Interferon--present and future prospects

Lessons from SARS‑CoV‑2 and its variants (Review)

COVID-19 has swept through mainland China by human-to-human transmission. The rapid spread of SARS-CoV-2 and its variants, including the currently prevalent Omicron strain, pose a serious threat worldwide. The present review summarizes epidemiological investigation and etiological analysis of genomic, epidemiological, and pathological characteristics of the original strain and its variants, as well as progress in diagnosis and treatment. Prevention and control measures used during the current Omicron pandemic are discussed to provide further knowledge of SARS-CoV-2.

Biologic rhythms in the immune system

In all of its components, the immune system shows regularly recurring, rhythmic variations in numerous frequencies; the circadian (about 24 h) rhythms are the best explored. The circadian variations in immunocompetent cells circulating in the peripheral blood are of a magnitude to require attention in medical diagnostics. Both the humoral arm and the delayed (cellular) arm of the immune system function in a rhythmic manner. The response of the immune system to introduction of an antigen and to challenge of the sensitized organism varies in extent in the circadian frequency range and also in lower frequencies, for example, of about a week (circaseptan) or seasonally (circannual). The medical application of the biologic rhythms of the immune system extends to diagnostic measures, as well as treatment.

Biological activities of human interferon and 2'-5' oligoadenylates in plants

Exogenous human interferon 2 (IFN) and 2'-5' oligoadenylates (2-5A) have been shown to cause at least a dual physiological effect in tobacco and wheat: (i) increased cytokinin activity and (ii) induced synthesis of numerous proteins, among which members of two groups of stress proteins have been identified, namely pathogenesis-related (PR) and heat shock (HS) proteins. These effects were observed only by low concentrations of these substances: IFN at 0.1-1 u/ml and 2-5A at 1-10 nM.

Regulation of muscle acetylcholine receptor-channel function by interferon

The effect of the antiviral agent interferon (IFN) on the function of the nicotinic acetylcholine receptor (AChR) channel, has been investigated in both mammalian cultured myotubes and adult fibres, using the single channel recording patch-clamp technique. Shortened AChR-channel lifetime, and occasionally reduced channel conductance and slowed opening frequency were seen with fibroblast IFN (IFN-beta) in the mouse myotubes, and with IFN-beta and leucocytes IFN (IFN-alpha), in the rat muscle fibres. These effects paralleled an increase in the cytosolic level of cAMP. This suggests that IFN exerts a regulatory action on AChR function. A similar regulatory action on other receptor may be responsible for some of the neurological side effects observed in patients treated with IFN.

Bovine peripheral blood leukocyte population dynamics following treatment with recombinant bovine interferon-alpha I1

The in vitro functional activity of bovine peripheral blood lymphocytes and the population dynamics of the major peripheral blood leukocyte subpopulations were investigated following the administration of recombinant bovine interferon-alpha I1 (rBoIFN-alpha I1). The intramuscular injection of rBoIFN-alpha I1 induced a 24-h lymphopenia characterized by a decrease in both circulating T and non-T/non-B lymphocytes. An increased CD4/CD8 ratio indicated that there was a relatively greater depletion of the CD8 equivalent subpopulation of T lymphocytes. These changes in lymphocyte trafficking were observed in the absence of a cortisolemia. Coincidental with the lymphopenia, there was a marked decrease in the amplitude of mitogen-induced lymphocyte proliferation responses that probably was caused by a numerical deficit rather than functional deficit in the responder T cells.

Epstein-Barr virus-associated malignancies

The infectious aspects of cancer in humans were epidemiologically pioneered by Dr. David Burkitt through his observations of lymphomatous tumors seen in children in equatorial Africa. Years, later, the Epstein-Barr virus (EBV) was shown to be intimately associated with such tumors and is now recognized as a component of some B-cell lymphomas and nasopharyngeal carcinoma. Still the questions of an active, passive, or accessory role persist. The ability of this virus to cause immunosuppressive hemopoietic disturbances in individuals infected with EBV but not developing cancer raise questions about host susceptibility, host immune response, and possible coconspiring, infectious, oncogenic agents. Recent associations of EBV antibody found in diseases, such as squamous cell carcinoma of the head and neck and acquired immunodeficiency syndromes, point to its possible accessory role as an immunosuppressive agent. The ability of EBV to spread by extracellular and intracellular mechanisms demonstrates its variable infectious potential. Numerous EBV-transformed human cell lines attest to its ability to confer "immortality" with uncontrolled growth patterns. This review critically examines the association of EBV with various malignancies, the type of evidence which links it there, and the implications for further investigations and therapy.

Interferon sensitivity of fibroblast cell cultures derived from patients with neoplasms of the head and neck

Interferon (IFN) is a protein with antiviral activity that has been shown to inhibit the growth of many different types of cells. We have measured the IFN sensitivity of nine cell cultures isolated from patients with squamous cell carcinoma and one with malignant melanoma of the head and neck. Normal-appearing fibroblast cultures isolated from these tissues appear quite sensitive to the antiviral effects of IFN. When the encephalomyocarditis virus yield reduction assay is used, these diploid cells are as sensitive to IFN-alpha as are newborn foreskin fibroblast cultures. A similar antiviral effect is seen with IFN-gamma. These cells are relatively insensitive to the antigrowth effect of both IFN preparations as measured by 3H thymidine incorporation and direct observations of cell growth. This is the same relative sensitivity as fibroblasts derived from normal patients. Since these cells are at least 100 times less sensitive to the antigrowth action of the IFNs, it appears unlikely that the IFNs play a significant role in the control of normal fibroblast growth, in contrast to the sensitivity of malignant cell lines.