Ravindranath Mepur H, Ravindranath Narendranath M, El Hilali Fatiha, Selvan Senthamil R, Filippone Edward J
Department of Hematology and Oncology, Children's Hospital, Los Angeles, CA 90027, USA.
Emeritus Research Scientist at Terasaki Foundation Laboratory, Santa Monica, CA 90064, USA.
Antibodies (Basel). 2022 Mar 2;11(1):18. doi: 10.3390/antib11010018.
Serum anti-HLA-I IgG are present in non-alloimmunized males, cancer patients, and transplant recipients. Anti-HLA-I antibodies are also present in intravenous immunoglobulin (IVIg), prepared from the plasma of thousands of healthy donors. However, the HLA-Ia reactivity of IVIg diminishes markedly after passing through HLA-E HC-affinity columns, suggesting that the HLA-I reactivity is due to antibodies formed against HLA-E. Hence, we examined whether anti-HLA-E antibodies can react to HLA-I alleles. Monoclonal IgG antibodies (mAbs) against HCs of two HLA-E alleles were generated in Balb/C mice. The antibodies were analyzed using multiplex bead assays on a Luminex platform for HLA-I reactivity. Beads coated with an array of HLA heterodimers admixed with HCs (LABScreen) were used to examine the binding of IgG to different HLA-Ia (31-HLA-A, 50-HLA-B, and 16-HLA-C) and Ib (2-HLA-E, one each of HLA-F and HLA-G) alleles. A striking diversity in the HLA-Ia and/or HLA-Ib reactivity of mAbs was observed. The number of the mAbs reactive to (1) only HLA-E ( = 25); (2) all HLA-Ib isomers ( = 8); (3) HLA-E and HLA-B ( = 5); (4) HLA-E, HLA-B, and HLA-C ( = 30); (5) HLA-E, HLA-A*1101, HLA-B, and HLA-C ( = 83); (6) HLA-E, HLA-A, HLA-B, and HLA-C ( = 54); and (7) HLA-Ib and HLA-Ia ( = 8), in addition to four other minor groups. Monospecificity and polyreactivity were corroborated by HLA-E monospecific and HLA-I shared sequences. The diverse HLA-I reactivity of the mAbs are compared with the pattern of HLA-I reactivity of serum-IgG in non-alloimmunized males, cancer patients, and ESKD patients. The findings unravel the diagnostic potential of the HLA-E monospecific-mAbs and immunomodulatory potentials of IVIg highly mimicking HLA-I polyreactive-mAbs.
血清抗 HLA-I IgG 存在于未发生同种免疫的男性、癌症患者和移植受者体内。抗 HLA-I 抗体也存在于静脉注射免疫球蛋白（IVIg）中，IVIg 是从数千名健康供体的血浆中制备而来。然而，IVIg 通过 HLA-E 重链亲和柱后，其 HLA-Ia 反应性显著降低，这表明 HLA-I 反应性是由针对 HLA-E 形成的抗体所致。因此，我们研究了抗 HLA-E 抗体是否能与 HLA-I 等位基因发生反应。在 Balb/C 小鼠中产生了针对两种 HLA-E 等位基因重链的单克隆 IgG 抗体（mAb）。使用基于 Luminex 平台的多重微珠分析对这些抗体进行 HLA-I 反应性分析。用包被有一系列与重链混合的 HLA 异二聚体的微珠（LABScreen）来检测 IgG 与不同 HLA-Ia（31 种 HLA-A、50 种 HLA-B 和 16 种 HLA-C）和 Ib（2 种 HLA-E、各 1 种 HLA-F 和 HLA-G）等位基因的结合情况。观察到 mAb 在 HLA-Ia 和/或 HLA-Ib 反应性方面存在显著差异。对（1）仅对 HLA-E 有反应的 mAb（=25 种）；（2）对所有 HLA-Ib 异构体有反应的 mAb（=8 种）；（3）对 HLA-E 和 HLA-B 有反应的 mAb（=5 种）；（4）对 HLA-E、HLA-B 和 HLA-C 有反应的 mAb（=30 种）；（5）对 HLA-E、HLA-A*1101、HLA-B 和 HLA-C 有反应的 mAb（=83 种）；（6）对 HLA-E、HLA-A、HLA-B 和 HLA-C 有反应的 mAb（=54 种）；以及（7）对 HLA-Ib 和 HLA-Ia 有反应的 mAb（=8 种）进行了分析，此外还有其他四个较小的组。通过 HLA-E 单特异性和 HLA-I 共享序列证实了单特异性和多反应性。将 mAb 的不同 HLA-I 反应性模式与未发生同种免疫的男性、癌症患者和终末期肾病患者血清 IgG 的 HLA-I 反应性模式进行了比较。这些发现揭示了 HLA-E 单特异性 mAb 的诊断潜力以及高度模拟 HLA-I 多反应性 mAb 的 IVIg 的免疫调节潜力。
