Millen Sebastian, Thoma-Kress Andrea K
FAU Junior Research Group "Retroviral Pathogenesis" and BMBF Junior Research Group in Infection Research "Milk Transmission of Viruses", Institute of Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
Front Med (Lausanne). 2022 Mar 11;9:867147. doi: 10.3389/fmed.2022.867147. eCollection 2022.
Breastfeeding is recommended by the World Health Organization for at least 6 months up to 2 years of age, and breast milk protects against several diseases and infections. Intriguingly, few viruses are transmitted breastfeeding including Human T-cell leukemia virus Type 1 (HTLV-1). HTLV-1 is a highly oncogenic yet neglected retrovirus, which primarily infects CD4 T-cells and causes incurable diseases like HTLV-1-associated inflammatory conditions or Adult T-cell leukemia/lymphoma (ATLL) after lifelong viral persistence. Worldwide, at least 5-10 million people are HTLV-1-infected and most of them are unaware of their infection posing the risk of silent transmissions. HTLV-1 is transmitted cell-containing body fluids such as blood products, semen, and breast milk, which constitutes the major route of mother-to-child transmission (MTCT). Risk of transmission increases with the duration of breastfeeding, however, abstinence from breastfeeding as it is recommended in some endemic countries is not an option in resource-limited settings or underrepresented areas and populations. Despite significant progress in understanding details of HTLV-1 cell-to-cell transmission, it is still not fully understood, which cells in which organs get infected the oral route, how these cells get infected, how breast milk affects this route of infection and how to inhibit oral transmission despite breastfeeding, which is an urgent need especially in underrepresented areas of the world. Here, we review these questions and provide an outlook how future research could help to uncover prevention strategies that might ultimately allow infants to benefit from breastfeeding while reducing the risk of HTLV-1 transmission.
世界卫生组织建议母乳喂养至少6个月，直至2岁，母乳可预防多种疾病和感染。有趣的是，通过母乳喂养传播的病毒很少，包括1型人类T细胞白血病病毒（HTLV-1）。HTLV-1是一种高度致癌但被忽视的逆转录病毒，主要感染CD4 T细胞，在病毒终身持续存在后会引发无法治愈的疾病，如HTLV-1相关炎症或成人T细胞白血病/淋巴瘤（ATLL）。在全球范围内，至少有500万至1000万人感染了HTLV-1，其中大多数人并未意识到自己已被感染，这带来了隐性传播的风险。HTLV-1通过含有细胞的体液传播，如血液制品、精液和母乳，这是母婴传播（MTCT）的主要途径。传播风险会随着母乳喂养时间的延长而增加，然而，在资源有限的地区或代表性不足的地区及人群中，像一些流行国家所建议的那样完全停止母乳喂养并非可行之选。尽管在了解HTLV-1细胞间传播细节方面取得了重大进展，但仍未完全弄清楚哪些器官中的哪些细胞会通过口腔途径被感染、这些细胞是如何被感染的、母乳如何影响这种感染途径以及如何在母乳喂养的情况下抑制口腔传播，而这在世界上代表性不足的地区尤为迫切需要解决。在此，我们对这些问题进行综述，并展望未来的研究如何有助于揭示预防策略，最终或许能让婴儿在受益于母乳喂养的同时降低HTLV-1传播风险。
