Novel features of retroviruses associated with human diseases

Abstract

The last decade has witnessed a new chapter in the history of retrovirology. As of now, four human retroviruses have been identified and molecularly characterized.They are associated with a wide spectrum of human diseases including cancer, immunodefi~iency and neurological disorders. fly virtue of their clinical relevance, their novel genes and regulatory mechanisms these viruses have become the focal point of research in retrovirology. The study of these viruses is of fundamental importance in understanding the mechanisms leading to transformation of human cells and distortion of the immunological state.

Role of Central Leptin Signaling in the Starvation-Induced Alteration of B-Cell Development

“…It is known that nutritional deprivation or malnutrition leads to immune suppression in humans and animals (Cason et al, 1986;Chandra, 1991;Lord et al, 1998;Chan et al, 2006). Here, we provided evidence that B-cell development in the bone marrow is altered by nutritional deprivation in parallel with decreased serum leptin concentrations.…”

“…Such neuroendocrine alteration represents an adaptive response to energy deficiency. It is also known that nutritional deprivation or malnutrition suppresses immune function in humans and animals, thereby conferring higher susceptibility to infectious diseases (Cason et al, 1986;Chandra, 1991). For instance, nutritional deprivation induces atrophy of lymphoid tissues such as thymus and spleen and decreases the number of circulating T and B cells (Chandra, 1991;Lord et al, 1998;Chan et al, 2006).…”

Feeding the immune system

“…It is well known that undernutrition impairs the immune system, suppressing immune functions that are required for protection against pathogens and increasing susceptibility to infection (5)(6)(7) . Undernutrition leading to impairment of immune function can be due to insufficient intake of energy and macronutrients and/or due to deficiencies in specific micronutrients.…”

“…These may occur in combination. There are a number of reviews of the effect of proteinenergy malnutrition on aspects of immune function and on susceptibility to infection (5)(6)(7)(21)(22)(23) . Practically all forms of immunity are affected by protein-energy malnutrition but non-specific defences and cell-mediated immunity are more severely affected than humoral (antibody) responses (21)(22)(23) .…”

“…For a broader consideration of the topic the reader is referred to two multi-author books (1,2) , recent textbook chapters (3,4) , earlier comprehensive reviews of the topic (5)(6)(7) and the topic-and nutrient-specific reviews cited within this paper.…”