Improvement of HIV-specific immunity in HIV-infected twins treated with highly active antiretroviral therapy, interleukin 2, and syngeneic adoptively transferred cells

Failure of low-dose recombinant human IL-2 to support the survival of virus-specific CTL clones infused into severe combined immunodeficient foals: lack of correlation between in vitro activity and in vivo efficacy

Although CTL are important for control of lentiviruses, including equine infectious anemia virus (EIAV), it is not known if CTL can limit lentiviral replication in the absence of CD4 help and neutralizing antibody. Adoptive transfer of EIAV-specific CTL clones into severe combined immunodeficient (SCID) foals could resolve this issue, but it is not known whether exogenous IL-2 administration is sufficient to support the engraftment and proliferation of CTL clones infused into immunodeficient horses. To address this question we adoptively transferred EIAV Rev-specific CTL clones into four EIAV-challenged SCID foals, concurrent with low-dose aldesleukin (180,000U/m2), a modified recombinant human IL-2 (rhuIL-2) product. The dose was calculated based on the specific activity on equine PBMC in vitro, and resulted in plasma concentrations considered sufficient to saturate high affinity IL-2 receptors in humans. Despite specific activity on equine PBMC that was equivalent to recombinant equine IL-2 and another form of rhuIL-2, aldesleukin did not support the engraftment and expansion of infused CTL clones, and control of viral load and clinical disease did not occur. It was concluded that survival of Rev-specific CTL clones infused into EIAV-challenged SCID foals was not enhanced by aldesleukin at the doses used in this study, and that in vitro specific activity did not correlate with in vivo efficacy. Successful adoptive immunotherapy with CTL clones in immunodeficient horses will likely require higher doses of rhuIL-2, co-infusion of CD4+ T lymphocytes, or administration of equine IL-2.

CpG oligodeoxynucleotides allow for effective adoptive T-cell therapy in chronic retroviral infection

Adoptive T-cell therapy in cancer or chronic viral infections is often impeded by the development of functional impairment of the transferred cells. To overcome this therapeutic limitation we combined adoptive transfer of naive, virus-specific CD8+ T cells with immunostimulative CpG oligodeoxynucleotides (ODNs) in mice chronically infected with the Friend retrovirus. The CpG-ODN co-injection prevented the T cells from developing functional defects in IFNgamma and granzyme production and degranulation of cytotoxic molecules. Thus, the transferred T cells were able to reduce chronic viral loads when combined with CpG-ODNs. This strategy provides a new approach for developing successful adoptive T-cell therapy against chronic infections.

Adoptive transfer of syngeneic T cells in HIV-1 discordant twins indicates rapid regulation of T-cell homeostasis

The safety and efficacy of adoptive T-cell transfer (ATT) was tested in the context of viral suppression in syngeneic twins discordant for human immunodeficiency virus type 1 (HIV-1) infection. Human leucocyte antigen-matched T cells of seven HIV-negative twins were obtained by lymphapheresis and immediately transfused into the HIV-infected sibling. Four twins received 12 ATTs each, with a mean of 2.10 +/- 0.97 x 10(9) CD4(+) T cells and 1.74 +/- 0.81 x 10(9) CD8(+) T cells. Additional transfers were performed in three more twin pairs to study the short-term kinetics of transfused syngeneic T cells. Mean CD4(+) T-cell counts increased significantly, by 0.133 +/- 0.136 x 10(9) cells/l at 1 h and 0.144 +/- 0.12 x 10(9) cells/l at 3 h post-transfusion (P < 0.0001). Short-term kinetic studies suggested a rapid clearance of transferred T cells from the peripheral blood within minutes due to a distribution to marginal pools. After a mean follow up of 39 months, however, a sustained increase of the mean CD4(+) T-cell count was observed (from 0.232 x 10(9) to 0.523 x 10(9) cells/l) without changes of plasma viraemia. We conclude that ATT combined with highly active antiretroviral therapy is safe and leads to a considerable increase in CD4(+) T-cell numbers. The clearance kinetics of the transfused cells from peripheral blood indicates a very rapid regulation of T-cell homeostasis in HIV infection.

Clinical experience with therapeutic AIDS vaccines

Recently, there has been a renewed interest in therapeutic vaccination as an adjunct or alternative to current treatment options for HIV. The first immunotherapeutic trial relevant to this topic was published in 1983. Since then, several dozen therapeutic vaccine trials have been carried out. The results have consistently shown that although in vitro-measured HIV-specific immune responses were evident as a result of vaccination, clinical improvement has been seldom observed. The instances of apparent clinical benefit however, were invariably associated with the usage of vaccines that acted in accord with the principles of allo- or autoimmunization. The majority of these vaccines were derived from the blood of HIV carriers or a cell culture and therefore inherently contained host-cell antigens unrelated to HIV. These observations raise the issue of whether this clinically successful approach has been unduly neglected. Most commercial vaccines on the market today are made the old-fashioned way, but very little support or attention has been given to the development of such vaccines for AIDS therapy. The current strategy, biased toward vaccines which have shown little evidence of clinical efficacy, is shortsighted and needs to be revised.

Combinatorial immunotherapies for infectious diseases

Combating pathogenic organisms by combinatorial approaches involving appropriate immune response molecules and antimicrobial drugs represents a progessively more apparent and successful therapeutic paradigm for the treatment of acute and chronic persistent infectious diseases. This review explores areas of current innovation and provides an update of the present state of knowledge concerning combination of chemotherapy with several immune-based interventions in infections. In the future, a better understanding of microbial immune modulation and evasion may continue to open new avenues of inquiry and carefully targeted application of adjunctive immunotherapies.

Alternative therapies: a common practice among men and women living with HIV

This study examined the prevalence and factors associated with alternative therapy use in an ethnically diverse, gender-balanced sample of persons living with HIV/AIDS. More than two thirds (67%) of the participants who were taking HIV-related medications were also taking an alternative supplement. Half of the sample (50%) reported that they took one or more multivitamins, 17% reported using mineral supplements, 12% reported using Chinese herbs, and 12% reported using botanicals. Substantial proportions of the sample also reported using acupuncture (31%), massage (23%), and meditation (28%) to specifically treat HIV-related symptoms. Women were four times more likely to use alternative therapies than men. Also, Caucasians were nearly four times more likely to use alternative treatments compared to other ethnic groups. The results of this study indicate a strong need to assess individual patients' use of alternative treatment approaches as well as to further investigate their efficacy among HIV-positive patients.