Julia P. Roboz

Increased expression of activation markers on CD8 lymphocytes in children with human immunodeficiency virus-1 infection.

ABSTRACT: The aims of the present study were to analyze the impact of perinatal human immunodeficiency virus (HIV)-1 infection on lymphocyte maturation in children, to determine the expression of activation markers on CD8+ cells, and to define predictors of survival in HIV-infected children. Seventy-one children presenting HIV-related symptoms were included in the study; 29 were less than 2 y old and 42 were 2 to 12 y of age. Results were compared with those obtained in normal children of a similar age. In HIV-infected children the proportion of CD4+ and CD8+ CD45RA+ cells was significantly decreased, whereas that of CD8+, CD8+CD38+, and CD8+CD45RO+ cells was strikingly increased compared with controls. In children less than 2 y old the absolute number of CD4+ and CD8+CD45RA+ cells decreased, and the number of CD8+CD45RO+ cells increased significantly, whereas the number of CD8+ and CD8+CD38+ cells did not change. The absolute number of CD4+ T cells declined with age both among controls and among HIV-infected children. In contrast, the absolute number of CD8+ cells and CD8 subsets decreased with age only in controls but not in infected children. In HIV-1-infected children the expression of the CD38 and CD45RO markers on CD8+ cells was significantly correlated, indicating that these were activated cells. The survival of less than 2-y-old children with AIDS symptoms was positively correlated with the total number of CD8 cells and CD8+CD38+ cells at time of entry into the study. Most of the children who died by the end of the study had a CD8 count of less than 750/mm3 and a CD38+CD8+ count of less than 600/mm3 when first seen, whereas most of those who were alive had higher counts.

Inverse relationship between HIV-1 p24 antigenemia, anti-p24 antibody and neutralizing antibody response in all stages of HIV-1 infection

A double blind cohort study was conducted on 149 homosexual males and 36 patients with AIDS to investigate the relationship between HIV-1 antigenemia, the presence of neutralizing antibody (NA) activity and specific anti-viral core protein (p24) antibody (Ab) in the sera of HIV infected individuals during their progression to AIDS. All AIDS patients and 68% (101/149) of the homosexual males were HIV seropositive upon entering the study. Of those 48 (32%) homosexuals who were HIV negative at the onset, three seroconverted during the two year observation period. Retrospective studies of the HIV(-) subjects sequentially stored serum samples demonstrated an early transient appearance of gag encoded p24 antigen (Ag) which preceded their production of NA and specific anti-p24 Ab. Following their seroconversion, no more circulating p24 Ag could be detected. Among the 101 HIV positive homosexuals, 16% rapidly progressed to AIDS and seven of these 16 (44%) subjects eventually died during the two year observation period. In this group of individuals with poor prognosis, presence of NA and anti-p24 Ab commenced at the onset reaching peak levels just prior to developing AIDS and began to decline as the clinical course worsened. Their circulating level of p24 Ag remained undetectable as long as there was quantifiable NA and anti-p24 Ab in their sera. Reappearance of circulatory p24 Ag, on the other hand, was associated with high risk for progression to AIDS.2+hus, while only 11

IMMUNOLOGIC DYSFUNCTION AMONG PBB‐EXPOSED MICHIGAN DAIRY FARMERS*

In 1973 inadvertent contamination occurred in a special farm feed supplement for lactating cows. Polybrominated biphenyls (PBBs) were used in place of magnesium oxide resulting in serious harm to farm animals, including cattle, chickens, geese, ducks. Farm families, accustomed to eating their own products, were most heavily exposed. To further study the impact of PBBs, 45 adult Michigan farm residents who were originally examined in a clinical field survey were further studied with respect to their immunologic status. For comparison, 46 dairy farm residents in Wisconsin, who had not eaten PBB-contaminated food, were examined, as were 79 healthy subjects in New York City. Abnormalities in the Michigan group included significant decrease in absolute numbers and percentages of T and B-lymphocytes and increased number of lymphocytes with no detectable surface markers (null cells). Significant reduction of in vitro immune function was noted in 35--40% of the Michigan farm residents who had eaten food containing PBB. Despite the absence of any apparent numerical reduction, both T and B lymphocyte subpopulations of peripheral blood lymphocytes showed evidence of functional defect. Ten of the 45 Michigan farmers studied showed impaired PHA-induced blastogeneic response, due to the decreased number and percent of T-cells in the PBLs. The decreased immune function detected among the PBB-exposed farm residents tended to affect families as a unit and was independent of exposed individuals age or sex, speaking against the possibility of genetic predisposition.

Impaired immune function and identification of polybrominated biphenyls (PBB) in blood compartments of exposed Michigan dairy farmers and chemical workers.

In 1973 PBBs were accidentally mixed into animal feed, resulting in marked toxic effects. Meat and dairy products were widely consumed in Michigan. To determine the impact of PBBs, 55 exposed Michigan farm residents, 11 Michigan chemical workers and 46 non-exposed Wisconsin farmers were examined. Abnormalities included decreased number of T-lymphocytes with concomitant increase of lymphocytes with no detectable surface markers, null cells, and altered lymphocyte function. Data obtained from skin testing using standard recall antigens, showed no consistent correlation between the delayed cutaneous hypersensitivity response and the impaired lymphocyte function. PBB (hexa) in separated white blood cells and red cells was positively identified and quantified by gas chromatography-mass spectrometry. PBB and immunological abnormalities were not detected in non-exposed Wisconsin dairy farm residents.

Specific immunotherapy with neuraminidase-modified leukemic cells: experimental and clinical trials.

The data presented establish the therapeutic effectiveness of immunotherapy with neuraminidase-treated allogeneic myeloblasts in combination with sustaining chemotherapy in patients with acute myelocytic leukemia. The in vivo and in vitro immunologic tests indicate normal immunocompetence in patients receiving immunotherapy versus control patients treated with chemotherapy alone. These findings correlate well with the improved duration of remission as the direct result of the immunotherapy.

3-m-Bromoacetylamino benzoic acid ethyl ester : A new cancericidal agent that activates the apoptotic pathway through caspase-9

The mechanism underlying the cancericidal activity of 3-m-bromoacetylamino benzoic acid ethyl ester (3-BAABE) was investigated. 3-BAABE exerted a strong cancericidal effect on human leukemia and lymphoma cells (IC(50) < 0.2 microgram/mL) and on cell lines of prostate, colon, ductal, and kidney cancer (IC(50) 0.8 to 0.88 microgram/mL). Multiple drug resistance (MDR) had no effect on the susceptibility of human lymphoma cells to 3-BAABE, since Daudi/MDR(20) and wild-type Daudi cells had a similar susceptibility to the cytotoxic effect of 3-BAABE. The cancericidal effect of 3-BAABE, which was not associated with changes in the cell cycle, was mediated by apoptosis. Thus, cells exposed to 3-BAABE displayed the DNA fragmentation ladder characteristic for apoptosis, associated with a marked increase of the activity of apoptosis effector caspases-3 and -6, which was followed by proteolytic cleavage of DNA fragmentation factor (DFF) and poly(ADP-ribose) polymerase (PARP). Exposure of tumor cells to 3-BAABE increased the activity of apical caspase-9, but had no effect on caspase-8. Complete inhibition of 3-BAABE-induced apoptosis was exerted by LEHD-FMK, a caspase-9 inhibitor. DEVD-FMK, a caspase-3 inhibitor, and VEID-FMK, a caspase-6 inhibitor, partially inhibited 3-BAABE-induced apoptosis, whereas exposure to IETD-FMK, a caspase-8 inhibitor, had no effect. The fragmentation and elevated activity of caspase-9 in 3-BAABE-treated cells and the fact that only an inhibitor of caspase-9 abrogated 3-BAABE-induced apoptosis indicate that 3-BAABE is a distinctive compound that elicits apoptosis through a pathway that is limited specifically to activation of apical caspase-9.

Clinical Immunology Studies in Individuals Exposed to Environmental Chemicals

With the recognition that chemicals can have direct effect on the immune system the relatively new field of immunotoxicology is gaining wide support and interest, Gibson, Hubbard and Parke (1983). The objective of this article is to review some of our work on the immunotoxicology of asbestos and polybrominated biphenyls (PBB).

Effector lymphocyte response to homologous tumor antigens in various stages of malignant disease as monitored by leukocyte adherence inhibition — cell mediated immunity (LAI-CMI)

Leukocyte adherence inhibition-cell mediated immunity (LAI-CMI) studies were performed on leukocytes obtained from patients with various stages of breast cancer, colon carcinoma and lung cancer in order to monitor cell mediated immunity during tumor progression. In the presence of autologous serum, all patients with localized tumors showed positive LAI-CMI indexes (greater than 20%), while significant reduction of homologous tumor antigen recognition as measured by the LAI-CMI responses was observed in nearly all patients with Stage IV breast cancer, Duke C colon cancer and Stage III lung cancer. On substituting autologous serum with normal AB serum, leukocytes from patients with large tumor burdens responded to homologous tumor antigens. These results indicate the existence of organ-specific serum factor(s) which may mask the receptor sites on effector cells for tumor recognition. Patients with such serum blocking factor(s) showed significant increase of IgG immune complexes IgM, IgA and alpha-2-macroglobulins. Application of a protein A affinity column purification resulted in a major reduction of IgG and other immune globulins but not of alpha-2-macroglobulin. The blocking effects of autologous serum, however, were not completely abrogated by filtration on the protein A column, thus suggesting that SBF may be heterogeneous in nature and may occur in other serum protein fractions beside the immune globulins.

FUNCTIONAL INTEGRITY OF T, B, AND NATURAL KILLER CELLS IN HOMOSEXUAL SUBJECTS WITH PRODROMATA AND IN PATIENTS WITH AIDSa

We have examined the numbers of the total T (T11+) cells, T-helper (T4+) cells, T-suppressor (T8+) cells, NK cells (Leu7+), and the functional integrity of T, B, and NK cells in healthy male heterosexuals and compared the data to those obtained from AIDS patients and male homosexuals at risk. The absolute number of total T (T11+) and T-helper (T4+) cell populations were significantly reduced among most of the asymptomatic homosexual males and even more decreased in the AIDS patients. By contrast, the absolute numbers of T-suppressor cells (T8) remained virtually unaltered in the three study populations. The absolute numbers of circulating natural killer cells were similar in the controls and the homosexual subjects, but significantly reduced in the AIDS patients. Proliferative responses to T-cell mitogen (PHA) and T-cell dependent B-cell mitogen (PWM) were severely impaired in prodromal subjects and more so in the AIDS group. Response to PWM was unrelated to the total number of T-suppressor cells, but was associated with a significant decrease in T-helper cell number. Furthermore, all AIDS patients exhibited a significantly depressed NK-cell activity that could not be normalized by addition of alpha IFN or IL-2 and in most cases correlated with the reduced absolute number of NK (Leu7+) cells as well as T-helper cells (T4) and T4/T8 ratios. Three distinctive subgroups with normal (N-NK), significantly heightened (H-NK), and markedly lowered (L-NK) NK activity could be readily identified among the homosexual male population at risk. The N-NK and L-NK groups displayed marginal to no response to in vitro treatment with alpha IFN and interleukin-2. The NK-cell activity, however, in the H-NK group was moderately to strongly inhibited by inclusion of the two immunomodifiers.