Current insights and molecular docking studies of HIV-1 reverse transcriptase inhibitors

Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS), a lethal disease that is prevalent worldwide. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) data, 38.4 million people worldwide were living with HIV in 2021. Viral reverse transcriptase (RT) is an excellent target for drug intervention. Nucleoside reverse transcriptase inhibitors (NRTIs) were the first class of approved antiretroviral drugs. Later, a new type of non-nucleoside reverse transcriptase inhibitors (NNRTIs) were approved as anti-HIV drugs. Zidovudine, didanosine, and stavudine are FDA-approved NRTIs, while nevirapine, efavirenz, and delavirdine are FDA-approved NNRTIs. Several agents are in clinical trials, including apricitabine, racivir, elvucitabine, doravirine, dapivirine, and elsulfavirine. This review addresses HIV-1 structure, replication cycle, reverse transcription, and HIV drug targets. This study focuses on NRTIs and NNRTIs, their binding sites, mechanisms of action, FDA-approved drugs and drugs in clinical trials, their resistance and adverse effects, their molecular docking studies, and highly active antiretroviral therapy (HAART).

Ambient particulate matter, a novel factor hindering life spans of HIV/AIDS patients: Evidence from a ten-year cohort study in Hubei, China

BACKGROUND

The life spans of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients have been extended in the era of antiretroviral therapy. However, few studies have considered the influence of the environment on the life expectancy of people living with HIV/AIDS. Several studies have investigated mortality and air pollution associations, but the evidence for associations between long-term exposure to particulate matter (PM) and mortality among HIV/AIDS patients remains extremely sparse.

METHODS

We conceived a dynamic cohort study by enrolling people with HIV/AIDS from 103 counties in Hubei province, China from 2010 to 2019, with 23,809 persons and 78,457.2 person-years of follow-up. The county-level annual concentrations of PM_2.5 and PM₁₀ were extracted from the ChinaHighAirPollutants dataset. Cox proportional hazards models with time-varying exposures were conducted to assess the associations between PM and mortality.

RESULTS

Per 1 μg/m³ increased in PM_2.5 and PM₁₀ would elevate 0.69 % (95 % CIs: 0.39, 1.00) and 0.39 % (95 % CIs: 0.18, 0.59) risk of all-cause deaths (ACD) and 1.65 % (95 % CIs: 1.14, 2.17) and 0.90 % (95 % CIs: 0.56, 1.24) of AIDS-related deaths (ARD), respectively. Significantly stronger associations of PM-ARD were found in patients aged over 60 years old, with corresponding excess risk of 2.66 % (95 % CIs: 1.76, 3.58) for PM_2.5 and 1.62 (95 % CIs: 1.01, 2.23) for PM₁₀.

CONCLUSIONS

This study added to the existing evidence that long-term exposure to ambient PM adversely affects the life spans of HIV/AIDS patients. Hence, public health departments should take proactive measures to prevent further life loss and promote survival among those living with HIV/AIDS.

OUP accepted manuscript

Background

Persons living with human immunodeficiency virus are an underserved population for evidence-based cancer treatment. Paclitaxel and carboplatin (PCb) is an active regimen against a variety of solid tumors, including several seen in excess in patients with HIV infection. We performed a pilot trial to evaluate the safety of full-dose PCb in people living with human immunodeficiency virus and cancer.

Methods

Eligible patients, stratified by concurrent antiretroviral therapy (ART) that included CYP3A4 inhibitors or not, received paclitaxel (175 mg/m²) in combination with carboplatin (target AUC 6) intravenously every 3 weeks for up to 6 cycles.

Results

Sixteen evaluable patients received 64 cycles of PCb, including 6 patients treated with CYP3A4 inhibiting ART (ritonavir). The adverse event profile was consistent with the known toxicity profile of PCb, with no differences between the 2 strata. There were 4 partial responses (25%, 95% CI: 7%-52%), and overall, CD4+ lymphocyte count was similar after completion of therapy (median: 310/μL) compared with baseline values (median: 389/μL). Pharmacokinetic studies in 6 patients revealed no significant differences in C_max or AUC_inf for paclitaxel between the 2 cohorts.

Conclusion

Full doses of PCb chemotherapy are tolerable when given concurrently with ART in people living with human immunodeficiency virus with cancer, including patients receiving CYP3A4 inhibitors.

ClinicalTrials.gov Identifier

NCT01249443.

Human herpesvirus 6A accelerates AIDS progression in macaques

Although HIV is the necessary and sufficient causative agent of AIDS, genetic and environmental factors markedly influence the pace of disease progression. Clinical and experimental evidence suggests that human herpesvirus 6A (HHV-6A), a cytopathic T-lymphotropic DNA virus, fosters the progression to AIDS in synergy with HIV-1. In this study, we investigated the effect of coinfection with HHV-6A on the progression of simian immunodeficiency virus (SIV) disease in pig-tailed macaques (Macaca nemestrina). Inoculation of HHV-6A resulted in a rapid appearance of plasma viremia associated with transient clinical manifestations and followed by antibody seroconversion, indicating that this primate species is susceptible to HHV-6A infection. Whereas animals infected with HHV-6A alone did not show any long-term clinical and immunological sequelae, a progressive loss of CD4(+) T cells was observed in all of the macaques inoculated with SIV. However, progression to full-blown AIDS was dramatically accelerated by coinfection with HHV-6A. Rapid disease development in dually infected animals was heralded by an early depletion of both CD4(+) and CD8(+) T cells. These results provide in vivo evidence that HHV-6A may act as a promoting factor in AIDS progression.

Altered P-glycoprotein expression in AIDS patients with HIV encephalitis

Penetrance of anti-retroviral drugs into the CNS depends partly on the activity of P-glycoprotein (P-gp), an ATP-dependent efflux pump involved in restricting entry of lipophilic drugs into the brain. The present study characterizes the patterns of P-gp expression in the brains of AIDS patients and examines its relationship with clinical and neuropathological indicators of HIV encephalitis (HIVE). For this purpose, brain tissue collected at autopsy from 26 subjects with a history of HIV (9 without HIVE; 17 with HIVE) was analyzed. Immunocytochemical staining and Western blot analyses for regional P-gp expression were performed and levels were correlated with neuropathological indicators and with HIV RNA. Double labeling experiments were performed with antibodies against astroglial (GFAP), endothelial (CD31), microglial (CD45) and neuronal (MAP2) cell markers. In the HIVE-negative cases, P-gp immunoreactivity was associated primarily with endothelial cells. HIVE-positive cases showed extensive immunolabeling of astroglial and microglial cells, but relatively less endothelial cell immunolabeling. No neuronal P-gp immunostaining was detected in brain tissue from any cases in the study. In the HIVE-positive cases with extensive astroglial labeling, the most intense immunoreactivity was detected in white matter. A subset of HIVE-positive cases displayed intense P-gp immunostaining of astrocytes closely associated with blood vessels in the cortex. Both the immunocytochemical and Western blot analyses showed a significant correlation between P-gp expression and HIV RNA levels. In conclusion, P-gp immunoreactivity was detected largely in glial cells in tissue from HIVE-positive patients. Furthermore, in HIVE-positive patients, brain viral burden and P-gp levels were significantly higher than those in HIVE-negative patients. Taken together, our data suggest that P-gp may be part of a central pathway mediating viral compartmentalization in the brains of HIV-infected individuals and may play a significant part in HIV disease progression in the brain.

Case report. Phaeohyphomycosis caused by Phialophora verrucosa developed in a patient with non-HIV acquired immunodeficiency syndrome

A 53-year-old woman had asymptomatic multiple nodules on her gluteal region for 6 months. She had a history of systemic corticosteroid treatment for Evans' syndrome. Recently she had developed an immunodeficiency condition with CD4+ cell depletion without an HIV infection and a normal serum gamma globulin level. A smear from the purulent exudate of the nodules revealed many brown-coloured hyphae, spores and few large dark-brown cells. A short, hairy, dark-brown coloured colony was cultivated on Sabouraud glucose agar. Slide culturing revealed only a Phialophora-type conidia formation, and the fungus was diagnosed as Phialophora verrucosa. Severe immunosuppressive condition (non-HIV acquired immunodeficiency syndrome) of this patients after systemic corticosteroid treatment for Evans' syndrome predisposed an opportunistic cutaneous fungal infection due to P. verrucosa. Cases with cutaneous infection due to P. verrucosa reported in Japan are summarized and discussed.

Lymphoepithelial cyst of the parotid gland--a case report

The lymphoepithelial cyst has been commonly termed branchial cleft cyst or branchial cyst. Although many theories, including the branchial apparatus theory, thymic duct theory, and inclusion theory, have been put forward, the etiology is still controversial. Parotid lymphoepithelial cysts are rare and could be divided into two groups, AIDS-related and non-AIDS related, by the relationship with HIV infection. A non-AIDS related lymphoepithelial cyst of left parotid gland in an 81-year-old man presenting as a parotid tumor is described. A left partial parotidectomy was carried out to remove the lesion. There was no recurrence after 2 years. Lymphoepithelial cysts of the parotid gland are often misdiagnosed as other benign tumors in spite of detailed preoperative investigations. Thus a pathological proof is needed for precise diagnosis. In addition, we also need to take the possibility of HIV infection into consideration, although Taiwan is not an AIDS epidemic area.

[The effect of herbal medicines on the immunodeficient animals by injecting cancer chemotherapeutic agent-special reference to age related recovery of the function]

The acquired immunodeficiency of the host plays an essential role in the occurrence of infections even with low pathogenic bacteria. The increase of cases with MRSA and/or pseudomonas infection is one of the serious problems in hospital management in Japan for the elderly as well as pediatric patients. In the present study, mitomycin C (MMC)-treated hosts were prepared in young, adult and old mice to test the immunopotentiating action of the promising Chinese herbal medicine, Tohki-Rikuoh-Toh (TRT), Hotyu-Ekki-Toh (HET) and Juzen-Taiho-Toh (JTT). The effect of these herbal medicines on organ structure and its function in the MMC-treated hosts is clarified and discussed for medical use. 4-5, 8-10 and over 50 week old male C57BL/6 (Clea Japan Inc.) were injected with MMC at a dosage of 3 to 5 mg/kg to inhibit the bone marrow, thus creating a mouse model with reduced immunopotential. A powder extract of TRT, HET and JTT was administrated orally at a dosage of 500 mg/kg/day for seven consecutive days. The white cell number and the subset analysis were carried out by the FACS method. The bactericidal effect of the host was monitored by NBT reduction test. Peritoneal macrophages were prepared by the adherence technique. The macrophage phagocytic activity was examined by an ACAS system. After the administration of TRT, HET and JTT, the body weights recovered as much as 90%, especially in young animals which had been reduced to 75% of their normal values. After MMC-treatment, with the herbal medicines, HET was good for young mice while JTT was effective for the old ones. As for the effect on B cells, the plaque-forming cells (PFC) of spleen cells were compared among the groups. As a result, PFC in the HET group was 184% and the other two were 80 approximately 95% as compared to 76% in the MMC-treated ones. The number of white blood cells in the MMC-treated mice returned to 80% of their normal value. In addition, the phagocytic activity of macrophages increased to 50% although that of the non-treated group was only 20%. The phagocytic activity also recovered in the JTT and TRT of 131% to 95%, respectively compared to 11% in the MMC-treated control. When TRT, HET and JTT were administered orally to mouse models whose immunopotential had been inhibited, the herbal medicines activated both quantitatively and qualitatively, showing themselves to be effective interstitial medicines. In addition, the data from the animal models showed no side effects, confirming the complete efficacy of the drug. Moreover, there was no direct anti-bactericidal effect from these medicines, suggesting that the immunomodulating action of this medicine is host-mediated. It is interesting that quantitative and qualitative recovery were seen when HET was administered to MMC-treated young hosts while JTT was good for the old. With this investigation, the effective components are still unknown for different generations, and we need to clarify this aspect for better understanding of the efficacy of herbal medicines.

The role of drugs in the origin of AIDS

It is proposed that the new American and European AIDS epidemics are caused by recreational and anti-HIV drugs rather than by human immunodeficiency virus (HIV). Chronologically, the AIDS epidemic in the 1980s followed a massive escalation in the consumption of recreational drugs that started in the 1960s and 70s. Epidemiologically, both epidemics derive about 80% of their victims from the same groups of 20-44 year-olds, of which 90% are males. In America 32% of these are intravenous drug users and their children, about 60% are male homosexuals who are long-term users of oral aphrodisiac drugs and an unknown percentage are prescribed the cytotoxic DNA chain terminator AZT, as inhibitor of HIV. Direct evidence indicates that these drugs are necessary for HIV-positives and sufficient for HIV-negatives to develop AIDS diseases. The drug-AIDS hypothesis predicts correctly that: (i) AIDS is new in the US, because the drug epidemic is new, while the HIV epidemic is old--fixed at a constant 1 million Americans since 1985; (ii) despite an increase in venereal diseases, AIDS remains restricted to long-term drug users and small groups with clinical deficiencies; (iii) over 72% of AIDS occurs in 20-44 year-old males, because they make up over 80% of hard psychoactive drug use; (iv) distinct AIDS diseases correlate with the use of distinct drugs, eg Kaposi's sarcoma with nitrite inhalants, tuberculosis with intravenous drugs, and leukopenia, anemia, and nausea with AZT; (v) AIDS diseases are only acquired after long-term drug consumption, rather than after single contacts as the virus-hypothesis predicts. The drug hypothesis can be tested epidemiologically and experimentally in animals. It predicts that most AIDS can be prevented by stopping the consumption of drugs, and provides a rational basis for therapy.

Volatile nitrites. Use and adverse effects related to the current epidemic of the acquired immune deficiency syndrome

Early reports of the acquired immune deficiency syndrome (AIDS) in homosexual men suggested that the cause might be related to homosexual life-style practices, including use of recreational drugs. Inhalation of volatile nitrites is a possible contributing factor in AIDS because their pharmacologic properties lead to toxicity. Metabolism of N-nitroso compounds produces mutagens, teratogens, and potent carcinogens in 39 different animal species, and volatile nitrites have deleterious effects on human lymphocytes in vitro and in vivo. In relation to the current AIDS epidemic, the timing of production and sales of volatile nitrites for recreational use is the only new life-style factor that might answer the question "why AIDS now?" Prevalence of nitrite use among male homosexuals is very high, and almost every reported case of Kaposi's sarcoma during the past three years includes a history of prior nitrite use. The age of the group of patients in whom Kaposi's sarcoma and AIDS are developing is consistent with a cohort initially exposed seven to 10 years ago. Cessation of nitrite use could reduce the epidemic.