Impact of Aging on CD4 Immunity to Flu. We have defined extensive age-associated defects in immune system response particulariy in naive CD4 T cells that give poor effector responses and the generation of impaired memory cells. In the first funding cycle we found that pro-inflammatory cytokines (IL-1, IL-6 and TNFa) could reverse many of the defects in effector generation, and that surrogates of viral products that stimulate immune cells, called TLR agonists, induce production of these by DC presenting antigen to the T cells. We identified IL-6 production by DC during the cognate interaction as key for increasing expansion and blocking death of responding aged naive CD4 T cells. The activation also restores memory responses to some extent. Now we will define the molecular pathways leading to the """"""""rescue"""""""" of the naTve CD4 T responses using a combination of reductionist in vitro approaches and carefully designed adoptive transfer models, that will allow us to determine the cellular and molecular mechanisms involved. We will use highly tractable TcR Tg models as well as polyclonal studies to dissect mechanisms. We will analyze rescue pathways in vivo as well as extend the studies to CDS T cells in mouse and to human CD4 and CDS T cells (part of Project 5). These studies will generate important information that could contribute to the development in future of better strategies, using TLR agonists, to more effectively vaccinate the elderiy and we expect to be able to develop a unified theory of how aging develops in T cells, what defects exist and which can be overcome and how in mice and man.
In the elderly, influenza results in high morbidity and mortality and current subunit vaccines are largely ineffective. Pandemic strains completely evade previous Ab-based immunity induced by current vaccines. Because their immune systems are defective and they respond to poorly to new infections, the elderly are at great risk. Our studies will evaluate whether TLR agonists, can overcome immune defects and may be combined with vaccines to give robust T cell immunity that will be broadly reactive to new strains.
|Lanzer, Kathleen G; Cookenham, Tres; Reiley, William W et al. (2018) Virtual memory cells make a major contribution to the response of aged influenza-naïve mice to influenza virus infection. Immun Ageing 15:17|
|Kuchel, George A (2018) Frailty and Resilience as Outcome Measures in Clinical Trials and Geriatric Care: Are We Getting Any Closer? J Am Geriatr Soc 66:1451-1454|
|Lorenzo, Erica C; Bartley, Jenna M; Haynes, Laura (2018) The impact of aging on CD4+ T cell responses to influenza infection. Biogerontology 19:437-446|
|Parham, Kourosh; Kuchel, George A; McElhaney, Janet E et al. (2018) A Relationship Between Blood Levels of Otolin-1 and Vitamin D. Otol Neurotol 39:e269-e273|
|Brahmakshatriya, Vinayak; Kuang, Yi; Devarajan, Priyadharshini et al. (2017) IL-6 Production by TLR-Activated APC Broadly Enhances Aged Cognate CD4 Helper and B Cell Antibody Responses In Vivo. J Immunol 198:2819-2833|
|Merani, Shahzma; Pawelec, Graham; Kuchel, George A et al. (2017) Impact of Aging and Cytomegalovirus on Immunological Response to Influenza Vaccination and Infection. Front Immunol 8:784|
|Bartley, Jenna M; Zhou, Xin; Kuchel, George A et al. (2017) Impact of Age, Caloric Restriction, and Influenza Infection on Mouse Gut Microbiome: An Exploratory Study of the Role of Age-Related Microbiome Changes on Influenza Responses. Front Immunol 8:1164|
|Swain, Susan L; Kugler-Umana, Olivia; Kuang, Yi et al. (2017) The properties of the unique age-associated B cell subset reveal a shift in strategy of immune response with age. Cell Immunol 321:52-60|
|Tabtabai, Ryan; Haynes, Laura; Kuchel, George A et al. (2017) Age-Related Increase in Blood Levels of Otolin-1 in Humans. Otol Neurotol 38:865-869|
|Masters, A R; Haynes, L; Su, D-M et al. (2017) Immune senescence: significance of the stromal microenvironment. Clin Exp Immunol 187:6-15|
Showing the most recent 10 out of 59 publications