Detection of CTL activity in PBMCS taken from HIV-ENV immunized individuals after in vitro viral infection

The cellular immune response to the AIDS virus in healthy individuals immunized with HIV-1 antigens has not yet been entirely understood. Unlike HIV-1 infected patients where direct measurements of anti HIV-1 CTL activities can be readily performed with fresh peripheral blood mononuclear cells, uninfected volunteers immunized against HIV-1 antigens have fewer circulating CTL necessitating an in vitro activation in order to amplify the cytotoxic signal and make it measurable. This study presents experiments where specific CTLs are successfully obtained simply by in vitro infection of PBMCs from HIV-1 Envelope immunized individuals.

Cytotoxic T lymphocytes specific for HIV-1 gp160 antigen and synthetic P18IIIB peptide in an HLA-A11-immunized individual

Cytotoxic T cell determinants should be an important component of an anti-human immunodeficiency virus (HIV) vaccine. The epitopes of proteins can be defined with short synthetic peptides for class I-restricted CTLs. An immunodominant CTL epitope from the HIV-1 IIIB envelope protein gp160 comprising 15 amino acids (residues 315-329: RIQRGPGRAFVTIGK) (P18IIIB) has been identified that is recognized by class I MHC molecule H-2d-restricted murine CD8+ CTLs. We have investigated the epitope specificity of anti-HIV-1 CTLs in immunized individuals and we found that the CTL response was restricted by more than one class I MHC molecule, including HLA-A2 and HLA-A3. In the present work, we also show that the response against P18IIIB peptide is restricted by the HLA-A11 molecule in an individual immunized by vaccinia virus expressing gp160 protein. This peptide could thus be recognized in association with different HLA class I allotypes. This work has implications for vaccine strategies, using the P18 peptide.

Identification of CD4 and major histocompatibility complex functional peptide sites and their homology with oligopeptides from human immunodeficiency virus type 1 glycoprotein gp120: role in AIDS pathogenesis

CD4 molecules interact with class II major histocompatibility complex molecules as a critical costimulatory signal in CD4+ cell immune activation. CD4 also recognizes a specific region of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 forming a binding site for early stages of HIV-1 infection. We designed two software packages, AUTOMAT and CRITIC, which allowed us to identify similarities between regions of HIV-1 proteins and immunoregulatory protein sequences stored in data banks. In this report we have characterized (i) a pentapeptide, SLWDQ, found in both CD4 and HIV-1 gp120, which surprisingly had remained undetected in these two well-studied molecules until now, and (ii) an HLA sequence corresponding to the putative functional site of H2 I-A. We found that a region of gp120 (residues 254-263) known to be similar to a sequence in HLA class II beta chain overlaps this functional region. We showed experimentally that these two CD4 and HLA peptide segments inhibit CD4+ cell immune activation. There is strong inhibition (50% up to 80%) of immune activation by SLWDQ-containing gp120 segments and a lesser inhibition by the gp120 HLA-homologous segment. In addition, we found that SLWDQ induced in HIV-1-infected individuals a humoral (antibody) and cellular (cytotoxic T lymphocyte) immune reaction. We propose that these HIV-1 gp120 segments, together with the known CD4-binding region, may contribute to the HIV-1-induced immunosuppression by two mechanisms affecting CD4-HLA interaction during T-cell immune activation: autoimmune reaction toward CD4 and direct interference with the CD4-HLA costimulatory signal inducing CD4+ cell anergy with, as a consequence, generation of immunosuppression.

Human cytomegalovirus (HCMV) late-mRNA detection in peripheral blood of AIDS patients: diagnostic value for HCMV disease compared with those of viral culture and HCMV DNA detection

A reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect a human cytomegalovirus (HCMV) late mRNA in peripheral blood leukocytes (PBL) of 102 human immunodeficiency virus-infected individuals. The clinical value of this new technique for the diagnosis of acute HCMV disease was evaluated in comparison with viral culture and direct amplification of viral DNA (PCR). The sensitivity of the RT-PCR was slightly lower than that of the two other methods, but its specificity was 94%, compared to 55 and 32% for culture and PCR, respectively. Transcription of this late mRNA is linked to viral replication, and its detection in PBL confirms that these cells can support a complete viral cycle. The relationship between complete replicative cycles and HCMV disease makes RT-PCR a useful clinical tool.

Envelope protein and p18(IIIB) peptide recognized by cytotoxic T lymphocytes from humans immunized with human immunodeficiency virus envelope

Cytotoxic T cells are the main antigen-specific effector cells of the cellular immune system and MHC class I restricted cytotoxic T-lymphocyte (CTL) responses in mice, acting against the HIV-1 envelope protein, are known to be predominantly directed against an amino acid sequence in the third hypervariable domain. We have investigated the epitope specificity of anti-HIV-1 CTL in healthy human volunteers inoculated with a recombinant vaccinia expressing the HIV-1 gp160 envelope gene. Their isolated lymphocytes were stimulated in vitro with autologous HIV-1 infected cells. Our results show that immunization with recombinant virus is able to generate virus-specific CTLs to the HIV-1 gp160 envelope protein and to a 15-residue synthetic peptide corresponding to a highly variable region of the envelope p18(IIIB). The CTL response was restricted by class I MHC molecules HLA-A2 and A3 that commonly occur in the human population.

Striking similarities between HIV-1 Env protein and the apoptosis mediating cell surface antigen Fas. Role in the pathogenesis of AIDS

We have designed a computer strategy in order to detect systematically peptidic sites with the potential of interfering with the immune regulatory processes. Applying this software to HIV-1 proteins has led us to unravel a few peptidic sites which could either act directly or be the targets of an auto-immune reaction during HIV-1 infection. We previously reported that the SLWDQ pentapeptide identity with a critical site of CD4 could trigger in HIV-1 infected individuals both an humoral and a cellular autoimmune reaction. In this study, we focused on surprising similitudes unravelled by our software Automat, between HIV-1/2 and another immunoregulatory molecule, the Fas protein which is also called the apoptosis-mediating cell-surface antigen.

An unusual case of mycosis fungoides presenting as sarcoidosis or granulomatous mycosis fungoides

The authors describe a case of cutaneous and lymph node granulomas first reported as sarcoidosis. As skin sarcoidlike reactions disappeared, the development of typical histologic and immunopathologic features of cutaneous mycosis fungoides suggested granulomatous mycosis fungoides. This case illustrates the difficulties in differentiating true systemic sarcoidosis associated with mycosis fungoides from sarcoidlike reactions when extensive granulomas obscure the underlying cutaneous lymphoma. This report emphasizes the utility of immunohistochemical analysis to identify the early cutaneous T-lymphomatous infiltrate, initially admixed with epithelioid and giant cell granulomas. This technique also made it possible to characterize a Ki-1-positive anaplastic large-cell lymphoma when the transformation of mycosis fungoides into highly malignant lymphoma occurred in the lymph node.

Rapid detection of cytomegalovirus DNA in cerebrospinal fluid of AIDS patients with neurologic disorders

A polymerase chain reaction (PCR)-based method was used to detect cytomegalovirus (CMV) DNA in 82 cerebrospinal fluid (CSF) samples from 67 patients infected by human immunodeficiency virus (HIV). The test was positive for 14 patients, 8 of whom had CMV-related neurologic disease proven by viral culture of CSF or histologic examination. Encephalitis was the most frequent manifestation in patients with positive PCR results, but CMV DNA was also present in some patients with peripheral neuropathy or polyradiculomyelitis. All patients with proven CMV neurologic disease were positive by PCR. In contrast, viral culture was negative for 4 of the 8 patients and pathologic studies were available only for 5. The specificity of the PCR-based assay could not be assessed precisely because of the lack of a reference standard, but the results correlated well with clinical course and results of the other methods. These findings suggest that the PCR-based method may be a useful noninvasive tool for the rapid diagnosis of CMV-related neurologic disease.

Cell-mediated immunity against HGP-30, a group-specific peptide of HIV p17 in individuals infected with the AIDS virus

HGP-30, the synthetic peptide analogue and active component in an HIV-1 (human immunodeficiency virus, type 1) p 17 core-based experimental vaccine, has previously been shown to induce cytotoxic and helper T-lymphocyte responses. In order to further define the T-helper cell responses which are known to play a role in enhancing the immunological response to foreign antigens, we studied the response of individuals infected with HIV to HGP-30 at various stages of disease progression. We have investigated the proliferative cellular response of peripheral blood mononuclear cells (PBMCs) derived from individuals infected with HIV-1 to HGP-30. We have found a PBMC proliferative response to HGP-30 in 40% of the healthy seroconverted patients, in 35% of the CDC stage III patients and in 18% of the CDC stage IV patients. There was no correlation between the proliferative response to HGP-30 and other antigens such as HIV-like proteins or tetanus toxoid not to CD4 cell count. HLA-DR typing revealed the possible presentation of HGP-30 by several different class II molecules. Since these class II molecules occur frequently in the general population, HGP-30 appears to contain broadly reactive epitopes and thus is not restricted as are many peptide vaccines. Due to its broad reactivity and extreme conservation in many HIV-1 strains. HGP-30 is one of the promising candidates for inclusion as a subunit vaccine against HIV-1.

Removal of gp160 induced bio-hazards for a safe AIDS vaccine candidate

In the first AIDS vaccine trial, immunizing preparations were based on HIV-1 Env protein (gp160). Immunogenic properties of gp160 which trigger both a humoral and cellular immune response have since justified its use in various vaccine programs, both past and present. Many reports however have underlined deleterious effects on the immune system--anti-HIV-1 enhanced antibodies, anti-CD4 autoantibodies, and inhibition of T cell activation by HIV-1--particularly associated with the Env protein. The present study shows that gp160 presented in a biologically inactivated but immunogenic form, as used in our trial, could avoid these complications. Bio-hazards associated with gp160 which indeed could be removed by appropriate treatment of the native protein, should be taken into consideration in AIDS vaccine programs.

[Treatment with iloprost of critical ischemia of the lower limbs associated with cardiac insufficiency. Study of the interaction with pharmacokinetics of digoxin]

Twelve patients with critical ischaemia of the lower limbs were treated with iloprost. The purpose of this study was to investigate for a possible iloprost-digoxin interaction and to evaluate the clinical benefit provided by short- or long-term iloprost therapy. The pharmacokinetics of digoxin were studied before and during iloprost treatment. Under iloprost the absorption of digoxin was delayed by about one hour, but the area under the plasma digoxin concentration curve remained unmodified. In 11 of our 12 patients the clinical effect of iloprost was satisfactory both immediately and after 6 months. Pain vanished in 6 patients and diminished in 6 patients. All skin ulcers were healed. In most cases this improvement persisted beyond the study period: 2 patients treated at the beginning of the study and who are still followed up have remained improved after 2 1/2 years. Two patients with pain relapse received iloprost in repeated 10 days' courses with successful results. The treatment was relatively well tolerated (headaches, flushing, abdominal pain). Thus, iloprost can avoid amputation in severe arteritis unsuitable for revascularization and for which there is no effective treatment. Patients under digoxin may continue to take this drug in the same doses during treatment with iloprost.

[Treatment with iloprost of critical ischemia of the lower limbs associated with cardiac insufficiency. Study of interaction with the pharmacokinetics of digoxin]

We have treated with intravenous iloprost twelve patients suffering from cardiac insufficiency compensated under oral digoxin (NYHA class II) associated with severe limb ischaemia due to arterial insufficiency. Our aim was to study its possible interaction on digoxin levels and to evaluate the long-term efficacy of iloprost. Although iloprost slowed the digoxin absorption by approximately one hour, we found no clinically significant difference between the digoxin pharmacokinetic data before and during treatment by iloprost. Moreover, 11 out of the 12 patients had a good clinical fate after the treatment, which persisted at 6 months. The pain disappeared in 4 and diminished in 7; and all skin ulcers healed. This improvement has lasted up to two and a half years in two patients. The clinical tolerance of iloprost was acceptable despite frequent headache and flushing associated with hypotension and nausea. We conclude that iloprost seems to be a very promising treatment of severe limb ischaemia when no intervention on the proximal arteries is possible. The patients on digoxin can continue their treatment without dose alteration while starting on iloprost.

HGP-30, a synthetic analogue of human immunodeficiency virus (HIV) p17, is a target for cytotoxic lymphocytes in HIV-infected individuals

Evaluation of the immune response of individuals exposed to human immunodeficiency virus (HIV) is an important component of any plan designed to lead toward the development of an AIDS vaccine. Since the levels of antibodies to HIV p17 and the synthetic p17 peptide HGP-30 correlate with stages of progression to AIDS, studies were initiated to determine whether cytotoxic lymphocytes directed toward target cells pulsed with HGP-30 and radioactive chromium were present in seropositive individuals. The significance of such cells in controlling HIV viral infection has recently been enhanced by reports that HIV p17 is on the surface of infected cells and that an inactivated virus vaccine depleted of viral envelope appears to be effective in controlling expression. The selection of HGP-30 as the p17 peptide to be evaluated in early studies is based on the presence of both T-cell and B-cell epitopes as predicted by computer modeling and mouse studies and the demonstration of in vitro neutralization activity by antibodies to the epitope. By using B-lymphoblastoid cells pulsed with HGP-30 and radioactive chromium as autologous targets and mixed leukocyte culture-expanded peripheral blood lymphocytes as effectors, CD8+ cytotoxic T lymphocytes against HGP-30-coated targets were identified in seropositive individuals. In this report we demonstrate that a synthetic p17 epitope can be a target for major histocompatibility complex-restricted cytotoxic T lymphocytes in HIV-infected individuals.

Discriminating between protective and enhancing HIV antibodies

Most attempts to produce a vaccine against HIV-1 infection are utilizing envelope protein components. Hypothetically such vaccine candidates could stimulate production of antibodies that enhance HIV-1 infection via the macrophage route of entry and, consequently, cannot be detected in the conventional neutralization assay. To study this hypothesis we report an assay designed to evaluate the protective/enhancing activity of serum from seropositive immunized or infected individuals. Highly purified activated FcR-bearing monocytes-macrophages were infected with HIV-1 in the presence of the sera, then washed and cocultured with activated peripheral blood mononuclear cells (PBMC) from a normal donor. Productive viral infection, as evaluated by p24 antigen semiquantitative assay in the culture supernatants, allow evaluation of protective/enhancing activity of the sera. The data clearly show that protective rather than enhancing activity is present in the serum of env protein-immunized individuals.

[Periarteritis nodosa with heart valve disease disclosed by occlusion of the central artery of the retina]

We report a case of periarteritis nodosa revealed by blindness due to occlusion of the central retinal artery. The disease appeared after a serous otitis and was accompanied by thrombocytosis. Its outcome was favourable under corticosteroid therapy, but it was complicated by aortic valve regurgitation. Lesions of fibrinoid necrosis were found on the aortic cusps removed during surgical replacement. It seems highly probable that the ocular and valvular lesions were specific, although this cannot be directly demonstrated. The case presented here is exceptional, and the relevant literature is reviewed.

Two familial cases of malignant Reiter's syndrome

A Cambodian man and his son concomitantly developed malignant Reiter's syndrome soon after their arrival in France. In both cases generalized skin lesions of pustular psoriasis and systemic features were present. The son died after 2 years of unresponsive continuously progressive disease. The father received pulses of high dose immunosuppressants that worked rapidly and prevented a life threatening course. These 2 cases illustrate the pathophysiologic hypothesis of Reiter's syndrome, emphasizing the role of environmental triggering factors and the relationship between spondylarthropathies in B27 positive patients. Fatal cases of Reiter's syndrome are very rare in the review of the literature.

Fibroblast-dependent tumorigenicity of cells in nude mice: implication for implantation of metastases

The inadequate nature of the microenvironment is one of several factors considered in the failure of tumor engraftment in athymic mice; in the present work, we have tried to more adequately reconstitute it by injecting tumor cells together with fibroblasts. We have demonstrated that the s.c. co-inoculation of fibroblasts with different kinds of tumor cells of animal origin [rat rhabdomyosarcoma (RMS) 9-4/0, rat hepato-carcinoma FAO] or human origin (colonic adenocarcinoma HT29, Ewing's sarcoma pleural metastasis EW-S1) is necessary for tumor take and growth when the number of tumor cells alone is below the tumorigenic dose. We have shown that the s.c. coinoculation of 10(6) fibroblasts and 10(2) RMS 9-4/0 tumor cells induced a tumor take in all the recipient mice, while 10(2) tumor cells alone never gave any tumor. With a tumorigenic number of RMS 9-4/0 tumor cells (10(4), addition of 10(6) fibroblasts decreased the delay between cell injection and tumor appearance, thereby increasing tumor take and growth rate. These results were observed not only in nude animals (mice and rats) used as recipient animals but also in normal WAG rats receiving the syngeneic RMS 9-4/0 tumor cells, and they were independent of the nature or origin of the different fibroblasts cells. This helper effect has also been observed in the normal WAG rats. I.v. injection of tumor cells from a poorly metastatic 9-4/8 subline, derived from the RMS 9-4/0 line and mixed with 10(6) fibroblasts, gave a high number of lung colonies. Addition of 10(6) irradiated 9-4/8 tumor cells instead of fibroblasts did not increase the lung colonizing potential. Fibroblast-conditioned medium mixed with tumor cells instead of fibroblasts also enhanced tumor take and size but to a lesser extent than did the fibroblasts themselves. Only endothelial cells cultured from porcine aorta had a similar helper effect among the cells tested. It is argued in the discussion that the proliferating state of cultivated fibroblasts is a determinant factor conferring upon them the ability to promote tumor cell growth, while fibroblasts very numerous at the implantation site but quiescent might not be efficient in cooperation. Changes in fibroblast morphology and physiology may be necessary in order for tumor cells to express their tumorigenicity.

[Principal muco-cutaneous aspects encountered in AIDS]

Due to the high frequency and variety of the mucous cutaneous signs, the dermatologists are facing many cases of AIDS. These signs are no specific but only the consequence of a cellular immunodeficiency; they can be encountered in other situations, more specifically after an immunosuppressive treatment. Therefore, the diagnosis can be evocated only from AIDS association of the mucous cutaneous manifestations with other clinical, epidemiological and biological signs. The Kaposi's sarcoma which is present in 35 of the observed AIDS is in fact the cutaneous aspect of a cellular immunodeficiency. In one hand, the clinical lesions have a quiet involvement without any associated disorder. At the opposite, cutaneous lesions have a fulminant dissemination associated to lymph nodes and/or visceral involvement and opportunistic infections: these cases have a very severe prognosis. Kaposi's sarcoma is not observed in the cases of post-transfusional AIDS. Chronical herpes occurs frequently during this syndrome, the lesions lasting above six weeks associated to anal or genital localizations. Chronical candidosis, clinically associated, has a mucous cutaneous localization with involvement of the oral cavity, progressively extending digestive system and respiratory tracts.

[Kaposi's disease. 2 recent cases]

Known since 1872, the multifocal angiosarcoma called Kaposi's sarcoma takes different forms in different communities. It develops slowly among the mediterranean populations and Jewish Central Europe and most rapidly among Bantus, in Africa, and white homosexuals. Another aspect of the disease has been described in patients with transplanted kidney, where it seems to be associated with immunosuppressive treatments. The recent outbreak of Kaposi's sarcoma among homosexuals in New York and San Francisco raises new and difficult problems concerning its aetiology, as the outbreak cannot be entirely explained by pressure from sexually transmissible diseases. Having observed two new cases in France, the authors have attempted to re-evaluate the pathophysiological factors of the disease, the most constant of which seems to be a considerable degree of immunodepression, perhaps partly due to chronic infection.