J. L. McCoy

Human cell-mediated immunity to tuberculin as assayed by the agarose micro-droplet leukocyte migration inhibition technique: Comparison with the capillary tube assay

Direct and indirect agarose microdroplet migration inhibition assays were performed with log dilutions (50--5 X 10(-8) microgram/ml) of soluble purified protein derivative (PPD) of tuberculin and leukocytes (4 X 10(5)/droplet) from PPD skin test positive or negative individuals. Some tests were run in parallel with the capillary tube method. Inhibition of migration of leukocytes from 9/11 PPD skin test positive donors studied was observed in direct tests when employing PPD doses ranging from 1--50 microgram/ml PPD. Inhibition of migration of leukocytes from some PPD skin reactive donors was obtained with as little as 5 X 10(-3)--5 X 10(-7) microgram/ml (i.e., 5 nanograms to 0.5 picograms). Some inhibition of leukocyte migration was seen with skin test negative donors (presumably toxicity) with the higher doses of PPD (50 microgram/ml), but generally little inhibition was observed with these donors at lower doses. Comparative experimetns of the agarose micromethod and the capillary tube technique indicated that the agarose assay was more sensitive in that it could detect reactivity with 2--4 logs lower antigen concentration. Indirect assays using supernatants of cultures of PPD triggered mononuclear cells and indicator granulocytes in agarose droplets demonstrating that a lymphokine (presumable leukocyte inhibitory factor) was being produced and suggested that cell-mediate immune (CMI) reactions were operative. The results indicate the usefulness of this technique in the sensitive-detection of CMI against such antigens as soluble PPD. The assay should prove useful in quantitative assessment of cell-mediated reactivity by using a wide range of antigen concentrations and the leukocytes from as little as 2--5 ml of blood.

Cell-Mediated Immunity to Melanoma-Associated Antigens in Patients With Ocular Malignant Melanoma

We tested 11 patients with choroidal melanomas and 32 control subjects for cell-mediated immunity to melanoma-associated antigens by an in vitro leukocyte migration inhibition assay. Five of seven patients with choroidal melanomas, who received two melanoma extracts used in this series of experiments, had significant leukocyte migration inhibition as compared with none of 17 normal subjects. Four of five melanoma patients who received a third melanoma extract had significant leukocyte migration inhibition as did three of four normal controls, indicating that the extract showed nonspecific inhibition. These data agreed with the concept that patients with choroidal melanomas have cell-mediated immunity to common melanoma-associated antigens.

Brief communication: Technical modifications of the human agarose microdroplet leukocyte migration inhibition assay

Direct leukocyte migration inhibition assays using the capillary tube technique can be used to demonstrate cell-mediated immunity in vitro. Unfortunately, the cumbersome nature of this technique makes it time consuming and difficult to perform. Similar results have been obtained using the direct agarose microdroplet leukocyte migration inhibition assay. In this paper, modifications of the agarose technique are outlined which insure standardization of droplets and ease of performance of the assay. Additionally a technique is described to reduce the time required for calculation of results.

Protective effects of interferon in mice previously exposed to lethal irradiation

The radioprotective action of interferon (IF) in increasing the survival time of mice lethally irradiated 24 h previously was evaluated. A single intraperitoneal injection of 30,000 units of IF administered 1 day following a LD/sub 100/ dose of irradiation significantly prolonged the mean survival time of the animals. Multiple inoculations of IF given 1,3, and 5 days after irradiation only slightly increased the survival time over that observed in mice receiving single injections. Marked decreases in total number of splenocytes were observed in irradiated mice as well as in the mice receiving postirradiation IF therapy, whereas total peripheral white blood cell counts were not appreciably changed when evaluated 3 days after X irradiation. Natural lymphocyte killer activity of splenocytes from irradiated animals receiving IF was significantly increased, suggesting that the protective action of IF could be partially attributable to the boosting of some depressed immune functions.

Hodgkin’s Disease in Siblings: A Family Study

Hodgkins disease may sporadically occur in more than one member of a family. A family in which two siblings were documented to have the nodular sclerosing form of the disease was studied for immunological competency, distribution of HL-A antigens, and Epstein-Barr virus (EBV) antibody titers. All family members examined, except the living individual with HD, had no significant abnormality in humoral and cellular immunity. HL-A antigens previously reported to appear in Hodgkins disease with increased frequency were not found. Antibody titers to the viral capsid antigen of EBV were normal. Therefore, none of the genetically associated laboratory tests related to cancer (particularly Hodgkins disease) were found in this family. The evidence from this family thus supports the probable importance of environmental factors in the etiology of Hodgkins disease, particularly in the nodular sclerosis group.