Immunologic Abnormalities in HIV Infection

Experimental evidence for the existence of the passive antitumor defense system formed by the synergistic action of certain small substances of the circulatory system

In AIDS, only a few types of tumors (mainly Kaposi's sarcoma and non-Hodgkin's lymphoma) increase in incidence despite global abnormalities in the immune system. In addition, the reason for the higher incidence of these tumors is not immunosuppression but other agents. This shows that the immune system has no absolute role in the prevention of tumors. Consequently, the fact that tumors do not develop in the majority of the population during their lifetime, indicates the existence of other defense system(s). We demonstrated previously that a mixture of 16 substances (selected experimentally out of 89 compounds of the circulatory system using the synergistic tumor cell-killing effect as criteria) had a cytotoxic effect (inducing apoptosis) in vitro and in vivo on tumor cell lines, but not on normal cells in vitro or animals. In our hypothesis these substances (L-tryptophan, L-tyrosine, L-methionine, L(-)malate, L-ascorbate, L-arginine, L-phenylalanine, L-histidine, 2-deoxy-D-ribose, d-biotin, pyridoxine, adenine, riboflavin, D(+)-mannose, orotate, and hippurate) are the active agents of a passive antitumor defense system (PADS). On the basis of the results, a tablet and a cream were developed, and an infusion is in preclinical phase. In this study we demonstrate that the above-mentioned substances can kill tumor cells when the experimental protocols, concentrations, and cell numbers are chosen to be comparable to the physiological conditions that exist in the living system when these substances fight against arising cancer cells. The results of our experiments demonstrate that the PADS really works in the human body.

Lymphoid markers, activation markers, and adhesion molecules in cutaneous biopsy specimens from HIV+ patients with disease progression. The Military Medical Consortium for the Advancement of Retroviral Research

BACKGROUND

One important factor in understanding the pathogenesis of human immune deficiency virus (HIV) disease is documenting the patterns of immune dysregulation present in HIV-positive patients. The cells which home to skin are mainly certain subsets of T cells and, as opposed to the peripheral blood, where circulating factors may inhibit terminal phenotypic differentiation, the cutaneous environment potentiates differentiation during cutaneous eruptions.

OBJECTIVE

The authors' aim was to characterize the inflammatory dermatoses in biopsy specimens from HIV-positive patients with immunohistochemical stains for lymphoid markers, activation markers, and adhesion molecules and to determine if there was any correlation with the type of dermatosis and the HIV-disease stage.

METHODS

Lymphoid and activation markers as well as adhesion molecules were studied on cutaneous biopsy specimens from 96 inflammatory dermatoses in HIV-positive patients. The dermatoses included psoriasiform dermatoses with and without a lichenoid component, perivascular lymphoid dermatoses, perivascular and periadnexal inflammatory dermatoses, spongiotic dermatoses, granulomatous dermatoses, and neutrophilic dermatoses with and without vasculitis.

RESULTS

Although there was a decrease in CD4/CD8 ratios in the cutaneous inflammatory dermatoses with progression of the disease, the ratios of CD4/CD8 cells were far higher than those in the peripheral blood. There were also increasing numbers of CD23+ cells and increased E-Selectin expression on endothelial cells from the early stages of disease, with no consistent pattern of ICAM-1 expression on epithelial cells with disease progression.

CONCLUSIONS

The expression of lymphoid markers, activation markers, and adhesion molecules in the skin with progression of HIV disease, is consistent with a T helper (Th)1 to Th0/Th2 cytokine pattern of immune dysregulation. This cytokine pattern may be modified by the cytopathic effects of HIV on lymphoid and dendritic populations and by effects of other concurrent infections. Significant numbers of CD4+ T cells in skin infiltrates, with low peripheral CD4 T-cell counts, suggest that the cutaneous T-cell populations may be distinctive.

Apoptosis of tumor cells induced by substances of the circulatory system

Despite global abnormalities of the immune system, such as in AIDS, the incidence of only a few kinds of tumor increases, and even in the development of these tumors the degree of immunosuppression seems not to be a critical factor. This means that the known immune system has no significant role in the tumor preventing mechanism. Thus, the fact that tumors do not develop in the majority of the population during their lifetime, indicates the existence of an additional defense mechanism of the immune system. We demonstrated previously that this defense is produced by the synergistic action of certain substances of the circulatory system. Here we report that the substances taking part in the defense induced, but only when they were used together, the apoptosis of tumor cells, but not normal cells, as was detected by different methods. Other substances of the circulatory system did not show similar effects. These results further support the existence of the mentioned defense mechanism called by us the Passive Antitumor Defense System.

Immunological and virological markers of HIV-disease progression

This review, based upon scientific literature, evaluates a number of immunological and virological markers for their usefulness as prognostic indicators for progression of HIV disease. The most widely studied marker, the CD4 positive T lymphocyte count, is perhaps the best single indicator of stage of illness. Serum factors such as neopterin and beta-2 microglobulin, alone and in combination with CD4 cell counts, have been shown to have good predictive value. Measurement of viral burden by quantification of viral RNA levels in plasma and immune cells also holds promise for following disease progression. It is recommended that a combination of these factors be monitored in evaluating stage of illness and responses to therapy in HIV-infected persons.

Inhibition of the growth of a murine and various human tumor cell lines in culture and in mice by mixture of certain substances of the circulatory system

It is well documented that despite global abnormalities of the immune system in AIDS and other immune deficiency diseases or in immunosuppressed patients, the incidence of only a few kinds of tumor increases, and that the degree of immunosuppression seems not to be a critical factor in the development of even these tumors. The fact that tumors do not develop in the majority of population during their lifetime, despite the ineffectiveness of the known immune system against the majority of tumors, can only be explained by hypothesizing that the living system has an additional defense mechanism against tumors. On the bases of literary data, it can be assumed that the effective agents of this defense mechanism are certain substances of the circulatory system. We proved this hypothesis by being able to select thirteen substances of the circulatory system from 71 compounds tested, using the synergistic tumor cell-killing effect as criteria. The mixture containing the thirteen substances (L-tryptophan, L-tyrosine, L-methionine, L(-)-malate, L-ascorbate, L-arginine, L-phenylalanine, L-histidine, 2-deoxy-D-ribose, d-biotin, pyridoxine, adenine and riboflavin) had a cytotoxic effect against Sp2/0-Ag14 mouse and K562, HEp-2, HeLa and Caco-2 human tumor cell lines in well-controlled conditions, but it was not cytotoxic against Vero normal cell line. The mixture of the above substances increased significantly the survival time of mice (T/C% 148.1) injected i.p. with Sp2/0-Ag14 mouse myeloma cells by killing more than 2 logs (99%) of the cells. Approximately the same 2 logs cell kill was found counting the Sp2/0-Ag14 cells in the ascitic fluid of control and treated animals after finishing treatment. The above mixture slowed down the growth of HeLa solid tumor significantly (T/C%, the least value 35.7). The weight loss of control and treated group during treatment did not differ significantly.

Psychology, immunology, and HIV

The interdisciplinary field of psychoneuroimmunology (PNI), which aims to clarify the relationship between psychological factors and immunity, can also play a role in our understanding of individual susceptibility to, progression of immunologically mediated disease. Mechanisms proposed to account for the profoundly damaging effects of human immunodeficiency virus (HIV) on immune function do only partially explain the variability in individual rates of progression, suggesting, therefore, that other immunomodulatory factors are also involved. Studies have examined the proposal that the effects of stress and HIV may interact in some complex way, and psychological, physiological and virological evidence for the role of stress in HIV progression is discussed in detail. A critical review of HIV-specific research in PNI, which can be broadly divided into cross-sectional, longitudinal, and intervention studies, and studies of long-term survivors, reveals that the relationship between stress and HIV progression remains equivocal, because of limitations due to methodological difficulties and to our inadequate understanding of immunology and HIV. A model is proposed for the influence of psychosocial stress on progression in HIV disease, which takes account of some of these difficulties.

Mechanisms of cytopenia in human immunodeficiency virus infection

Human immunodeficiency virus (HIV) infection often has effects on the hematopoietic system which can be distinguished from the concurrent effects of medications or opportunistic infections. Exactly how the virus mediates these effects remains uncertain, but both in vivo and in vitro studies have pointed up possible direct and indirect modes of hematopoietic suppression. Whether a significant fraction of CD34+ cells in vivo are infected with HIV remains controversial, but most studies using in situ polymerase chain reaction techniques would suggest not. Other more indirect modes of hematopoietic cell suppression such as production of autoantibodies, production of other humoral inhibitory factors, T-cell mediated suppression of hematopoiesis, or production of inhibitory or stimulatory cytokines may also be contributory. It is probable that several of these mechanisms may occur simultaneously, and an increased understanding of their role may lead to improved strategies to correct the cytopenias which often accompany HIV disease.

Thrombotic microangiopathy and retroviral infections: a 13-year experience

Eleven of fifty serum samples collected from patients with a diagnosis of thrombotic microangiopathy (TMA), from 1979 to 1991, tested positive for antiretroviral antibodies. Seven had human immunodeficiency virus (HIV) infection, and four had human lymphotrophic virus, type I (HTLV-I) infection. All patients were treated with plasma exchange and/or infusion, but only two of the HIV-infected patients obtained a complete response (CR) and one of them died after a few months. Combined results from the literature indicate that most patients with HIV infection survive less than one year from the initial diagnosis of TMA. In the setting of HIV infection, TMA is a treatable condition, but survival for most patients is less than 12 months. Three of the four HTLV-I infected patients with TMA had a CR. These observations strongly suggest that both HIV and HTLV-I infections are associated with TMA, but rigorous epidemiologic studies will be needed to determine the relative risk for each. Retroviral infections should be considered in patients with TMA, especially if the patient has associated risk factors and demographic characteristics.

Lipopolysaccharide restores anti-Candida albicans growth inhibition activity of polymorphonuclear neutrophils from retrovirus-immunosuppressed mice

It has been documented that the immune function of leukocytes may be markedly suppressed after infection of mice with the murine retrovirus Friend leukemia virus (FLV). Antimicrobial activity of polymorphonuclear neutrophils (PMNs) against Candida albicans is impaired after retrovirus infection of mice, and this occurs as early as 3 days after infection of genetically susceptible BALB/c mice. By 2 weeks after infection, there was essentially very little growth inhibition of C. albicans by PMNs from the FLV-infected mice. However, when bacterial lipopolysaccharide (LPS), a known activator of macrophages and PMNs, was added to PMNs from the FLV-infected mice, anti-C. albicans activity was restored to normal levels. This restoration of anti-C. albicans activity of FLV-infected mouse PMNs was observed after stimulation with as little as 0.01 micrograms of LPS per ml. The data obtained show that the impaired antimicrobial function of PMNs from retrovirus-infected mice can be readily restored by a biological response modifier such as bacterial LPS.

Cell-mediated and humoral immune responses in children infected with human immunodeficiency virus during the first four years of life

OBJECTIVES

To determine whether cell-mediated and humoral immune responses to recall antigens develop in children infected with the human immunodeficiency virus (HIV) and, if so, whether these responses are retained.

METHODS

Children infected with HIV and uninfected children born to mothers infected with HIV were compared with respect to lymphoproliferative responses to recall antigens and protective levels of antibody to bacterial toxoids during the first 4 years of life.

RESULTS

Children infected with HIV who were enrolled in a prospective study of the natural history of the infection were relatively normal (1) in their lymphoproliferative responses to diphtheria toxoid, tetanus toxoid, and Candida, and (2) in their ability to make protective diphtheria and tetanus antitoxins during the first 2 years of life. During the next 2 years, attrition was noted in both lymphoproliferative and humoral responses. Attrition in response was not necessarily correlated with declining numbers of helper T cells.

CONCLUSIONS

These results suggest that both cellular and humoral immune responses develop early in life in most children infected with HIV, while they remain relatively well both clinically and immunologically. Previously reported severe immune deficits in these children were probably attributable to advanced clinical disease when they were first studied.