Frooman Marielle B, Choi Klara, Kahn Maya Z, Yang Li-Yen, Cunningham Aubrielle, RisCassi Jenna M, McShan Andrew C
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Sci Rep. 2025 Mar 12;15(1):8614. doi: 10.1038/s41598-025-92191-6.
Human Leukocyte Antigens (HLA) are immunoreceptors that present peptide antigens at the cell surface to T cells as a primary mechanism of immune surveillance. Malaria, a disease associated with the Plasmodium parasite, claims > 600,000 lives per year globally with most deaths occurring in Africa. Development of efficacious prophylactic vaccines or therapeutic treatments for malaria has been hindered by the lack of a basic understanding of the role of HLA-mediated peptide antigen presentation during Plasmodium infection. In particular, there is (i) little understanding of which peptide antigens are presented by HLAs in the context of malaria, and (ii) a lack of structural insights into Plasmodium peptide antigen presentation by HLAs, which underpins peptide/HLA stability, specificity, cross-presentation across HLA alleles, and recognition by T cell receptors. To begin to address these knowledge gaps, we identify and characterize candidate peptide antigens derived from Plasmodium falciparum with potential for presentation by common class I HLA alleles. We computationally screen nine proteins from the P. falciparum proteome to predict eight peptides with potential for cross-presentation by common alleles in African populations, HLA-A02:01 and HLA-B08:01. We then validate the predictions by producing recombinant HLAs in complex with the eight identified peptides by in vitro refolding. We evaluate the folding and thermal stability of the resulting sixteen peptide/HLA complexes by CD spectroscopy and nanoDSF. In silico modeling of peptide/HLA complexes informs a plausible structural basis for mechanisms for cross-presentation of P. falciparum peptides across HLA-A02:01 and HLA-B08:01 alleles. Finally, we expand our identified P. falciparum peptides to cover a broader range of HLA alleles in malaria endemic populations with experimental validation provided for HLA-C07:01 and HLA-E01:03. Together, our results are a step forward towards a deeper understanding of the potential for multi-allele cross-presentation of peptides in malaria. These results further inform future development of multivalent vaccine strategies targeting HLA profiles in malaria endemic populations.
人类白细胞抗原（HLA）是免疫受体，其在细胞表面将肽抗原呈递给T细胞，作为免疫监视的主要机制。疟疾是一种与疟原虫相关的疾病，全球每年有超过60万人死于该病，其中大多数死亡发生在非洲。由于对HLA介导的肽抗原呈递在疟原虫感染过程中的作用缺乏基本了解，有效的疟疾预防性疫苗或治疗方法的开发受到了阻碍。具体而言，存在以下问题：（i）对疟疾背景下HLA呈递的肽抗原了解甚少；（ii）缺乏对HLA呈递疟原虫肽抗原的结构见解，而这是肽/HLA稳定性、特异性、跨HLA等位基因交叉呈递以及T细胞受体识别的基础。为了开始填补这些知识空白，我们鉴定并表征了源自恶性疟原虫的候选肽抗原，这些抗原具有被常见的I类HLA等位基因呈递的潜力。我们通过计算筛选恶性疟原虫蛋白质组中的九种蛋白质，以预测八种有可能被非洲人群中常见等位基因HLA-A02:01和HLA-B08:01交叉呈递的肽。然后，我们通过体外重折叠产生与八种鉴定出的肽形成复合物的重组HLA，来验证这些预测。我们通过圆二色光谱法和纳米差示扫描荧光法评估所得的十六种肽/HLA复合物的折叠和热稳定性。肽/HLA复合物的计算机模拟为恶性疟原虫肽跨HLA-A02:01和HLA-B08:01等位基因交叉呈递的机制提供了一个合理的结构基础。最后，我们将鉴定出的恶性疟原虫肽扩展到覆盖疟疾流行人群中更广泛的HLA等位基因范围，并对HLA-C07:01和HLA-E01:03进行了实验验证。总之，我们的结果朝着更深入了解疟疾中肽的多等位基因交叉呈递潜力迈出了一步。这些结果进一步为针对疟疾流行人群中HLA谱的多价疫苗策略的未来发展提供了信息。
