Vol 5-4 Original Research Article

Epitope-based Multi-variant SARS-Cov-2 Vaccine Design: Shared Epitopes Among the Natural SARS-Cov-2 Spike Glycoprotein and 5 of its Variants (D614G, α, β, γ, δ) with High in Silico Binding Affinity to Human Leukocyte Antigen (HLA) Class II Molecules

Spyros A. Charonis1,2, Apostolos P. Georgopoulos1,2*

1The HLA SARS-CoV-2 Research Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN 55417, USA

2Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA

DOI: 10.29245/2578-3009/2021/4.1223 View / Download Pdf
Vol 5-4 Original Research Article

Apoptosis of Circulating Heterophils; Implications for the Interpretation of the Heterophil/Lymphocyte Ratio

Paul F. Cotter

Cotter Laboratory, Arlington, MA 02476, USA

The aim is to demonstrate a variety of apoptotic heterophils (equivalents of mammalian neutrophils) occurring in hemograms of 50 apparently healthy pullets housed in cages. These atypical cells are found in blood with normal total white cell levels (TWBC, ~20K) and in those ranging up to 100(K) a leukocytosis/leukemoid reaction level. Conversely heterophil/lymphocyte (H/L) ratios in all hens ranged between 0.14 – 0.50 (homeostasis). The Arneth index (a heterophil age measure) of 1.8 computed using only intact heterophils indicated a “left-shift”, suggesting inflammation even in the context of a normal hemogram.

The results: atypical heterophils with condensed (pyknotic) and fragmented nuclei (karyorrhexis), ruffled cytoplasmic membranes (zeiosis), apoptotic body formation, and other characteristics of apoptosis circulated in the blood of the study hens. Highly unusual cells as a monocyte containing a phagocytosed apoptotic body composed of heterophil granules, and a Mott cell (atypical plasmacyte) were also found.

More importantly, heterophils displaying thin, swollen and externalized nuclei suggestive of an unusual form of karyolysis were present. These cells were often seen in the company of free or RBC associated bacteria and fungi. There were also two examples of bacteria phagocytosed by apoptotic cells.

Other types of apoptotic cells were in 16/50 (32%) of hens from the study sample. These included small and medium size lymphocytes, monocytes, and metamyelocytes. Frank evidence of bacteremia (5/50, 10%) fungemia (4/50, 8%) and both (1/50, 2%) were detected. This suggests a relation between hematological atypia and the presence of circulating microorganisms possibly mediated through the release of toxins. Atypia of the circulation are sentinels, an alert to investigators or clinicians who are interested in the relation between the composition of blood and stress measurement or disease.

Conclusions: these observations apply to apparent morphologic plasticity of the heterophil, its role in the innate immune system, and its use in determining stress. In the cases described here the initial computation of the H/L ratios suggested the absence of stress. Moreover, this occurred in the context of either a normal or a high TWBC. However, heterophil age indicated a left-shift; a population predominated by young cells. This situation occurs when there is a demand to replace cells that have left the circulation either due to inflamed tissues or to death while circulating. Therefore, circulating apoptotic cells suggest stress even when the H/L is low and the TWBC is normal.

DOI: 10.29245/2578-3009/2021/4.1222 View / Download Pdf