HIV and AIDS

The anti-idiotypic antibody 1F7 selectively inhibits cytotoxic T cells activated in HIV-1 infection

Circulating CD8+ T lymphocyte numbers rise substantially following infection with HIV-1. This expanded CD8+ T cell population includes HIV-specific CTL and CTL that kill activated uninfected CD4+ lymphocytes. Experimental, epidemiological and clinical evidence supports the possibility that expansion of CD8+ CTL contributes to CD4+ T cell depletion and disease progression in human HIV infection. Therefore, modulation of CD8+ T cell numbers or of certain CD8+ CTL activated in HIV-infected individuals may be beneficial. It was found that 1F7, a mAb against an idiotype common to anti-HIV and anti-simian immunodeficiency virus (SIV) antibodies, selectively inhibited both anti-HIV CTL and CTL against uninfected CD4+ T cells. Alloantigen-specific CTL and NK cells from either HIV-infected individuals or controls were unaffected by 1F7. Prolonged incubation of CD8+ T cells from HIV-infected individuals with 1F7 induces apoptosis, which was shown to be reflected functionally in reduced total CTL activity and in especially reduced CTL activity against uninfected CD4+ lymphocytes. The selective reactivity of 1F7 with certain CD8+ CTL could be applied towards the modulation of CD8+ T cell responses involved in AIDS pathogenesis.

The HIV/AIDS epidemic: its evolutionary implications for human ecology with special reference to the immune system

The epidemiology of AIDS in Africa is discussed. Serological and clinical data on virology and population genetics are related to current theories of heterosexual transmission and to cultural practices involving the exchange or transmission of body fluids between individuals, such as female and male genital mutilation and indigenous or 'folk' medicine, as well as non-Western medical uses of medical syringes. A review of the relationship of autoimmune conditions, graft-vs-host disease and the retrovirus/oncogene involvement is presented. These data place in a new perspective concepts of widespread heterosexual infection and transmission of HIVs as well as their relation to AIDS in the context of the evolution of the human immune system.

Pitfalls in the use of surrogate markers for human immunodeficiency virus disease: further evidence on pathogenesis

The administration of drugs to human immunodeficiency virus patients with a pronounced CD4+ T lymphocytopenia may cause non-specific binding of the murine antibodies used in flow cytometry. This has produced spurious reports of early thymocytes in the circulating blood of human immunodeficiency virus-infected individuals following treatment with an anti-adhesion monoclonal mouse antibody (Cytolin+). Recent clinical experience with Cytolin+ confirms the pathogenic role of leukocyte adhesion pathways in human immunodeficiency virus infection. However, this experience also illustrates how comparisons of viral burden can be misleading. For nine patients with low CD4 counts, Cytolin+ alone reduced the mean ribonucleic acid-polymerase chain reaction by 0.45 log to 39 800 particles per mL. Ten patients with more advanced disease added Cytolin+ to an established regimen of standard antiretroviral drugs. Their mean polymerase chain reaction was only reduced by 0.2 log to 91 501. Yet, 67% of the former patients experienced a major clinical event within seven months, whereas the latter patients remained stable during this time.

The solution to the seven mysteries of AIDS: the 'Trojan horse'

It is concluded that the sperm is the cause of AIDS but that HIV may slightly alter the symptoms of this disease, as compared to idiopathic CD4+ T-lymphocytopenia, or ICL, where the sperm, but not HIV, is assumed present. In the proposed mechanism, the sperm selectively accepts into its interior only macrophage-tropic HIV through its CD4+ antigens and carries this HIV into a person through four possible pathways: rectum (anal sex), genital ulcers, blood transfusions, and female circumcision. Then the sperm acts as a 'Trojan horse' by entering HLA-DR+ CD4+ T cells and releasing the HIV into these cells. The released HIV in turn mutates to a form capable of attacking CD4+ T cells. Thus the sperm by a 'Trojan horse' mechanism has changed the tropism of HIV. However, experimental evidence indicates that this mutated HIV is essentially non-toxic. In contrast, it is concluded that the sperm is extremely toxic since it is capable of inducing autoimmune reactions (by means of its CD4+ antigens) and is capable of entering and destroying HLA-DR+ CD8+ and HLA-DR+ CD4+ T cells in either the presence or absence of HIV (AIDS or ICL). Hence, the mysteries of AIDS can be explained by the presence of the toxic sperm and its complicated interactions with HIV (the 'Trojan horse' mechanism).