Table 1.
Sex differences in innate and adaptive immune responses in adults *.
| Immune Component | Characteristic | Sex Difference |
|---|---|---|
| Sex differences in the innate immune system | ||
| TLR pathways | TLR pathway gene expression | Higher in females |
| TLR7 expression | Higher in females | |
| IL-10 production by TLR9-stimulated PBMCs | Higher in males | |
| APCs | APC efficiency | Higher in females |
| Dendritic cells | TLR7 activity | Higher in females |
| Type 1 interferon activity | Higher in females | |
| Macrophages | TLR4 expression | Higher in males |
| Activation | Higher in females | |
| Phagocytic capacity | Higher in females | |
| Pro-inflammatory cytokine production | Higher in males | |
| IL-10 production | Higher in females | |
| Neutrophils | Phagocytic capacity | Higher in females |
| TLR expression | Higher in males | |
| NK cells | NK cell numbers | Higher in males |
| Sex differences in the adaptive immune system | ||
| Thymus | Size of thymus | Larger in males |
| T cells | CD4+ T cell counts | Higher in females |
| CD4/CD8 T cell ratio | Higher in females | |
| CD8+ T cell counts | Higher in males | |
| Number of activated T cells | Higher in females | |
| T cell proliferation | Greater in females | |
| Cytotoxic T cells | Increased cytotoxic activity in females | |
| TH1 versus TH2 cell bias | TH2 cell bias in females, TH1 cell bias in males | |
| Treg cell numbers | Increased in males | |
| B cells | B cell numbers | Increased in females |
| Immunoglobulins | Antibody production | Higher in females |
APC, antigen-presenting cell; IL, interleukin; NK, natural killer; PBMCs, peripheral blood mononuclear cells; TH, T helper; TLR, Toll-like receptor; Treg, regulatory T. * Based on data from humans and rodents and primary cell cultures. Reproduced with permission from [26].