Leukemias are highly immunogenic but have a low mutational load, providing few mutated peptide targets. Thus, the identification of alternative neoantigens is a pressing need. Here, we identify 36 MHC class I–associated peptide antigens with O-linked β-N-acetylglucosamine (O-GlcNAc) modifications as candidate neoantigens, using three experimental approaches. Thirteen of these peptides were also detected with disaccharide units on the same residues and two contain either mono- and/or di-methylated arginine residues. A subset were linked with key cancer pathways, and these peptides were shared across all of the leukemia patient samples tested (5/5). Seven of the O-GlcNAc peptides were synthesized and five (71%) were shown to be associated with multifunctional memory T-cell responses in healthy donors. An O-GlcNAc-specific T-cell line specifically killed autologous cells pulsed with the modified peptide, but not the equivalent unmodified peptide. Therefore, these post-translationally modified neoantigens provide logical targets for cancer immunotherapy.

Summary Coronavirus 19 (COVID‐19) has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand the prevalence of autoantibodies associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS‐CoV‐2, suffering from COVID‐19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on the intensive therapy unit (ITU) for non‐COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID‐19 ITU group compared with non‐COVID‐19 ITU disease control patients and that autoantibodies were also found in the serum 3–5 months post‐COVID‐19 infection. Non‐COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID‐19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that respiratory viral infection with SARS‐CoV‐2 is associated with the detection of a limited profile of tissue‐specific autoantibodies, detectable using routine clinical immunology assays. Further studies are required to determine whether these autoantibodies are specific to SARS‐CoV‐2 or a phenomenon arising from severe viral infections and to determine the clinical significance of these autoantibodies.

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Eosinophilic leukocytes are attracted into the preovulatory follicle and regressing corpus luteum of sheep. Eosinophils produce a wide array of potent bioactive substances that could play a role in ovarian function. Circulatory eosinophils were depleted by treatment of ewes with prednisolone, thereby producing ovarian eosinopenia. Ovulation occurred in these animals. However, circulatory concentrations of progesterone during the ensuing luteal phase were less than normal. This insufficiency was attributed in part to a suppressed angiogenic response in the formative corpus luteum. Regression of the corpus luteum induced by prostaglandin F2 alpha was not affected by administration of prednisolone. Thus, an obligatory role of eosinophils in the mechanics of ovulation and luteal regression in the sheep is unlikely.

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