performed in mice challenged with tumor cells admixed at 1/10 cell ratio with nonreactive lymphocytes from CE-2-bearing mice. The L3T4+ lymphocyte subset is mainly responsible for this enhancement. This reaction is abolished when recipient mice are sub-lethally irradiated, treated with cyclosporin A, or when the reactivity of L3T4+ and asialo GM1+ cells is suppressed. A similarly efficient LATI is found on combining the daily peptide injections with that of 10 U of IL-2. LATI stemming from this association, too, is abolished when mice are irradiated or treated with anti-L3T4 antibody, whereas it is not affected by cyclosporin A or anti-asialo GM1 antibody. Finally, a tumor-specific immune memory is acquired by about 50% of mice after LATI induced by IL-1 beta or 163-171 peptide alone and by about 80% of mice after LATI induced by peptide and lymphocytes from tumor-bearing mice or peptide and IL-2. These findings could lead to the building of a molecularly defined system to induce efficient immune recognition of tumor cells by using a peptide that does not cause any of the several inflammation-associated changes induced by the whole IL-1 beta.

Animals↗
PubMed1989

Lymphokine-activated tumor inhibition: combinatory activity of a synthetic nonapeptide from interleukin-1, interleukin-2, interleukin-4, and interferon-gamma injected around tumor-draining lymph nodes.

This report initially reviews the progressive steps of research designed to build up a new, well-defined helper system triggering both the non-specific and the tumor-specific immune reactivity of a host bearing a tumor, in order to impair tumor growth. Tumor-specific T-helper lymphocytes were first generated in vitro from the spleen of mice with evident tumors. As these lymphocytes inhibit tumor growth by recruiting host reactivity through the release of lymphokines, the peri-tumoral injection of interleukin-2 (IL-2) was then experimented. Repeated injections of 10 units of IL-2 are only weakly effective, but its triggering of an efficient anti-tumor reactivity is markedly enhanced when non-reactive lymphocytes directly obtained from tumor-bearing mice are artificially admixed with the challenge tumor cells. Lastly, in order to ascertain whether lymphocytes themselves could be dispensed with, lymphokines were injected around tumor-draining lymph nodes. Ten daily injections of 1 pg of the 163-171 synthetic nonapeptide of human IL-1 beta appeared very efficient in activating tumor inhibition, particularly when combined with IL-4 or (to a lesser extent) IL-2.

Animals↗
PubMed1989

B cells from chronic lymphocytic leukemia (CLL) patients are strong inducers of proliferation and major histocompatibility complex (MHC)-unrestricted [natural killer (NK)-like] cytotoxicity in normal T-lymphocytes.

We studied the ability of chronic lymphocytic leukemia (CLL) B cells to stimulate proliferation and major histocompatibility complex (MHC)-unrestricted [natural killer (NK)-like] cytotoxicity in a mixed lymphocyte tumor-cell culture (MLTC). CLL-derived B cells induced a significantly higher proliferative response than did B cells from healthy normal donors. Comparable levels of interferon and interleukin-2 production were detected in the mixed lymphocyte cultures (MLC) set up with normal B cells from healthy donors and in MLTC. Higher levels of NK-like cytotoxic activity were induced after stimulation with CLL than with normal B cells in nonlytic precursors. Inhibition experiments with specific monoclonal antibodies indicate that the NK-like response in MLTC is attributable to HLA class II antigens, which are expressed at comparable levels on CLL and normal B cells. Percoll gradient centrifugation of the MLC and MLTC recovered cells demonstrated that the NK-like effectors in both types of cultures were blast-transformed, highly mitotic cells.

B-Lymphocytes↗
PubMed1989

Effect of low doses of interleukin-2 injected perilymphatically and peritumorally in patients with advanced primary head and neck squamous cell carcinoma.

For 10 days, four patients with advanced squamous cell carcinoma of the head and neck received two daily injections of 100 units of natural IL-2, one around the tumor, the second near the tumor-draining lymph nodes. No side effects were observed. Histologic and ultrastructural examination of tumor and lymph nodes recovered at surgery showed that in many instances neoplastic cells were intermingled with numerous lymphocytes and eosinophils. Lymph nodes displayed hyperplasia of both cortical and paracortical areas and epithelioid venules infiltrated by lymphocytes and granulocytes. In a few cases, a decrease or disappearance of neoplastic lesions was also documented both clinically and histologically.

Aged↗
PubMed1988

Treatment of recurrent squamous cell carcinoma of the head and neck with low doses of interleukin-2 injected perilymphatically.

Ten patients with recurrent squamous cell carcinoma of the head and neck received daily injections of interleukin-2 (IL-2) from the Jurkat T-cell line purified by high pressure liquid chromatography for 10 days. Two hundred units of IL-2 in 0.5 ml were injected 1.5 cm from the insertion of the sternocleidomastoid muscle on the mastoid. When possible, courses were repeated at 45-day intervals. IL-2 was ineffective in two patients who had already undergone functional or radical neck dissection. By contrast, in six patients with contralateral or bilateral cervical lymph nodes, complete or partial disappearance of the tumor was observed. The injections were occasionally followed by moderate local swelling and lymph node pain, but no systemic disturbances.

Adult↗
PubMed1988

Obligatory role of IFN-gamma in induction of lymphokine-activated and T lymphocyte killer activity, but not in boosting of natural cytotoxicity.

The biological role of the murine IFN-gamma endogenously secreted during cell activation has been probed by the use of a rat mAb (AN18) that specifically neutralizes its activity. When An18 mAb is added to the cultures of BALB/c and C57BL/6 nylon nonadherent spleen cells (naSpc) stimulated for 18 h with 1000 U of IL-2, the normally released IFN-gamma can no longer be detected in the supernatants and the IL-2-induced proliferative response is markedly reduced as compared with control cultures set up in the presence of an unrelated rat mAb. By contrast, the increased natural cytotoxicity is not affected. The 96-h culture of both BALB/c and C57BL/6 naSpc in the presence of 1000 U of IL-2 resulted in marked lymphocyte proliferation and generation of lymphokine-activated killer activity. The presence of An18 mAb strongly inhibited both functions. Similarly, when naSpc were stimulated with mitomycin C-inactivated allogeneic leukocytes in the presence of An18 mAb, the normal proliferative response and specific cytotoxicity were almost abolished, whereas the secretion of IL-2 was in no way affected. Lymphocytes recovered from 3-day cultures stimulated by IL-2 or allogeneic cells in the presence of An18 mAb displayed a decrease of the expression of the p55 chain of IL-2R, as shown by flow cytofluorimetry. Moreover, binding experiments with 125I-labeled IL-2 showed that lymphocytes from allostimulated cultures set up in the presence of An18 mAb display a decreased number of low affinity and almost no high affinity IL-2R as compared with control cultures. These data show that endogenous IFN-gamma plays an obligatory role for the de novo induction of cytolytic activity in lymphokine-activated killer cells and CTL, most probably by affecting the membrane expression of high affinity IL-2R.

Animals↗
PubMed1988

Interferon-gamma is not an antiviral, but a growth-promoting factor for T lymphocytes.

The effects of interferon (IFN)-gamma or IFN-alpha/beta on virus yield, (2'-5')oligo(A) synthetase activation, H-2 antigen expression and proliferation of T lymphocytes have been investigated. Under the culture conditions used, vesicular stomatitis virus or Semliki Forest virus replication in T cells was not impaired by the addition of IFN-gamma, whereas it was completely inhibited by the addition of IFN-alpha/beta. In contrast, B cell lines, macrophage-transformed cell lines and fibroblasts were fully protected by both IFN-gamma as well as IFN-alpha/beta following virus infection. The lack of sensitivity of T lymphocytes to the antiviral effects of IFN-gamma was not due to absence of specific membrane receptors, since in saturation binding experiments with 125I-labeled murine IFN-gamma most T cell lines displayed a number of binding sites and a degree of affinity comparable to those found on B cells, which are fully sensitive to IFN-gamma antiviral activity. Analysis of IFN-induced dsRNA-dependent (2'-5')oligo(A) synthetase activity, one of the biochemical markers for cellular responses to IFN, showed that it was not induced in T lymphocytes after IFN-gamma treatment, whereas IFN-alpha/beta induced high levels. Both IFN-gamma and IFN-alpha/beta enhanced H-2 antigen expression on T cells as well as on cells of different histological type. Moreover, when IFN-gamma was tested for its antiproliferative activity on T cells, it was found to consistently potentiate the response of these cells to mitogens or growth factors, rather than inhibit their proliferation. Taken as a whole these results suggest that on T lymphocytes IFN-gamma should not be regarded as an antiviral agent, but rather as a modulator of T cell growth and functional differentiation, transducing intracellular signals dissimilar to those observed with target cells of different origin.

2',5'-Oligoadenylate Synthetase↗
PubMed1988

Helper strategy in tumor immunology: expansion of helper lymphocytes and utilization of helper lymphokines for experimental and clinical immunotherapy.

Two main kinds of immune strategy are possible against neoplasia. The first potentiates a selected effector arm. In vitro culture with exogenous interleukin-2 (IL-2) increases the activity of natural killer cells and leads to the expansion of T cytotoxic lymphocytes. Systemic reinfusion of both of these cells with high doses of IL-2 mediates the regression of a variety of murine and human tumors. In an alternative strategy, a few regulatory lymphocytes turn on immune reactivity by triggering a cascade of interconnected effector functions. The efficacy of this strategy rests on the repertoire of effector mechanisms moved to action. An effective immunoregulatory maneuver is the addition of helper determinants on the surface of tumor cells. Its power can be further increased by the pre-induction of helper T lymphocytes specific to the helper determinants. This approach can be achieved in mice by coupling muramyl dipeptides to tumor cells, along with eliciting T lymphocytes specifically reactive to Bacillus Calmette-Guerin. Noncytotoxic T helper lymphocytes produce factors which recruit nonspecific (macrophages) as well as specific (cytolytic T lymphocytes) anti-tumor attacking cells. In this way protection can be afforded against primary tumors and metastases, as well as leukemia cells. As the activity of helper lymphocytes rests mostly on lymphokine release, the use of molecularly defined lymphokines mimicking T-helper functions has also been attempted. In a few experimental models, the association of low doses of IL-2 with non-reactive lymphocytes from tumor-bearing mice promotes an effective anti-tumor reaction in the host. Moreover, the combination of distinct lymphokines can also build a molecularly defined helper system able to activate in sequence non-specific and specific anti-tumor reactions in vivo. Trials intended to evaluate the clinical impact of these helper approaches in the management of human tumors are being started or are already under way.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1988

Release of interleukin-2-like material by B-chronic lymphocytic leukemia cells. An autocrine or paracrine model of production and utilization?

In a series of untreated patients with B-cell chronic lymphocytic leukemia (B-CLL), the capacity of the neoplastic B-cell population to release an interleukin-2 like factor (IL-2lf) was assessed. While unstimulated purified leukemic B-cells showed no IL-2lf production, in 16 of the 27 cases tested (59.2%) significant amounts of IL-2lf (4.3-125 U) were released following activation with phytohemagglutinin (PHA) and the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). In seven further cases (25.9%), small quantities of IL-2lf (0.2-1.7 U) were detected, while only in four (14.8%) no release was found. In 11 of the 20 cases (55%), PHA alone was also capable of inducing the production of limited amounts of IL-2lf (0.4-8 U). Only small amounts were released from B lymphocytes isolated from normal tonsils both with PHA and PHA plus TPA. Further purification using a fluorescence activated cell sorter suggests that the IL-2lf is truly produced by leukemic B cells and blocking experiments with the PC-61 monoclonal antibody indicate that IL-2lf and IL-2 use the same cell membrane receptor. However, co-cultures of leukemic B cells with small amounts of autologous or allogeneic T lymphocytes enhanced the amount of IL-2lf released into the supernatant to values markedly higher than those released by T- or B cells alone. Unlike normal B lymphocytes, unstimulated purified leukemic B cells from 17 out of 23 B-CLL cases (73.9%) were capable of absorbing variable amounts of exogenous IL-2. In addition, in six of the 11 cases tested (54.5%) IL-2 alone was capable of producing a 2-4 fold increase of thymidine uptake. In six out of eight cases (75%), a 2-5 fold enhancement of the proliferative response was observed when the leukemic B cells were co-stimulated with Staphylococcus aureus Cowan 1 (SAC) and IL-2. Moreover, when the cells were pre-activated with SAC or with PHA plus TPA and then further stimulated with IL-2, a 2-20 fold increase in proliferative response was found in the majority of cases studied. These findings indicate that elevated quantities of IL-2lf may be released in B-CLL particularly due to the B- and T cell interconnections, and that the leukemic B cells appear capable of absorbing IL-2 and of proliferating after costimulation with IL-2.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMed1988

Autocrine or paracrine models of cytokine production and utilization in B-cell chronic lymphocytic leukaemia.

The possibility that autocrine or paracrine mechanisms of cytokine production and utilization may take place in patients with B-cell chronic lymphocytic leukaemia (B-CLL) is discussed. In particular, evidence is provided for a likely role of interleukin 2 (IL2) on the neoplastic B-cell compartment. Furthermore, the possibility that tumor necrosis factor (TNF) may also be involved is suggested.

Humans↗
PubMed1987

Interleukin 2 activated tumor inhibition in vivo depends on the systemic involvement of host immunoreactivity.

Daily local administration at the tumor challenge site of 10 injections of 10 U of recombinant interleukin 2 (IL 2) obtained from different factories induces a consistent, though limited inhibition of the growth of CE-2, a poorly immunogenic methylcholanthrene-induced tumor. By contrast, almost complete tumor inhibition is observed when these injections are performed in mice challenged with tumor cells admixed at 1:5 cell ration with nylon wool column purified lymphocytes obtained from tumor-bearing animals. The host immune system plays a fundamental role in this lymphokine-activated tumor inhibition (LATI), which is derived from the local combination of IL 2 and nonreactive lymphocytes. When the host is sublethally irradiated, or the reactivity of L3T4 and Asialo GM1 lymphocytes is suppressed by in vivo antibody treatment, in fact, LATI no longer takes place. Daily injections of antibody to murine interferon-gamma or cyclosporin A have the same effect, indicating that lymphokine release plays an important role in the recruitment of host reactivity. The morphological data show that when LATI is taking place the tumor challenge area becomes infiltrated by mononuclear cells and granulocytes (mostly eosinophils), which establish close contacts with each other and with tumor cells as determined at ultrastructural analysis. Tumor draining lymph nodes display marked expansion of cortical and paracortical areas. Lymphocyte proliferation, interferon-gamma release and cytotoxicity against CE-2 and YAC-1 target cells are greatly enhanced during LATI. Contralateral lymph nodes and the spleen also show a slight increment of these functions. In mice challenged with CE-2 tumor cells only and receiving daily IL 2 injections, these reaction functions (with the exception of interferon-gamma secretion) are also enhanced, though to a lesser extent than during LATI and only in tumor-draining lymph nodes. Last, the growth of a second contralateral tumor challenge is significantly impaired during or after LATI, showing that a persistent and effective systemic reactivity can be quickly induced in this way.

Animals↗