The Gracefully Aging Immune System

Abstract

Prolonged life expectancy in the 20th century has been one of humankind's greatest triumphs. However, the substantial increase in the human life span has ushered in a new concern: healthy aging. Because infectious diseases prominently contribute to morbidity in the particularly vulnerable elderly population, strategies for preventing these diseases would have a clear impact on improving healthy aging. Thus, vaccines and immunization strategies tailored for the elderly population are needed, and vaccines should be developed to take into consideration the peculiar age-induced variations of immune responsiveness. The conference "Ageing and Immunity" recently held in Siena, Italy, has reviewed and discussed several possible causes of immune senescence, as well as strategies for counteracting this waning of immune responsiveness and for restoring immunocompetence. In addition, examples of diseases that should be targeted by vaccination in the senior population were considered.

Human and murine hematopoietic stem cell aging is associated with functional impairments and intrinsic megakaryocytic/erythroid bias

“…Our results show a megakaryocyte/ erythrocyte transcriptional profile that strongly associates with aged HSCs and support the notion that an increased HSC frequency with age may be a compensatory mechanism to sustain sufficient blood cell replenishment. However, these compensatory mechanisms do not fully maintain optimal functions of HSCs and progenitor cells in elderly human, as evidenced by the frequency of age-related hematological defects, including anemia and reduced immune responses [2][3][4]. A deeper understanding of the events underlying this functional decline may support interventional approaches to prevent or ameliorate the aging hematopoietic phenotype.…”

“…Concomitantly, the prevalence of age-related diseases increases [1], where elderly individuals often present with alterations in the blood cell system, including reduced adaptive immune responses [2], increased anemia incidence [3,4], and increased risk of myeloid diseases [5]. Recent insights further suggest that processes underlying physiological aging can resemble pathogenic events in other diseases, such as cancer [6].…”

In Search of Factors Negatively Affecting Vaccine Immunity to Pertussis in Preschool Children Before the Administration of the First Booster

“…In 70% of the cases a contact with an infected adult was confirmed and in 50% of the cases an active infection of pertussis in one of the parents was noted. The aforementioned results show how important the administration of boosters (dTpa) to adults (pregnant mothers, fathers, relatives aged ≥ 65) is if they spend much time with the children, particularly those who have incomplete immunisation against pertussis [40,44,45].…”

Preclinical modeling of hematopoietic stem cell transplantation – advantages and limitations

“…Immunological and physiological alterations associated with the aging process may explain age-associated increases in GVHD severity, including increased immune senescence, impaired tissue repair mechanisms, increased allo-reactivity of recipient antigen-presenting cells and lymphocytes, and the development of chronic low-grade inflammation, termed 'inflammaging' [4]. Further, aging is associated with increasing ratios of visceral fat to lean muscle mass, which contributes significantly to establishing a state of chronic inflammation [5].…”