Celsa Spina

Alterations in cytotoxic and phenotypic subsets of natural killer cells in acquired immune deficiency syndrome (AIDS)

Testing of cytotoxic function using a panel of natural killer (NK)-sensitive target cells, including a unique herpes simplex virus-infected Raji-cell target, was performed in conjunction with phenotypic cell analysis by dual-color flow cytometry to characterize the NK system. Subjects included in the study were at risk for or infected with the etiologic agent of the acquired immune deficiency syndrome (AIDS), human immunodeficiency virus (HIV). A generalized defect in NK function was temporally correlated with disease manifestations, as evidenced by deficient NK lytic function in patients with AIDS and AIDS-related complex (ARC). Healthy at-risk subjects, including those seropositive for HIV, exhibited robust NK-cell function. Phenotypic analysis revealed that normal proportions of the NK-associated CD16+ (Leu11) Leu7− and CD16+(Leu11)Leu7+ lymphocyte subsets were maintained throughout the clinical progression of HIV infection. However, the proportion and numbers of cells of the CD8+(Leu2)Leu7+ subset were increased in AIDS, ARC, and healthy at-risk subjects, including those seronegative for HIV. These results are consistent with a qualitative defect in the NK system in AIDS, perhaps secondary to CD4-cell depletion and a concomitant lack of essential accessory factors. The elevation in CD8+(Leu2)/Leu7+ cells is not solely the result of HIV infection and may be a general response to viruses and/or other antigenic stimulation.

Intraperitoneal immunotherapy of epithelial ovarian carcinoma with Corynebacterium parvum

Corynebacterium parvum was administered intraperitoneally to 21 patients with epithelial ovarian cancer. Nineteen patients had surgically measurable disease and two received adjuvant therapy. Surgically confirmed responses were documented in six of 19 patients (31.6%), with two complete responses (10.5%) and four partial responses (21.1%). Three patients (15.8%) had stable disease, and 10 patients (52.6%) had disease progression. The mean survival of the patients who had a complete response was 35.5 months; the four patients who had a partial response the mean survival was 26.6 months, and of the nonresponders the mean survival was 12.6 months (p less than 0.02). The mean survival of the entire group was 18.2 months. Initial response and patient survival correlated with the amount of disease pretreatment. Thus six responding patients had less than or equal to 5 mm maximum diameter tumors, that is, minimal residual disease. Toxicity in the 86 courses of therapy included abdominal pain in 78% of cases, fever in 56%, nausea in 40%, and vomiting in 22%. Stimulation of cytotoxic lymphocytes resulted from the administration of C. parvum, which induced a significant increase of both intraperitoneal natural killer lymphocyte cytotoxicity and antibody-dependent cell-mediated cytotoxicity in six of nine patients tested; these two types of cytotoxicity correlated with response to therapy and may be partially responsible for the surgically documented tumor regression. While the clinical usefulness of intraperitoneal C. parvum is limited because of its toxicity, intraperitoneal immunotherapy may prove useful in patients with minimal residual ovarian cancer when more refined agents become available.

Cytotoxic studies in human newborns: Lessened allogeneic cell-induced (augmented) cytotoxicity but strong lymphokine-activated cytotoxicity of cord mononuclear cells☆

Nonspecific cytotoxic responses such as natural killer activity can be increased in vitro by incubating effector cells with soluble factors or allogeneic cells. We sought to determine if newborn cells, known to be deficient in most cytotoxic responses, including resting NK activity, could develop enhanced cytotoxic responses following incubation with allogeneic cells (augmented cytotoxicity) or with lymphokines (lymphokine-activated cytotoxicity). Cord whole mononuclear cells (WMC) incubated with irradiated Raji cells for 5 days develop lower levels of cytotoxicity toward K562 targets at both a 20:1 effector:target (E:T) ratio (39 +/- 2.7% vs 49 +/- 3.6%) and a 10:1 E:T ratio (29 +/- 2.6% vs 40 +/- 3.6%) than do adult cells. Lessened specific cytotoxicity of cord cells developed toward the sensitizing Raji cells was also observed at both E:T ratios. Attempts to enhance the induced cytotoxicity by incubation with interferon or isoprinosine were unsuccessful. In contrast, lymphokine (i.e., interleukin 2)-activated killer (LAK) cytotoxicity is not deficient in cord WMC. Indeed, the level of LAK cytotoxicity is equivalent to that observed with similarly treated adult cells despite a lower baseline level of cytotoxicity toward the target cells. In the presence of purified IL-2 for 5 days, cord WMC cytotoxicity against K562 cells increased from 12 +/- 2.6 to 71 +/- 4.2% and against Raji cells increased from 9.6 +/- 2.5 to 48 +/- 6.7%. Similarly treated adult cells increased their killing against K562 from 23 +/- 4.2 to 61 +/- 4.5% and against Raji from 12 +/- 3.0 to 36 +/- 5.3%. This substantial lymphokine-activated cytotoxicity of newborn cells suggests the possibility of therapeutic intervention with purified lymphokines in neonatal infections or neoplasms.

Soluble suppressor factor produced by pokeweed mitogen-stimulated human peripheral blood leukocytes☆

Abstract Human peripheral blood leukocytes were exposed to either PWM or Con A mitogens. Cells activated by both these mitogens were able to depress proliferation in an MLC, and to inhibit the generation of spontaneous killer cell (SK) and induced T-cell cytotoxic activity. PWM-activated cells incubated in media for 48 hr were able to elaborate a soluble factor in vitro . This factor suppressed cytotoxicity, and was active only when present at the initiation of MLC cultures. In contrast, cells exposed to Con A were able to suppress immune responsiveness, but this population did not release a soluble factor which could inhibit cytotoxicity. PWM induction appears to be dependent on phagocytic cells, while Con A activation is less dependent on this adherent population. An enriched adherent cell population, stimulated with PWM, was able to suppress cytotoxicity. Thus, the PWM-stimulated system of suppression is mediated through a soluble factor and is dependent on adherent cells.

The use of three baseline values in intervention studies: application to evaluation of immune modulation therapies

In studying the effects of a treatment intervention on immunological parameters, we have found that three baseline values are a practical number to obtain on each patient. Three baseline values 1) increase the chances of detecting a statistically significant effect of the intervention, 2) provide an assessment of the daily variability of the assay and patients, and 3) enable the identification of individual patients who demonstrate significant changes associated with the intervention.