Immune responses in humans while receiving adoptive immunotherapy with recombinant interleukin-2 and lymphokine-activated killer cells: acute anergy to mitogens and recall antigens

T-cell function after interleukin-2 therapy in HIV-infected patients is correlated with serum cortisol concentrations

OBJECTIVES

To examine the effects of interleukin (IL)-2 therapy on in-vitro lymphocyte responsiveness in HIV-infected patients and to correlate these data with serum cortisol concentrations.

DESIGN

German prospective study.

METHODS

In adult patients (n = 32) treated with 9 x 10(6) IU/day interleukin-2, lymphocyte transformation tests (LTT), serum cortisol concentrations and CD4 T-cell counts were assessed before, during and after IL-2 therapy.

RESULTS

A significant decrease in responses towards mitogens and recall antigens (P < 0.05) was observed on day 7 after starting a 4- to 5-day IL-2 therapy as compared to baseline. Serum cortisol levels increased (P < 0.0001) reaching a maximum on day 4, and were still elevated on day 7 (P < 0.005). CD4 T-cell counts significantly decreased with a minimum on day 2 before increasing 2.4-fold above baseline on day 7 (P < 0.005 each). A positive correlation (P < 0.05 each) was observed for changes in cortisol levels and in LTT mitogen and antigen reactions (both day 7 - 0), changes in cortisol levels (day 3 - 0) and CD4 cell counts on day 2, and corticotrophin releasing hormone test results and LTT antigen reactions on day 7. LTT responses, cortisol levels and CD4 T-cell counts returned to baseline on day 30.

CONCLUSION

Serum cortisol concentrations are predictive of functional and numerical changes of T cells induced by IL-2 therapy.

Bypassing tumor-associated immune suppression with recombinant adenovirus constructs expressing membrane bound or secreted GITR-L

Recent evidence has resurrected the concept of specialized populations of T lymphocytes that are able to suppress an antigen-specific immune response. T-regulatory cells (T-reg) have been characterized as CD4+ CD25+ T cells. Previous reports describing differential gene expression analysis have shown that the glucocorticoid-induced tumor necrosis family receptor family-related gene (GITR) is upregulated in these cells. Furthermore, antibodies specific for GITR have been shown to inhibit the T-suppressor function of CD4+ CD25+ T-reg. The ligands for both mouse and human GITR have been cloned recently. We have inserted the sequences for natural, membrane-bound GITR-ligand (GITR-L) and a truncated secreted form of GITR-L (GITR-Lsol) into the adenovirus-5 genome. Coculture experiments show that cells infected with Ad-GITR-L and supernatants from cells infected with Ad-GITR-Lsol can increase the proliferation of both CD4+ CD25- and CD8+ T cells in response to anti-CD3 stimulation, in the presence, as well as in the absence, of CD4+ CD25+ T cells. The virus constructs were injected into growing B16 melanoma tumors. Ad-GITR-L was shown to attract infiltration with both CD4+ and CD8+ T cells. Both constructs were shown to inhibit tumor growth.

Effects of subcutaneous interleukin-2 therapy on phenotype and function of peripheral blood mononuclear cells in human immunodeficiency virus infected patients

In the context of clinical therapy with recombinant human interleukin-2 (IL-2), we monitored immunological alteration in 10 human immunodeficiency virus type-I (HIV-1)-infected individuals, on stable antiretroviral therapy, who had a CD4+ cell count between 200 and 500 cells/mm3. Subcutaneous IL-2 was prescribed thrice weekly (at a dose of 3 x 10(6) IU) for 24 weeks and the patients were followed-up for 32 weeks. IL-2 treatment induced an increase in the CD4+ percentage (P<0.001) and CD4+ cell count (P<0.009). Furthermore. natural killer (NK) cell activity was increased (P<0.001) at week 8 of treatment, whereas lymphokine-activated killer (LAK) cell activity showed a transient, nonsignificant increase at week 8 and was reduced (P<0.001) at 32 weeks. However, the cytotoxic T-lymphocyte (CTL) activity decreased against HIV antigens, and the proliferative response to Candida, IL-2 and phytohaemagglutinin (PHA) declined during the first 8 weeks (P<0.05) and returned to baseline levels after 32 weeks. The HIV RNA level did not change during IL-2 therapy; however, after 8 weeks of follow-up a significant increase (P<0.001) in viral load was observed. In

Salvage immunotherapy with subcutaneous recombinant interleukin 2 (rIL-2) and alpha-interferon (A-IFN) for stage D3 prostate carcinoma failing second-line hormonal treatment

Immunotherapy with subcutaneous rIL-2 and alpha IFN was administered to stage D3 prostate cancer patients after failure of secondary treatment with oral estramustine phosphate. Of a total of 15 patients, 2 are in partial response, with estramustine maintained after 44+ and 36+ weeks, respectively. Response to estramustine was observed initially in 7 of 13 patients, with a median duration of 12 weeks (range 8-20). No response to estramustine was observed in the remaining 6 patients. After the failure of estramustine, 13 patients were treated with immunotherapy. After the first cycle, progression of disease no therapy was given to those patients. A reduction of PSA levels was observed during the first cycle in 2 patients (15.3%); levels subsequently increased during the second cycle of treatment. A partial response was observed in 4 patients (30.7%), with a reduction of PSA levels in 3. The duration of response was 28 and 32 weeks in 2 patients who survived after failure for 18 and 21 weeks, respectively. Two patients are still alive, with continued partial response at 62+ and 42+ weeks. Side effects were represented mainly by a flu-like syndrome, associated with fever and nausea in all patients. The serum concentration of IL-10 was measured in 8 patients under study and in 11 matched controls. Levels higher than mean + 2D of controls before, during, or after immunotherapy were correlated with treatment failure, whereas levels below 6 ng/ml were encountered among the patients who showed a clinical response and a reduction of PSA during treatment. Within the limitations of this pilot study, it appears difficult to distinguish between a spontaneously slowly progressing disease and a true response to therapy.

Reversible anergy in circulating lymphocytes of cancer patients during interleukin-2 therapy

Interleukin-2 plays a crucial role in enhancing the antitumor immune response. Clinical trials, mainly in renal cell carcinoma and melanoma patients, have been carried out with encouraging results. Recent reports demonstrated that interleukin-2 therapy may depress the immune response either in vitro or in vivo. We decided to monitor, in nine renal cancer patients, the proliferative responses and the parallel variations in Ca2+ homeostasis of peripheral blood lymphocytes collected before, during and after the first cycle of a 3-day interleukin-2 systemic administration. The proliferative response to phytohemagglutinin or concanavalin A significantly dropped early during interleukin-2 infusion. Consistently, an impairment in mobilizing Ca2+, either from internal stores or via influx from outside, was observed. Results obtained with a mAb-alpha CD3 molecular complex strongly suggested that the TCR/CD3 signal transduction pathway was defective. In contrast, no major variations were observed in the general machinery controlling Ca2+ homeostasis nor in the total Ca(2+)-releasable pool. Patients' lymphocytes, cultured in vitro for 3 days in medium alone, showed an almost complete recovery in their ability to respond to mitogens. In conclusion, we show that interleukin-2 administration in cancer patients induces a reversible state of anergy in circulating lymphocytes, assessed both by the reduction in the proliferative response and the block of the mitogen-activated intracellular Ca2+ signalling.

Early IL-2/sIL-2R surge following surgery leads to temporary immune refractoriness

High serum level of immunoreactive but not biologically active IL-2 was detected 1 day after surgery in patients undergoing major operation (abdominal, open-heart), in proportion to the tissue injury caused by surgical trauma. IL-2 values were highest in those patients who underwent open-heart surgery and received blood transfusions. In all patients they declined in the third and fourth post-operative days. Elevated serum levels of soluble IL-2 receptors (sIL-2R) were already present 1 day after operation, and peaked in the third and fifth post-operative days after mitogen triggering. Blood lymphocytes derived from operated patients secreted reduced amounts of both IL-2 and sIL-2R compared with control lymphocytes. The extent and duration of this reduction were also proportional to the tissue trauma and were affected by blood transfusions. Based on these data we suggest that early post-operative systemic immunological activation (appearance of IL-2 in the serum) is followed by elevation of sIL-2R, which then interferes with IL-2-dependent immunity. Blood lymphocytes are probably not involved in the post-operative immunological activation. The trigger for and the site of IL-2/sIL-2R synthesis are not yet clear.

Immunotherapy of colorectal cancer

Specific and nonspecific stimulation of the host immune system to reject cancer is an attractive concept that is just beginning to mature. Results with crude extracts and nonspecific immune stimulation have been variable. However, the recent observations of improved survival after administration of levamisole plus 5-fluorouracil in the adjuvant setting have made an impact on the treatment of colorectal cancer. Animal studies consistently show that immune therapies are most effective for disease that is not advanced. Thus, the small benefit seen with levamisole, a low toxicity immunomodulator, suggests that much more impressive results can be anticipated with more potent and specific agents. Postsurgical autologous tumor cell vaccine has been effective in some prospective randomized trials; in others, no benefit was found. The identification and purification of allogeneic tumor-associated antigens has lead to enhanced antigen-specific host cell-mediated immunity; this may result in more consistent antitumor effects. The current development of chemically defined immune adjuvants of low toxicity allows tumor-specific immune stimulation to be tested in high-risk apparently healthy patients after resection of colorectal cancer (Stages II and III). The influx of information regarding immune cell populations, cell-surface markers, and cytokines has fostered extensive exploration of lymphocyte stimulation, in vitro cell growth and expansion, and in vivo evaluation in patients with advanced cancer. Modest tumor response rates have been documented with adoptive transfer of lymphokine-activated killer cells and interleukin-2. Improved results are anticipated with the more potent tumor-infiltrating lymphocytes and specific in vitro sensitization of draining lymph node cells to autologous and allogeneic tumor antigens. Murine monoclonal antibodies specific for cell-surface markers, such as carcinoembryonic antigen, have been tested for their value in the diagnosis and therapy of colorectal cancer. A small response rate has been seen with single and multiple injections of C017-1A, a monoclonal antibody specific for colonic and pancreatic cancer. The development of antiidiotypic antibodies in these patients may have been important in those that responded to this type of therapy. However, laboratory evidence suggests that monoclonal antibody conjugated to a cytotoxic agent (i.e., radionuclide, drug, or toxin) should be much more effective. Radioimmunotherapy trials in the nude mouse model bearing human colon cancer xenografts showed good tumor incorporation of the radionuclide (yttrium 90 or iodine 131), inhibition of tumor growth, and long-term survival.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunosuppression follows systemic T lymphocyte activation in the burn patient

A general consensus that thermal injury affects T lymphocyte function adversely is supported particularly by the observation that burned patients' lymphocytes secrete reduced levels of biologically active IL-2 in vitro. In the same patients, however, high serum concentrations of the low-affinity IL-2 receptor (IL2R alpha), a product of an IL-2-activated gene, have been observed. In this study a significant proportion of patients also demonstrated over-physiological levels (from 2 to 500 U/ml) of serum IL-2 ascertained by immunoassay. Increases in serum IL-2 content correlated significantly (P less than 0.02) with those of serum IL-2R alpha during the first week post-burn. Later, serum IL-2R alpha levels continued to increase up to 30 days while IL-2 eventually declined. Thus, augmented secretion of IL-2R alpha appears related to the high serum IL-2 content. Therefore refractoriness to further immune stimulation may be due to early activation of the lymphoid system, rather than to an intrinsic incapacity of T lymphocytes for generating sequential responses.

Soluble interleukin 2-receptor alpha secretion is related to altered interleukin 2 production in thermally injured patients

This study examines the relationship between the capacity for interleukin-2 (IL2) production and the magnitude of the in vitro and in vivo secretion of IL2R alpha in 43 patients with major burns (30-90 per cent total body surface area). Throughout the postburn period a significant (P less than 0.001-0.05) proportion of patients studied demonstrated increasingly high levels of serum IL2 ranging from 2 to over 500 U/mL. Serum IL2R alpha also increased, reaching its highest levels at 15-40 days postburn, while serum IL2 gradually declined. In this period in vitro IL2 production and IL2R alpha secretion in patient's cultures were significantly reduced compared to control. However, in parallel cultures supplemented with exogenous IL2, IL2R alpha levels could be significantly increased (2.5 fold). IL2R alpha levels also approached normal in peripheral blood mononuclear cell cultures from recovering patients whose in vitro IL2 production had improved. These observations suggest that in the burn patient altered synthesis and/or secretion of the soluble form of IL2R alpha may be related to IL2 content. Above physiological levels of IL2R alpha and its ligand in postburn serum also indicate that thermal injury induces strong in vivo activation of the lymphoid system.