Inquiry Basket
Loading ......
Human T-cell lymphotropic virus (HTLV) is a tumorigenic RNA virus, which was listed as an infectious disease term in 2019. It belongs to the family of retroviruses and is divided into HTLV-1, HTLV-2, HTLV-3, and HTLV-4 types. Among them, HTLV-1 and HTLV-2 types are clearly associated with diseases. The virus was first discovered in the early 1980s. The virus particles are spherical with a diameter of about 100nm, and the envelope contains gp46 and gp21 proteins. The genome is a single stranded RNA, containing structural genes such as gag, pol, eno, as well as regulatory genes such as tax and rex. HTLV-1 is mainly popular in southwestern Japan, Africa, and the Caribbean region. The transmission routes include mother to child transmission (mainly through breastfeeding), sexual contact, and blood transmission. About 5% of infected individuals develop adult T-cell leukemia/lymphoma, 0.25%-4% develop HTLV-1-related myelopathy, and can also cause diseases such as uveitis and arthritis. At present, there is no specific treatment method, and only symptomatic treatment is provided for complications.
Figure 1. T-lymphotropic Virus.( Verdonck, Kristien, et al.2007)
HTLV-1 is a retrovirus belonging to the family Retroviridae and the genus Delta Retrovirus. It has a sense RNA genome that is reverse transcribed into DNA and then integrated into cellular DNA. Once integrated, HTLV-1 only exists as a pre virus and can spread between cells through viral synapses. Very few (if any) free virus particles are produced, and although the virus is present in genital secretions, there is usually no detectable virus in plasma. Like HIV, HTLV-1 mainly infects CD4+T cells. The viral RNA is packaged in an icosahedral capsid within the inner envelope of the protein. The lipid shell originates from host cells, but contains viral transmembrane proteins and surface proteins. The virus particles are spherical with a diameter of approximately 100 nanometers.
The global distribution of HTLV-I is highly heterogeneous, occurring locally in different regions. In areas where HTLV-I is found, its incidence varies greatly, and the epidemic clusters are usually located near populations with lower disease rates. This pattern may be influenced by the founder effect, indicating that the transmission time of the virus in isolated groups is prolonged, but this theory deserves further research. Consistent research findings indicate that the prevalence of HTLV-1 increases with age, with adult females typically having a higher prevalence than males. Regions widely considered to have epidemic areas include Japan, Iran, the Americas, the Caribbean, Melanesia, Central and West Africa, and Australia. Globally, densely populated countries such as India and Nigeria, as well as most parts of North and East Africa, still lack strong data. Therefore, current global prevalence estimates based on known prevalence regions may underestimate the true global prevalence.
HTLV-1 has three main transmission pathways. Vertical transmission is the most common, as infected mothers transmit the virus to their children through this method. Considering that there are almost no viral particles in human plasma, the risk to the fetus in the uterus is very low. Most vertical infections occur through breastfeeding. About 25% of infants breastfed by infected mothers are infected, while less than 5% of children born to infected mothers but not breastfed are infected. Sexual transmission is the second most common, where one person infects another through the exchange of bodily fluids. Some evidence suggests that male to female transmission is more effective than female to male transmission. For example, a study in Japan found that the male to female transmission rate is 61%, while the female to male transmission rate is less than 1%.
| Host Genetic Factors | Details |
| CD4 and CXCR4/CCR5 | Genetic variations in these receptors affect viral entry efficiency. Individuals with reduced CXCR4 expression have lower risk of HTLV-1 infection or disease progression. |
| TP53 | The tumor suppressor gene encoding p53. Mutations or deletions in TP53 impair apoptosis of Tax-transformed T cells, promoting malignant progression. |
| NFKB1 | The gene encoding the p50 subunit of NF-κB. Polymorphisms that enhance NF-κB activation increase susceptibility to ATLL, as Tax-mediated signaling is amplified. |
| HLA Genes | Certain HLA alleles are associated with enhanced HTLV-1-specific cytotoxic T lymphocyte (CTL) responses, reducing disease risk. |
The treatment for opportunistic infections varies depending on the type of disease, ranging from careful observation to aggressive chemotherapy and antiretroviral drugs. Adult T-cell lymphoma is a common complication of HTLV infection and requires aggressive chemotherapy, typically R-CHOP. Other treatment methods for HTLV infected patients with ATL include interferon alpha, zidovudine combined with interferon alpha, and CHOP combined with arsenic trioxide. The treatment of HTLV spinal cord disease is more limited, mainly focusing on symptomatic treatment. The treatment methods studied include corticosteroids, plasma exchange, cyclophosphamide, and interferon, which may temporarily improve symptoms of spinal cord disease.
HTLV represents a unique challenge in retrovirology—an inefficiently transmitted virus with a long latency period, yet capable of causing devastating diseases. With renewed focus on antiviral development, vaccine research, and global surveillance, there is hope to reduce the burden of HTLV-associated morbidity and mortality. As our understanding of its molecular pathogenesis deepens, targeted therapies and preventive strategies will likely emerge, addressing a long-unmet public health need.
Reference
| Target | Cat. No. | Product Name | Host | Isotype | |
| / | DMAB9608 | Anti-T-lymphotropic Virus 1 TAX monoclonal antibody, clone ZSIUMW-2uby | Mouse | IgG2a | Inquiry |
Loading ......
